The adult boar testicular and epididymal transcriptomes

ABSTRACT: 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

ORGANISM(S): Sus scrofa

PROVIDER: GSE15614 | GEO | 2009/09/01

SECONDARY ACCESSION(S): PRJNA116695

REPOSITORIES: GEO