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Milan Gelnar - One of the best experts on this subject based on the ideXlab platform.
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Gyrodactylus malalai sp. nov. (Monogenea, Gyrodactylidae) from Nile tilapia, Oreochromis niloticus (L.) and Redbelly tilapia, Tilapia zillii (Gervais) (Teleostei, Cichlidae) in the Lake Turkana, Kenya
Acta Parasitologica, 2012Co-Authors: Iva Přikrylová, Blažek Radim, Milan GelnarAbstract:Gyrodactylus malalai sp. nov. is described from the fin surface of cichlid fishes Oreochromis niloticus (L.) and Tilapia zillii (Gervais) caught in Lake Turkana (Kenya). The new species morphologically resembles Gyrodactylus nyanzae Paperna, 1973, but can be readily distinguished by the shape of the marginal hook sickles and the size of its hamuli. The sequence data of rDNA spanning partial 18S, internal transcribe spacer 1 and 2 and the 5.8S gene is unique within GenBank. Genetically, as most similar Gyrodactylus ergensi Přikrylová, Matějusová, Musilová et Gelnar, 2009 was found (97.5%). Moreover, a specimen of G. cichlidarum from O. niloticus , and a specimen G. ergensi from Sarotherodon galilaeus (L.) were collected during sampling in Kenya. Likewise, additional sampling of O. niloticus from the Blue Nile in Sudan revealed the presence of the newly described species. These findings represent the first records of gyrodactylids in both African countries.
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gyrodactylus malalai sp nov monogenea gyrodactylidae fromnile tilapia oreochromis niloticus l and redbelly tilapia tilapia zillii gervais teleostei cichlidae in the laketurkana kenya
Acat Parasitologica, 2012Co-Authors: Iva Přikrylova, Radim Blažek, Milan GelnarAbstract:Gyrodacytlus malalai sp. nov. is described from the fin surface of cichlid fishes Oreochromis niloticus (L.) and Tilapia zillii (Gervais) caught in Lake Turkana (Kenya). The new species morphologically resembles Gyrodactylus nyanzae Paperna, 1973, but can be readily distinguished by the shape of the marginal hook sickles and the size of its hamuli. The sequence data of rDNA spanning partial 18S, internal transcribe spacer 1 and 2 and the 5.8S gene is unique within GenBank. Genetically, as most similar Gyrodactylus ergensi Přikrylova, Matějusova, Musilova et Gelnar, 2009 was found (97.5 %). Moreover, a specimen of G. cichlidarum from O. niloticus, and a specimen G. ergensi from Sarotherodon galilaeus (L.) were collected during sampling in Kenya. Likewise, additional sampling of O. niloticus from the Blue Nile in Sudan revealed the presence of the newly described species. These findings represent the first records of gyrodactlids in both African countries.
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Gyrodactylus species (Monogenea: Gyrodactylidae) on the cichlid fishes of Senegal, with the description of Gyrodactylus ergensi n. sp. from Mango tilapia, Sarotherodon galilaeus L. (Teleostei: Cichilidae)
Parasitology Research, 2009Co-Authors: Iva Přikrylová, Iveta Matějusová, Naďa Musilová, Milan GelnarAbstract:The first record of Gyrodactylus species Nordmann, 1832 on the cichlid fish from Senegal is reported. Gyrodactylus parasites were found on four host species studied, Hemichromis fasciatus , Hemichromis letournaeuxi , Oreochromis niloticus , and Sarotherodon galilaeus . Gyrodactylus cichlidarum Paperna (Bamidgeh 13:14–29, 1968 ) were collected from H. fasciatus , and its identity was confirmed based on the morphometrical comparison with the holotype specimens of G. cichlidarum . Only one specimen of Gyrodactylus sp. was noted on H. letournaeuxi . The gyrodactylid specimens on O. niloticus and S. galilaeus were described as Gyrodactylus ergensi n. sp. based on the detailed morphometrical analysis supported by sequencing. The haptoral sclerites of G. ergensi n. sp., which closely resemble those of Gyrodactylus nyanzae Paperna, 1973, are compared with the type material and discussed. A partial sequence of the internal transcribed spacer recombinant DNA (ITS rDNA) was obtained from two specimens of G. ergensi , and a close relationship between G. ergensi n. sp. and G. cichlidarum is suggested based on 92% similarity in ITS rDNA region.
Jeandominique Durand - One of the best experts on this subject based on the ideXlab platform.
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hordes of phages in the gut of the tilapia Sarotherodon melanotheron
Scientific Reports, 2018Co-Authors: Yvan Bettarel, Jacques Panfili, Awa Ndiaye, Marine Combe, Antoinette Adingra, Thierry Bouvier, Jeandominique DurandAbstract:Preliminary studies conducted on the human gastro-intestinal tract have revealed that enteric viral communities play a preponderant role in microbial homeostatis. However to date, such communities have never been investigated in the fish gut. Herein, we examined the main ecological traits of viruses in the digestive tract of a euryhaline fish, the tilapia Sarotherodon melanotheron. Individuals were collected at 8 different sites in Senegal covering a salinity gradient from 3 to 104‰, and showing large disparities in their organic pollutant concentrations. Results showed that the gut of S. melanotheron is home to a highly abundant viral community (0.2–10.7 × 109 viruses ml−1), distinct from the surrounding water, and essentially composed of phages of which a substantial proportion is temperate (the fraction of lysogenized cells-FLC ranging from 8.1 to 33.0%). Also, a positive and significant correlation was detected between FLC and the concentrations of polycyclic aromatic hydrocarbon in sediment, while no clear relationships were found between salinity and any of the microbial parameters considered. Finally, our data suggest that virus-bacteria interactions within the fish intestine are likely sensitive to the presence of particular xenobiotics, which may compromise the balance in the gut microbiota, and subsequently affect the health of their host.
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genetic diversity and adaptability of Sarotherodon melanotheron cichlidae in coastal ecosystem
Ethology Ecology & Evolution, 2012Co-Authors: Ahou Nicole Yoboue, B A Adepogourene, D Seka, Jeandominique Durand, Jacques Panfili, Raymond LaëAbstract:We analysed the genetic diversity of nine populations of two subspecies of Sarotherodon melanotheron using allozymes in relation to the existence of environmental pressures. The genetic variability of Sarotherodon melanotheron melanotheron in the Ivorian ecosystem (A = 1.23, He = 0.04 and P(95%) = 11.11) was lower than that of Sarotherodon melanotheron heudelotii of the estuaries in Gambia and Saloum (A = 1.68, He = 0.08 and P(95%) = 22.23). The analysis of allelic diversity revealed that the individuals of S. m. melanotheron subspecies from a much polluted environment (lagoon of Grand-Lahou or Ebrie) presented a relatively higher frequency of allele GPI-2*80 than those of a less polluted environment (Aby lagoon and Ayame lake). The allele IDH-2*90 was expressed only in the specimens of S. m. heudelotii found in the Saloum estuary, a very saline environment compared to the estuary of Gambia. A deficit of heterozygosis was observed with the tilapia Sarotherodon melanotheron. This study confirmed the poss...
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Multiparametric approach for assessing environmental quality variations in West African aquatic ecosystems using the black-chinned tilapia (Sarotherodon melanotheron) as a sentinel species
Environmental Science and Pollution Research, 2012Co-Authors: Awa Ndiaye, Jeandominique Durand, Wilfried Sanchez, Hélène Budzinski, Olivier Palluel, Pape Ndiaye, Khady Diouf, Jacques PanfiliAbstract:The study highlights the potential of the black-chinned tilapia to be used as a sentinel to assess environmental contaminants based on the use of a set of biomarkers. The usefulness of fish species as sentinels for assessing aquatic environment contamination was tested using a set of biomarkers in Senegalese environments characterized by multi-pollution sources. The black-chinned tilapia (Sarotherodon melanotheron) was selected as a sentinel because of its abundance, wide distribution in all coastal aquatic ecosystems and physiological properties. The potential influence of confounding factors such as salinity on biomarker in the tilapia has been examined. Individuals were sampled during two seasons (dry and wet) in eight sites characterized by various degrees of anthropogenic contamination and different salinities (from 0 to 102 psu). Biomarkers-including growth rate (GR), condition factor (CF), biotransformation enzymes such as 7-ethoxyresorufin-O-deethylase (EROD) and glutathione-S-transferase (GST), lipid peroxidation (TBARS) and acetylcholinesterase (AChE)-were measured. Chemical contaminant [polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs)] levels showed different sources of contamination with relatively high concentrations of PAHs in the Hann Bay and Foundiougne locations. The most sensitive biomarker present in different sites according to the principal component analysis is EROD. Few variations of the AChE activity and TBARS levels were found. No clear relationship was found between biomarker responses and salinity, but GR and CF were lower in hypersaline conditions. Tilapia is responsive to environmental contaminants such as PAHs, OCPs and PCBs. The Sarotherodon melanotheron multiparametric approach showed a better discrimination of sites.
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differential expression of the heat shock protein hsp70 in natural populations of the tilapia Sarotherodon melanotheron acclimatised to a range of environmental salinities
BMC Ecology, 2010Co-Authors: Francois Bonhomme, Mbaye Tine, David J Mckenzie, Jeandominique DurandAbstract:Background The relationship between environmental variation and induction of heat shock proteins (Hsps) has been much documented under experimental conditions. However, very little is known about such induction in natural populations acclimatised to prevailing environmental conditions. Furthermore, while induction of stress proteins has been well documented in response to environmental contaminants and thermal stressors, little is known about whether factors, such as extreme salinity, are also potential inductors. The black-chinned tilapia Sarotherodon melanotheron is unusual for its ability to colonise estuarine environments in West Africa that are characterised by extremely high salinities. The relationships between mRNA levels of the 70 kDa heat shock protein (Hsp70) and Na+, K+-ATPase1α (Naka) in the gills, environmental salinity, and a life-history trait (condition factor) were investigated in wild populations of this species sampled from three locations in the Saloum estuary, at salinities ranging from 40 to 100 psu.
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transcriptional responses of the black chinned tilapia Sarotherodon melanotheron to salinity extremes
Marine Genomics, 2008Co-Authors: Mbaye Tine, Francois Bonhomme, Jeanfrancois Baroiller, Helena Dcotta, Julien De Lorgeril, Elodie Pepey, Jeandominique DurandAbstract:Sarotherodon melanotheron is one of the most euryhaline teleosts able to withstand variations in environmental salinity ranging from freshwater (FW) to 130%0 hyper-saline waters (HSW). Although significant progress has been made in exploring the cellular and molecular changes that accompany salinity adaptation in teleosts, little is known about the effects of long-term acclimation to HSW. We sought to identify in this tilapia species the genes whose transcription is induced by long-term acclimation either to HSW or FW. Two subtractive cDNA libraries were made from gills of fish acclimated for 45 days to either condition, with 320 partial cDNA sequences encoding proteins potentially involved in the response to the two salinity extremes. The ESTs comparisons with genomic databases allowed putative functions to be attributed to 197 of these genes. The suppression subtractive hybridisation (SSH) results were validated by Real-time PCR for 13 candidate genes having presumably a role in osmoregulation, supplemented by Na+, K+- ATPase a-subunit and carbonic anhydrase, two genes known to be implicated in this function. In fish acclimated to both salinity extremes, the functional category of cellular process was the predominant one, which may indicate high cellular turnover rates in FW and HSW-adapted fish. The acclimation to FW and HSW also appeared to trigger the expression of genes involved in transport activity, biological regulation and metabolic processes, at a higher level in fish acclimated to HSW, suggesting higher metabolic activity in this situation. These results are a first step towards the identification of key molecular processes involved in the fish acclimation to extreme salinities. (Resume d'auteur)
Iva Přikrylová - One of the best experts on this subject based on the ideXlab platform.
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Gyrodactylus malalai sp. nov. (Monogenea, Gyrodactylidae) from Nile tilapia, Oreochromis niloticus (L.) and Redbelly tilapia, Tilapia zillii (Gervais) (Teleostei, Cichlidae) in the Lake Turkana, Kenya
Acta Parasitologica, 2012Co-Authors: Iva Přikrylová, Blažek Radim, Milan GelnarAbstract:Gyrodactylus malalai sp. nov. is described from the fin surface of cichlid fishes Oreochromis niloticus (L.) and Tilapia zillii (Gervais) caught in Lake Turkana (Kenya). The new species morphologically resembles Gyrodactylus nyanzae Paperna, 1973, but can be readily distinguished by the shape of the marginal hook sickles and the size of its hamuli. The sequence data of rDNA spanning partial 18S, internal transcribe spacer 1 and 2 and the 5.8S gene is unique within GenBank. Genetically, as most similar Gyrodactylus ergensi Přikrylová, Matějusová, Musilová et Gelnar, 2009 was found (97.5%). Moreover, a specimen of G. cichlidarum from O. niloticus , and a specimen G. ergensi from Sarotherodon galilaeus (L.) were collected during sampling in Kenya. Likewise, additional sampling of O. niloticus from the Blue Nile in Sudan revealed the presence of the newly described species. These findings represent the first records of gyrodactylids in both African countries.
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Gyrodactylus species (Monogenea: Gyrodactylidae) on the cichlid fishes of Senegal, with the description of Gyrodactylus ergensi n. sp. from Mango tilapia, Sarotherodon galilaeus L. (Teleostei: Cichilidae)
Parasitology Research, 2009Co-Authors: Iva Přikrylová, Iveta Matějusová, Naďa Musilová, Milan GelnarAbstract:The first record of Gyrodactylus species Nordmann, 1832 on the cichlid fish from Senegal is reported. Gyrodactylus parasites were found on four host species studied, Hemichromis fasciatus , Hemichromis letournaeuxi , Oreochromis niloticus , and Sarotherodon galilaeus . Gyrodactylus cichlidarum Paperna (Bamidgeh 13:14–29, 1968 ) were collected from H. fasciatus , and its identity was confirmed based on the morphometrical comparison with the holotype specimens of G. cichlidarum . Only one specimen of Gyrodactylus sp. was noted on H. letournaeuxi . The gyrodactylid specimens on O. niloticus and S. galilaeus were described as Gyrodactylus ergensi n. sp. based on the detailed morphometrical analysis supported by sequencing. The haptoral sclerites of G. ergensi n. sp., which closely resemble those of Gyrodactylus nyanzae Paperna, 1973, are compared with the type material and discussed. A partial sequence of the internal transcribed spacer recombinant DNA (ITS rDNA) was obtained from two specimens of G. ergensi , and a close relationship between G. ergensi n. sp. and G. cichlidarum is suggested based on 92% similarity in ITS rDNA region.
Jacques Panfili - One of the best experts on this subject based on the ideXlab platform.
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hordes of phages in the gut of the tilapia Sarotherodon melanotheron
Scientific Reports, 2018Co-Authors: Yvan Bettarel, Jacques Panfili, Awa Ndiaye, Marine Combe, Antoinette Adingra, Thierry Bouvier, Jeandominique DurandAbstract:Preliminary studies conducted on the human gastro-intestinal tract have revealed that enteric viral communities play a preponderant role in microbial homeostatis. However to date, such communities have never been investigated in the fish gut. Herein, we examined the main ecological traits of viruses in the digestive tract of a euryhaline fish, the tilapia Sarotherodon melanotheron. Individuals were collected at 8 different sites in Senegal covering a salinity gradient from 3 to 104‰, and showing large disparities in their organic pollutant concentrations. Results showed that the gut of S. melanotheron is home to a highly abundant viral community (0.2–10.7 × 109 viruses ml−1), distinct from the surrounding water, and essentially composed of phages of which a substantial proportion is temperate (the fraction of lysogenized cells-FLC ranging from 8.1 to 33.0%). Also, a positive and significant correlation was detected between FLC and the concentrations of polycyclic aromatic hydrocarbon in sediment, while no clear relationships were found between salinity and any of the microbial parameters considered. Finally, our data suggest that virus-bacteria interactions within the fish intestine are likely sensitive to the presence of particular xenobiotics, which may compromise the balance in the gut microbiota, and subsequently affect the health of their host.
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genetic diversity and adaptability of Sarotherodon melanotheron cichlidae in coastal ecosystem
Ethology Ecology & Evolution, 2012Co-Authors: Ahou Nicole Yoboue, B A Adepogourene, D Seka, Jeandominique Durand, Jacques Panfili, Raymond LaëAbstract:We analysed the genetic diversity of nine populations of two subspecies of Sarotherodon melanotheron using allozymes in relation to the existence of environmental pressures. The genetic variability of Sarotherodon melanotheron melanotheron in the Ivorian ecosystem (A = 1.23, He = 0.04 and P(95%) = 11.11) was lower than that of Sarotherodon melanotheron heudelotii of the estuaries in Gambia and Saloum (A = 1.68, He = 0.08 and P(95%) = 22.23). The analysis of allelic diversity revealed that the individuals of S. m. melanotheron subspecies from a much polluted environment (lagoon of Grand-Lahou or Ebrie) presented a relatively higher frequency of allele GPI-2*80 than those of a less polluted environment (Aby lagoon and Ayame lake). The allele IDH-2*90 was expressed only in the specimens of S. m. heudelotii found in the Saloum estuary, a very saline environment compared to the estuary of Gambia. A deficit of heterozygosis was observed with the tilapia Sarotherodon melanotheron. This study confirmed the poss...
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Multiparametric approach for assessing environmental quality variations in West African aquatic ecosystems using the black-chinned tilapia (Sarotherodon melanotheron) as a sentinel species
Environmental Science and Pollution Research, 2012Co-Authors: Awa Ndiaye, Jeandominique Durand, Wilfried Sanchez, Hélène Budzinski, Olivier Palluel, Pape Ndiaye, Khady Diouf, Jacques PanfiliAbstract:The study highlights the potential of the black-chinned tilapia to be used as a sentinel to assess environmental contaminants based on the use of a set of biomarkers. The usefulness of fish species as sentinels for assessing aquatic environment contamination was tested using a set of biomarkers in Senegalese environments characterized by multi-pollution sources. The black-chinned tilapia (Sarotherodon melanotheron) was selected as a sentinel because of its abundance, wide distribution in all coastal aquatic ecosystems and physiological properties. The potential influence of confounding factors such as salinity on biomarker in the tilapia has been examined. Individuals were sampled during two seasons (dry and wet) in eight sites characterized by various degrees of anthropogenic contamination and different salinities (from 0 to 102 psu). Biomarkers-including growth rate (GR), condition factor (CF), biotransformation enzymes such as 7-ethoxyresorufin-O-deethylase (EROD) and glutathione-S-transferase (GST), lipid peroxidation (TBARS) and acetylcholinesterase (AChE)-were measured. Chemical contaminant [polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs)] levels showed different sources of contamination with relatively high concentrations of PAHs in the Hann Bay and Foundiougne locations. The most sensitive biomarker present in different sites according to the principal component analysis is EROD. Few variations of the AChE activity and TBARS levels were found. No clear relationship was found between biomarker responses and salinity, but GR and CF were lower in hypersaline conditions. Tilapia is responsive to environmental contaminants such as PAHs, OCPs and PCBs. The Sarotherodon melanotheron multiparametric approach showed a better discrimination of sites.
Mbaye Tine - One of the best experts on this subject based on the ideXlab platform.
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differential expression of the heat shock protein hsp70 in natural populations of the tilapia Sarotherodon melanotheron acclimatised to a range of environmental salinities
BMC Ecology, 2010Co-Authors: Francois Bonhomme, Mbaye Tine, David J Mckenzie, Jeandominique DurandAbstract:Background The relationship between environmental variation and induction of heat shock proteins (Hsps) has been much documented under experimental conditions. However, very little is known about such induction in natural populations acclimatised to prevailing environmental conditions. Furthermore, while induction of stress proteins has been well documented in response to environmental contaminants and thermal stressors, little is known about whether factors, such as extreme salinity, are also potential inductors. The black-chinned tilapia Sarotherodon melanotheron is unusual for its ability to colonise estuarine environments in West Africa that are characterised by extremely high salinities. The relationships between mRNA levels of the 70 kDa heat shock protein (Hsp70) and Na+, K+-ATPase1α (Naka) in the gills, environmental salinity, and a life-history trait (condition factor) were investigated in wild populations of this species sampled from three locations in the Saloum estuary, at salinities ranging from 40 to 100 psu.
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transcriptional responses of the black chinned tilapia Sarotherodon melanotheron to salinity extremes
Marine Genomics, 2008Co-Authors: Mbaye Tine, Francois Bonhomme, Jeanfrancois Baroiller, Helena Dcotta, Julien De Lorgeril, Elodie Pepey, Jeandominique DurandAbstract:Sarotherodon melanotheron is one of the most euryhaline teleosts able to withstand variations in environmental salinity ranging from freshwater (FW) to 130%0 hyper-saline waters (HSW). Although significant progress has been made in exploring the cellular and molecular changes that accompany salinity adaptation in teleosts, little is known about the effects of long-term acclimation to HSW. We sought to identify in this tilapia species the genes whose transcription is induced by long-term acclimation either to HSW or FW. Two subtractive cDNA libraries were made from gills of fish acclimated for 45 days to either condition, with 320 partial cDNA sequences encoding proteins potentially involved in the response to the two salinity extremes. The ESTs comparisons with genomic databases allowed putative functions to be attributed to 197 of these genes. The suppression subtractive hybridisation (SSH) results were validated by Real-time PCR for 13 candidate genes having presumably a role in osmoregulation, supplemented by Na+, K+- ATPase a-subunit and carbonic anhydrase, two genes known to be implicated in this function. In fish acclimated to both salinity extremes, the functional category of cellular process was the predominant one, which may indicate high cellular turnover rates in FW and HSW-adapted fish. The acclimation to FW and HSW also appeared to trigger the expression of genes involved in transport activity, biological regulation and metabolic processes, at a higher level in fish acclimated to HSW, suggesting higher metabolic activity in this situation. These results are a first step towards the identification of key molecular processes involved in the fish acclimation to extreme salinities. (Resume d'auteur)