title: Robertsonian polymorphism in chromosomes of Oryzomys subflavus (Rodentia, Cricetidae).
abstract: Eighty-four specimens of Oryzomys subflavus, collected in the State of Pernambuco, Brazil, were studied. A Robertsonian chromosome polymorphism, characterized by a varying diploid number of 50, 49, 48, and 46, was found. All specimens showed a chromosome arm number of 56. G-banding patterns in somatic cells allowed identification of the chromosome pairs (2, 3, 5, and 7) involved in centric fusion. C-banding revealed the presence of constitutive heterochromatin near the centromere the X chromosome and those of the autosomes. The Y chromosome presented a large heterochromatic block in the distal portion of its long arm.
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000235:genetics*; D002871:Chromosome Banding; D002875:Chromosomes / Q000032:analysis / Q000648:ultrastructure; D005260:Female; D006570:Heterochromatin / Q000032:analysis; D007621:Karyotyping; D008297:Male; D011110:Polymorphism, Genetic; D012730:Sex Chromosomes / Q000032:analysis
chemical_list: D006570:Heterochromatin