Comparison of in vivo collected oocytes from animals with high and low oocyte developmental potential (HOP, LOP) at both the immature and mature stage
ABSTRACT: Comparative transcriptomic analyses were performed at both the immature and at the mature stages between oocytes collected from cows with a high or low embryo development potential (HOP, LOP) as characterized by in vitro fertilization and embryo development. 1 biological replicate each from 3 HOP animals and 3 LOP animals, both at the immature stage and mature stage
Project description:Cumulus cells, surrounding the oocyte, play a key role in the acquisition of oocyte competence to be fertilized and to sustain early embryo development. Cumulus cells contribute to oocyte development by metabolizing energy substrates such as glutathione that may protect the oocyte from oxidative stress damages. The aim of our study was to compare transcriptomics profiles of cumulus enclosed (CEO) and cumulus denuded (CDO) oocytes after in vitro maturation. Global transcriptional profiling was performed using cumulus enclosed and cumulus denuded oocytes after in vitro maturation. Matured oocytes were obtained after 22h of maturation with (CEO) or without (CDO) cumulus cells and four replicates of 25 oocytes were collected for RNA extraction. Gene expression analysis was performed by comparing CDO versus CEO oocytes that represents a total of 8 slides using a dye swap hybridisation protocol.
Project description:The fruit fly Drosophila melanogaster is a good model to unravel the molecular mechanisms of innate immunity, and has led to some important discoveries on the sensing and signalling of microbial infections. The response of drosophila to virus infections remains poorly characterized, and appears to involve two facets. On one hand RNA interference (RNAi) involves the recognition and processing of dsRNA into small interfering (si) RNAs by the host ribonuclease Dicer-2 (Dcr-2), whereas on the other hand an inducible response controlled by the evolutionarily conserved JAK/STAT pathway contributes to the antiviral host defence. In order to clarify the contribution of the siRNA and JAK/STAT pathways to the control of viral infections, we have compared the resistance of flies wild-type or mutant for Dcr-2 or the JAK kinase Hopscotch (Hop) to infections by seven RNA or DNA viruses belonging to different families. Our results reveal a unique susceptibility of hop mutant flies to infection by DCV and CrPV, two members of the Dicistroviridae family. Genome-wide microarray analysis confirmed that different sets of genes were induced following infection by DCV (GSE2828) or two unrelated RNA viruses, FHV and SINV. Overall, our data reveal that RNAi is an efficient antiviral mechanism, operating against a large range of viruses, including a DNA virus. By contrast, the antiviral contribution of the JAK/STAT pathway appears to be virus-specific. For each experimental challenge (FHV, 48 or 72 hours after infection; SINV, 4 or 8 days after infection), three biologically independent samples composed of 45 male Oregon R flies were used. Infection has been performed by injecting viral stocks prepared in Tris solution. Injection of the same volume of Tris has been used as control. Infected flies were then incubated for 48 or 72 hours in the case of FHV and 4 days or 8 days in the case of SINV.
Project description:Due to its small and sequenced genome, short generation time, efficient transformation and increasing genetic resources, Brachypodium distachyon is an emerging model for grasses. Despite this, data capturing gene expression patterns across different organs and developmental stages is missing. We have generated a comprehensive gene expression atlas for Brachypodium, capturing 9 different organs and developmental stages
Project description:Background - Mammalians gamete production takes place in the testis but when they exit this organ, although spermatozoa have a specialized and distinct morphology, they are immotile and infertile. It is only after their travel in the epididymis that sperm acquire their motility and fertility. Epididymis can be divided in three gross morphological regions, head (caput), body (corpus) and tail (cauda), containing a long and unique convoluted tubule connecting the testis to the vas deferens. Results - In this study, the testis, the efferent ducts (vas efferens, VE), nine distinct successive epididymal segments and the deferent duct (vas deferens, VD) of four adult boars of known fertility were isolated and their mRNA extracted. The gene expression of each of these samples was analyzed using a pig generic 9K nylon microarray (AGENAE program; GEO accession number: GPL3729) spotted with 8931 clones derived from normalized cDNA banks from different pig tissues including testis and epididymis. Differentially expressed transcripts were obtained with moderated t-tests and F-tests and two data clustering algorithms based either on partitioning around medoïds (top down PAM) or hierarchical clustering (bottom up HCL) were combined for class discovery and gene expression analysis. Tissue samples analysis defined seven transcriptomic units: testis, vas efferens and five epididymal transcriptomic units. Meanwhile transcripts formed only four clusters related to the tissues. We have then used a specific statistical method to sort out genes specifically overexpressed (markers) in testis, VE or in each of the five transcriptomic units of the epididymis (including VD). Among these markers some well-known epididymal genes were retrieved while some were new genes or genes not yet reported in these boar tissues. The specific regional expression of some of these genes was further validated by PCR and Q-PCR. We also searched for specific pathways and functions using available gene ontology information. Conclusions - This study fulfilled the gap between those done in rodents and human, and provides tools that will be useful for further studies on the biochemical processes responsible for the formation and maintain of the epididymal regionalization and the development of a fertile spermatozoa. Keywords: tissue type comparaison 96 samples - 12 tissue samples from 4 boars
Project description:Cumulus cells surrounding the oocyte were sampled at the following stages: developmentally incompetent or poorly competent prophase I oocytes (NC1 oocytes), developmentally competent prophase I oocytes (C1 oocytes), and developmentally competent metaphase II oocytes (C2 oocytes). NC1 samples were collected from immature, unexpanded cumulus-oocytes complexes (COC) from prepubertal (3-week-old) mice, C1 samples from immature, unexpanded cumulus-oocytes complexes (COC) from adult (8-week-old) and C2 samples from mature, expanded COCs obtained from the oviduct from 8-week-old mice after standard superovulation protocol. Global transcriptional profiling was performed using cumulus cells collected from murine ovarian follicles during in vivo oocyte developmental competence acquisition. Cumulus cells were collected at 3 stages: early stage follicles (prophase I arrested oocytes, meiotically competent but developmentally incompetent, n=5), late stage follicles (prophase I arrested oocytes, meiotically competent and developmentally competent, n=5) and ovulatory follicles collected in vivo (metaphase II arrested oocytes, developmentally fully competent, n=5).
Project description:RNA sequence analysis of hop leaves infected with Hop stunt viriod revealed dynamic changes in hop gene expression. Overall design: High Throughput Sequencing analysis was used to identify the effect of Hop stunt viroid and hop powdery mildew on hop transcriptome in single and mixed infections
Project description:The proteome and secretome of human oocytes was studied by shotgun LCMSMS, starting from pools of 100 cells. Exploiting SP3, a novel technology for proteomic sample preparation using magnetic beads, we scaled down proteome analysis to single cells. Despite the low protein content of only ~100ng per cell, we consistently identified ~450 proteins from individual oocytes. When comparing proteomes of individual oocytes at the germinal vesicle (GV) and metaphase II (MII) stage by label-free quantification, we found several proteins preferentially expressed in matuare and immature cells.
Project description:In cattle, almost all fully grown vesicle stage oocytes (GV) have the ability to resume meisos, develop to Metaphase II stage (MII), support fertilization and progress through the early embryonic cycles in vitro. Yet without intensive selection, the majority fail to develop to the blastocyst stage. Using the Affymetrix Bovine Genome Array, global mRNA expression analysis of immature (GV) and in vitro matured (IVM) bovine oocytes was carried out to characterize the transcriptome of the bovine oocyte and to identify the key pathways associated with oocyte meiotic maturation and developmental potential. Immature and in vitro matured bovine oocytes were collected for RNA extraction and hybridization on Affymetrix GeneChip Bovine Genome array. Careful removal of cumulus and selection of oocytes was carried out under the stereo microscope in order to examine the actual cumulus-free temporal oocyte gene expression profiles. Immature oocytes at time 0 h and in vitro matured oocytes at 24 h were collected for analysis.
Project description:piRNAs are 26-30nt germ-line specific small non-coding RNAs that have evolutionarily conserved function in mobile genetic element silencing and maintenance of genome integrity. It has been shown that Drosophila Hsp70/90 Organizing Protein Homolog (Hop) – a co-chaperone interacts with piRNA binding protein Piwi and mediates silencing of phenotypic variations. However, it is not known if Hop has a direct role in piRNA biogenesis and transposon silencing. Here, we show that knock down of Hop in the germ-line nurse cells (GLKD) of Drosophila ovaries leads to activation of transposable elements. Females without germ-line Hop can lay eggs but the eggs do not hatch into larvae. GLKD of Hop leads to accumulation of γ-H2Av foci in the germline indicating increased DNA damage in the ovary. We also show that Hop is required for efficient piRNA biogenesis. Based on these results, we conclude that Hop is a critical component of piRNA pathway and it maintains genome integrity by silencing transposable elements. Overall design: Total mRNA profiles of ovaries from nos.Luc (Control) and Hop germline knockdown conditions. Total small RNA profiles of ovaries from nos.Luc (Control) and Hop germline knockdown conditions.
Project description:The hop plant, Humulus lupulus L., contains an exceptionally high content of secondary metabolites, the hop iso-α-acids, which possess a range of beneficial properties including antiseptic action. Studies performed on the mode of action of hop iso-α-acids have hitherto been restricted to lactic acid bacteria. The present study investigates molecular mechanisms of hop iso-α-acid resistance in the model eukaryote Saccharomyces cerevisiae. Growth inhibition occurred at concentrations of hop iso-α-acids that were an order of magnitude higher than those found with hop-tolerant prokaryotes. Chemostat-based transcriptome analysis and phenotype screening of the S. cerevisiae haploid gene deletion collection were used as complementary methods to screen for genes involved in hop iso-α-acids detoxification and tolerance. Further analysis of deletion mutants confirmed that yeast tolerance to hop iso-α-acids involves two major processes: active export of iso-α-acids across the plasma membrane and active proton pumping into the vacuole by the V-ATPase to enable vacuolar sequestration of iso-α-acids. Furthermore, iso-α-acids were shown to affect cellular metal homeostasis by acting as strong zinc and iron chelator. Experiment Overall Design: Two complementary genome-wide approaches were employed to investigate cellular responses of S. cerevisiae to hop extracts enriched in iso-α-acids. Microarray transcriptome analysis was performed on chemostat cultures of an S. cerevisiae reference strain grown in the presence and absence of iso-α-acids. In addition, screening of the nearly complete set of yeast open reading frame (ORF) haploid knock-outs generated by the Saccharomyces Genome Deletion Project (SGDP) (Open Biosystems) identified the mutants with increased hop sensitivity. Subsequently, involvement of selected genes and cellular processes in hop acid sensitivity and tolerance was analyzed by construction and detailed analysis of selected mutant strains.