Evaluation of the effectiveness of semen storage and sperm purification methods for spermatozoa transcript profiling

Different semen storage and sperm purification methods may affect the integrity of isolated spermatozoal RNA. RNA-Seq was applied to determine whether semen storage methods (pelleted vs. liquefied) and somatic cell lysis buffer (SCLB) vs. PureSperm (PS) purification methods affect the quantity and quality of sperm RNA. The results indicate that the method of semen storage does not markedly impact RNA profiling whereas the choice of purification can yield significant differences. RNA-Seq showed that the majority of mitochondrial and mid-piece associated transcripts were lost after SCLB purification, which indicated that the mid-piece of spermatozoa may have been compromised. In addition, the number of stable transcript pairs from SCLB-samples was less than that from the PS samples. This study supports the view that PS purification better maintains the integrity of spermatozoal RNAs.