Project description:Candida lusitaniae is an emerging human opportunistic yeast, which can switch from yeast to pseudohyphae, and one of the rare Candida species capable of sexual reproduction. Its haploid genome and the genetic tools available make it a model of interest to study gene function. This study describes the consequences of DPP3 inactivation on cell morphology and mating, both altered in the dpp3Δ knock-out. Interestingly, reintroducing a wild-type copy of the DPP3 gene in the dpp3Δ mutant failed to restore the wild-type phenotypes. Proteomic analyses showed that about 150 proteins were statistically deregulated in the dpp3Δ mutant, and that most of them did not return to their wild-type level in the reconstituted DPP3 strain. The analysis of the segregation of the dpp3Δ mutation and the phenotypes in the progeny of a cross (between the dpp3Δ knock-out and a wild-type strain) showed that the phenotypes are not linked to dpp3Δ, but to a secondary mutation. Genome sequencing of the dpp3Δ mutant allowed us to identify this secondary mutation.
Project description:Investigation of whole genome gene expression level changes in Plasmodium falciparum 3D7 delta-PfPuf2 mutant, compared to the wild-type strain 3D7. The mutation engineered into this strain render tanslational control. The mutants analyzed in this study are further described in Miao J, Li J, Fan Q, Li X, Li X, Cui L.2010. The Puf-family RNA-binding protein PfPuf2 regulates sexual development and sex differentiation in the malaria parasite Plasmodium falciparum. J Cell Sci. 123(7):1039-49 (PMID 20197405).
Project description:Commitment to and completion of sexual development are essential for Toxoplasma gondii to produce oocysts in the intestine of the feline host. Understanding of the molecular mechanism responsible for sexual commitment is extremely limited due to the lack of model systems. Here, we show that the transcription factors AP2XI-2 and AP2XII-1 associated with the epigenetic repressors MORC/HDAC3 complex are constitutively expressed in both tachyzoite and bradyzoite stages but not in the merozoite stage. Depletion of AP2XI-2 or AP2XII-1 elicits the expression of genes specific to merozoites, but they play different roles in the merogony process. Depletion of AP2XI-2 in type II Pru strain induced parasites to undergo merogony and produce mature merozoites in alkaline medium but not in neutral medium, whereas the AP2XII-1 depleted Pru strain underwent several rounds of schizogony and produced merozoites in neutral medium and more markedly under alkaline conditions. Furthermore, we show that two AP2XI-2 interacting proteins are also involved in repressing merozoite programming. Overall, these findings indicate that the merozoite primed pre-sexual commitment is controlled by an intricate regulatory network and that AP2XI-2 or AP2XII-1 depleted parasites can be used as a model to study the merogony in vitro.
Project description:The protein kinase Ime2 is known to have an important role in meiosis in the yeast Saccharomyces cerevisiae. However, the Neurospora crassa IME2 homolog functions in self/nonself recognition as well as in the development of fungal sexual structures called protoperithecia. In N. crassa, protoperithecia are induced upon nitrogen starvation. We were interested in gene expression differences between an ime-2 deletion strain and a wild type strain, and due to the role of ime-2 during sexual development, carried out these arrays on media that was lacking in nitrogen.
Project description:Investigation of whole genome gene expression level changes in response to different light conditions of the H. jecorina CBS999.97(MAT1-2) parental strain (W) and the deletion strain delta-env1 (E). These two strains were grown on malt extract agar(Merck) at 25℃ in four different conditions: (1) 24L: constant light illumination (24L); (2) 12L12D: in a 12h light/dark cycle and then 6h light illumination; (3) 12D12L: in a 12h dark/light cycle and then 6h constant darknes; (4) 24D: constant darkness. The wild-type strain is potent for sexual development in 12D12L, 12L12D and 24D, whereas the delta-env1 mutant undergo sexual development only in 24D. By contrast, the wild-type strain is female sterile in 24L, and the delta-env1 mutant is female sterile in 12D12L, 12L12D and 24D. Our results reveal that conidation-specific genes, mating locus gene, h-type maitng pheromone genes, and genes invovled in processing and secretion of h-type mating pheromone are significantly upregulated in all four female sterile conditions (W-24L, E-12L12D, E-12D12L and E-24L).
