Karyotype and chromosome variability in the armadillo Chaetophractus villosus, in Argentina.

L F ROSSI; LUACES J P; ALONSO F; M S MERANI

CYTOGENETIC AND GENOME RESEARCH

KARGER

Lugar: Basel; Año: 2014

1424-8581

Karyotype and cytotype variations for the large hairy arma- dillo (Chaetophractus villosus) were studied throughout the species? Argentine distribution. Peripheral blood lympho- cyte cultures of 421 animals were used to obtain mitotic metaphases. Preparations were subjected to conventional staining, G- and C-banding, and FISH involving a telomeric probe. Meiotic analysis was performed on testis material from 10 adults. Spermatocytes were examined for synapto- nemal complexes in microspreads. The karyotype (2n = 60 XX/XY; FN = 84 without XY) showed an autosomal comple- ment of 6 metacentric and 7 submetacentric chromosomes; the remainder was acrocentric. The X chromosome was sub- metacentric and the Y acrocentric. Centromeric C+ marks were observed in all chromosomes except pair 16. Three NOR signals were detected in 6q, 12p, and 26p. Two chromo- somal rearrangements were characterized in chromosome pair 1 a pericentric inversion seen in the material from Ja- cinto Aráuz, General Madariaga and Pellegrini and a deletion in the material from Loma Verde. Interstitial telomeric sig- nals were observed in chromosome pairs 4, 12, 16, and 26. Pachytene spermatocyte analysis confirmed the basic chro- mosome number and morphologies observed in mitotic karyotypes. The evolution of C. villosus involved chromo- somal rearrangements as recorded for other species of its superorder. The present results establish the basis for the cytogenetic characterization of this species.