Sperm RNA quantity and PRM1, PRM2, and TH2B transcript levels reflect sperm characteristics and early embryonic development

Abstract

Abstract Spermatozoa have a highly complex RNA profile. Several of these transcripts are suggested as biomarkers for male infertility and contribute to early development. To analyze the differences between sperm RNA quantity and expression of protamine (PRM1 and PRM2) and testis-specific histone 2B (TH2B) genes, spermatozoa from 33 patients who enrolled in assisted reproduction treatment (ART) program were analyzed. Sperm RNA of teratozoospermic (T), oligoteratozoospermic (OT), and normozoospermic (N) samples was extracted, and the differences in transcript levels among the study groups were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). The correlations of total RNA per spermatozoon and the expression of the transcripts were evaluated in relation to sperm characteristics and preimplantation embryo development. The mean (±standard deviation) RNA amount per spermatozoon was 28.48 (±23.03) femtogram in the overall group and was significantly higher in the OT group than that in N and T groups. Total sperm RNA and gene expression of PRM1 and PRM2 genes were related to preimplantation embryo development and developmental arrest. Specific sperm characteristics were correlated with the expressions of PRM1, PRM2, or TH2B genes. We conclude that the sperm RNA amount and composition are important factors and might influence early embryonic development and also differ in different cases of male infertility.