Genetic diversity of the Green Turtle (Testudines: Cheloniidae: Chelonia mydas (Linnaeus, 1758)) population nesting at Kosgoda Rookery, Sri Lanka

Main Article Content

E. M.L. Ekanayake
http://orcid.org/0000-0001-7476-2452
T. Kapurusinghe
http://orcid.org/0000-0003-2556-6003
M. M. Saman
http://orcid.org/0000-0002-6659-5575
D. S. Rathnakumara
http://orcid.org/0000-0002-6817-3042
P. Samaraweera
http://orcid.org/0000-0002-6155-7457
R. S. Rajakaruna
http://orcid.org/0000-0001-7939-947X

Abstract

We determined the genetic diversity of the Green Turtle Chelonia mydas (Linneaus, 1758) nesting at Kosgoda rookery, the second largest sea turtle aggregation on the southwestern coast of Sri Lanka.  Skin tissue samples were collected from 68 nesting females and genetic diversity was estimated using six microsatellite loci.  High genetic diversity was observed within the population as all loci analyzed were highly polymorphic with a total of 149 alleles observed.  The mean number of alleles per locus was 24.7 and the mean observed and expected heterozygosity across all loci were 0.75 and 0.93, respectively.  It appears that five out of six loci were not in Hardy-Weinberg equilibrium, while micro-checker analysis suggested that the Kosgoda Green Turtle population was possibly in equilibrium.  The viability of a population is unlikely to be reduced if high genetic diversity is maintained within it.  Although the Green Turtle population nesting at Kosgoda is small compared to other nesting rookeries in the world, the high genetic diversity observed suggests that the population may not be undergoing a bottleneck.

Article Details

How to Cite
[1]
Ekanayake, E.M., Kapurusinghe, T., Saman, M.M., Rathnakumara, D.S., Samaraweera, P. and Rajakaruna, R.S. 2017. Genetic diversity of the Green Turtle (Testudines: Cheloniidae: Chelonia mydas (Linnaeus, 1758)) population nesting at Kosgoda Rookery, Sri Lanka. Journal of Threatened Taxa. 9, 6 (Jun. 2017), 10261–10268. DOI:https://doi.org/10.11609/jott.2797.9.6.10261-10268.
Section
Articles
Author Biographies

P. Samaraweera, Department of Molecular Biology and Biotechnology, Faculty of Science, University of Peradeniya, Peradeniya, Sri Lanka

Department of Molecular Biology and Biotechnology

R. S. Rajakaruna, Department of Zoology, Faculty of Science, University of Peradeniya, Galaha Road, Peradeniya 20400, Sri Lanka Postgraduate Institute of Science, University of Peradeniya, Galaha Road, Peradeniya 20400, Sri Lanka

Department of Zoology

References

Ahmad, M., D.O.F. Skibinski & J.A. Beardmore (1977). An estimate of the amount of genetic variation in the common mussel Mytilus edulis. Biochemical Genetics 15(9/10): 833–846.

Amarasooriya, K.D. (2000). Classification of marine turtle nesting beaches of southern Sri Lanka, pp. 228–237. In: Pilchar, N. & G. Ismail (eds.). Sea Turtles of The Indo Pacific, Research, Management and Conservation. Proceedings of the second ASEAN Symposium and workshop on sea turtle biology and conservation.

Bagda, E., F. Bardakci & O. Turkozan (2012). Lower genetic structuring in mitochondrial DNA than nuclear DNA among the nesting colonies of Green Turtles (Chelonia mydas) in the Mediterranean. Biochemical Systematics and Ecology 43: 192–199.

Bjorndal, K.A., A.B. Bolten & S. Troeng (2005). Population structure and genetic diversity in green turtles nesting at Tortuguero, Costa Rica, based on mitochondrial DNA control region sequences. Marine Biology 147: 1449–1457.

Bourjea, J., S. Lapegue, L. Gagnevin, D. Broderick, J.A. Mortimer, S. Ciccione, D. Roos, C. Taquet & H. Grizel (2007). Phylogeography of the green turtle, Chelonia mydas in the southwest Indian Ocean. Molecular Ecology 16: 175–186.

Bowen, B.W. & S.A. Karl (2007). Population genetics and phylogeography of sea turtles. Molecular Ecology 16: 4886–4907.

Callen, D.F., A.D. Thompson, Y. Shen, H.A. Phillips, R.I. Richards, J.C. Mulley & G.R. Sutherland (1993). Incidence and origin of “null†alleles in the (AC)n microsatellite markers. American Journal of Human Genetics 52: 922–927.

Dethmers, K.E.M. & P.W.J. Baxter (2010). Extinction risk analysis of exploited Green Turtle stocks in the Indo-Pacific. Animal Conservation 14: 140–150.

Dethmers, K.E.M., D. Broderick, C. Moritz, N.N. FitzSimmons, C.J. Limpus, S. Lavery, S. Whiting, S., Guinea, R.I.T Prince & R. Kennett (2006). The genetic structure of Australasian Green Turtles (Chelonia mydas): exploring the geographical scale of genetic exchange. Molecular Ecology 15: 3931–3946.

DeWoody, J., J.D. Nason & V.D. Hipkins (2006). Mitigating scoring errors in microsatellite data from wild populations. Molecular Ecology Notes 6: 951–957.

DeWoody, J.A. & J.C. Avise (2000). Microsatellite variation in marine, freshwater and anadromous fishes compared with other animals. Journal of Fish Biology 56: 461–473;

http://doi.org/10.1371/journal.pone.0015465

Dutton, P.H. & A. Frey (2009). Characterization of polymorphic microsatellite markers for the green turtle (Chelonia mydas). Molecular Ecology Resources 9: 354–356.

Ekanayake, E.M.L., R.S. Rajakaruna, T. Kapurusinghe, M.M. Saman, P. Samaraweera & K.B. Ranawana (2012). A declining trend of nesting frequency of sea turtles at the largest rookery in Sri Lanka. T.T. Jones and B.P. Wallace (Comp.). Proceedings of the thirty-first Annual Symposium on Sea Turtle Biology and Conservation. NOAA Technical Memorandum, NOAA NMFS-SEFSC-631, 201.

Ekanayake, E.M.L., T. Kapurusinghe, M.M. Saman, & A.M.D.S. Rathnakumara (2013b). Re-nesting movements and post-nesting migrations of green turtles tagged in two turtle rookeries in Sri Lanka. J. Blumenthal, A. Panagopoulou, and A.F. Rees, Compilers. Proceedings of the Thirtieth Annual Symposium on Sea Turtle Biology and Conservation. NOAA Technical Memorandum NMFS-SEFSC-640, 123.

Ekanayake, E.M.L., T. Kapurusinghe, M.M. Saman, P. Samaraweera, K.B. Ranawana, & R.S. Rajakaruna (2010). Nesting Behaviour of the Green Turtle at Kosgoda Rookery, Sri Lanka. Ceylon Journal of Science (Biological Science) 39(2): 109–120.

Ekanayake, E.M.L., T. Kapurusinghe, M.M. Saman, P. Samaraweera, K.B. Ranawana and R.S. Rajakaruna (2013a). Paternity of Green Turtles (Chelonia mydas) clutches laid at Kosgoda, Sri Lanka. Herpetological Conservation and Biology 8: 27–36.

Ekanayake, E.M.L., T. Kapurusinghe, M.M. Saman, R.S. Rajakaruna, P. Samaraweera & K.B. Ranawana (2008). Nesting Frequency of Marine Turtles Visiting on Kosgoda Beach, Southern Sri Lanka. Rees, A.F., M. Frich, A. Panagopoulou & K. Williams (Comp.). Proceedings of the Twenty-Seventh Annual Symposium on Sea Turtle Biology and Conservation, South Carolina, USA. NOAA Technical Memorandum NMFS-SEFSC-569: 232–233.

Excoffier, L., G. Laval & S. Schneider (2005). Arlequin, version 3.1: an integrated software package for population genetics data analysis. Evolutionary Bioinformatics Online 1: 47–50.

Excoffier, L., P. Smouse & J. Quattro (1992). Analysis of molecular variance inferred from metric distances among DNA haplotypes: application to human mitochondrial DNA restriction data. Genetics 131: 479–491.

FitzSimmons, N.N. (1998). Single paternity of clutches and sperm storage in the promiscuous green turtle (Chelonia mydas). Molecular Ecology 7: 575–584.

FitzSimmons, N.N., C. Moritz & S.S. Moor (1995). Conservation and dynamics of microsatellite loci over 300 million years of marine turtle evolution. Molecular Biology and Evolution 12(3): 432–440.

FitzSimmons, N.N., C. Moritz, C.L. Limpus, L. Pope & R. Prince (1997). Geographic structure of mitochondrial and nuclear gene polymorphisms in Australian Green Turtle populations and male-biased gene flow. Genetics 147: 1843–1854.

Formia, A., B.J. Godley, J.F. Dontaine & M.W. Bruford (2006). Mitochondrial DNA diversity and phylogeography of endangered Green Turtle (Chelonia mydas) populations in Africa. Conservation Genetics 7: 353–369.

Frankham, R. (2006). Genetics and Extinction. Biological Conservation 126: 131–140.

Frey, A., P.H. Dutton & G.H. Balazs (2013). Insights on the demography of cryptic nesting by green turtles (Chelonia mydas) in the main Hawaiian Islands from genetic relatedness analysis. Journal of Experimental Marine Biology and Ecology 442: 80–87.

Gullberg, A., H. Tegelstrom & M. Olsson (1997). Microsatellites in the Sand Lizard (Lacerta agilis): description, variation, inheritance, and applicability. Biochemical Genetics 35: 281–295.

Guo, S.W. & E.A. Thompson (1992). Performing the exact test of Hardy-Weinberg proportion for multiple alleles. Biometrics 48(2): 361–372.

Karl, S.A., B.W. Bowen & J.C. Avise (1992). Global population genetic structure and male-mediated gene flow in the green turtle (Chelonia mydas): RFLP analyses of anonymous nuclear loci. Genetics 131: 163–173.

Kumar, S., J. Gupta, N. Kumar, K. Dikshit, N. Navani, P. Jain & M. Nagarajan (2006). Genetic variation and relationships among eight Indian Riverine Buffalo breeds. Molecular Ecology 15: 593–600.

Lee, P.L.M. (2008). Molecular ecology of marine turtles: New approaches and future directions. Journal of Experimental Marine Biology and Ecology 356: 25–42.

LeRoux, R.A., P.H. Dutton, F.A. Abreu-Grobois, C.J. Lagueux, C.L. Campbell, E. Delcroix, E. Chevalier, J.A. Horrocks, Z. Hillis0starr, S. Troeng, E. Harrison & S. Stapleton (2012). Re-examination of population structure and phylogeography of Hawksbill Turtles in the wider Caribbean using longer mtDNA sequences. Journal of Heredity 103(6): 806–820.

Luty, J.A., Z. Guo, H.F. Willard, D.H. Ledbetter, S. Ledbetter & M. Litt (1990). Five polymorphic microsatellite VNTRs on the human X chromosome. American Journal of Human Genetics 46(4): 776–783.

Lynch, M. (1996). A quantitative-genetic perspective on conservation issues, pp. 471–501. In: Avise, J.C. & J.L. Hamrick (eds.). Conservation Genetics: Case Studies from Nature. Chapman and Hall, New York.

Naro-Maciel, E., J.H. Becker, E.H.S.M. Lima, M.A. Marcovaldi & R. Desalle (2007). Testing dispersal hypotheses in foraging green Sea Turtles (Chelonia mydas) of Brazil. Journal of Heredity 98(1): 29–39.

Naro-Maciel, E., M. Le, N.N. FitzSimmons & G. Amato (2008). Evolutionary relationships of marine turtles: a molecular phylogeny based on nuclear and mitochondrial genes. Molecular Phylogenetics and Evolution 49: 659–662.

Norris, A.T., D.G. Bradley & E.P. Cunningham (1999). Microsatellite genetic variation between and within farmed and wild Atlantic Salmon (Salmo salar) populations. Aquaculture 180: 247–264.

O’Connell, M. & J.M. Wright (1997). Microsatellite DNA in fishes. Biomedical and Life Sciences 7(3): 331–363.

Pemberton, J.M., J. Slate, D.R. Bancroftt & J.A. Barrett (1995). Nonamplifying alleles at microsatellite a caution for parentage and population loci: studies. Molecular Ecology 4: 249–252.

Queller, D.C., J.E. Strassmann & C.R. Hughes (1993). Microsatellites and kinship. Trends in Ecology and Evolution 8: 285–288.

Richardson, P.B., A.C. Broderick, M.S. Coyne, L. Ekanayake, T. Kapurusinghe, C. Premakumara, S. Ranger, M.M. Saman, M.J. Witt & B.J. Godley (2013). Satellite telemetry reveals behavioural plasticity in a Green Turtle population nesting in Sri Lanka. Marine Biology 160(6): 1415–1426.

Rico, C., I. Rico & G. Hewitt (1996). 470 Million years of conservation of microsatellite loci among fish species. Proceedings of the Royal Society Biological Sciences 263(1370): 549–557; http://doi.org/10.1098/rspb.1996.0083

Roberts, M.A., T.S. Schwartz & S.A. Karl (2004). Global population genetic structure and male-mediated gene flow in the Green Sea Turtle (Chelonia mydas): analysis of microsatellite loci. Genetics 166: 1857–1870.

Seminoff, J.A. (2004). Guest editorial: Sea Turtles, Red Listing, and the need for regional assessments. Marine Turtle Newsletter 106: 4–6.

Shriver, M.D., L. Jin, E. Boerwinkle, R. Deka, R.E. Ferrell & R. Chakraborty (1995). A novel measure of genetic distance for highly polymorphic tandem repeat loci. Molecular Biology and Evolution 12(5): 914–920.

Slatkin, M. & L. Excoffier (1996) Testing for linkage disequilibrium in genotypic data using the EM algorithm. Heredity 76: 377–383.

van Oosterhout, C., W.F. Hutchinson, D.P.M. Wills & P. Shipley (2004). MICRO-CHECKER: software for identifying and correcting genotyping errors in microsatellite data. Molecular Ecology Notes 4: 535–538.

Wallace, B.P., A.D. DiMatteo, B.J. Hurley, E.M. Finkbeiner, A.B. Bolten, M.Y. Chaloupka, B.J. Hutchinson, F.A. Abreu-Grobois, D. Amorocho, K.A. Bjorndal, J. Bourjea, B.W. Bowen, R.B. Dueñas, P. Casale, B.C. Choudhury, A. Costa, P.H. Dutton, A. Fallabrino, A. Girard, M. Girondot, M.H. Godfrey, M. Hamann, M. López-Mendilaharsu, M.A. Marcovaldi, J.A. Mortimer, J.A. Musick, R. Nel, N.J. Pilcher, J.A. Seminoff, S. Troëng, B. Witherington & R.B. Mast (2010). Regional Management Units for marine turtles: A novel framework for prioritizing conservation and research across multiple scales. PLoS ONE 5(12): e15465; http://doi.org/10.1371/journal.pone.0015465

Xu, Z., J.H. Primavera, L.D. De la Pena, P. Pettil, J. Belak & A. Alcivar-Waren (2001). Genetic diversity of wild and cultured Black Tiger Shrimp Penaeus monodon in the Philippines using microsatellites. Aquaculture 199: 13–40.

Yilmaz, C., O. Turkozan & F. Bardakci (2011). Genetic structure of

Loggerhead Turtle (Caretta caretta) populations in Turkey. Biochemical Systematics and Ecology 39: 266–276.

Young, A., T. Boyle & T. Brown (1996). The population genetic consequences of habitat fragmentation for plants. Trends in Ecology & Evolution 11(10): 413–418.