Phylogenetic relationships and karyotype evolution in the sigmodontine rodent Akodon (2n = 10 and 2n = 16) from Brazil

Author(s)

Silva, Maria José de J. ; Patton, James L. ; Yonenaga-Yassuda, Yatiyo ^[3]

• Document type: Journal article
• Source: GENETICS AND MOLECULAR BIOLOGY; v. 29, n. 3, p. 469-474, 2006.
• Field of knowledge: Biological Sciences - Genetics

Abstract

Comparison of G-bands from 2n = 10 and 2n = 16 karyotypes of Akodon revealed tandem fusions, pericentric inversions and Robertsonian rearrangement in autosomes and addition/deletion of constitutive heterochromatin in sex chromosomes. Cytochrome-b sequences indicate that the 2n = 10 karyotype is a new species and show it to be a sister taxon of the 2n = 14, 2n = 15 and 2n = 16 karyotypes. Indeed, this group shows a particular evolutionary situation in which a unique taxonomic unit based on morphological data can be detected, but, karyologically, it can be separated into two groups (2n = 14-15-16 and 2n = 10). Cytochrome-b sequences show a finer resolution, indicating that these four karyotypes represent three molecular entities (2n = 14-15, 2n = 16 and 2n = 10) that may be derived from a common ancestor with a 2n = 16 karyotype. (AU)

• FAPESP's process: 98/05075-7 - Systematics, Evolution and Conservation of Eastern Brazilian Mammals
• Grantee: Mario de Vivo
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants