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Comparative chromosome painting in six species of Oligoryzomys (Rodentia, Sigmodontinae) and the karyotype evolution of the genus.

Di-Nizo CB, Ventura K, Ferguson-Smith MA, O'Brien PC, Yonenaga-Yassuda Y, Silva MJ - PLoS ONE (2015)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Ecologia e Evolução, Instituto Butantan, São Paulo, São Paulo, Brazil.

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.

No MeSH data available.


Related in: MedlinePlus

Tandem fusions in pair 1 of low diploid number species.(a)O. rupestris (2n = 46) chromosome 1 hybridized by eight different O. moojeni probes; (b)Oligoryzomys sp. 2 (2n = 44) chromosome 1 hybridized by nine different O. moojeni probes.
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pone.0117579.g007: Tandem fusions in pair 1 of low diploid number species.(a)O. rupestris (2n = 46) chromosome 1 hybridized by eight different O. moojeni probes; (b)Oligoryzomys sp. 2 (2n = 44) chromosome 1 hybridized by nine different O. moojeni probes.

Mentions: Chromosome painting in O. rupestris (2n = 46) and Oligoryzomys sp. 2 (2n = 44) showed almost the same hybridization pattern. As O. rupestris and Oligoryzomys sp. 2 have very similar karyotypes and totally different from other species of the same genus, it is likely that they are closely phylogenetically related. In O. rupestris, pair 1 was hybridized by eight OMO probes while nine probes hybridized pair 1 of Oligoryzomys sp. 2 (Fig. 7). In addition, ORU 2/ OSP 2 were hybridized by four probes and ORU 3/ OSP 3 by three probes (Fig. 8), showing that tandem fusion events occurred during karyotype differentiation of both species, providing the lowest known diploid number of the genus.


Comparative chromosome painting in six species of Oligoryzomys (Rodentia, Sigmodontinae) and the karyotype evolution of the genus.

Di-Nizo CB, Ventura K, Ferguson-Smith MA, O'Brien PC, Yonenaga-Yassuda Y, Silva MJ - PLoS ONE (2015)

Tandem fusions in pair 1 of low diploid number species.(a)O. rupestris (2n = 46) chromosome 1 hybridized by eight different O. moojeni probes; (b)Oligoryzomys sp. 2 (2n = 44) chromosome 1 hybridized by nine different O. moojeni probes.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4320059&req=5

pone.0117579.g007: Tandem fusions in pair 1 of low diploid number species.(a)O. rupestris (2n = 46) chromosome 1 hybridized by eight different O. moojeni probes; (b)Oligoryzomys sp. 2 (2n = 44) chromosome 1 hybridized by nine different O. moojeni probes.
Mentions: Chromosome painting in O. rupestris (2n = 46) and Oligoryzomys sp. 2 (2n = 44) showed almost the same hybridization pattern. As O. rupestris and Oligoryzomys sp. 2 have very similar karyotypes and totally different from other species of the same genus, it is likely that they are closely phylogenetically related. In O. rupestris, pair 1 was hybridized by eight OMO probes while nine probes hybridized pair 1 of Oligoryzomys sp. 2 (Fig. 7). In addition, ORU 2/ OSP 2 were hybridized by four probes and ORU 3/ OSP 3 by three probes (Fig. 8), showing that tandem fusion events occurred during karyotype differentiation of both species, providing the lowest known diploid number of the genus.

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Ecologia e Evolução, Instituto Butantan, São Paulo, São Paulo, Brazil.

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.

No MeSH data available.


Related in: MedlinePlus