The Role of Polyploidy in the Evolution of Gender Dimorphism: An Experimental Approach Using Fragaria vesca Allison Kwok Advisor: University of Guelph, 2013 Dr. Brian C Husband The evolution of gender dimorphism is associated with the incidence of polyploidy in several plant taxa, but the underlying causes of this relationship are not well understood. Here I investigate the direct and indirect ...

A specialized transducing phage, SP beta c2 dglnA2, of Bacillus subtilis was used to construct partial diploids with various glutamine auxotrophs. The overproduction of manganese-stimulated glutamine synthetase no longer occurred in the diploids. The kinetics of heat inactivation of the enzyme extracted from two diploids suggests that there was subunit mixing.

Two loci (the incompatibility or mating type loci), a and b, govern the life cycle of Ustilago maydis, a fungal pathogen of corn. U. maydis diploids heterozygous at both a and b (a[unk] b[unk]) form mycelial colonies (Fuz(+) phenotype), induce tumors, and produce teliospores able to undergo meiosis. We report here the isolation and characterization of nonmycelial (Fuz(-)) derivatives. These Fuz...

The cellular localization of IGF-I, IGF-II and MSTN proteins was investigated during ontogenesis of triploid sea bass (Dicentrarchus labrax) by an immunohistochemical approach. The results were compared with those observed in diploids. IGF-I immunostaining was mainly observed in skin, skeletal muscle, intestine and gills of both diploids and triploids. From day 30 of larval life, IGF-I immunore...

During the process of sporulation, a/alpha diploids degrade about 50% of their vegetative proteins. This degradation is not sporulation specific, for asporogenous diploids of a/a mating type degrade their vegetative proteins in a fashion similar to that of their a/alpha counterparts. Diploids lacking carboxypeptidase Y activity, prc1/prc1, show about 80% of wild-type levels of protein degradati...

We have developed a method by which the extent of physical exchange of DNA molecules can be determined throughout meiosis in the yeast Saccharomyces cerevisiae. We have used this technique to analyze the effect of five meiosis-defective mutations (rad6, rad50, rad52, rad57 and spo11) on the physical exchange of DNA molecules. In the same experiments, we have also measured other meiotic paramete...

The embryo culture technique has been improving, but the detailed demands for energy substrates such as glucose, fructose, pyruvate and lactate of preimplantation embryos are still unclear. In the present study, the demands of pig preimplantation embryos at each different developmental stage were investigated by use of parthenogenetic diploids as a model of pig preimplantation embryos. Pig part...

Yeast cells undergo diploid-specific developments such as spore formation via meiosis and pseudohyphal development under certain nutrient-limited conditions. Studies on these aspects require homozygous diploid mutants, which are generally constructed by crossing strains of opposite mating-type with the same genetic mutation. So far, there has been no direct way to generate and select diploids f...