Publication Date:
2012-04-17
Description:
Salinomys delicatus is considered a rare species due to its restricted and patchy distribution, poor records and low abundances. It is also the phyllotine with the lowest known diploid chromosome number (2n = 18), however its sex chromosome system has never been described. Here, we studied the chromosomes of six females and three males with bands G, C, DAPI/CMA 3 and meiosis. In males, the chromosome number was 2n = 19, with one large metacentric X-chromosome and two medium-sized acrocentrics absent in females. The karyotype of females was the same as previously described (2n = 18, FN = 32), with X-chromosomes being metacentric and the largest elements of the complement. In males, the two acrocentrics and the large metacentric form a trivalent in meiotic prophase. This indicates that S. delicatus has XY 1 Y 2 sex chromosomes, which is confirmed by G and DAPI bands. Constitutive heterochromatin (CH) is restricted to small pericentromeric blocks in all chromosomes. The X-chromosome shows the largest block of centromeric CH, which could favor the establishment of this X-autosome translocation. This sex chromosome system is rare in mammals and, compared with other phyllotine rodents, S. delicatus seems to have undergone a major chromosome restructuring during its karyotypic evolution. Content Type Journal Article Pages 1143-1147 DOI 10.1007/s10709-011-9616-7 Authors C. Lanzone, Grupo de Investigaciones de la Biodiversidad, IADIZA, CONICET, CCT-Mendoza, CC 507, CP5500 Mendoza, Argentina D. Rodríguez, Grupo de Investigaciones de la Biodiversidad, IADIZA, CONICET, CCT-Mendoza, CC 507, CP5500 Mendoza, Argentina P. Cuello, Grupo de Investigaciones de la Biodiversidad, IADIZA, CONICET, CCT-Mendoza, CC 507, CP5500 Mendoza, Argentina S. Albanese, Grupo de Investigaciones de la Biodiversidad, IADIZA, CONICET, CCT-Mendoza, CC 507, CP5500 Mendoza, Argentina A. Ojeda, Grupo de Investigaciones de la Biodiversidad, IADIZA, CONICET, CCT-Mendoza, CC 507, CP5500 Mendoza, Argentina V. Chillo, Grupo de Investigaciones de la Biodiversidad, IADIZA, CONICET, CCT-Mendoza, CC 507, CP5500 Mendoza, Argentina D. A. Martí, Laboratorio de Genética Evolutiva, Universidad Nacional de Misiones, CONICET, Félix de Azara 1552, CP3300 Posadas, Misiones, Argentina Journal Genetica Online ISSN 1573-6857 Print ISSN 0016-6707 Journal Volume Volume 139 Journal Issue Volume 139, Number 9
Print ISSN:
0016-6707
Electronic ISSN:
1573-6857
Topics:
Biology
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