Male-derived accessory gland proteins that are transferred to females during mating have profound effects on female reproductive physiology including increased ovulation, mating inhibition, and effects on sperm utilization and storage. The extreme rates of evolution seen in accessory gland proteins may be driven by sperm competition and sexual conflict, processes that may ultimately drive complex interactions between female-and male-derived molecules and sperm. However, little is known of how gene expression in female reproductive tissues changes in response to the presence of male molecules and sperm. To characterize this response, we conducted parallel genomic and proteomic analyses of gene expression in the reproductive tract of 3-day-old unmated and mated female Drosophila melanogaster. Using DNA microarrays, we identified 539 transcripts that are differentially expressed in unmated vs. mated females and revealed a striking peak in differential expression at 6 h postmating and a marked shift from primarily down-regulated to primarily up-regulated transcripts within 3 h after mating. Combining two-dimensional gel electrophoresis and liquid chromatography mass spectrometry analyses, we identified 84 differentially expressed proteins at 3 h postmating, including proteins that appeared to undergo posttranslational modification. Together, our observations define transcriptional and translational response to mating within the female reproductive tract and suggest a bimodal model of postmating gene expression initially correlated with mating and the final stages of female reproductive tract maturation and later with the declining presence of male reproductive molecules and with sperm maintenance and utilization.accessory gland proteins ͉ reproduction ͉ reproductive tract ͉ sperm ͉ sexual conflict

Mating triggers physiological and behavioral changes in females.To understand how females effect these changes, we used microarray, proteomic, and comparative analyses to characterize gene expression in oviducts of mated and unmated Drosophila females. The transition from non-egg laying to egg laying elicits a distinct molecular profile in the oviduct. Immune-related transcripts and proteins involved in muscle and polarized epithelial function increase, whereas cell growth and differentiation-related genes are down-regulated. Our combined results indicate that mating triggers molecular and biochemical changes that mediate progression from a ''poised'' state to a mature, functional stage.antimicrobial peptides ͉ network ͉ reproduction

Antibody diversification necessitates targeted mutation of regions within the immunoglobulin locus by activation-induced cytidine deaminase (AID). While AID is known to act on single-stranded DNA (ssDNA), the source, structure, and distribution of these substrates in vivo remain unclear. Using the technique of in situ bisulfite treatment, we characterized these substrates—which we found to be unique to actively transcribed genes—as short ssDNA regions, that are equally distributed on both DNA strands. We found that the frequencies of these ssDNA patches act as accurate predictors of AID activity at reporter genes in hypermutating and class switching B cells as well as in Escherichia coli. Importantly, these ssDNA patches rely on transcription, and we report that transcription-induced negative supercoiling enhances both ssDNA tract formation and AID mutagenesis. In addition, RNaseH1 expression does not impact the formation of these ssDNA tracts indicating that these structures are distinct from R-loops. These data emphasize the notion that these transcription-generated ssDNA tracts are one of many in vivo substrates for AID.

Background: In both vertebrates and invertebrates, the oviduct is an epithelial tube surrounded by visceral muscles that serves as a conduit for gamete transport between the ovary and uterus. While Drosophila is a model system for tubular organ development, few studies have addressed the development of the fly's oviduct. Recent studies in Drosophila have identified mating-responsive genes and proteins whose levels in the oviduct are altered by mating. Since many of these molecules (e.g. Muscle LIM protein 84B, Coracle, Neuroglian) have known roles in the differentiation of muscle and epithelia of other organs, mating may trigger similar differentiation events in the oviduct. This led us to hypothesize that mating mediates the last stages of oviduct differentiation in which organ-specific specializations arise.

Agrobacterium, the only known organism capable of trans-kingdom DNA transfer, genetically transforms plants by transferring a segment of its DNA, T-DNA, into the nucleus of the host cell where it integrates into the plant genome. One of the central events in this genetic transformation process is nuclear import of the T-DNA molecule, which to a large degree is mediated by the bacterial virulence protein VirE2. VirE2 is distinguished by its nuclear targeting, which occurs only in plant but not in animal cells and is facilitated by the cellular VIP1 protein. The molecular mechanism of the VIP1 function is still unclear. Here, we used in vitro assays for nuclear import and quantification of proteinprotein interactions to directly demonstrate formation of ternary complexes between VirE2, VIP1, and a component of the cellular nuclear import machinery, karyopherin ␣. Our results indicate that VIP1 functions as a molecular bridge between VirE2 and karyopherin ␣, allowing VirE2 to utilize the host cell nuclear import machinery even without being directly recognized by its components.Agrobacterium, the only known organism capable of transkingdom DNA transfer (1), elicits neoplastic growths on many plant species. Moreover, although plants represent the natural hosts for Agrobacterium, this microorganism can also transform a wide range of other eukaryotic species, ranging from fungi (2, 3) to human cells (4). This genetic transformation is achieved by transporting a single-stranded copy (T-strand) 1 of the bacterially transferred DNA (T-DNA) from the tumor-inducing plasmid into the plant cell nucleus and then by integration into the host genome (5, 6). These processes are likely mediated by two Agrobacterium proteins VirD2 and VirE2, which are believed to directly associate with the T-strand, forming a transport (T-) complex (7). In the T-complex, one molecule of VirD2 is covalently attached to the 5Ј end of the T-strand, whereas VirE2, a single-stranded (ss)DNA binding protein, is presumed to cooperatively coat the remainder of the ssDNA molecule (5,7,8). Both VirD2 and VirE2 proteins are targeted to the host cell nucleus (9 -15), but VirE2 alone is sufficient to transport ssDNA into the nucleus of the plant cell (16).Although VirE2 accumulates in the cell nucleus even in very diverse plant species (9), it fails to enter the nucleus of yeast or animal cells (15,(17)(18)(19). VirE2 nuclear import in non-plant systems is promoted by expression of an Arabidopsis protein, VIP1, that interacts with VirE2 (19). Because VIP1, a basic leucine zipper motif protein, shows no significant homology to known animal or yeast proteins, it was suggested to be a cellular factor responsible, at least in part, for plant-specific VirE2 nuclear import (19). The role of VIP1 in the nuclear import of transfer complexes is also consistent with observations that VIP1, which by itself is unable to associate with ssDNA, is able to interact with VirE2, whereas the latter is bound to the ssDNA, forming ternary VIP1-VirE2-ssDNA complexes in vitro (19)....