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Lucia Martinezfresneda - One of the best experts on this subject based on the ideXlab platform.
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seasonal variation in sperm freezability associated with changes in testicular germinal epithelium in domestic ovis aries and wild ovis musimon sheep
Reproduction Fertility and Development, 2019Co-Authors: Lucia Martinezfresneda, E Obrien, Rosario Velazquez, A Toledanodiaz, Carlos M Martinezcaceres, Dawit Tesfaye, K Schellander, F A Garciavazquez, Julian SantiagomorenoAbstract:The aim of this study was to examine ovine sperm cryoresistance during the rutting season (RS) and its association with sperm head area and seminiferous epithelium proliferation. Small ruminants show fluctuating testosterone levels throughout the year, which could interfere with spermatogenesis and sperm cryopreservation. Ejaculates, testicular biopsies and blood were collected during the middle and at the end of the RS (Middle-RS vs End-RS) during periods of high and low testosterone levels in Merino and Mouflon rams. Fresh and frozen–thawed sperm quality, sperm morphometry, seminiferous tubule morphometry and testicular proliferation markers (proliferating cell nuclear antigen, proliferation marker protein Ki-67 and transcription factor GATA-4) were evaluated. Post-thaw sperm viability was higher in the End-RS group in both Merino (69.9 ± 8.2 vs 41.6 ± 7.3%; P = 0.020) and Mouflon rams (40.9 ± 3.3 vs 24.2 ± 5.0%; P = 0.008). Mouflons had larger sperm head area at the End-RS (38.3 ± 0.2 vs 34.3 ± 0.1 µm2; P = 0.029), whereas there was no difference between Merino groups (35.7 ± 0.5 vs 34.8 ± 1.0 µm2). Seminiferous tubule morphometry and proliferation markers showed higher levels of germinal epithelium proliferation in the Middle-RS of both species. In conclusion, sperm freezability is affected during the RS in domestic and wild rams, which could be correlated with changes that occur during spermatogenesis, since there is an effect of season on cell proliferation in the testis.
Seth W. Judge - One of the best experts on this subject based on the ideXlab platform.
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changes in habitat use and distribution of Mouflon in the kahuku unit of hawai i volcanoes national park
Pacific Conservation Biology, 2016Co-Authors: Bronson Palupe, Christina R. Leopold, Steven C. Hess, Jonathan K.j. Faford, Dexter Pacheco, Seth W. JudgeAbstract:European Mouflon sheep (Ovis gmelini musimon) were introduced to Kahuku Ranch on Hawai‘i Island in 1968 and 1974 for trophy hunting and have been detrimental to the native ecosystem by trampling, bark stripping, and browsing vegetation. In 2003, Hawai‘i Volcanoes National Park acquired Kahuku Ranch and managers began removing Mouflon. The objective of this project was to determine whether hunting has changed the distribution of Mouflon in Kahuku, to better understand Mouflon behaviour and to expedite eradication efforts. Locations from hunting and GPS telemetry data during 2007–14 were used to determine the effect of hunting on Mouflon distribution by examining distance to roads and habitat use. Mouflon seemed to avoid roads after hunting pressure increased and their distribution within vegetation types changed over time. Mouflon without hunting pressure were detected in native shrub habitat in 68% of all observations. Hunted Mouflon were encountered less in native shrub habitat and more in other habitats including open forest, closed forest, and areas with no vegetation. These changes suggest that hunting has influenced the distribution of Mouflon over time away from native shrub and into other vegetation types where they may be more difficult to control.
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Changes in habitat use and distribution of Mouflon in the Kahuku Unit of Hawai‘i Volcanoes National Park
Pacific Conservation Biology, 2016Co-Authors: Bronson Palupe, Christina R. Leopold, Steven C. Hess, Jonathan K.j. Faford, Dexter Pacheco, Seth W. JudgeAbstract:European Mouflon sheep (Ovis gmelini musimon) were introduced to Kahuku Ranch on Hawai‘i Island in 1968 and 1974 for trophy hunting and have been detrimental to the native ecosystem by trampling, bark stripping, and browsing vegetation. In 2003, Hawai‘i Volcanoes National Park acquired Kahuku Ranch and managers began removing Mouflon. The objective of this project was to determine whether hunting has changed the distribution of Mouflon in Kahuku, to better understand Mouflon behaviour and to expedite eradication efforts. Locations from hunting and GPS telemetry data during 2007–14 were used to determine the effect of hunting on Mouflon distribution by examining distance to roads and habitat use. Mouflon seemed to avoid roads after hunting pressure increased and their distribution within vegetation types changed over time. Mouflon without hunting pressure were detected in native shrub habitat in 68% of all observations. Hunted Mouflon were encountered less in native shrub habitat and more in other habitats including open forest, closed forest, and areas with no vegetation. These changes suggest that hunting has influenced the distribution of Mouflon over time away from native shrub and into other vegetation types where they may be more difficult to control.
Bruno Lucio Masala - One of the best experts on this subject based on the ideXlab platform.
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Haemoglobin phenotypes of the wild European Mouflon sheep living on the island of Sardinia.
Animal genetics, 2009Co-Authors: Salvatore Naitana, Sergio Ledda, Laura Manca, Elena Cocco, Bruno Lucio MasalaAbstract:Haemoglobin (Hb) phenotypes have been studied in 100 wild European Mouflons living on the island of Sardinia by means of isoelectric focusing (pH 6.7-7.7 range) of the native tetramers, acid-urea-Triton gel-electrophoresis, and reversed-phase HPLC of globin chains. The result indicates the presence of two beta-globin alleles one of which, corresponding to the beta B, being the most common (f = 0.94). None were carriers of the earlier described Hb A. The new Hb was provisionally named Hb M. Severely anaemic Mouflons were able to synthesize Hb C at expense of the Hb B alone, thus suggesting structural and physiological homologies between Mouflon beta B and sheep beta A globin genes, and between the newly observed beta M allele and the beta B of the domestic Sardinian sheep.
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The sequence and phylogenesis of the α-globin genes of Barbary sheep (Ammotragus lervia), goat (Capra hircus), European Mouflon (Ovis aries musimon) and Cyprus Mouflon (Ovis aries ophion)
Comparative biochemistry and physiology. Part D Genomics & proteomics, 2009Co-Authors: Monica Pirastru, Paolo Mereu, Laura Manca, Chiara Multineddu, Mara Sannai, El Said El Sherbini, Eleftherios Hadjisterkotis, András Náhlik, Paul Franceschi, Bruno Lucio MasalaAbstract:In order to investigate the polymorphism of ?-globin chain of hemoglobin amongst caprines, the linked (I)? and (II)? globin genes of Barbary sheep (Ammotragus lervia), goat (Capra hircus), European Mouflon (Ovis aries musimon), and Cyprus Mouflon (Ovis aries ophion) were completely sequenced, including the 5? and 3? untranslated regions. European and Cyprus Mouflons, which do not show polymorphic ? globin chains, had almost identical ? globin genes, whereas Barbary sheep exhibit two different chains encoded by two nonallelic genes. Four different ? genes were observed and sequenced in goat, validating previous observations of the existence of allelic and nonallelic polymorphism. As in other vertebrates, interchromosomal gene conversion appears to be responsible for such polymorphism. Evaluation of nucleotide sequences at the level of molecular evolution of the (I)?-globin gene family in the caprine taxa suggests a closer relationship between the genus Ammotragus and Capra. Molecular clock estimates suggest sheep-Mouflon, goat-aoudad, and ancestor-caprine divergences of 2.8, 5.7, and 7.1 MYBP, respectively.
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A Comparative Study on the Functional Properties of the Wild European Mouflon and Domestic Sheep Hemoglobins
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 1997Co-Authors: Marcella Corda, Laura Manca, Bruno Giardina, Mariagiuseppina Pellegrini, Alessandra Olianas, Maria Teresa Sanna, Antonella Fais, Bruno Lucio MasalaAbstract:The functional properties of Hb B of the wild European Mouflon (Ovis gmelini musimon), Hb B of domestic sheep (Ovis aries), and Hb C isolated from anemic Mouflon were investigated. Mouflon and sheep Hbs appear to be very similar in their response to organic anions and protons, whereas sheep Hb B displays an oxygen affinity lower than that of Mouflon Hb B and sheep Hb A. Mouflon Hb B and Hb C, like sheep Hb A and Hb C, have similar efficiencies in transporting oxygen to the tissues. As in other ruminant Hbs, the effect of temperature on the oxygen affinity is slight. Data suggest that Mouflon Hb B is not only structurally, but even functionally, more similar to sheep Hb A than to sheep Hb B.
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Kinetics of the ontogenic and reversible hemoglobin switching in the Mouflon (Ovis musimon) and sheep × Mouflon hybrid
Comparative biochemistry and physiology. A Comparative physiology, 1991Co-Authors: Bruno Lucio Masala, Sergio Ledda, Laura Manca, Elena Cocco, Salvatore NaitanaAbstract:1. Hemoglobin (Hb) switching in the perinatal life of wild Mouflon (Ovis musimon) was characterized by the replacement of Hb F by 60% levels of Hb C, and subsequently of Hb C by Hb B. 2. The recently discovered Hb M variant was not replaced by Hb C; thus, Hb BM heterozygote newborns synthesized 30% Hb C at the expense of Hb B. 3. Hybrid B Mouflon x B sheep synthesized only 5% Hb C at birth but were able to produce 30% Hb C in adult life following induced anemia. 4. Adult BB and BM Mouflons, after the same extent of induced anemia, synthesized HB C levels similar to those produced at birth. The results indicate a Mouflon beta-globin gene cluster arrangement similar to those of sheep and goat, the beta C gene having an intermediate expression. Results also suggest a selective disadvantage in hybrid animals.
Julian Santiagomoreno - One of the best experts on this subject based on the ideXlab platform.
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seasonal variation in sperm freezability associated with changes in testicular germinal epithelium in domestic ovis aries and wild ovis musimon sheep
Reproduction Fertility and Development, 2019Co-Authors: Lucia Martinezfresneda, E Obrien, Rosario Velazquez, A Toledanodiaz, Carlos M Martinezcaceres, Dawit Tesfaye, K Schellander, F A Garciavazquez, Julian SantiagomorenoAbstract:The aim of this study was to examine ovine sperm cryoresistance during the rutting season (RS) and its association with sperm head area and seminiferous epithelium proliferation. Small ruminants show fluctuating testosterone levels throughout the year, which could interfere with spermatogenesis and sperm cryopreservation. Ejaculates, testicular biopsies and blood were collected during the middle and at the end of the RS (Middle-RS vs End-RS) during periods of high and low testosterone levels in Merino and Mouflon rams. Fresh and frozen–thawed sperm quality, sperm morphometry, seminiferous tubule morphometry and testicular proliferation markers (proliferating cell nuclear antigen, proliferation marker protein Ki-67 and transcription factor GATA-4) were evaluated. Post-thaw sperm viability was higher in the End-RS group in both Merino (69.9 ± 8.2 vs 41.6 ± 7.3%; P = 0.020) and Mouflon rams (40.9 ± 3.3 vs 24.2 ± 5.0%; P = 0.008). Mouflons had larger sperm head area at the End-RS (38.3 ± 0.2 vs 34.3 ± 0.1 µm2; P = 0.029), whereas there was no difference between Merino groups (35.7 ± 0.5 vs 34.8 ± 1.0 µm2). Seminiferous tubule morphometry and proliferation markers showed higher levels of germinal epithelium proliferation in the Middle-RS of both species. In conclusion, sperm freezability is affected during the RS in domestic and wild rams, which could be correlated with changes that occur during spermatogenesis, since there is an effect of season on cell proliferation in the testis.
Bronson Palupe - One of the best experts on this subject based on the ideXlab platform.
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changes in habitat use and distribution of Mouflon in the kahuku unit of hawai i volcanoes national park
Pacific Conservation Biology, 2016Co-Authors: Bronson Palupe, Christina R. Leopold, Steven C. Hess, Jonathan K.j. Faford, Dexter Pacheco, Seth W. JudgeAbstract:European Mouflon sheep (Ovis gmelini musimon) were introduced to Kahuku Ranch on Hawai‘i Island in 1968 and 1974 for trophy hunting and have been detrimental to the native ecosystem by trampling, bark stripping, and browsing vegetation. In 2003, Hawai‘i Volcanoes National Park acquired Kahuku Ranch and managers began removing Mouflon. The objective of this project was to determine whether hunting has changed the distribution of Mouflon in Kahuku, to better understand Mouflon behaviour and to expedite eradication efforts. Locations from hunting and GPS telemetry data during 2007–14 were used to determine the effect of hunting on Mouflon distribution by examining distance to roads and habitat use. Mouflon seemed to avoid roads after hunting pressure increased and their distribution within vegetation types changed over time. Mouflon without hunting pressure were detected in native shrub habitat in 68% of all observations. Hunted Mouflon were encountered less in native shrub habitat and more in other habitats including open forest, closed forest, and areas with no vegetation. These changes suggest that hunting has influenced the distribution of Mouflon over time away from native shrub and into other vegetation types where they may be more difficult to control.
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Changes in habitat use and distribution of Mouflon in the Kahuku Unit of Hawai‘i Volcanoes National Park
Pacific Conservation Biology, 2016Co-Authors: Bronson Palupe, Christina R. Leopold, Steven C. Hess, Jonathan K.j. Faford, Dexter Pacheco, Seth W. JudgeAbstract:European Mouflon sheep (Ovis gmelini musimon) were introduced to Kahuku Ranch on Hawai‘i Island in 1968 and 1974 for trophy hunting and have been detrimental to the native ecosystem by trampling, bark stripping, and browsing vegetation. In 2003, Hawai‘i Volcanoes National Park acquired Kahuku Ranch and managers began removing Mouflon. The objective of this project was to determine whether hunting has changed the distribution of Mouflon in Kahuku, to better understand Mouflon behaviour and to expedite eradication efforts. Locations from hunting and GPS telemetry data during 2007–14 were used to determine the effect of hunting on Mouflon distribution by examining distance to roads and habitat use. Mouflon seemed to avoid roads after hunting pressure increased and their distribution within vegetation types changed over time. Mouflon without hunting pressure were detected in native shrub habitat in 68% of all observations. Hunted Mouflon were encountered less in native shrub habitat and more in other habitats including open forest, closed forest, and areas with no vegetation. These changes suggest that hunting has influenced the distribution of Mouflon over time away from native shrub and into other vegetation types where they may be more difficult to control.