Sex chromosomes polymorphisms inOryzomysaff.subflavus(Cricetidae, Rodentia) from Central Brazil

Abstract

SUMMARY -Specimens of Oryzomys aff. subflavus collected in Central Brazil displayed a karyotype with 2n =58 and FN = 70, not described previously. Sex chromosomes polymorphisms were identified: the X could be a large submetacentric (Xa), a large subtelocentric (Xb) or a large subtelocentric smaller than Xb (Xc) and the Y appeared as a medium submetacentric (Ya), a medium subtelocentric (Yb) or a medium acrocentric (Yc). G-and C-banding, as well as chromosomal measurements were used to establish the rearrangements involved in the sex chromosomes variability.

Advances in cytogenetics of Brazilian rodents: cytotaxonomy, chromosome evolution and new karyotypic data

“…In fact, many of these cases were solved after the integration of different disciplines. For instance, for many years cytogenetic information indicated that the previous “Oryzomys subflavus” could, in fact, be more than one species, since nine different karyotypes were attributed to a single taxonomic entity (Maia and Hulak 1981, Almeida and Yonenaga-Yassuda 1985, Svartman and Almeida 1992, Silva 1994). Nowadays, after interdisciplinary studies with morphology and molecular phylogeny, it is possible to recognize eight species (Weksler et al 2006, Percequillo et al 2008, Tavares et al 2011, Bonvicino et al 2014).…”

New Karyotypes of Two Related Species of Oligoryzomys Genus (Cricetidae, Rodentia) Involving Centric Fusion with Loss of NORs and Distribution of Telomeric (TTAGGG)n, Sequences

“…Sex chromosome polymorphism represents an evident characteristic of the Oryzomyini group and in the majority of the cases, the variations are caused by addition/deletion of constitutive heterochromatin (SILVA 1994;ALMEIDA and YONENAGA-YASSUDA 1991;SVARTMAN and ALMEIDA 1992). The intra-individual heteromorphism of the X chromosome in Oligoryzomys sp.…”

Extensive genomic reshuffling involved in the karyotype evolution of genus Cerradomys (Rodentia: Sigmodontinae: Oryzomyini)

“…It was previously described as a subgenus of Oryzomys ( Oryzomys subflavus ) ( Weksler et al , 2006 ; Percequillo, 2015 ). From 1981 to 2002, different karyotypes were described suggesting that the genus was not monotypic ( Maia and Hulak, 1981 ; Almeida and Yonenaga-Yassuda, 1985 ; Svartman and Almeida, 1992 ; Andrades-Miranda et al , 2002 ), and this was confirmed later using molecular and morphological studies ( Bonvicino and Moreira, 2001 ; Langguth and Bonvicino, 2002 ; Bonvicino, 2003 ). Then, Oryzomys subflavus became Oryzomys gr.…”