Modeling body size evolution in Felidae under alternative phylogenetic hypotheses

The use of phylogenetic comparative methods in ecological research has advanced during the last twenty years, mainly due to accurate phylogenetic reconstructions based on molecular data and computational and statistical advances. We used phylogenetic correlograms and phylogenetic eigenvector regression (PVR) to model body size evolution in 35 worldwide Felidae (Mammalia, Carnivora) species using two alternative phylogenies and published body size data. The purpose was not to contrast the phylogenetic hypotheses but to evaluate how analyses of body size evolution patterns can be affected by the phylogeny used for comparative analyses (CA). Both phylogenies produced a strong phylogenetic pattern, with closely related species having similar body sizes and the similarity decreasing with increasing distances in time. The PVR explained 65% to 67% of body size variation and all Moran's I values for the PVR residuals were non-significant, indicating that both these models explained phylogenetic structures in trait variation. Even though our results did not suggest that any phylogeny can be used for CA with the same power, or that ôgoodõ phylogenies are unnecessary for the correct interpretation of the evolutionary dynamics of ecological, biogeographical, physiological or behavioral patterns, it does suggest that developments in CA can, and indeed should, proceed without waiting for perfect and fully resolved phylogenies.

Los felinos: ¿Una alternativa en estudios de toxicología genética?

Felines: an alternative in genetic toxicology studies? The micronuclei (MN) test carry out in peripheral blood is fast, simple, economic and it is used to detect genotoxic environmental agents. MN are fragments of chromosomes or complete chromosomes remaining in the cytoplasm after cell division, which increase when organisms are exposed to genotoxic agents. Therefore, species with the highest values of spontaneous micronucleated erythrocytes (MNE) are the most suitable to be potentials biomonitor of micronucleogenic agents, using a drop of blood. Nine species of Felines that present spontaneous MNE in peripheral blood are shown. From these species, the cat has been previously proven, with positive results and also lion (Panthera leo), yaguaroundi (Felis yagoaroundi), lynx (Lynx ruffus), jaguar (Panthera onca), puma (Puma concolor), tiger (Panthera tigris), ocelote (Felis padalis) and leopard (Panthera pardus) display spontaneous MNE, and with this characteristic this Family can be propose like a potential group to be used in toxicogenetic studies. Rev. Biol. Trop. 56 (2): 969-974. Epub 2008 June 30.

La prueba de micronúcleos (MN) en sangre periférica es rápida, sencilla, económica y sirve para detectar genotóxicos ambientales. Los MN son fragmentos de cromosomas o cromosomas completos que por alguna causa quedan fuera del núcleo en mitosis, pero que incrementan significativamente cuando los organismos que los presentan de manera espontánea se exponen a genotóxicos. Por lo tanto, el requisito para que una especie pueda ser utilizada para esta prueba es que presente eritrocitos micronucleados espontáneos (EMNe), con lo que estas especies pueden ser potenciales bioindicadores de genotóxicos micronucleogénicos, con sólo una gota de su sangre. En el presente articulo es mostramos 9 especies de felinos que como característica general presentan EMNe. Del total de especies de felinos, el gato ha sido previamente probado, con resultados positivos y ya que también el león, yaguaroundi, lince, jaguar, puma, tigre de bengala, ocelote y leopardo presentan EMNe, esta familia puede ser propuesta como un grupo potencialmente adecuado para estudios de toxicogenética. En otras palabras, cada una de estas especies puede llegar a ser un modelo potencial para determinar exposición a genotóxicos en nuestro entorno, de una manera sencilla y rápida.

Genetic diversity of microsatellite loci in Leopardus pardalis, Leopardus wiedii and Leopardus tigrinus

The microsatellite loci FCA045, FCA077, FCA008, and FCA096 are highly variable molecular markers which were used to determine the genetic diversity in 148 captive Leopardus sp. The PCR-amplified products of microsatellite loci were characterized in ABI Prism 310 Genetic Analyzer. Allele numbers, heterozygosity, polymorphism information content, exclusive allele number, and shared alleles were calculated. Sixty-five alleles were found and their sizes ranged from 116 to 216 bp in four microsatellite loci. The heterozygosity ranged from 0.36 to 0.81 in Leopardus pardalis, 0.57 to 0.67 in L. tigrinus and 0.80 to 0.92 in L. wiedii. The polymorphism information content was from 0.80 to 0.88 in L. pardalis, 0.76 to 0.88 in L. tigrinus and 0.77 to 0.90 in L. wiedii. The margay (L. wiedii) showed the highest index of polymorphism among the three species in this study. These results imply that microsatellite DNA markers can help in the study of the genetic diversity of Leopardus specimens.

Genetic variability of Herpailurus yagouaroundi, Puma concolor and Panthera onca (Mammalia, Felidae) studied using Felis catus microsatellites

We used four microsatellite loci (Fca08, Fca45, Fca77 and Fca96) from the domestic cat, Felis catus, to investigate genetic variability in specimens of Herpailurus yagouaroundi (jaguarundi, otter cat, eyra), Puma concolor (cougar, mountain lion, puma) and Panthera onca (jaguar) held in various Brazilian zoos. Samples of DNA from the cats were PCR amplified and then sequenced before being analyzed using the CERVUS program. Our results show a mean polymorphic information content (PIC) of 0.83 for H. yagouaroundi, 0.66 for P. concolor and 0.69 for P. onca and a mean of 10.3 alleles for the Fca08 locus, 5.3 for Fca 45, 9 for Fca 77 and 14 for Fca 96. These results indicate a relatively high level of genetic diversity for the specimens studied.