title: Extensive Chromosomal Reorganization in the Evolution of New World Muroid Rodents (Cricetidae, Sigmodontinae): Searching for Ancestral Phylogenetic Traits.
abstract: Sigmodontinae rodents show great diversity and complexity in morphology and ecology. This diversity is accompanied by extensive chromosome variation challenging attempts to reconstruct their ancestral genome. The species Hylaeamys megacephalus--HME (Oryzomyini, 2n = 54), Necromys lasiurus--NLA (Akodontini, 2n = 34) and Akodon sp.--ASP (Akodontini, 2n = 10) have extreme diploid numbers that make it difficult to understand the rearrangements that are responsible for such differences. In this study we analyzed these changes using whole chromosome probes of HME in cross-species painting of NLA and ASP to construct chromosome homology maps that reveal the rearrangements between species. We include data from the literature for other Sigmodontinae previously studied with probes from HME and Mus musculus (MMU) probes. We also use the HME probes on MMU chromosomes for the comparative analysis of NLA with other species already mapped by MMU probes. Our results show that NLA and ASP have highly rearranged karyotypes when compared to HME. Eleven HME syntenic blocks are shared among the species studied here. Four syntenies may be ancestral to Akodontini (HME2/18, 3/25, 18/25 and 4/11/16) and eight to Sigmodontinae (HME26, 1/12, 6/21, 7/9, 5/17, 11/16, 20/13 and 19/14/19). Using MMU data we identified six associations shared among rodents from seven subfamilies, where MMU3/18 and MMU8/13 are phylogenetic signatures of Sigmodontinae. We suggest that the associations MMU2entire, MMU6proximal/12entire, MMU3/18, MMU8/13, MMU1/17, MMU10/17, MMU12/17, MMU5/16, MMU5/6 and MMU7/19 are part of the ancestral Sigmodontinae genome.
authors.affiliation: Laboratório de Citogenética, Centro de Estudos Avançados da Biodiversidade, ICB, Universidade Federal do Pará, Belém, Pará, Brasil.
authors.forename: Adenilson Leão
authors.initials: AL
authors.lastname: Pereira
authors.affiliation: Laboratório de Citogenética, Centro de Estudos Avançados da Biodiversidade, ICB, Universidade Federal do Pará, Belém, Pará, Brasil.
authors.forename: Stella Miranda
authors.initials: SM
authors.lastname: Malcher
authors.affiliation: Laboratório de Citogenética, Centro de Estudos Avançados da Biodiversidade, ICB, Universidade Federal do Pará, Belém, Pará, Brasil.|CNPq Researcher, Brasília, Brasil.
authors.forename: Cleusa Yoshiko
authors.initials: CY
authors.lastname: Nagamachi
authors.affiliation: Cambridge Resource Center for Comparative Genomics, Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Patricia Caroline Mary
authors.initials: PC
authors.lastname: O'Brien
authors.affiliation: Cambridge Resource Center for Comparative Genomics, Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Malcolm Andrew
authors.initials: MA
authors.lastname: Ferguson-Smith
authors.affiliation: Laboratório de Zoologia e Ecologia de Vertebrados, ICB, Universidade Federal do Pará, Belém, Pará, Brasil.
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Mendes-Oliveira
authors.affiliation: Laboratório de Citogenética, Centro de Estudos Avançados da Biodiversidade, ICB, Universidade Federal do Pará, Belém, Pará, Brasil.|CNPq Researcher, Brasília, Brasil.
authors.forename: Julio Cesar
authors.initials: JC
authors.lastname: Pieczarka
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002871:Chromosome Banding; D020223:Chromosome Painting; D002875:Chromosomes; D005260:Female; D006570:Heterochromatin / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence; D059785:Karyotype; D008297:Male; D010802:Phylogeny; D016205:Sigmodontinae / Q000235:genetics*
chemical_list: D006570:Heterochromatin