Introgressive hybridization in a Spiny-Tailed Iguana, Ctenosaura pectinata , and its implications for taxonomy and conservation

PeerJ

article

Eugenia Zarza¹  Víctor H. Reynoso¹  Christiana M. A. Faria⁴  Brent C. Emerson⁶ 

[1] Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México;Grupo Académico de Biotecnología Ambiental;CONACYT;School of Biological Sciences, University of East Anglia;Departamento de Biologia, Universidade Federal do Ceará, Campus do Pici;Island Ecology and Evolution Research Group, Instituto de Productos Naturales y Agrobiología

关键词: Gene flow;    Genotypic cluster;    Hybridization;    Conservation genetics;    Mexico;    Microsatellites;    mtDNA;   

DOI  :  10.7717/peerj.6744

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Introgression, the transmission of genetic material of one taxon into another through hybridization, can have various evolutionary outcomes. Previous studies have detected signs of introgression between western populations of the Mexican endemic and threatened spiny-tailed iguana, Ctenosaura pectinata. However, the extent of this phenomenon along the geographic distribution of the species is unknown. Here, we use multilocus data together with detailed geographic sampling to (1) define genotypic clusters within C. pectinata; (2) evaluate geographic concordance between maternally and biparentally inherited markers; (3) examine levels of introgression between genotypic clusters, and (4) suggest taxonomic modifications in light of this information. Applying clustering methods to genotypes of 341 individuals from 49 localities of C. pectinata and the closely related C. acanthura, we inferred the existence of five genotypic clusters. Contact zones between genotypic clusters with signatures of interbreeding were detected, showing different levels of geographic discordance with mtDNA lineages. In northern localities, mtDNA and microsatellites exhibit concordant distributions, supporting the resurrection of C. brachylopha. Similar concordance is observed along the distribution of C. acanthura, confirming its unique taxonomic identity. Genetic and geographic concordance is also observed for populations within southwestern Mexico, where the recognition of a new species awaits in depth taxonomic revision. In contrast, in western localities a striking pattern of discordance was detected where up to six mtDNA lineages co-occur with only two genotypic clusters. Given that the type specimen originated from this area, we suggest that individuals from western Mexico keep the name C. pectinata. Our results have profound implications for conservation, management, and forensics of Mexican iguanas.

【 授权许可】

CC BY