Fig. 5 in Hybridization Between the Endangered Unisexual Gray-Checkered Whiptail Lizard (Aspidoscelis dixoni) and the Bisexual Western Whiptail Lizard (Aspidoscelis tigris) in Southwestern New Mexico

Fig. 5. Karyotypes of two whiptail lizards (Aspidoscelis) from Antelope Pass, Peloncillo Mountains, Hidalgo County, New Mexico. A, Diploid unisexual A. dixoni C (AMNH R-148360, fig. 3), with 2n 5 46 chromosomes. This taxon is a clone with its ultimate ancestor having been an F1 hybrid between A. tigris marmorata (haploid complement of chromosomes in the upper two rows) X A. gularis septemvittata (haploid complement in the lower two rows of A). Note that the X chromosome that was ultimately inherited from marmorata (third largest, upper row) was apparently fissioned at the centromere (arrow) forming two additional set II-sized macrochromosomes (here arranged to suggest the ancestral unfissioned state in marmorata). Note also that the missing microchromosome of A. dixoni C is illustrated as missing from the marmorata genome (o at the right end of the second row), although we do not know from which genome it was actually lost. B, Triploid hybrid female of A. dixoni C X A. t. punctilinealis (AMNH R-148141, fig. 3), with 3n 5 69 chromosomes arranged in six rows. Rows 2 and 4 represent the haploid complement most recently inherited from A. t. punctilinealis, including its intact X chromosome (third largest). Rows 1, 3, 5, and 6 represent the two haploid complements inherited from A. dixoni C, including the fissioned X (arrow) chromosome and missing microchromosome (o), as in A, above. Bar represents 10 Mm.