Chromosomal polymorphism plays a major role in speciation processes in mammals with high rates of karyotypic evolution, as observed in the family Cervidae. One remarkable example is the genus Mazama that comprises wide inter- and intra-specific chromosomal variability. To evaluate the impact of chromosomal polymorphisms as reproductive barriers within the genus Mazama, inter-specific hybrids between Mazama gouazoubira and Mazama nemorivaga (MGO × MNE) and intra-specific hybrids between cytotypes of Mazama americana (MAM) differing by a tandem (TF) or centric fusion (Robertsonian translocations-RT) were evaluated. MGO × MNE hybrid fertility was evaluated by the seminal quality and testicular histology. MAM hybrids estimation of the meiotic segregation products was performed by sperm-FISH analysis. MGO × MNE hybrids analyses showed different degrees of fertility reduction, from severe subfertility to complete sterility. Regarding MAM, RT, and TF carriers showed a mean value for alternate segregation rate of 97.74%, and 67.23%, and adjacent segregation rate of 1.80%, and 29.07%, respectively. Our results suggested an efficient post-zygotic barrier represented by severe fertility reduction for MGO × MNE and MAM with heterozygous TF. Nevertheless, RT did not show a severe effect on the reproductive fitness in MAM. Our data support the validity of MGO and MNE as different species and reveals cryptic species within MAM.

Department of Genetics and Reproductive Biotechnologies Central European Institute of Technology Veterinary Research Institute 621 00 Brno Czech Republic

Laboratório de Dosagens Hormonais Faculdade de Medicina Veterinária e Zootecnia Universidade de São Paulo FMVZ USP 05508 270 São Paulo Brazil

Núcleo de Pesquisa e Conservação de Cervídeos Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista NUPECCE FCAV UNESP 14884 900 Jaboticabal Brazil

Citace poskytuje Crossref.org