Inter‐species hybridization among Neotropical cats of the genusLeopardus, and evidence for an introgressive hybrid zone betweenL. geoffroyiandL. tigrinusin southern Brazil

Abstract

Natural hybrid zones between distinct species have been reported for many taxa, but so far, few examples involve carnivores or Neotropical mammals in general. In this study, we employed mitochondrial DNA (mtDNA) sequences and nine microsatellite loci to identify and characterize a hybrid zone between two Neotropical felids, Leopardus geoffroyi and L. tigrinus, both of which are well-established species having diverged from each other c. 1 million years ago. These two felids are mostly allopatric throughout their ranges in South America, with a narrow contact zone that includes southern Brazil. We present strong evidence for the occurrence of hybridization between these species and identify at least 14 individuals (most of them originating from the geographical contact zone) exhibiting signs of interspecific genomic introgression. The genetic structure of Brazilian L. tigrinus populations seems to be affected by this introgression process, showing a gradient of differentiation from L. geoffroyi correlated with distance from the contact zone. We also corroborate and extend previous findings of hybridization between L. tigrinus and a third related felid, L. colocolo, leading to an unusual situation for a mammal, in which the former species contains introgressed mtDNA lineages from two distinct taxa in addition to its own.

Phylogenomic evidence for ancient hybridization in the genomes of living cats (Felidae)

“…S8) showed large mitochondrial and nuclear divergence (11.0%-15.3% and 0.5%-0.6%, respectively) from Brazilian tigrinas, as well as from the Geoffroy's cat and kodkod (L. guigna). Tigrinas have not been extensively sampled for genetic variation across the northern part of their range; however, our data support previous observations based solely on mtDNA (Johnson et al 1999;Trigo et al 2008) of the potential existence of an additional, presently unrecognized Central American cat species.…”

“…Recent genetic evidence suggests complex patterns of admixture in felids of the Neotropical genus Leopardus, including the presence of cryptic species (Trigo et al 2008(Trigo et al , 2013. These observations are matched by the prevalence of felid hybridization in captivity (Gray 1972), which has generated numerous hybrids of both large cats and medium to small cats.…”

“…Although hybrid zones between related cat species have been reported (Schwartz et al 2004;Homyack et al 2008;Trigo et al 2008Trigo et al , 2013, the extent to which ancient and contemporary introgression has occurred is poorly understood on broad geographic and genomic scales. Recent genetic evidence suggests complex patterns of admixture in felids of the Neotropical genus Leopardus, including the presence of cryptic species (Trigo et al 2008(Trigo et al , 2013.…”

“…Recent genetic analyses demonstrated complex speciation/hybridization affecting at least four species within this group: two tigrina species, one from northeastern Brazil (Leopardus tigrinus) that possesses pampas cat (L. colocolo) mitochondria within a tigrina-like nuclear background, and a recently proposed sister species from southeastern Brazil (L. guttulus, not sampled here) which hybridizes with the Geoffroy's cat (L. geoffroyi) in a narrow hybrid zone in southern Brazil (Trigo et al 2008(Trigo et al , 2013(Trigo et al , 2014. As predicted, the northeastern tigrina we genotyped possessed pampas cat mtDNA within a tigrina nuclear DNA background (Supplemental Fig.…”

Taxonomic revision of the tigrina Leopardus tigrinus (Schreber, 1775) species group (Carnivora, Felidae)

“…This molecular study also showed no evidence of gene flow between the southern population (L. guttulus) and the northeastern Brazilian population (named in the article as L. tigrinus), which have contiguous geographical distributions. Although these two closely related species do not interbreed, there are reports of hybridization between L. guttulus and L. geoffroyi in the state of Rio Grande do Sul, southern Brazil Trigo et al, 2008Trigo et al, , 2013Trigo et al, , 2014, and with Leopardus braccatus (named in the article as Leopardus colocolo) in Central Brazil (Trigo et al, 2008(Trigo et al, , 2013(Trigo et al, , 2014. In a recent molecular study, Li et al (2016) reported that the tigrinas from Northeastern Brazil had pampas cat mtDNA within a tigrina nDNA background, as well as nuclear signatures indicating an ancient hybridization with L. geoffroyi.…”