Population genetics and spatial structure in two Andean cats (the Pampas cat, Leopardus pajeros and the Andean Mountain cat, L. jacobita) by means of nuclear and mitochondrial markers and some notes on skull biometrics

RUIZ-GARCÍA M.; COSSÍOS D.; LUCHERINI M.; YÁÑEZ J.; PINEDO-CASTRO M.; ANGERS B.

Molecular Population Genetics, Phylogenetics, Evolutionary Biology and Conservation of the Neotropical Carnivores

Nova Science Publishers

Año: 2012; p. 187 - 244

In this chapter, we show complementary results to the works of Cossíos et al., (2009, 2012), on the genetic structure and phylogenetics of two small Andean cats, the Pampas cat (Leopardus pajeros) and the Andean mountain cat (Leopardus jacobita). In the present study we increased the samples sizes to 235 individuals for L. pajeros and 115 individuals for L. jacobita, effectively making these samples the largest to date for these two species. We analyzed five microsatellites for L. pajeros and seven microsatellites for L. jacobita as well as the hypervariable domain 1 (HVS-1) of the mtDNA control region for both species. The main results obtained were as follows: 1- The levels of gene diversity for L. pajeros with microsatellites were considerable higher than in L. jacobita (average H = 0.73 vs. 0.42, respectively), with the first similar to other Neotropical felids but the second one lower than other Neotropical felids and many other Neotropical mammals analyzed from this point of view. The same was recorded for mtDNA sequences, with the Pampas cat ( = 0.0513) presenting more than 10 times higher nucleotide diversity than the Andean mountain cat ( = 0.0047). The sample which could represent the putative morphological subspecies, L. p. budini, was that which yielded the highest levels of gene diversity. This could mean that this is the original L. pajeros form from which the other forms derived. Alternatively, the northern area of Argentina, where L. p. budini occurs, could be a hybridization zone among several L. pajeros forms. 2- Microsatellite heterogeneity for the Pampas cat was significant but it was relatively low with regard to the high genetic heterogeneity found for L. jacobita for microsatellites. For mtDNA, the genetic heterogeneity was very high and similar for both species. This could indicate that for the Pampas cat the gene flow is male biased, meanwhile the Andean mountain cat populations are hardly isolated in the high land deserts of the Andes and the gene flow is more restricted for both males and females. Also this analysis puts in doubt that L. pajeros pajeros and L. pajeros crucinus are two different subspecies. Furthermore, this analysis revealed that if the different gene pools determined in L. pajeros are classified as different subspecies, then four different subspecies, or at least, four different evolutionary lineages must be consider in L. jacobita. 3- The assignation analyses presented relatively low percentages of correct assignation for L. pajeros, while the percentages of percentages of adequate assignation for L. jacobita were very high. This is related with the fact that gene flow estimates among the populations of the Pampas cat are considerably higher than for the populations of the Andean mountain cat for nuclear markers. 4- L. pajeros presented more evidence of population expansions during its history for microsatellites than did L. jacobita. For mtDNA, both species did not reveal traces of population expansions and L. jacobita showed a trend indicative of a moderate bottleneck. 5- Both species showed 4-5 % of mutations with multiple steps and different mutation rates for the microsatellites employed. 6- The effective number estimates were around 10 times higher for L. pajeros than for L. jacobita independently of the procedures employed. The effective sizes for L. pajeros ranged from 80,000 to 330,000 and for L. jacobita ranged from 12,000 to 38,000. However, these estimates seem to be higher than the current census sizes. The procedures of Hill (1981) and Pudovkin et al., (1996) were not useful for effective number estimations in this case. 7- Both species presented significant spatial structure related with isolation by distance and monotonic clinal trends, but this spatial structure was more developed in L. jacobita. Around 35 % of the genetic differences were explained by the geographical distances among the populations in L. pajeros, while around 64 % of the genetic differences were explained by geographical distances in L. jacobita. 8- The northern Chilean Pampas cat population seems to be an extension of the Peruvian and north Bolivian L. p. garleppi in contradiction with García-Perea (1994), who denominated that population as a new subspecies L. colocolo wolffsohni. Nevertheless, more samples of that region are needed to have total clarity of what Pampas cat is living there. Additionally, in Bolivia, we determined the existence, at least, of two putative subspecies (garleppi and steinbachi). Finally, although molecular conclusive studies are needed, the first molecular studies indicate that the existence of a unique Pampas cat species is more probably than three different species such as García-Perea (1994) proposed.