Identification of plu genes and cis-acting elements of PCNA in the Drosophila genus using conservation of gene order

The genetics and cell biology of Wolbachia-host interactions

Wolbachia are gram-negative bacteria that are widespread in nature, carried by the majority of insect species as well as some mites, crustaceans, and filarial nematodes. Wolbachia can range from parasitic to symbiotic, depending upon the interaction with the host species. The success of Wolbachia is attributed to efficient maternal transmission and manipulations of host reproduction that favor infected females, such as sperm-egg cytoplasmic incompatibility (CI). Much remains unknown about the mechanistic basis for Wolbachia-host interactions. Here we summarize the current understanding of Wolbachia interaction with insect hosts, with a focus on Drosophila. The areas of discussion include Wolbachia transmission in oogenesis, Wolbachia distribution in spermatogenesis, induction and rescue of the CI phenotype, Wolbachia genomics, and Wolbachia-membrane interactions.

Drosophila Genome-Scale Screen for PAN GU Kinase Substrates Identifies Mat89Bb as a Cell Cycle Regulator

Although traditional organism-based mutational analysis is powerful in identifying genes involved in specific biological processes, limitations include incomplete coverage and time required for gene identification. Biochemical screens using cell transfection or yeast two-hybrid methods are rapid, but they are limited by cDNA library quality. The recent establishment of "uni-gene sets" has made it feasible to biochemically screen an organism's entire genome. Radiolabeled protein pools prepared from the Drosophila Gene Collection were used in a Drosophila in vitro expression cloning ("DIVEC") screen for substrates of PAN GU kinase, which is crucial for S-M embryonic cell cycles. Ablation of one identified substrate, Mat89Bb, by RNAi produces a polyploid phenotype similar to that of pan gu mutants. Xenopus embryos injected with Mat89Bb morpholinos arrest with polyploid nuclei, and Mat89Bb RNAi in HeLa cells gives rise to multinucleated cells. Thus, Mat89Bb plays an evolutionarily conserved role as a crucial regulator of both cell cycle and development.