RESEARCH ARTICLE Differential Genes Expression between Fertile and Infertile Spermatozoa Revealed by Transcriptome Analysis

Background It was believed earlier that spermatozoa have no traces of RNA because of loss of most of the cytoplasm. Recent studies have revealed the presence of about 3000 different kinds of mRNAs in ejaculated spermatozoa. However, the correlation of transcriptome profile with infertility remains obscure. Methods Total RNA from sperm (after exclusion of somatic cells) of 60 men consisting of individuals with known fertility (n=20), idiopathic infertility (normozoospermic patients, n=20), and asth-enozoospermia (n=20) was isolated. After RNA quality check on Bioanalyzer, Affymetrix-GeneChip Human Gene 1.0 ST Array was used for expression profiling, which consisted of>30,000 coding transcripts and>11,000 long intergenic non-coding transcripts. Results Comparison between all three groups revealed that two thousand and eighty one transcripts were differentially expressed. Analysis of these transcripts showed that some transcripts [ri-bosomal proteins (RPS25, RPS11, RPS13, RPL30, RPL34, RPL27, RPS5), HINT1, HSP90AB1, SRSF9, EIF4G2, ILF2] were up-regulated in the normozoospermic group, but down-regulated in the asthenozoospermic group in comparison to the control group. Some transcripts were specific to the normozoospermic group (up-regulated: CAPNS1