Sperm samples (SS) from infertile patients (IP) undergoing intracytoplasmic sperm injection (ICSI) or intrauterine insemination (IUI) show profound different expression profiles (EP)

Abstract

OBJECTIVE: Basic SS analysis presents limited predictive power on pregnancy achievement by assisted reproductive techniques (ARTs). Other molecular factors as mRNA present within spermatozoa have recently been described. Our group listed genes differentially expressed (GDE) from SS from pregnant (group P) vs. those non pregnant (group NP) by microarray technology in couples undergoing homologous IUI and ICSI. Our aim is to characterize differential gene EP between SS achieving or not pregnancy in ICSI and IUI cycles. DESIGN: Nested cases and controls study, where 10 SS (5 that achieved pregnancy and 5 failing to conceive) were obtained from IP undergoing IUI with healthy female partners and ICSI cycle with oocytes from young donors. After freezing aliquots of the SS employed for both treatments we compared their respective mRNA expression profiles. Finally 4 microarrays in duplicate were performed with sperm samples from group P vs. NP from both techniques. MATERIALS AND METHODS: SS mRNA was extracted using Trizol, suspended in DEPC-treated water and frozen at -80ºC until the microarray experiments were performed. RNAs were analyzed on Agilent Bioanalyzer 2100 and those genes differentially expressed (GDE) at least twice, with statistically significant differences between P and NP in IUI and ICSI SS were listed and compared. RESULTS: Total number of genes expressed (TNG) in IUI microarray was 19938 and 19229 in ICSI. About 70 % of TNG was common in both procedures. Around 50% of GDE in group P of ICSI group were GDE in group P from IUI group too. There are more GDE (950) in IUI group compared with ICSI group (49). CONCLUSIONS: These data reveals that sperm EP is consistent and molecular features required to pregnant are different in IUI and ICSI procedures. These differences could be potentially employed to detect ICSI and IUI success markers, although it needs to be further explored in order to figure out their biological roles.