title: B-chromosome systems in the pocket mouse, Perognathus baileyi: meiosis and C-band studies.
abstract: The heterochromatin characteristics and meiotic behavior of the B-chromosome system of the pocket mouse, Perognathus baileyi, and described. B-chromosomes are associated both with a meiotic accumulation mechanism and with an increase in average chiasma frequency in the A-chromosome set in males. Three morphological classes of B-chromosomes are recognizable, and the mechanisms of origin of each are discussed.
mesh_terms: D000818:Animals; D002869:Chromosome Aberrations; D003434:Crossing Over, Genetic; D006570:Heterochromatin / Q000032:analysis*; D008297:Male; D008540:Meiosis; D008938:Mitosis; D012377:Rodentia
chemical_list: D006570:Heterochromatin