Comparative Chromosome Painting in Six Species of Oligoryzomys (Rodentia, Sigmodontinae) and the Karyotype Evolution of the Genus

Author(s)

Di-Nizo, Camilla Bruno ^[1] ; Ventura, Karen ^{[2, 3, 4]} ; Ferguson-Smith, Malcolm Andrew ^[3] ; Mary O'Brien, Patricia Caroline ^[3] ; Yonenaga-Yassuda, Yatiyo ^[2] ; Silva, Maria Jose de J. ^[1]

Affiliation

^[1] Inst Butantan, Lab Ecol & Evolucao, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Inst Biociencias, Dept Genet & Biol Evolut, Sao Paulo - Brazil

^[3] Univ Cambridge, Dept Vet Med, Cambridge Resource Ctr Comparat Genom, Cambridge - England

^[4] Univ Fed Itajuba, Inst Recursos Nat, Itajuba, MG - Brazil

• Document type: Journal article
• Source: PLoS One; v. 10, n. 2 FEB 6 2015.
• Web of Science Citations: 11

Abstract

Oligoryzomys belongs to the tribe Oryzomyini, and contains about 22 species. Diploid numbers range from 2n = 44 in Oligoryzomys sp. 2 to 2n = 72 in O. utiaritensis and phylogenetic relationships are not well defined. The high morphological convergence leads to misidentification of taxonomic entities and the species are often identified by chromosomal characters. Until now, the genus has been studied only by classical cytogenetic approaches. To understand the chromosomal evolution of Oligoryzomys, we developed chromosome probes from a female of Oligoryzomys moojeni (OMO) with 2n = 70 and hybridized to other five Oligoryzomys species. The probes painted 31 segments on O. fornesi (OFO) with 2n = 62; 32 segments on O. microtis (OMI), 2n = 64; 33 segments on O. nigripes (ONI), 2n = 62 and on O. rupestris (ORU), 2n = 46; and 34 on Oligoryzomys sp. 2 (OSP), 2n = 44. OMO probes 4 and 5 showed a syntenic association in O. fornesi, O. microtis and O. nigripes and were also presented in the same pair, although disrupted, in O. rupestris and Oligoryzomys sp. 2. Concerning O. rupestris and Oligoryzomys sp. 2, species with the lowest diploid numbers of the genus, a total of 8 probes hybridized to 11 segments on the largest pair of ORU 1 and 9 probes hybridized to 12 segments on OSP 1. Also, OMO 6 painted three segments in ORU, corresponding to the proximal segment of ORU 2q, and the whole of ORU 19 and 20. In OSP, the segment corresponding to ORU 20 was homologous to OSP 1p. OMO X showed signals of hybridization in both X and Y chromosomes. Extensive chromosomal rearrangements, that could not be detected by classical cytogenetic techniques, such as pericentric inversions or repositioning of centromeres, Robertsonian rearrangements and tandem fusions/fissions, as well as gain/activation or loss/inactivation of centromeres and telomeric sequences have driven the huge genome reshuffling in these closely related species. (AU)

• FAPESP's process: 05/04557-3 - Cytogenetic and molecular studies on neotropical small rodents from Brazil
• Grantee: Maria José de Jesus Silva
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 10/03432-0 - Chromosome evolution on the genus Oligoryzomys (Cricetidae: Sigmodontinae): comparative studies by conventional cytogenetic and chromosome painting
• Grantee: Camilla Bruno Di Nizo
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 11/50146-6 - Comparative phylogeography, phylogeny, paleoclimate modeling, and taxonomy of neotropical reptiles and amphibians
• Grantee: Miguel Trefaut Urbano Rodrigues
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants