The parthogenetic lizard species Cnemidophorus tesselatus is composed of diploid populations formed by hybridization of the bisexual species C. tigris and C. septemvittatus, and of triploid populations derived from a cross between diploid tesselatus and a third bisexual species, C. sexlineatus. An analysis of allozymic variation in proteins encoded by 21 loci revealed that, primarily because of...

Lycoris radiata is an important medicinal and ornamental plant of China. In the present study, somatic chromosome counts and karyotype analyses, which are important aspects of plant phylogeny and evolution, were performed in 466 individuals from 25 L. radiata populations by root tip squash method. Chromosome counts revealed that 10 populations were diploid (2n = 2x = 22) and 15 were triploid (2...

ROM a consideration of chromosome evolution in Drosophila, it has been suggested F (MULLER and PAINTER 1932) that in the basal heterochromatin, regions of genetic homology might exist between all of the chromosomes in D. melanogaster. In a cytological study of the chromocenter in salivary gland nuclei, PROKOFYEVA (1935) describes connections (which she interprets to be conjugations of homologou...

We describe two methods of producing viable and fertile autotetraploid Pacific oyster (Crassostrea gigas Thunberg) based on the use of normal-sized oocytes produced by normal diploid females. Our methods showed that the oocyte size is not a limiting factor for the success of the induction to autotetraploidy. These methods offer means of direct introgression of genetic progress from elite diploi...

Incompatibilities between parental genomes decrease viability of interspecific hybrids; however, deviations from canonical gametogenesis such as genome endoreplication and elimination can rescue hybrid organisms. To evaluate frequency and regularity of genome elimination and endoreplication during gametogenesis in hybrid animals with different ploidy, we examined genome composition in oocytes o...