Deletion and testicular expression of DAZ [deleted in azoospermia] gene in patients with non-obstructive azoospermia

Deletions of the DAZ [deleted in azoospermia] genes within the human Y chromosome's AZFc region are the most common cause of spermatogenesis failure. These deletions are usually assessed by analyses of genomic DNA extracted from peripheral leukocytes. DAZ genes are expressed in male germ cells. In this prospective study, we investigated DAZ expression and deletion in 102 consecutive infertile men presenting with non-obstructive azoospermia in Avesina Research Institute, Tehran, Iran during 2005-6. In this prospective study, we extracted genomic DNA from peripheral blood leukocytes for detection of DAZ deletions and testicular biopsies for histopathological assessment and analyses of DAZ expression level by reverse transcription polymerase chain reaction. DAZ levels were normalized to expression of the housekeeping Phosphoglucomutase 1 gene. In four out of 102 patients [3.9%], we found DAZ deletion. DAZ expression was observed in 60 [61.2%] of 98 other patients. Expression was not detected in patient with Sertoli cell-only syndrome, but observed in 37 of 40 [92.5%] patients with maturation arrest and 20 of 26 [76.9%] with hypospermatogenesis. The absence of DAZ expression could result in quantitative reduction of germ cells and might be observed despite of normal genomic DNA constitution. We recommend to check DAZ testicular expression and genomic DNA deletion, in non-obstructive azoospermia. This is more recommended to avoid transmission of genetic abnormalities which might lead to infertility in male offspring, when assisted reproductive techniques [ART] are performed

Expression of synaptonemal complex protein 3 [SYCP3] m RNAin the testis: a molecular marker for spermatogenesis in azoospermic men

Men with unexplained infertility and azoospermia are often observed in the context of genetic defects. The expression of a wide variety of genes is developmentally regulated during human meiosis. Synaptonemal Protein 3 [SYCP3] gene, located on chromosome 12, encodes a DNA-binding protein as the structural component of the synaptonemal complex,which mediates the synopsis or homologous pairing of chromosomes during meiosis. Absence of SYCP3 in mice may lead to male infertility as well as female sub-fertility. SYCP3 expression analysis could be a tool for the prediction of human spermatogenesis progression, especially in infertile men. SYCP3 mRNA expression in testicular samples of 110 patients with non-obstructive azoospermia were studied in Avesina Infertility Clinic in Tehran, Iran during 2005 and early 2006. Semi-quantitative nested reverse transcriptase-PCR was employed in order to find the strength of gene expression. Using histopathological scoring for all samples, the expression level of SYCP3 during spermatogenesis was also evaluated. Testicular SYCP3 mRNA expression was observed in 67 patients [60.9%]. The expression level correlated with the degree of spermatogenic failure [p<0.0001]. While this gene had been expressed in patients with hypo-spermatogenesis and maturation arrest, a lack of expression was seen in those with spermatogonial arrest, Sertoli cell-only syndrome and testicular atrophy. These data indicate that SYCP3 is expressed in the human testis and it is restricted to germ cells. Our findings, in association with those obtained in experimental animals, show that lack of SYCP3 expression may have negative effects on spermatogenesis and male fertility. SYCP3 gene expression may help detect specific spermatogenesis stages in conjunction with histopathological findings