Project description:So as to compare fungal mating-type chromosomes across a range of Microbotryum species, comparative genomics analyses were conducted, and were informed by RNASeq data. In this instance, different stages of the lifecycle of M. violaceum infecting D. pavonius were compared via RNASeq.
Project description:Phytophthora infestans is a filamentous plant pathogen. It belongs to the class Oomycota within the Stramenopiles. Despite the importance of sexual reproduction in P. infestans, many aspects of the mating process remain unknown. In this study we are investigating its mating mechanisms using different molecular techniques. Isolates with A1 and A2 mating types from Sweden, the Netherlands and the UK, were used for this purpose because mating frequencies are known to differ among European countries. RNA was prepared from the “mating-zone” between the 4 Swedish, 1 Dutch and 1 British pairs. RNA-seq analysis was performed on an Illumina HiSeq 2500 platform and data normalized to parental isolates growing individually.
Project description:Neurospora tetrasperma is a pseudohomothallic filamentous ascomycete with a large (~ 7 Mbp) region of suppressed recombination surrounding its mating-type (mat) locus. The suppressed recombination has lead to sequence divergence between the two mating-type chromosomes of wild-type heterokaryotic strains, while the remaining genome is largely homoallelic. In this study, we use microarray technology to manifest expression divergence linked to mating type in N. tetrasperma. N. tetrasperma and N. crassa, were grown on agar regimes inducing sexual growth (Synthetic Crossing medium) and vegetative growth (Vogel's Medium), respectively.
Project description:Recombination suppression on fungal mating-type chromosomes without mating-type loci linkage and with loss of function of HD mating-type genes
Project description:Modes of sexual reproduction in eukaryotic organisms are highly diversified. The human fungal pathogen Candida albicans undergoes a phenotypic switch from the white to the opaque phase in order to become mating-competent. In this study, we report that functionally and morphologically differentiated white and opaque cells show a coordinating behavior in the process of mating. Although white cells are mating-incompetent, they are induced to produce sexual pheromones when treated with opposite pheromones or interacted with opaque cells of an opposite mating type. In a co-culture system, pheromones released by white cells induce opaque cells to form mating projections and thus facilitate both opposite- and same-sex mating of opaque cells. Deletion of genes encoding the pheromone precursor proteins and inactivation of the pheromone response signaling pathway (Ste2-MAPK-Cph1) impair the promoting role of white cells (MTLa) in sexual mating of opaque cells. White and opaque cells communicate via a paracrine pheromone signaling and thus create an environment conducive to sexual mating. This coordination behavior of the two different cell types may be a trade-off strategy between sexual and asexual lifestyles in C. albicans.
Project description:Reproductive traits that influence female remating and competitive fertilization rapidly evolve in response to sexual selection and sexual conflict. One such trait, observed across diverse animal taxa, is the formation of a structural plug inside the female reproductive tract, either during or shortly after mating. In Drosophila melanogaster, male seminal fluid forms a mating plug inside the female bursa, which has been demonstrated to influence sperm entry into storage and latency of female remating. Processing of the plug, including its eventual ejection from the female's reproductive tract, influences the competitive fertilization success of her mates and is mediated by female × male genotypic interactions. However, female contributions to plug formation and processing have received limited attention. Using developmental mutants that lack glandular female reproductive tract tissues, we reveal that these glandular tissues are essential for the mating plug to be ejected. We further use proteomics to demonstrate that female glandular proteins, and especially proteolytic enzymes, contribute to mating plug composition and that the absence of glands has a widespread impact of plug formation and composition. Together, these phenotypic and molecular data resolve molecular mechanisms of important postmating, intersexual interactions and cryptic female choice.
Project description:Sexual reproduction facilitates infection by the production of both a lineage advantage and infectious sexual spores in the ubiquitous human fungal pathogen Cryptococcus deneoformans. However, the regulatory determinants specific for initiating mating remain poorly understood. Here, we identified a velvet family regulator, Cva1, that strongly promotes sexual reproduction in C. deneoformans. This regulation was determined to be specific, based on a comprehensive phenotypic analysis of cva1 under 25 distinct in vitro and in vivo growth conditions. We further revealed that Cva1 plays a critical role in the initiation of early mating events, especially sexual cell-cell fusion, but is not important for the late sexual development stages or meiosis. Thus, Cva1 specifically contributes to mating activation. Importantly, a novel mating-responsive surface protein, Cfs1, serves as the key target of Cva1 during mating, since its absence nearly blocks cell-cell fusion in C. deneoformans and its sister species C. neoformans. Together, our findings provide insight into how C. deneoformans ensures regulatory specificity of mating.