Genetic assessment of mating system, kinship, and population structure in the burrowing rodent Clyomys laticeps

Mating systems are a fundamental aspect of a species’ biology, often contributing to patterns of dispersal, kinship, and genetic structure. Although rodents in the family Echimyidae are taxonomically, morphologically, and ecologically diverse, little is known about their reproductive behavior, including its effects on demographic and genetic structure. To characterize the genetic mating system of the burrowing echimyid, the broad-headed spiny rat ( Clyomys laticeps (Thomas, 1909)), tissue samples were obtained from 53 individuals captured in Parque Estadual da Serra de Caldas Novas (GO, Brazil) between May 2018 and February 2020. Individual genotypes generated from 10 polymorphic microsatellite loci were used to test the predictions that (1) C. laticeps displays a polygynandrous mating system and (2) male-biased natal dispersal, with the result that (3) kin structure is more pronounced among females. Parentage assignment analyses revealed that both males and females produced offspring with multiple partners across different rounds of reproduction, indicating a temporally polygynandrous mating system. Coefficients of relatedness among males did not differ from those among females, providing no evidence of sex-biased dispersal or sex-based kin structure. Consistent with these findings, genetic variation within the study population was not strongly structured and no evidence of significant inbreeding was detected. Thus, in addition to providing one of the first characterizations of the genetic mating system of an echimyid rodent, our analyses contribute to understanding of patterns of demography and population genetic structure in these animals.