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G-band patterns of the Siberian snow sheep, Ovis nivicola alleni, 2n=52, were compared with the patterns reported in 2n=54 wild Asiatic mouflon and 2n=54 North American sheep and those in domestic sheep with 2n=54, 53, and 52. The three largest pairs of biarmed autosomes displayed indistinguishable, presumably homologous, G-banding patterns in all types of sheep. The banding and morphology of the fourth pair of biarmed autosomes in O.nivicola differed from those of the three translocation variants described in domestic sheep. Wild sheep with 2n=54 may have evolved monophyletically from an ancestral 2n=58-56-54 population or polyphyletically by a series of independent, nonrandom fusions. In contrast, the fouth pair of biarmed autosomes in O.nivicola and in 2n=52 domestic sheep variants may have resulted from random fusions of different chromosomes.

G-band patterns of the bharal (Pseudois nayaur), 2n = 54, were compared with those of wild sheep (Ovis dalli stonei), 2n = 54, and the Persian wild goat (Capra hircus), 2n = 60. Patterns of the longer segments of the biarmed chromosomes of Pseudois were similar to those of the longer biarmed segments of Ovis, whereas the shorter segments differed. Biarmed chromosomal segments had G-band homologies with specific acrocentric autosomes of Capra and were ranked as follows in descending order of relative lengths: Pseudois 1:4/13; 2:1/27 and 3:3/29; and for Ovis 1:1/5; 2:3/10 and 3:4.9. Arm ratios and relative lengths of the biarmed chromosomes were compared. The Y chromosome of Pseudois is a small biarmed chromosome that resembles those of Capra and Ovis. Hemoglobin B was observed in the bharal and was indistinguishable from Hb B of Ovis using starch-gel electrophoresis. The transferrin "zone pair" of Pseudois migrated more slowly in starch-gel electrophoresis than do any of the known transferrin types in sheep and goats. We refer to this transferrin as Pseudois Tf A. The biarmed formations of Pseudois and Ovis are discussed in relation to karyotype evolution and possible speciation.