Project description:The testis tissue-based trans-omics was a feasible approach to find more missing proteins (MPs) because it was reported higher gene expression found in testis tissues. Three testis tissues and two protein separation strategies were selected to quantitatively evaluate gene expression abundance at the proteomic and transcriptomic levels. The project have been jointly supervised by Ping Xu and Siqi Liu.
Project description:The testis tissue-based trans-omics was a feasible approach to find more missing proteins (MPs) because it was reported higher gene expression found in testis tissues. Three testis tissues and two protein separation strategies were selected to quantitatively evaluate gene expression abundance at the proteomic and transcriptomic levels. The project have been jointly supervised by Ping Xu and Siqi Liu.
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:Understanding the extent of genomic transcription and its functional relevance is a central goal in genomics research. However, detailed genome‐wide investigations of transcriptome complexities in major mammalian organs and their underlying cellular sources, transcriptional mechanisms, and functional relevance have been scarce. Here we first show, using extensive RNA‐seq data, that transcription of both functional and nonfunctional genomic elements is substantially more widespread in the testis than in other organs across representative mammals. By scrutinizing the transcriptomes of all main testicular cell types in the mouse, we then reveal that meiotic spermatocytes and especially post‐meiotic round spermatids have remarkably diverse transcriptomes, which explains the high transcriptome complexity of the testis as a whole. The widespread transcriptional activity in spermatocytes and spermatids encompasses protein‐coding genes and long noncoding RNA genes but also poorly conserved intergenic sequences, suggesting that much of it is not of immediate functional relevance. Rather, our analyses of genome‐wide epigenetic data show that this prevalent transcription, which apparently promoted the birth of new genes during evolution, results from a highly permissive chromatin state during and after meiosis that may ultimately facilitate the replacement of histones by protamines during late spermatogenesis. To study the cellular source and mechanisms of high transcriptome complexity in the mammalian testis, we generated strand-specific deep coverage RNA‐Seq data for purified sertoli cells, spermatogonia, spermatocytes, spermatids and spermatozoa as well as for brain, liver and the whole testis from the mouse. We prepared 8 sequencing libraries for the polyadenylated RNA fraction of each sample and sequenced each library in 3 lanes of the Illumina Genome Analyser IIx platform, yielding a total of >60 millions strand-specific reads of 76 base pairs per sample. In addition, we generated ChIP-Seq data for the H3K4me2 modification as well as RRBS data for brain, liver, testis, spermatocytes and spermatids. RNA-seq, ChIP-seq and RRBS data were generated from the same individual or pool of individuals, in the case of purified cells. ChIP-Seq data for the H3K4me2 modification as well as RRBS data for brain, liver, testis, spermatocytes and spermatids