Project description:Here, we demonstrate that Nematostella vectensis, Ciona intestinalis, Apis mellifera, and B. mori, show two distinct populations of genes differentiated by gene-body CpG density. Genome-scale DNA methylation profiles for A. mellifera spermatozoa reveal CpG-poor genes are methylated in the germ line, as predicted by the depletion of CpGs. We find an evolutionarily conserved distinction between CpG-poor and -rich genes: the former are associated with basic biological processes, the latter with more specialized functions. This distinction is strikingly similar to that recently observed between euchromatin-associated genes in Drosophila that contain intragenic histone 3 lysine 36 trimethylation (H3K36me3) and those that do not, even though Drosophila doesnât display CpG density bimodality or methylation. We confirm that a significant number of CpG-poor genes in N. vectensis, C. intestinalis, A. mellifera and B. mori are orthologs of H3K36me3- rich genes in Drosophila. We propose that over evolutionary time, gene-body H3K36me3 has influenced gene-body DNA methylation levels, and consequently the gene-body CpG density bimodality characteristic of invertebrates that harbor CpG methylation.
Project description:Here, we demonstrate that Nematostella vectensis, Ciona intestinalis, Apis mellifera, and B. mori, show two distinct populations of genes differentiated by gene-body CpG density. Genome-scale DNA methylation profiles for A. mellifera spermatozoa reveal CpG-poor genes are methylated in the germ line, as predicted by the depletion of CpGs. We find an evolutionarily conserved distinction between CpG-poor and -rich genes: the former are associated with basic biological processes, the latter with more specialized functions. This distinction is strikingly similar to that recently observed between euchromatin-associated genes in Drosophila that contain intragenic histone 3 lysine 36 trimethylation (H3K36me3) and those that do not, even though Drosophila doesnM-CM-"M-BM-^@M-BM-^Yt display CpG density bimodality or methylation. We confirm that a significant number of CpG-poor genes in N. vectensis, C. intestinalis, A. mellifera and B. mori are orthologs of H3K36me3- rich genes in Drosophila. We propose that over evolutionary time, gene-body H3K36me3 has influenced gene-body DNA methylation levels, and consequently the gene-body CpG density bimodality characteristic of invertebrates that harbor CpG methylation. Examination of DNA methylation in Apis Mellifera sperm
Project description:In honey bees, Vitellogenin (Vg) is hypothesized to be a major factor affecting hormone signaling, food-related behavior, immunity, stress resistance and lifespan. Likewise microRNAs play important roles in posttranscriptional gene regulation and affect many biological processes thereby showing many parallels to Vg functions. The molecular basis of Vg and microRNA interactions is largely unknown. Here, we exploited the well-established RNA interference (RNAi) protocol for Vg knockdown to investigate its effects on microRNA population in honey bee forager’s brain and fat body tissue. To identify microRNAs that are differentially expressed between tissues in control and knockdown foragers, we used µParaflo® microfluidic oligonucleotide microRNA microarrays. Our results show 76 and 74 miRNAs were expressed in the brain of control and knockdown foragers whereas 66 and 69 miRNAs were expressed in the fat body of control and knockdown foragers respectively. Target prediction identified potential seed matches for differentially expressed subset of microRNAs affected by Vg knockdown. These candidate genes are involved in a broad range of biological processes including insulin signaling, juvenile hormone (JH) and ecdysteroid signaling previously shown to affect foraging behavior. Thus, here we demonstrate a causal link between Vg expression-variation and variation in the abundance of microRNAs in different tissues with possible consequences for regulation of foraging behavior.
Project description:In honey bees, Vitellogenin (Vg) is hypothesized to be a major factor affecting hormone signaling, food-related behavior, immunity, stress resistance and lifespan. Likewise microRNAs play important roles in posttranscriptional gene regulation and affect many biological processes thereby showing many parallels to Vg functions. The molecular basis of Vg and microRNA interactions is largely unknown. Here, we exploited the well-established RNA interference (RNAi) protocol for Vg knockdown to investigate its effects on microRNA population in honey bee forager’s brain and fat body tissue. To identify microRNAs that are differentially expressed between tissues in control and knockdown foragers, we used µParaflo® microfluidic oligonucleotide microRNA microarrays. Our results show 76 and 74 miRNAs were expressed in the brain of control and knockdown foragers whereas 66 and 69 miRNAs were expressed in the fat body of control and knockdown foragers respectively. Target prediction identified potential seed matches for differentially expressed subset of microRNAs affected by Vg knockdown. These candidate genes are involved in a broad range of biological processes including insulin signaling, juvenile hormone (JH) and ecdysteroid signaling previously shown to affect foraging behavior. Thus, here we demonstrate a causal link between Vg expression-variation and variation in the abundance of microRNAs in different tissues with possible consequences for regulation of foraging behavior.
Project description:Apis mellifera intermissa (Buttel-Reepen, 1906) is the native honeybee subspecies of Algeria. A.m.intermissa occurs in Tunisia, Algeria and Morocco, between the Atlas and the Mediterranean and Atlantic coasts (Ruttner, 1988), in an area of more than 2500 km long. Intermissa indicates the position through this bee races between tropical Africa and European breeds (Peyvel, 1994). The settlement area of the Tellian extends from Tunisia to Morocco. Ruttner et al (1978) describes the pure Tellian. It is a black hair of his coat poverty brings out the black color. It is a small size, there are some times light illumination on the tergites. This bee is very aggressive, nervous, sick to take part, as swarms huge fall and even produced many brood and can build up to one hundred queen cells (Le Conte, 2002). A.m.intermissa is prone to swarming, shows an aggressive behaviour and an abundant use of propolis (Ruttner 1988). This study is part of the project funded by the USAID Grant No. TA-MOU-08-M29-075.
Project description:Apis mellifera syriaca is the native honeybee subspecies of Jordan and much of the Middle East. It expresses behavioral adaptations to a regional climate with very high temperatures, nectar dearth in summer, attacks of the Oriental wasp Vespa orientalis and in most cases it is resistant to varroa mites. The Thorax control sample of A. m. syriaca in this experiment was originally collected and stored since 2001 from Wadi Ben Hammad a remote valley in the southern region of Jordan. Using morphometric and Mitochondrial DNA markers it was proved that bees from this area had show higher similarity than other samples collected from the Middle East as represented by reference samples collected in 1952 by Brother Adam. The samples L1-L5 are collected from the National Center for Agricultural Research and Extension breading apiary which was originally established for the conservation of Apis mellifera syriaca. Goal was to use the genetic information in the breeding for varroa resistant bees and to determine the successfulness of this conservation program. Project funded by USAID-MERC grant number: TA-MOU-09-M29-075.
Project description:This is one of expressional parts of the study. These data were correlated to epigenetic marks and CG density of genes in analyzed cells. The whole study has a following summary: To elucidate possible roles of DNA methylation and chromatin marks in transcription, we performed epigenetic profiling of chromosome 19 in human bronchial epithelial cells (HBEC) and in the colorectal cancer cell line HCT116 as well as its counterpart with double knockout of DNMT1 and DNMT3B (HCT116-DKO). We found that H3K9me3 forms intragenic chromatin blocks along genes with low CpG density in the gene body. Analysis of H3K36me3 profiles indicated that this mark associates either with active genes with low CpG density and H3K9me3 in the gene body or with active genes with high CpG density and DNA hypermethylation in the gene body. In HCT116 cells with double knockout of DNMT1 and DNMT3B, transcription of genes with low CpG density in the gene body was highly elevated and associated with promoter DNA demethylation and rearrangement of H3K9me3 and H3K36me3 occupation. Our finding suggests that similar to DNA methylation, H3K9me3 may play a role in intragenic gene regulation. Further, we observed that a combination of low CpG density in gene bodies together with H3K9me3 and H3K36me3 marking is a specific epigenetic feature of zinc finger (ZNF) genes, which comprise 90% of all genes carrying both histone marks on chromosome 19. For high CpG density genes, transcription and H3K36me3 occupancy were not changed in condition of partial or intensive loss of DNA methylation in gene bodies in the HCT116-DKO cell line. siRNA experiments with SETD2 knockdown in both HBEC and HCT116-DKO cell lines failed to reduce DNA methylation in gene bodies under conditions of H3K36me3 depletion. Our study suggests that the H3K36me3 and DNA methylation marks in gene bodies are established independently from each other and points to similar functional roles of intragenic DNA methylation and intragenic H3K9me3 for CpG-rich and CpG-poor genes, respectively. Expressional changes associated with SETD2 siRNA transfection in HBEC Compare siRNA vs. control
Project description:Sexual reproduction brings genes from two parents – matrigenes and patrigenes – into one individual. These genes, despite being unrelated, should show nearly perfect cooperation because each gains equally through production of offspring. However, an individual’s matrigenes and patrigenes can have different probabilities of being present in other relatives, so that kin selection could act on them differently. Such intragenomic conflict could be implemented by partial or complete silencing (imprinting) of an allele by one of the parents. Evidence supporting this theory is seen in offspring-mother interactions, with patrigenes favoring acquisition of more of the mother's resources if some of the costs fall on half siblings who do not share the patrigene. The kinship theory of intragenomic conflict is little tested in other contexts, but it predicts that matrigene-patrigene conflict may be rife in social insects. We tested the hypothesis that honey bee worker reproduction is promoted more by patrigenes than matrigenes by comparing across 9 reciprocal crosses of two distinct genetic stocks. As predicted, hybrid workers show reproductive trait characteristics of their paternal stock, indicating enhanced activity of the patrigenes on these traits, greater patrigenic than matrigenic expression, and significantly increased patrigenic biased expression in reproductive workers. These results support both the general prediction that matrigene-patrigene conflict occurs in social insects and the specific prediction that honey bee worker reproduction is driven more by patrigenes. The success of these predictions suggests that intragenomic conflict may occur in many contexts where matrigenes and patrigenes have different relatednesses to affected kin.