Sperm transcriptome of infertile men

Infertility is a widespread health problem, with rising incidence worldwide. Whether the infertility is caused by genetic or environmental factors, the reason for inability to reproduce can be the too low number of sperm or morphological or functional abnormality of the sperm. Therefore there can be a certain possibility that divergent causes would converge in common mechanisms impairing sperm functionality. A key step in the control of the cell phenotype is the regulation of gene expression. Therefore, the sperm transcriptome can reflect the impairment of proper regulatory networks acting during spermatogenesis and later, during sperm maturation. Also, it can be speculated that some sperm RNAs can influence the fitness of the early embryo, despite the small amount of sperm RNA. Although the changes in transcriptome are not always reflected by similar changes in the proteome, a relative ease of transcriptome interrogation makes it an excellent tool for hypothesis generation about infertility mechanisms and for a search for potential infertility biomarkers. We analyzed the transcriptome of 24 sperm samples using Affymetrix HuGene2.1ST microarrays. 6 participants were fertile men with normal sperm parameters, 5 samples were from infertile patients that presented low sperm motility (asthenozoospermia), and 7 samples with low motility as well as abnormal morphology (asthenoteratozoospermia) and 6 were infertile men with no semen abnormality. Differential expression of most significant genes was confirmed by qPCR.