Comparative Study of B Chromosomes in Neotropical Deer

Abstract

Among the Artiodactyla, Cervidae family, Neotropical brocket deer are represented by the genera Pudu, Pudella, Bisbalus, Mazama, Subulo and Passalites, and known to have a marked karyotypic diversity, with frequent observations of polymorphisms and chromosomal rearrangements. Another major variation is seen by the presence or absence of B chromosomes, both inter- and intraspecies. All species within the genus Mazama, Passalites and Subulo demonstrate intraindividual variability from Bs. B chromosomes have been described in only other two species in Artiodactyla, the Siberian roe deer (Capreolus pygargus) and Siberian musk deer (Moschus sibiricus). The B chromosomes are known as supernumerary chromosomes, that show non-Mendelian inheritance and do not produce visible phenotypic effect. Repetitive elements, transposable elements, genes, and pseudogenes were already identified in these chromosomes, using methodologies which involve isolating Bs via microdissection or flow sorting, followed by sequencing and employing reverse painting with FISH (Fluorescent in situ Hybridization). Regarding Neotropical deer, the molecular content of B chromosomes of species from the genus Mazama and Passalites was never studied before, and the limited number of studies hampers discussions on these topics. Because of that, the aim of the project is to bring unique information and shed light on the sequence composition of their B chromosomes, using molecular methods to increase the knowledge about these components in cervids.