Project description:This project investigated the effect of Cln3-deficiency on protein secretion in the social amoeba Dictyostelium discoideum by performing LC-MS/MS on conditioned media harvested from starved WT and cln3- cells.
Project description:The social amoeba Dictyostelium discoideum is vulnerable to infection by the pathogen that causes Legionnaire's Disease, Legionella pneumophila. Dictystelium cells lacking the dual-specificity phospahatase DupA are at least partially resistant to infection, and strikingly the expression profile of uninfected dupA null cells mirrors the profile of infected wild-type cells to a considerable extent. This suggests that DupA has a key role in regulating host defence systems.
Project description:The social amoebae (Dictyostelia) are a diverse group of Amoebozoa that achieve multicellularity by aggregation and undergo morphogenesis into fruiting bodies with terminally differentiated spores and stalk cells. There are four groups of dictyostelids, with the most derived being a group that contains the model species Dictyostelium discoideum.We have produced a draft genome sequence of another group dictyostelid, Dictyostelium purpureum, and compare it to the D. discoideum genome. The assembly (8.41 × coverage) comprises 799 scaffolds totaling 33.0 Mb, comparable to the D. discoideum genome size. Sequence comparisons suggest that these two dictyostelids shared a common ancestor approximately 400 million years ago. In spite of this divergence, most orthologs reside in small clusters of conserved synteny. Comparative analyses revealed a core set of orthologous genes that illuminate dictyostelid physiology, as well as differences in gene family content. Interesting patterns of gene conservation and divergence are also evident, suggesting function differences; some protein families, such as the histidine kinases, have undergone little functional change, whereas others, such as the polyketide synthases, have undergone extensive diversification. The abundant amino acid homopolymers encoded in both genomes are generally not found in homologous positions within proteins, so they are unlikely to derive from ancestral DNA triplet repeats. Genes involved in the social stage evolved more rapidly than others, consistent with either relaxed selection or accelerated evolution due to social conflict.The findings from this new genome sequence and comparative analysis shed light on the biology and evolution of the Dictyostelia.
Project description:spaA is a Cud-type transcription factor that is essential for spore cell differentiation of Dictyostelium discoideum, a social amoeba. ChIP-seq was performed to identify spaA target genes.