Population genetics of gharial Gavialis gangeticus in the Chambal River, India, using novel polymorphic microsatellite markers
The gharial Gavialis gangeticus is a Critically Endangered crocodylian endemic to the Indian subcontinent. The species has experienced a 95% population decline over the past 2 centuries. The largest self-sustaining population inhabits the protected National Chambal Sanctuary (NCS) in north India and...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Inter-Research
2024-02-01
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| Series: | Endangered Species Research |
| Online Access: | https://www.int-res.com/abstracts/esr/v53/p127-138/ |
| _version_ | 1797214493097328640 |
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| author | RK Singh J AjjiM JW Lang H Segu H Ramesh K Vasudevan |
| author_facet | RK Singh J AjjiM JW Lang H Segu H Ramesh K Vasudevan |
| author_sort | RK Singh |
| collection | DOAJ |
| description | The gharial Gavialis gangeticus is a Critically Endangered crocodylian endemic to the Indian subcontinent. The species has experienced a 95% population decline over the past 2 centuries. The largest self-sustaining population inhabits the protected National Chambal Sanctuary (NCS) in north India and represents >80% of extant gharials globally. We developed de novo a panel of polymorphic gharial-specific microsatellites, using whole genome information and microsatellite search tools. These 15 new markers have multiple numbers of polymorphic alleles that are more informative than those obtained from previous studies. Analyses of 93 scute samples collected across age classes from wild gharials residing in the NCS facilitated accurate assessments of genetic diversity and inbreeding coefficient and identified a historical bottleneck event. Estimates of the observed and expected heterozygosities were lower than those reported earlier. The inbreeding coefficient was low, and the population did not deviate significantly from Hardy-Weinberg equilibrium. The calculated M ratio and 2 heterozygosity tests detected a genetic bottleneck, which is consistent with historic sharp declines in population size, followed by recent recovery. These new gharial microsatellite markers are statistically robust and provide an improved means to assess the population genetics of the largest self-sustaining wild gharial population. This study will facilitate additional investigations on the genetic diversity of other extant gharial populations—not only the few remaining wild populations but also those in zoos and rearing facilities. Additional genetic studies of gharial in the NCS are warranted to inform management strategies. |
| first_indexed | 2024-04-24T11:15:03Z |
| format | Article |
| id | doaj.art-84b0fe3d932947748cc40cac60ad4222 |
| institution | Directory Open Access Journal |
| issn | 1863-5407 1613-4796 |
| language | English |
| last_indexed | 2024-04-24T11:15:03Z |
| publishDate | 2024-02-01 |
| publisher | Inter-Research |
| record_format | Article |
| series | Endangered Species Research |
| spelling | doaj.art-84b0fe3d932947748cc40cac60ad42222024-04-11T09:51:31ZengInter-ResearchEndangered Species Research1863-54071613-47962024-02-015312713810.3354/esr01297Population genetics of gharial Gavialis gangeticus in the Chambal River, India, using novel polymorphic microsatellite markersRK Singh0J AjjiM1JW Lang2H Segu3H Ramesh4K Vasudevan5CSIR -Centre for Cellular and Molecular Biology, Laboratory for the Conservation of Endangered Species, Hyderabad, Telangana 500048, IndiaGharial Ecology Project, Madras Crocodile Bank Trust, Mamallapuram, Tamil Nadu 603104, IndiaGharial Ecology Project, Madras Crocodile Bank Trust, Mamallapuram, Tamil Nadu 603104, IndiaCSIR -Centre for Cellular and Molecular Biology, Laboratory for the Conservation of Endangered Species, Hyderabad, Telangana 500048, IndiaCSIR -Centre for Cellular and Molecular Biology, Laboratory for the Conservation of Endangered Species, Hyderabad, Telangana 500048, IndiaCSIR -Centre for Cellular and Molecular Biology, Laboratory for the Conservation of Endangered Species, Hyderabad, Telangana 500048, IndiaThe gharial Gavialis gangeticus is a Critically Endangered crocodylian endemic to the Indian subcontinent. The species has experienced a 95% population decline over the past 2 centuries. The largest self-sustaining population inhabits the protected National Chambal Sanctuary (NCS) in north India and represents >80% of extant gharials globally. We developed de novo a panel of polymorphic gharial-specific microsatellites, using whole genome information and microsatellite search tools. These 15 new markers have multiple numbers of polymorphic alleles that are more informative than those obtained from previous studies. Analyses of 93 scute samples collected across age classes from wild gharials residing in the NCS facilitated accurate assessments of genetic diversity and inbreeding coefficient and identified a historical bottleneck event. Estimates of the observed and expected heterozygosities were lower than those reported earlier. The inbreeding coefficient was low, and the population did not deviate significantly from Hardy-Weinberg equilibrium. The calculated M ratio and 2 heterozygosity tests detected a genetic bottleneck, which is consistent with historic sharp declines in population size, followed by recent recovery. These new gharial microsatellite markers are statistically robust and provide an improved means to assess the population genetics of the largest self-sustaining wild gharial population. This study will facilitate additional investigations on the genetic diversity of other extant gharial populations—not only the few remaining wild populations but also those in zoos and rearing facilities. Additional genetic studies of gharial in the NCS are warranted to inform management strategies.https://www.int-res.com/abstracts/esr/v53/p127-138/ |
| spellingShingle | RK Singh J AjjiM JW Lang H Segu H Ramesh K Vasudevan Population genetics of gharial Gavialis gangeticus in the Chambal River, India, using novel polymorphic microsatellite markers Endangered Species Research |
| title | Population genetics of gharial Gavialis gangeticus in the Chambal River, India, using novel polymorphic microsatellite markers |
| title_full | Population genetics of gharial Gavialis gangeticus in the Chambal River, India, using novel polymorphic microsatellite markers |
| title_fullStr | Population genetics of gharial Gavialis gangeticus in the Chambal River, India, using novel polymorphic microsatellite markers |
| title_full_unstemmed | Population genetics of gharial Gavialis gangeticus in the Chambal River, India, using novel polymorphic microsatellite markers |
| title_short | Population genetics of gharial Gavialis gangeticus in the Chambal River, India, using novel polymorphic microsatellite markers |
| title_sort | population genetics of gharial gavialis gangeticus in the chambal river india using novel polymorphic microsatellite markers |
| url | https://www.int-res.com/abstracts/esr/v53/p127-138/ |
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