Citogenômica comparativa de morcegos da família Phyllostomidae na Amazônia

Abstract

Among the Chiropteran, the Phyllostomidae family is the most diverse clade of the Neotropics and in Amazon are found about 80 species. From a chromosomal point of view, Phyllostomidae stands out for presenting many karyotype variation, with diploid numbers ranging from 2n = 14 in Vampyressa melissa (Stenodermatinae) to 2n = 46 in Macrotus waterhousii (Macrotinae). There are several genetic mechanisms or processes that can result in numeric/structural chromosomal abnormalities and often repetitive DNA sequences are involved in this process. In order to understand the variety and karyotype evolution of this family, classical and molecular cytogenetic analyzes were performed on mitotic chromosomes of four species belonging to four subfamilies of distinct phylogenetic clades: Artibeus obscurus, Carollia perspicillata, Desmodus rotundus and Phylostomus elongatus. Artibeus obscurus presented NF = 56 and 2 N = 30/31, with 22m + 6st + XX / XY1Y2; C. perspicillata NF = 36 and 2N = 20/21, with 14m-sm + 4st + XX / XY1Y2; D. rotundus NF = 52 and 2 N = 28, and 26m-sm + XX / XY; P. elongatus NF = 60 and 2 N = 32, and 28m-sm + 2a + XX / XY. The distribution pattern of constitutive heterochromatin revealed a signal in the pericentromeric region in all chromosomes of the four analyzed species and intraspecific variations were observed when compared the results of this work with the one in existing literature. Regarding the signal of ribosomal DNA sites 18S and nucleolus organizer regions active in A. obscurus were shown in the terminal region of the pairs 5, 6 and 7; C. perspicillata in pericentromeric region of the X chromosome; D. rotundus in the centromeric region of pair 8 and in P. elongatus in the centromeric/terminal region of the pair 15. Conspicuous telomeric signals were observed in D. rotundus and P. elongatus, while in A. obscurus and C. perspicillata the terminals signals are blurred. Interstitial telomeric sites were absent in P. elongatus and present in other species, which may indicate mergers. The LINE-1 retroelement presented scattered signals, however in some chromosomes they are identical to the patterns of dark bands evident in the band G and is also accumulated on chromosome X. If compared the phylogenetic position of the studied species, it is noted that the most derived taxons accumulate high karyotype variation as repetitive elements.