The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Yingmei Zhang - One of the best experts on this subject based on the ideXlab platform.

  • response of male reproductive function to environmental heavy metal pollution in a free living Passerine bird Passer Montanus
    Science of The Total Environment, 2020
    Co-Authors: Ying Yang, Shengnan Wang, Huijie Zhang, Wenya Zhang, Yingmei Zhang
    Abstract:

    Abstract Heavy metals affect male reproductive function by impairing reproductive organs, disturbing reproductive hormone levels or directly affecting sperm quality. However, little attention has been given to the effect of environmental heavy metals on reproductive function in wild male birds. The present study investigated the alterations of reproductive function in male tree sparrows (Passer Montanus) exposed to environments contaminated by heavy metals in terms of testis parameters, reproductive hormone levels and sperm movement characteristics. Two plots, Baiyin (BY, mainly polluted by copper, zinc, lead and cadmium) and Liujiaxia (LJX, a relatively unpolluted area) were selected as sampling sites. The results showed that tree sparrows from BY (1) accumulated higher levels of cadmium in the testes, (2) showed lower superoxide dismutase (SOD) activity and malondialdehyde level, with higher total antioxidant capacity and apoptosis level in the testes, (3) showed higher plasma levels of estrogen, follicle stimulating hormone and luteinizing hormone (LH), and (4) had better sperm movement performance. Additionally, we found that testis size, SOD activity in testes and LH levels were decisive factors in sperm movement performance in tree sparrows. Heavy metal concentrations in testes negatively correlated with testis size, SOD activity in testes, and estrogen levels in tree sparrows. The present study indicates that heavy metals accumulating in testes of tree sparrows adversely affected some key indicators of male reproductive function. However, testicular function, reproductive hormone levels and sperm quality showed adaptive responses that tended to partially compensate for the negative effects in the heavy metal polluted area. This study further indicated that the regulation of testicular function and reproductive hormone levels was the main factor for better sperm quality in tree sparrows exposed to environments contaminated by heavy metals.

  • variation in genetic diversity of tree sparrow Passer Montanus population in long term environmental heavy metal polluted areas
    Environmental Pollution, 2020
    Co-Authors: Wenzhi Yang, Jian Ding, Ying Yang, Shengnan Wang, Gang Song, Yingmei Zhang
    Abstract:

    Abstract Genetic diversity is the bedrock of evolution. The “Genetic Erosion” hypothesis posits that environmental pollution could cause reduced genetic diversity. To explore the effects of heavy metal pollution on genetic diversity in natural populations, we selected an area with more than sixty years of heavy metal contamination (Baiyin, BY) and a relatively unpolluted one (Liujiaxia, LJX), and tree sparrow (Passer Montanus) as study models. Five tree sparrow populations were sampled in BY at sites differing in heavy metal pollution level. Lower genetic diversity based on seven microsatellite loci was observed in the five tree sparrow populations from BY compared with those from LJX. Analysis of molecular variance indicated no significant genetic differentiation between BY and LJX. However, the observed heterozygosity and allelic richness were negatively correlated to the lead and cadmium concentrations in the primary feathers of tree sparrow. Our results indicated the genetic diversity might have a negative response to long-term environmental heavy metal pollution in tree sparrow, supporting the “Genetic Erosion” hypothesis. Therefore, the findings shed lights on the possible effects of heavy metal pollution on genetic diversity of wild bird populations.

  • variation in sperm morphology and performance in tree sparrow Passer Montanus under long term environmental heavy metal pollution
    Ecotoxicology and Environmental Safety, 2020
    Co-Authors: Ying Yang, Jian Ding, Wenzhi Yang, Shengnan Wang, Huijie Zhang, Yingmei Zhang
    Abstract:

    Sperm morphology and performance traits are key determinants of male fertilization success, particularly when females copulate with multiple males. Such sperm traits have been reported to be influenced by environmental pollutants in various animals; however, such studies remain rare in free-living birds exposed to heavy metal pollution. In the present study, we selected tree sparrow (Passer Montanus) as the study object to explore the effect of long-term environmental heavy metal pollution on sperm morphology (assessed mainly by using the dimensions of different sperm components and the sperm abnormality rates) and sperm performance (indicated by sperm velocity), and to elucidate potential relationships between variations in sperm morphology and performance. Sperm ATP concentration was also assessed considering sperm morphology and performance could be linked via energy availability. According to our results, tree sparrows from heavy metal polluted area (1) accumulated cadmium at a higher level in their testes; (2) produced longer sperm with lower abnormality rates, in addition to sperm with longer flagella and smaller head/flagellum ratios; (3) their sperm swam faster compared to those from the relatively unpolluted area, while no differences were observed in sperm ATP concentrations. We also found that the levels of lead and cadmium in testes affected the sperm nucleus length, and the level of copper in testes was negatively related to the proportions of abnormal sperm. Furthermore, the present study showed that sperm velocity was negatively correlated with sperm head lengths, head/flagellum ratios and ATP concentrations. Our study results reveal that sperm morphology and performance in tree sparrows show positive variations to maximize male fertility ability under long-term environmental heavy metal pollution, where males increase sperm flagellum lengths to decrease head/flagellum ratios, as opposed to varying sperm energy production, to achieve higher sperm velocity.

  • effects of environmental metal pollution on reproduction of a free living resident songbird the tree sparrow Passer Montanus
    Science of The Total Environment, 2020
    Co-Authors: Jian Ding, Wenzhi Yang, Ying Yang, Shengnan Wang, Huijie Zhang, Xinkang Bao, Yingmei Zhang
    Abstract:

    Abstract Anthropogenic metal pollution is known to adversely affect bird reproduction; however, few systematic studies are available on the effects of metal pollution on breeding performance and parental investment in a common resident songbird, the tree sparrow (Passer Montanus). We conducted this study in two sites, a long-term heavy metal polluted site (Baiyin [BY]) and a relatively unpolluted site at approximately 110 km distance (Liujiaxia [LJX]), to assess the potential effects of environmental metal contamination on breeding parameters (clutch size, hatching success, fledging success, and growth of nestlings) and parental investment. The results showed smaller clutch size, lower fledging success, and differences in incubation behaviors of tree sparrows in BY than in LJX. Although there was no difference in parental body condition (residual body mass) between the two study sites, the parents responded differently with respect to reproduction due to varying metal levels in their habitats and bodies. Higher Cd levels in the primary feathers of females in BY were associated with lower clutch sizes. Parental investment including incubation duration and feeding rates showed no significant difference between the two sites during the incubation and nestling periods, but the frequencies of incubation visits were higher in BY. Parental behavior during the incubation period was also negatively affected by the parental Pb and Cd levels. Although the nestling growth patterns were relatively similar between the two sites, the nestlings were smaller, had lower body weight, and fledged later and fledging rate was also lower in BY than in LJX. Metal concentrations were higher in nestling organs and feces in BY. Taken together, metal pollution might adversely affect nestling growth condition. Our results suggest a negative response in the reproduction of tree sparrows to long-term environmental metal pollution.

  • optimal analysis conditions for sperm motility parameters with a casa system in a Passerine bird Passer Montanus
    Avian Research, 2019
    Co-Authors: Ying Yang, Jian Ding, Xiaojuan Bai, Yingmei Zhang, Rui Guo, Wenzhi Yang
    Abstract:

    Sperm motility parameters, which can be measured objectively and repeatedly by a computer-assisted sperm analysis (CASA) system, are important indicators of sperm quality. However, the sperm motility parameters assessed by a CASA system can be affected by various factors, including instrument components and settings, sperm preparation or analysis procedures. To date, no standardized protocol is available that would permit to assess sperm kinetic characteristics in Passerine birds and this lack precludes any comparison of sperm swimming ability and sperm quality across species. In this study, we chose the Tree Sparrow (Passer Montanus) as the object to evaluate sperm motility parameters, including sperm motility, sperm velocity and sperm movement trajectory, at different analysis time, temperatures and pH using the WLJY-9000 CASA system. Sperm motility parameters remained statistically unchanged at 1‒9 min. Progressive motility was similar at 38 °C and 40 °C, but a greater percentage of slow progressive sperm was detected at 38 °C compared to 40 °C and 42 °C. Additionally, progressive motility was lower and immotility was higher at 42 °C than 38 °C and/or 40 °C (close to the body temperature of the Tree Sparrow). The percentages of rapid progressive sperm, progressive sperm and immotile sperm were statistically similar at pH 7.0, 7.5 and 8.0 with the exception of lower percentage of progressive sperm at pH 7.0 compared to pH 7.5. In addition, slower sperm velocity and worse sperm movement trajectory were found at pH 6.0 and 9.0 than those at pH 8.0, 7.5 or 7.0. Our study indicates that the ideal conditions for sperm motility parameters assessment in Tree Sparrow are obtained between 1 and 9 min after dilution, an environment at body temperature (40 °C) and a pH around 7.5‒8.0. The results of this study provide a reference for the evaluation of sperm characteristics and sperm quality using a CASA system in Passerine birds.

Ying Yang - One of the best experts on this subject based on the ideXlab platform.

  • response of male reproductive function to environmental heavy metal pollution in a free living Passerine bird Passer Montanus
    Science of The Total Environment, 2020
    Co-Authors: Ying Yang, Shengnan Wang, Huijie Zhang, Wenya Zhang, Yingmei Zhang
    Abstract:

    Abstract Heavy metals affect male reproductive function by impairing reproductive organs, disturbing reproductive hormone levels or directly affecting sperm quality. However, little attention has been given to the effect of environmental heavy metals on reproductive function in wild male birds. The present study investigated the alterations of reproductive function in male tree sparrows (Passer Montanus) exposed to environments contaminated by heavy metals in terms of testis parameters, reproductive hormone levels and sperm movement characteristics. Two plots, Baiyin (BY, mainly polluted by copper, zinc, lead and cadmium) and Liujiaxia (LJX, a relatively unpolluted area) were selected as sampling sites. The results showed that tree sparrows from BY (1) accumulated higher levels of cadmium in the testes, (2) showed lower superoxide dismutase (SOD) activity and malondialdehyde level, with higher total antioxidant capacity and apoptosis level in the testes, (3) showed higher plasma levels of estrogen, follicle stimulating hormone and luteinizing hormone (LH), and (4) had better sperm movement performance. Additionally, we found that testis size, SOD activity in testes and LH levels were decisive factors in sperm movement performance in tree sparrows. Heavy metal concentrations in testes negatively correlated with testis size, SOD activity in testes, and estrogen levels in tree sparrows. The present study indicates that heavy metals accumulating in testes of tree sparrows adversely affected some key indicators of male reproductive function. However, testicular function, reproductive hormone levels and sperm quality showed adaptive responses that tended to partially compensate for the negative effects in the heavy metal polluted area. This study further indicated that the regulation of testicular function and reproductive hormone levels was the main factor for better sperm quality in tree sparrows exposed to environments contaminated by heavy metals.

  • variation in genetic diversity of tree sparrow Passer Montanus population in long term environmental heavy metal polluted areas
    Environmental Pollution, 2020
    Co-Authors: Wenzhi Yang, Jian Ding, Ying Yang, Shengnan Wang, Gang Song, Yingmei Zhang
    Abstract:

    Abstract Genetic diversity is the bedrock of evolution. The “Genetic Erosion” hypothesis posits that environmental pollution could cause reduced genetic diversity. To explore the effects of heavy metal pollution on genetic diversity in natural populations, we selected an area with more than sixty years of heavy metal contamination (Baiyin, BY) and a relatively unpolluted one (Liujiaxia, LJX), and tree sparrow (Passer Montanus) as study models. Five tree sparrow populations were sampled in BY at sites differing in heavy metal pollution level. Lower genetic diversity based on seven microsatellite loci was observed in the five tree sparrow populations from BY compared with those from LJX. Analysis of molecular variance indicated no significant genetic differentiation between BY and LJX. However, the observed heterozygosity and allelic richness were negatively correlated to the lead and cadmium concentrations in the primary feathers of tree sparrow. Our results indicated the genetic diversity might have a negative response to long-term environmental heavy metal pollution in tree sparrow, supporting the “Genetic Erosion” hypothesis. Therefore, the findings shed lights on the possible effects of heavy metal pollution on genetic diversity of wild bird populations.

  • variation in sperm morphology and performance in tree sparrow Passer Montanus under long term environmental heavy metal pollution
    Ecotoxicology and Environmental Safety, 2020
    Co-Authors: Ying Yang, Jian Ding, Wenzhi Yang, Shengnan Wang, Huijie Zhang, Yingmei Zhang
    Abstract:

    Sperm morphology and performance traits are key determinants of male fertilization success, particularly when females copulate with multiple males. Such sperm traits have been reported to be influenced by environmental pollutants in various animals; however, such studies remain rare in free-living birds exposed to heavy metal pollution. In the present study, we selected tree sparrow (Passer Montanus) as the study object to explore the effect of long-term environmental heavy metal pollution on sperm morphology (assessed mainly by using the dimensions of different sperm components and the sperm abnormality rates) and sperm performance (indicated by sperm velocity), and to elucidate potential relationships between variations in sperm morphology and performance. Sperm ATP concentration was also assessed considering sperm morphology and performance could be linked via energy availability. According to our results, tree sparrows from heavy metal polluted area (1) accumulated cadmium at a higher level in their testes; (2) produced longer sperm with lower abnormality rates, in addition to sperm with longer flagella and smaller head/flagellum ratios; (3) their sperm swam faster compared to those from the relatively unpolluted area, while no differences were observed in sperm ATP concentrations. We also found that the levels of lead and cadmium in testes affected the sperm nucleus length, and the level of copper in testes was negatively related to the proportions of abnormal sperm. Furthermore, the present study showed that sperm velocity was negatively correlated with sperm head lengths, head/flagellum ratios and ATP concentrations. Our study results reveal that sperm morphology and performance in tree sparrows show positive variations to maximize male fertility ability under long-term environmental heavy metal pollution, where males increase sperm flagellum lengths to decrease head/flagellum ratios, as opposed to varying sperm energy production, to achieve higher sperm velocity.

  • effects of environmental metal pollution on reproduction of a free living resident songbird the tree sparrow Passer Montanus
    Science of The Total Environment, 2020
    Co-Authors: Jian Ding, Wenzhi Yang, Ying Yang, Shengnan Wang, Huijie Zhang, Xinkang Bao, Yingmei Zhang
    Abstract:

    Abstract Anthropogenic metal pollution is known to adversely affect bird reproduction; however, few systematic studies are available on the effects of metal pollution on breeding performance and parental investment in a common resident songbird, the tree sparrow (Passer Montanus). We conducted this study in two sites, a long-term heavy metal polluted site (Baiyin [BY]) and a relatively unpolluted site at approximately 110 km distance (Liujiaxia [LJX]), to assess the potential effects of environmental metal contamination on breeding parameters (clutch size, hatching success, fledging success, and growth of nestlings) and parental investment. The results showed smaller clutch size, lower fledging success, and differences in incubation behaviors of tree sparrows in BY than in LJX. Although there was no difference in parental body condition (residual body mass) between the two study sites, the parents responded differently with respect to reproduction due to varying metal levels in their habitats and bodies. Higher Cd levels in the primary feathers of females in BY were associated with lower clutch sizes. Parental investment including incubation duration and feeding rates showed no significant difference between the two sites during the incubation and nestling periods, but the frequencies of incubation visits were higher in BY. Parental behavior during the incubation period was also negatively affected by the parental Pb and Cd levels. Although the nestling growth patterns were relatively similar between the two sites, the nestlings were smaller, had lower body weight, and fledged later and fledging rate was also lower in BY than in LJX. Metal concentrations were higher in nestling organs and feces in BY. Taken together, metal pollution might adversely affect nestling growth condition. Our results suggest a negative response in the reproduction of tree sparrows to long-term environmental metal pollution.

  • optimal analysis conditions for sperm motility parameters with a casa system in a Passerine bird Passer Montanus
    Avian Research, 2019
    Co-Authors: Ying Yang, Jian Ding, Xiaojuan Bai, Yingmei Zhang, Rui Guo, Wenzhi Yang
    Abstract:

    Sperm motility parameters, which can be measured objectively and repeatedly by a computer-assisted sperm analysis (CASA) system, are important indicators of sperm quality. However, the sperm motility parameters assessed by a CASA system can be affected by various factors, including instrument components and settings, sperm preparation or analysis procedures. To date, no standardized protocol is available that would permit to assess sperm kinetic characteristics in Passerine birds and this lack precludes any comparison of sperm swimming ability and sperm quality across species. In this study, we chose the Tree Sparrow (Passer Montanus) as the object to evaluate sperm motility parameters, including sperm motility, sperm velocity and sperm movement trajectory, at different analysis time, temperatures and pH using the WLJY-9000 CASA system. Sperm motility parameters remained statistically unchanged at 1‒9 min. Progressive motility was similar at 38 °C and 40 °C, but a greater percentage of slow progressive sperm was detected at 38 °C compared to 40 °C and 42 °C. Additionally, progressive motility was lower and immotility was higher at 42 °C than 38 °C and/or 40 °C (close to the body temperature of the Tree Sparrow). The percentages of rapid progressive sperm, progressive sperm and immotile sperm were statistically similar at pH 7.0, 7.5 and 8.0 with the exception of lower percentage of progressive sperm at pH 7.0 compared to pH 7.5. In addition, slower sperm velocity and worse sperm movement trajectory were found at pH 6.0 and 9.0 than those at pH 8.0, 7.5 or 7.0. Our study indicates that the ideal conditions for sperm motility parameters assessment in Tree Sparrow are obtained between 1 and 9 min after dilution, an environment at body temperature (40 °C) and a pH around 7.5‒8.0. The results of this study provide a reference for the evaluation of sperm characteristics and sperm quality using a CASA system in Passerine birds.

Wenzhi Yang - One of the best experts on this subject based on the ideXlab platform.

  • variation in genetic diversity of tree sparrow Passer Montanus population in long term environmental heavy metal polluted areas
    Environmental Pollution, 2020
    Co-Authors: Wenzhi Yang, Jian Ding, Ying Yang, Shengnan Wang, Gang Song, Yingmei Zhang
    Abstract:

    Abstract Genetic diversity is the bedrock of evolution. The “Genetic Erosion” hypothesis posits that environmental pollution could cause reduced genetic diversity. To explore the effects of heavy metal pollution on genetic diversity in natural populations, we selected an area with more than sixty years of heavy metal contamination (Baiyin, BY) and a relatively unpolluted one (Liujiaxia, LJX), and tree sparrow (Passer Montanus) as study models. Five tree sparrow populations were sampled in BY at sites differing in heavy metal pollution level. Lower genetic diversity based on seven microsatellite loci was observed in the five tree sparrow populations from BY compared with those from LJX. Analysis of molecular variance indicated no significant genetic differentiation between BY and LJX. However, the observed heterozygosity and allelic richness were negatively correlated to the lead and cadmium concentrations in the primary feathers of tree sparrow. Our results indicated the genetic diversity might have a negative response to long-term environmental heavy metal pollution in tree sparrow, supporting the “Genetic Erosion” hypothesis. Therefore, the findings shed lights on the possible effects of heavy metal pollution on genetic diversity of wild bird populations.

  • variation in sperm morphology and performance in tree sparrow Passer Montanus under long term environmental heavy metal pollution
    Ecotoxicology and Environmental Safety, 2020
    Co-Authors: Ying Yang, Jian Ding, Wenzhi Yang, Shengnan Wang, Huijie Zhang, Yingmei Zhang
    Abstract:

    Sperm morphology and performance traits are key determinants of male fertilization success, particularly when females copulate with multiple males. Such sperm traits have been reported to be influenced by environmental pollutants in various animals; however, such studies remain rare in free-living birds exposed to heavy metal pollution. In the present study, we selected tree sparrow (Passer Montanus) as the study object to explore the effect of long-term environmental heavy metal pollution on sperm morphology (assessed mainly by using the dimensions of different sperm components and the sperm abnormality rates) and sperm performance (indicated by sperm velocity), and to elucidate potential relationships between variations in sperm morphology and performance. Sperm ATP concentration was also assessed considering sperm morphology and performance could be linked via energy availability. According to our results, tree sparrows from heavy metal polluted area (1) accumulated cadmium at a higher level in their testes; (2) produced longer sperm with lower abnormality rates, in addition to sperm with longer flagella and smaller head/flagellum ratios; (3) their sperm swam faster compared to those from the relatively unpolluted area, while no differences were observed in sperm ATP concentrations. We also found that the levels of lead and cadmium in testes affected the sperm nucleus length, and the level of copper in testes was negatively related to the proportions of abnormal sperm. Furthermore, the present study showed that sperm velocity was negatively correlated with sperm head lengths, head/flagellum ratios and ATP concentrations. Our study results reveal that sperm morphology and performance in tree sparrows show positive variations to maximize male fertility ability under long-term environmental heavy metal pollution, where males increase sperm flagellum lengths to decrease head/flagellum ratios, as opposed to varying sperm energy production, to achieve higher sperm velocity.

  • effects of environmental metal pollution on reproduction of a free living resident songbird the tree sparrow Passer Montanus
    Science of The Total Environment, 2020
    Co-Authors: Jian Ding, Wenzhi Yang, Ying Yang, Shengnan Wang, Huijie Zhang, Xinkang Bao, Yingmei Zhang
    Abstract:

    Abstract Anthropogenic metal pollution is known to adversely affect bird reproduction; however, few systematic studies are available on the effects of metal pollution on breeding performance and parental investment in a common resident songbird, the tree sparrow (Passer Montanus). We conducted this study in two sites, a long-term heavy metal polluted site (Baiyin [BY]) and a relatively unpolluted site at approximately 110 km distance (Liujiaxia [LJX]), to assess the potential effects of environmental metal contamination on breeding parameters (clutch size, hatching success, fledging success, and growth of nestlings) and parental investment. The results showed smaller clutch size, lower fledging success, and differences in incubation behaviors of tree sparrows in BY than in LJX. Although there was no difference in parental body condition (residual body mass) between the two study sites, the parents responded differently with respect to reproduction due to varying metal levels in their habitats and bodies. Higher Cd levels in the primary feathers of females in BY were associated with lower clutch sizes. Parental investment including incubation duration and feeding rates showed no significant difference between the two sites during the incubation and nestling periods, but the frequencies of incubation visits were higher in BY. Parental behavior during the incubation period was also negatively affected by the parental Pb and Cd levels. Although the nestling growth patterns were relatively similar between the two sites, the nestlings were smaller, had lower body weight, and fledged later and fledging rate was also lower in BY than in LJX. Metal concentrations were higher in nestling organs and feces in BY. Taken together, metal pollution might adversely affect nestling growth condition. Our results suggest a negative response in the reproduction of tree sparrows to long-term environmental metal pollution.

  • optimal analysis conditions for sperm motility parameters with a casa system in a Passerine bird Passer Montanus
    Avian Research, 2019
    Co-Authors: Ying Yang, Jian Ding, Xiaojuan Bai, Yingmei Zhang, Rui Guo, Wenzhi Yang
    Abstract:

    Sperm motility parameters, which can be measured objectively and repeatedly by a computer-assisted sperm analysis (CASA) system, are important indicators of sperm quality. However, the sperm motility parameters assessed by a CASA system can be affected by various factors, including instrument components and settings, sperm preparation or analysis procedures. To date, no standardized protocol is available that would permit to assess sperm kinetic characteristics in Passerine birds and this lack precludes any comparison of sperm swimming ability and sperm quality across species. In this study, we chose the Tree Sparrow (Passer Montanus) as the object to evaluate sperm motility parameters, including sperm motility, sperm velocity and sperm movement trajectory, at different analysis time, temperatures and pH using the WLJY-9000 CASA system. Sperm motility parameters remained statistically unchanged at 1‒9 min. Progressive motility was similar at 38 °C and 40 °C, but a greater percentage of slow progressive sperm was detected at 38 °C compared to 40 °C and 42 °C. Additionally, progressive motility was lower and immotility was higher at 42 °C than 38 °C and/or 40 °C (close to the body temperature of the Tree Sparrow). The percentages of rapid progressive sperm, progressive sperm and immotile sperm were statistically similar at pH 7.0, 7.5 and 8.0 with the exception of lower percentage of progressive sperm at pH 7.0 compared to pH 7.5. In addition, slower sperm velocity and worse sperm movement trajectory were found at pH 6.0 and 9.0 than those at pH 8.0, 7.5 or 7.0. Our study indicates that the ideal conditions for sperm motility parameters assessment in Tree Sparrow are obtained between 1 and 9 min after dilution, an environment at body temperature (40 °C) and a pH around 7.5‒8.0. The results of this study provide a reference for the evaluation of sperm characteristics and sperm quality using a CASA system in Passerine birds.

  • variations in tree sparrow Passer Montanus egg characteristics under environmental metal pollution
    Science of The Total Environment, 2019
    Co-Authors: Jian Ding, Wenzhi Yang, Ying Yang, Xiaojuan Bai, Yingmei Zhang
    Abstract:

    Environmental metal pollution is known to adversely affect bird reproduction, for which the variations of egg characteristics are considered very important. Our study explored whether variations in egg characteristics, such as egg volume, eggshell spotting pattern, eggshell coloration, and eggshell thickness, were correlated with heavy metal levels (Cu, Zn, Pb, and Cd) and Ca levels in the eggshells of tree sparrows (Passer Montanus), a widespread Passerine species. Eggs were collected from a long-term heavy metal polluted area (Baiyin, BY, northwest China) and a relatively unpolluted area (Liujiaxia, LJX, northwest China). Our results showed that the embryonated (eggshell: Cu: p = 0.003, Pb: p = 0.002) and non-embryonated (egg contents: Pb: p = 0.044, Ca: p = 0.045) eggs collected from BY contained relatively higher metal concentrations than those from LJX. Eggs from BY were smaller in volume (p < 0.01) and thinner in eggshell thickness (p < 0.01) than those from LJX. Mean egg volume increased with clutch size in BY (p = 0.017), which was also accompanied by an increase in the within-clutch coefficient of variation (CV) for egg volume (p = 0.045). Clutches with a higher CV for egg volume tended to contain higher concentrations of Zn and Pb (Zn: p = 0.084; Pb: p = 0.081) in the eggshells from BY. No differences were found in the eggshell spotting coverage ratio of eggs; however, eggshells were much darker in BY than in LJX. A more aggregated eggshell spotting distribution indicated higher eggshell Zn and Pb levels (BY: Zn: p = 0.040, Pb: p = 0.076; LJX: Pb: p = 0.066). The results demonstrate that the egg characteristics of tree sparrows can be used as indicators of metal pollution, especially for the within-clutch CV for egg volume, eggshell spotting pattern and eggshell coloration.

Jian Ding - One of the best experts on this subject based on the ideXlab platform.

  • variation in genetic diversity of tree sparrow Passer Montanus population in long term environmental heavy metal polluted areas
    Environmental Pollution, 2020
    Co-Authors: Wenzhi Yang, Jian Ding, Ying Yang, Shengnan Wang, Gang Song, Yingmei Zhang
    Abstract:

    Abstract Genetic diversity is the bedrock of evolution. The “Genetic Erosion” hypothesis posits that environmental pollution could cause reduced genetic diversity. To explore the effects of heavy metal pollution on genetic diversity in natural populations, we selected an area with more than sixty years of heavy metal contamination (Baiyin, BY) and a relatively unpolluted one (Liujiaxia, LJX), and tree sparrow (Passer Montanus) as study models. Five tree sparrow populations were sampled in BY at sites differing in heavy metal pollution level. Lower genetic diversity based on seven microsatellite loci was observed in the five tree sparrow populations from BY compared with those from LJX. Analysis of molecular variance indicated no significant genetic differentiation between BY and LJX. However, the observed heterozygosity and allelic richness were negatively correlated to the lead and cadmium concentrations in the primary feathers of tree sparrow. Our results indicated the genetic diversity might have a negative response to long-term environmental heavy metal pollution in tree sparrow, supporting the “Genetic Erosion” hypothesis. Therefore, the findings shed lights on the possible effects of heavy metal pollution on genetic diversity of wild bird populations.

  • variation in sperm morphology and performance in tree sparrow Passer Montanus under long term environmental heavy metal pollution
    Ecotoxicology and Environmental Safety, 2020
    Co-Authors: Ying Yang, Jian Ding, Wenzhi Yang, Shengnan Wang, Huijie Zhang, Yingmei Zhang
    Abstract:

    Sperm morphology and performance traits are key determinants of male fertilization success, particularly when females copulate with multiple males. Such sperm traits have been reported to be influenced by environmental pollutants in various animals; however, such studies remain rare in free-living birds exposed to heavy metal pollution. In the present study, we selected tree sparrow (Passer Montanus) as the study object to explore the effect of long-term environmental heavy metal pollution on sperm morphology (assessed mainly by using the dimensions of different sperm components and the sperm abnormality rates) and sperm performance (indicated by sperm velocity), and to elucidate potential relationships between variations in sperm morphology and performance. Sperm ATP concentration was also assessed considering sperm morphology and performance could be linked via energy availability. According to our results, tree sparrows from heavy metal polluted area (1) accumulated cadmium at a higher level in their testes; (2) produced longer sperm with lower abnormality rates, in addition to sperm with longer flagella and smaller head/flagellum ratios; (3) their sperm swam faster compared to those from the relatively unpolluted area, while no differences were observed in sperm ATP concentrations. We also found that the levels of lead and cadmium in testes affected the sperm nucleus length, and the level of copper in testes was negatively related to the proportions of abnormal sperm. Furthermore, the present study showed that sperm velocity was negatively correlated with sperm head lengths, head/flagellum ratios and ATP concentrations. Our study results reveal that sperm morphology and performance in tree sparrows show positive variations to maximize male fertility ability under long-term environmental heavy metal pollution, where males increase sperm flagellum lengths to decrease head/flagellum ratios, as opposed to varying sperm energy production, to achieve higher sperm velocity.

  • effects of environmental metal pollution on reproduction of a free living resident songbird the tree sparrow Passer Montanus
    Science of The Total Environment, 2020
    Co-Authors: Jian Ding, Wenzhi Yang, Ying Yang, Shengnan Wang, Huijie Zhang, Xinkang Bao, Yingmei Zhang
    Abstract:

    Abstract Anthropogenic metal pollution is known to adversely affect bird reproduction; however, few systematic studies are available on the effects of metal pollution on breeding performance and parental investment in a common resident songbird, the tree sparrow (Passer Montanus). We conducted this study in two sites, a long-term heavy metal polluted site (Baiyin [BY]) and a relatively unpolluted site at approximately 110 km distance (Liujiaxia [LJX]), to assess the potential effects of environmental metal contamination on breeding parameters (clutch size, hatching success, fledging success, and growth of nestlings) and parental investment. The results showed smaller clutch size, lower fledging success, and differences in incubation behaviors of tree sparrows in BY than in LJX. Although there was no difference in parental body condition (residual body mass) between the two study sites, the parents responded differently with respect to reproduction due to varying metal levels in their habitats and bodies. Higher Cd levels in the primary feathers of females in BY were associated with lower clutch sizes. Parental investment including incubation duration and feeding rates showed no significant difference between the two sites during the incubation and nestling periods, but the frequencies of incubation visits were higher in BY. Parental behavior during the incubation period was also negatively affected by the parental Pb and Cd levels. Although the nestling growth patterns were relatively similar between the two sites, the nestlings were smaller, had lower body weight, and fledged later and fledging rate was also lower in BY than in LJX. Metal concentrations were higher in nestling organs and feces in BY. Taken together, metal pollution might adversely affect nestling growth condition. Our results suggest a negative response in the reproduction of tree sparrows to long-term environmental metal pollution.

  • optimal analysis conditions for sperm motility parameters with a casa system in a Passerine bird Passer Montanus
    Avian Research, 2019
    Co-Authors: Ying Yang, Jian Ding, Xiaojuan Bai, Yingmei Zhang, Rui Guo, Wenzhi Yang
    Abstract:

    Sperm motility parameters, which can be measured objectively and repeatedly by a computer-assisted sperm analysis (CASA) system, are important indicators of sperm quality. However, the sperm motility parameters assessed by a CASA system can be affected by various factors, including instrument components and settings, sperm preparation or analysis procedures. To date, no standardized protocol is available that would permit to assess sperm kinetic characteristics in Passerine birds and this lack precludes any comparison of sperm swimming ability and sperm quality across species. In this study, we chose the Tree Sparrow (Passer Montanus) as the object to evaluate sperm motility parameters, including sperm motility, sperm velocity and sperm movement trajectory, at different analysis time, temperatures and pH using the WLJY-9000 CASA system. Sperm motility parameters remained statistically unchanged at 1‒9 min. Progressive motility was similar at 38 °C and 40 °C, but a greater percentage of slow progressive sperm was detected at 38 °C compared to 40 °C and 42 °C. Additionally, progressive motility was lower and immotility was higher at 42 °C than 38 °C and/or 40 °C (close to the body temperature of the Tree Sparrow). The percentages of rapid progressive sperm, progressive sperm and immotile sperm were statistically similar at pH 7.0, 7.5 and 8.0 with the exception of lower percentage of progressive sperm at pH 7.0 compared to pH 7.5. In addition, slower sperm velocity and worse sperm movement trajectory were found at pH 6.0 and 9.0 than those at pH 8.0, 7.5 or 7.0. Our study indicates that the ideal conditions for sperm motility parameters assessment in Tree Sparrow are obtained between 1 and 9 min after dilution, an environment at body temperature (40 °C) and a pH around 7.5‒8.0. The results of this study provide a reference for the evaluation of sperm characteristics and sperm quality using a CASA system in Passerine birds.

  • variations in tree sparrow Passer Montanus egg characteristics under environmental metal pollution
    Science of The Total Environment, 2019
    Co-Authors: Jian Ding, Wenzhi Yang, Ying Yang, Xiaojuan Bai, Yingmei Zhang
    Abstract:

    Environmental metal pollution is known to adversely affect bird reproduction, for which the variations of egg characteristics are considered very important. Our study explored whether variations in egg characteristics, such as egg volume, eggshell spotting pattern, eggshell coloration, and eggshell thickness, were correlated with heavy metal levels (Cu, Zn, Pb, and Cd) and Ca levels in the eggshells of tree sparrows (Passer Montanus), a widespread Passerine species. Eggs were collected from a long-term heavy metal polluted area (Baiyin, BY, northwest China) and a relatively unpolluted area (Liujiaxia, LJX, northwest China). Our results showed that the embryonated (eggshell: Cu: p = 0.003, Pb: p = 0.002) and non-embryonated (egg contents: Pb: p = 0.044, Ca: p = 0.045) eggs collected from BY contained relatively higher metal concentrations than those from LJX. Eggs from BY were smaller in volume (p < 0.01) and thinner in eggshell thickness (p < 0.01) than those from LJX. Mean egg volume increased with clutch size in BY (p = 0.017), which was also accompanied by an increase in the within-clutch coefficient of variation (CV) for egg volume (p = 0.045). Clutches with a higher CV for egg volume tended to contain higher concentrations of Zn and Pb (Zn: p = 0.084; Pb: p = 0.081) in the eggshells from BY. No differences were found in the eggshell spotting coverage ratio of eggs; however, eggshells were much darker in BY than in LJX. A more aggregated eggshell spotting distribution indicated higher eggshell Zn and Pb levels (BY: Zn: p = 0.040, Pb: p = 0.076; LJX: Pb: p = 0.066). The results demonstrate that the egg characteristics of tree sparrows can be used as indicators of metal pollution, especially for the within-clutch CV for egg volume, eggshell spotting pattern and eggshell coloration.

Shengnan Wang - One of the best experts on this subject based on the ideXlab platform.

  • response of male reproductive function to environmental heavy metal pollution in a free living Passerine bird Passer Montanus
    Science of The Total Environment, 2020
    Co-Authors: Ying Yang, Shengnan Wang, Huijie Zhang, Wenya Zhang, Yingmei Zhang
    Abstract:

    Abstract Heavy metals affect male reproductive function by impairing reproductive organs, disturbing reproductive hormone levels or directly affecting sperm quality. However, little attention has been given to the effect of environmental heavy metals on reproductive function in wild male birds. The present study investigated the alterations of reproductive function in male tree sparrows (Passer Montanus) exposed to environments contaminated by heavy metals in terms of testis parameters, reproductive hormone levels and sperm movement characteristics. Two plots, Baiyin (BY, mainly polluted by copper, zinc, lead and cadmium) and Liujiaxia (LJX, a relatively unpolluted area) were selected as sampling sites. The results showed that tree sparrows from BY (1) accumulated higher levels of cadmium in the testes, (2) showed lower superoxide dismutase (SOD) activity and malondialdehyde level, with higher total antioxidant capacity and apoptosis level in the testes, (3) showed higher plasma levels of estrogen, follicle stimulating hormone and luteinizing hormone (LH), and (4) had better sperm movement performance. Additionally, we found that testis size, SOD activity in testes and LH levels were decisive factors in sperm movement performance in tree sparrows. Heavy metal concentrations in testes negatively correlated with testis size, SOD activity in testes, and estrogen levels in tree sparrows. The present study indicates that heavy metals accumulating in testes of tree sparrows adversely affected some key indicators of male reproductive function. However, testicular function, reproductive hormone levels and sperm quality showed adaptive responses that tended to partially compensate for the negative effects in the heavy metal polluted area. This study further indicated that the regulation of testicular function and reproductive hormone levels was the main factor for better sperm quality in tree sparrows exposed to environments contaminated by heavy metals.

  • variation in genetic diversity of tree sparrow Passer Montanus population in long term environmental heavy metal polluted areas
    Environmental Pollution, 2020
    Co-Authors: Wenzhi Yang, Jian Ding, Ying Yang, Shengnan Wang, Gang Song, Yingmei Zhang
    Abstract:

    Abstract Genetic diversity is the bedrock of evolution. The “Genetic Erosion” hypothesis posits that environmental pollution could cause reduced genetic diversity. To explore the effects of heavy metal pollution on genetic diversity in natural populations, we selected an area with more than sixty years of heavy metal contamination (Baiyin, BY) and a relatively unpolluted one (Liujiaxia, LJX), and tree sparrow (Passer Montanus) as study models. Five tree sparrow populations were sampled in BY at sites differing in heavy metal pollution level. Lower genetic diversity based on seven microsatellite loci was observed in the five tree sparrow populations from BY compared with those from LJX. Analysis of molecular variance indicated no significant genetic differentiation between BY and LJX. However, the observed heterozygosity and allelic richness were negatively correlated to the lead and cadmium concentrations in the primary feathers of tree sparrow. Our results indicated the genetic diversity might have a negative response to long-term environmental heavy metal pollution in tree sparrow, supporting the “Genetic Erosion” hypothesis. Therefore, the findings shed lights on the possible effects of heavy metal pollution on genetic diversity of wild bird populations.

  • variation in sperm morphology and performance in tree sparrow Passer Montanus under long term environmental heavy metal pollution
    Ecotoxicology and Environmental Safety, 2020
    Co-Authors: Ying Yang, Jian Ding, Wenzhi Yang, Shengnan Wang, Huijie Zhang, Yingmei Zhang
    Abstract:

    Sperm morphology and performance traits are key determinants of male fertilization success, particularly when females copulate with multiple males. Such sperm traits have been reported to be influenced by environmental pollutants in various animals; however, such studies remain rare in free-living birds exposed to heavy metal pollution. In the present study, we selected tree sparrow (Passer Montanus) as the study object to explore the effect of long-term environmental heavy metal pollution on sperm morphology (assessed mainly by using the dimensions of different sperm components and the sperm abnormality rates) and sperm performance (indicated by sperm velocity), and to elucidate potential relationships between variations in sperm morphology and performance. Sperm ATP concentration was also assessed considering sperm morphology and performance could be linked via energy availability. According to our results, tree sparrows from heavy metal polluted area (1) accumulated cadmium at a higher level in their testes; (2) produced longer sperm with lower abnormality rates, in addition to sperm with longer flagella and smaller head/flagellum ratios; (3) their sperm swam faster compared to those from the relatively unpolluted area, while no differences were observed in sperm ATP concentrations. We also found that the levels of lead and cadmium in testes affected the sperm nucleus length, and the level of copper in testes was negatively related to the proportions of abnormal sperm. Furthermore, the present study showed that sperm velocity was negatively correlated with sperm head lengths, head/flagellum ratios and ATP concentrations. Our study results reveal that sperm morphology and performance in tree sparrows show positive variations to maximize male fertility ability under long-term environmental heavy metal pollution, where males increase sperm flagellum lengths to decrease head/flagellum ratios, as opposed to varying sperm energy production, to achieve higher sperm velocity.

  • effects of environmental metal pollution on reproduction of a free living resident songbird the tree sparrow Passer Montanus
    Science of The Total Environment, 2020
    Co-Authors: Jian Ding, Wenzhi Yang, Ying Yang, Shengnan Wang, Huijie Zhang, Xinkang Bao, Yingmei Zhang
    Abstract:

    Abstract Anthropogenic metal pollution is known to adversely affect bird reproduction; however, few systematic studies are available on the effects of metal pollution on breeding performance and parental investment in a common resident songbird, the tree sparrow (Passer Montanus). We conducted this study in two sites, a long-term heavy metal polluted site (Baiyin [BY]) and a relatively unpolluted site at approximately 110 km distance (Liujiaxia [LJX]), to assess the potential effects of environmental metal contamination on breeding parameters (clutch size, hatching success, fledging success, and growth of nestlings) and parental investment. The results showed smaller clutch size, lower fledging success, and differences in incubation behaviors of tree sparrows in BY than in LJX. Although there was no difference in parental body condition (residual body mass) between the two study sites, the parents responded differently with respect to reproduction due to varying metal levels in their habitats and bodies. Higher Cd levels in the primary feathers of females in BY were associated with lower clutch sizes. Parental investment including incubation duration and feeding rates showed no significant difference between the two sites during the incubation and nestling periods, but the frequencies of incubation visits were higher in BY. Parental behavior during the incubation period was also negatively affected by the parental Pb and Cd levels. Although the nestling growth patterns were relatively similar between the two sites, the nestlings were smaller, had lower body weight, and fledged later and fledging rate was also lower in BY than in LJX. Metal concentrations were higher in nestling organs and feces in BY. Taken together, metal pollution might adversely affect nestling growth condition. Our results suggest a negative response in the reproduction of tree sparrows to long-term environmental metal pollution.