Chromosomal Relationships among Spiny Pocket Mice, Liomys (Heteromyidae), from Mexico

Abstract

This study focused on differentially stained karyotypes of the heteromyids Liomys pictus pictus, L. p. plantinarensis, L. spectabilis, and L. irroratus, and described their banding patterns of euchromatin and constitutive heterochromatin to decide if results fit expectations of chromosomal rearrangements leading to karyotypic evolution of the L. irroratus, L. spectabilis, and L. pictus lineage. Results confirmed most previous findings on diploid numbers of chromosomes and fundamental numbers (except for L. irroratus). Homologous G-banding patterns allowed identification of chromosome rearrangements such as centric fusions, pericentric inversions, and addition and deletion of euchromatin. Moreover, C-banding patterns showed that amounts and distribution of constitutive heterochromatin were different among species. Differentially stained karyotypes confirmed previous reports and contributed details on chromosomal morphology. Chromosomal rearrangements found mostly support hypotheses on karyotypic changes that led to chromosomal evolution of the Liomys lineage examined, although the lineage sequence may be different.