The Murine Testicular Transcriptome: Characterizing Gene Expression in the Testis During the Progression of Spermatogenesis1

TLDR

Microarray studies of gene expression in mammalian tissues can reveal developmental changes, and applying this to the testis offers a detailed view of genes involved in its maturation and spermatogenesis. To evaluate whether microarrays can effectively characterize gene expression changes as the testis develops from birth to adulthood. The authors profiled ~36,000 transcripts across 11 developmental stages of the testis using Affymetrix MGU74v2 GeneChip and generated cell‑type specific expression profiles to dissect functional actions of each testicular cell type. Statistical analysis identified 11,252 differentially expressed transcripts that clustered into five distinct temporal patterns, which align with cell‑specific expression profiles and illuminate the biological and chronological activities of testicular cell types during spermatogenesis.

Abstract

One of the most promising applications of microarrays is the study of changes in gene expression associated with the growth and development of mammalian tissues. The testis provides an excellent model to determine the ability of microarrays to effectively characterize the changes in gene expression as an organ develops from birth to adulthood. To this end, a developmental testis gene expression time course profiling the expression patterns of ∼36 000 transcripts on the Affymetrix MGU74v2 GeneChip platform at 11 distinct time points was created to gain a greater understanding of the molecular changes necessary for and elicited by the development of the testis. Additionally, gene expression profiles of isolated testicular cell types were created that can aid in the further characterization of the specific functional actions of each cell type in the testis. Statistical analysis of the data revealed 11 252 transcripts (9846 unique) expressed differentially in a significant manner. Subsequent cluster analysis produced five distinct expressional patterns within the time course. These patterns of expression are present at distinct chronological periods during testis development and often share similarities with cell-specific expression profiles. Analysis of cell-specific expression patterns produced unique and characteristic groups of transcripts that provide greater insight into the activities, biological and chronological, of testicular cell types during the progression of spermatogenesis. Further analysis of this time course can provide a distinct and more definitive view into the genes implicated, known and unknown, in the maturation, maintenance, and function of the testis and the integrated process of spermatogenesis.