SRS15881168 SAMN30524473 2975443 Holochilus nanus Holochilus nanus (HNA) (2n = 56 and FN = 56) belongs to the rodent tribe Oryzomyini, the most taxonomically diverse tribe of the Sigmodontinae subfamily. Comparative cytogenetic by ZooFISH on 15 Oryzomyini species using the entire chromosome set of HNA revealed a high genome reshuffling involving autosomal, sex, and B chromosomes. Within mammals, Bs are most frequent in rodents, which account for 70% of the mammalian species that bear them. Application of next generation sequencing in the analysis of B chromosomes revealed that they comprise fragments of standard chromosomes and organellar genomes. Therefore, we propose to analyze, for the first time, the whole genome sequence of HNA specimens with and without B chromosome, and two B chromosomes plus the Y of HNA, isolated by flow sorting, in order to investigate the sequence homology shared between B and the sex chromosomes of HNA. In addition, the sequenced genome of HNA will be used to search for repetitive DNA sequences, aiming at understanding the role of these elements in the karyotype variability of Oryzomyini species. bioproject 874065 PRJNA874065 bioproject 874067 PRJNA874067 strain not applicable isolate BIO 634 breed not applicable cultivar not applicable ecotype not applicable dev_stage Adulthood sex male tissue fibroblast cell_type fibroblast genotype 2n = 56, FN = 56, XY geo_loc_name Brazil lat_lon 2.71666667 S 44.83333333 W specimen_voucher BIO:634 BioSampleModel Model organism or animal