Genetic bottleneck and founder effect signatures in a captive population of common bottlenose dolphins Tursiops truncatus (Montagu 1821) in Mexico
- Published
- Accepted
- Subject Areas
- Conservation Biology, Genetics, Marine Biology, Molecular Biology
- Keywords
- Tursiops truncatus, microsatellites, genetic bottleneck, mtDNA, confined populations, Conservative Biology, genetic drift
- Copyright
- © 2018 Améndola-Pimenta et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2018. Genetic bottleneck and founder effect signatures in a captive population of common bottlenose dolphins Tursiops truncatus (Montagu 1821) in Mexico. PeerJ Preprints 6:e26891v1 https://doi.org/10.7287/peerj.preprints.26891v1
Abstract
Background. The captive cetacean industry is very profitable and popular worldwide, focusing mainly on leisure activities such as “Swim-with-dolphins” (SWD) programs. However, there is a concern for how captivity could affect the bottlenose dolphin Tursiops truncatus, which in nature is a highly social and widespread species. To date, there is little information regarding to the impact of restricted population size on their genetic structure and variability.
Methods. The aim of this study was to estimate the genetic diversity of a confined population of T. truncatus, composed of wild-born (n=25) from Cuba, Quintana Roo and Tabasco, and captive-born (n=24) dolphins in southern Mexico, using the hypervariable portion of the mitochondrial DNA and ten nuclear microsatellite markers: TexVet3, TexVet5, TexVet7, D18, D22, Ttr19, Tur4_80, Tur4_105, Tur4_141 and GATA098.
Results. Exclusive mtDNA haplotypes were found in at least one individual from each wild-born origin populations and in one captive-born individual; total mean haplotype and nucleotide diversities were 0.912 (±0.016) and 0.025 (±0.013) respectively. At microsatellite loci, low levels of genetic diversity were found with a mean number of alleles per locus of 4 (±2.36), and an average expected heterozygosity over all loci of 0.544 (±0.163). Measures of allelic richness and effective number of alleles were similar between captive-born and wild-born dolphins. No significant genetic structure was found with microsatellite markers, whereas the mtDNA data revealed a significant differentiation between wild-born organisms from Cuba and Quintana ROO.
Discussion. Data analysis suggests the occurrence of a recent genetic bottleneck in the confined population probably because of a strong founder effect, given that only a small number of dolphins with a limited fraction of the total species genetic variation were selected at random to start this captive population. The results herein provide the first genetic baseline information on a captive bottlenose dolphin population in Mexico.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Thirteen haplotypes ofcaptive Tursiops truncatus defined by35 variable sites within a 373bp fragment of the mitochondrial control region.
Estimated null alleles frequencies for each locus for ateach origin population of captive Tursiopstruncatus
Population differentiation estimated by pairwise F ST values for microsatellite databefore (below diagonal) and after (above diagonal) applying the Excluding NullAllele ENA correction method
Output generated withSTRUCTURE HARVESTER for K=1 to K=4 subpopulations of captive Tursiops truncatus.