The systematic status of the Iriomote cat (Prionailurus iriomotensisImaizumi 1967) and the subspecies of the leopard cat (Prionailurus bengalensisKerr 1792)

Variations in leopard cat (Prionailurus bengalensis) skull morphology and body size: sexual and geographic influences

The leopard cat, Prionailurus bengalensis (Kerr, 1792), is one of the most widespread Asian cats, occurring in continental eastern and southeastern Asia. Since 1929, several studies have focused on the morphology, ecology, and taxonomy of leopard cats. Nevertheless, hitherto there has been no agreement on basic aspects of leopard cat biology, such as the presence or absence of sexual dimorphism, morphological skull and body differences between the eleven recognized subspecies, and the biogeography of the different morphotypes. Twenty measurements on 25 adult leopard cat skulls from different Asian localities were analyzed through univariate and multivariate statistical approaches. Skull and external body measurements from studies over the last 77 years were assembled and organized in two categories: full data and summary data. Most of this database comprises small samples, which have never been statistically tested and compared with each other. Full data sets were tested with univariate and multivariate statistical analyses; summary data sets (i.e., means, SDs, and ranges) were analyzed through suitable univariate approaches. The independent analyses of the data from these works confirmed our original results and improved the overview of sexual dimorphism and geographical morphological variation among subspecies. Continental leopard cats have larger skulls and body dimensions. Skulls of Indochinese morphotypes have broader and higher features than those of continental morphotypes, while individuals from the Sunda Islands have skulls with comparatively narrow and low profiles. Cranial sexual dimorphism is present in different degrees among subspecies. Most display subtle sex-related variations in a few skull features. However, in some cases, sexual dimorphism in skull morphology is absent, such as in P. b. sumatranus and P. b. borneoensis. External body measurement comparisons also indicate the low degree of sexual dimorphism. Apart from the gonads, the longer hind foot of male leopard cats is the main feature of sexual dimorphism among P. b. bengalensis (and probably among P. b. horsfieldii too). External body measurements also indicated the absence of sexual dimorphism among individuals of P. b. borneoensis. Inter-subspecific skull comparisons provided a morphometric basis for differentiating some subspecies. Prionailurus b. horsfieldii and P. b. bengalensis were distinguished only by a subtle difference in PM(4) size, indicating that overall skull morphology does not appear to support their separate taxonomical status, in spite of the marked differences reported in their coat patterns. Geological events affecting the Sunda Shelf connection between the Sunda Islands and the mainland during the Last Glacial Maximum seem to have influenced directly the morphological pattern shown by leopard cat subspecies nowadays.

Lineage pattern, trans-species polymorphism, and selection pressure among the major lineages of feline MHC-DRB peptide-binding region

The long-term evolution of major histocompatibility complex (MHC) involves the birth-and-death process and independent divergence of loci during episodes punctuated by natural selection. Here, we investigated the molecular signatures of natural selection at exon-2 of MHC class II DRB gene which includes a part of the peptide-binding region (PBR) in seven of eight putative extant Felidae lineages. The DRB alleles in felids can be mainly divided into five lineages. Signatures of trans-species polymorphism among major allelic lineages indicate that balancing selection has maintained the MHC polymorphism for a long evolutionary time. Analysis based on maximum likelihood models of codon substitution revealed overall purifying selection acting on the feline DRB. Sites that have undergone positive selection and those that are under divergent selective pressure among lineages were detected and found to fall within the putative PBR. This study increased our understanding of the nature of selective forces acting on DRB during feline radiation.