New karyotypes and somatic and germ-cell banding in Akodon arviculoides (Rodentia, Cricetidae).
Chromosomal polymorphism resulting from three autosomal pericentric inversions and a complex rearrangement involving the largest chromosome of the complement (pair 1) in Akodon arviculoides (2n= 14, 15) is reported. G- and C-banding patterns in somatic and meiotic cells allowed the precise identification of all chromosomes and rearrangements. In meiosis of male specimens with 2n = 15, a large trivalent reflecting the complex rearrangement in autosomal pair 1 was observed. Two possible explanations for it are discussed. G- and C-bands in diplotene cells in heterozygotes for the inversions showed different configurations depending on the pairing in the inverted segments. Chiasma frequency data fro three specimens are analyzed.
D000818:Animals; D002871:Chromosome Banding; D007446:Chromosome Inversion; D002875:Chromosomes; D003434:Crossing Over, Genetic; D005260:Female; D005854:Germ Cells / Q000648:ultrastructure*; D007621:Karyotyping; D008297:Male; D008540:Meiosis; D011110:Polymorphism, Genetic; D012377:Rodentia / Q000235:genetics*