| Objective: Nearly 11% of all infertile men have idio- pathic azoospermia or oligozoospermia. To get rid of the affliction of patients with such diseases, learners are taking up with studying the mechanism of spermatogenesis and clearifing the pathophysiology mechanism of spermato- genesis impediment. It is indicated through molecular bio- logy and cell genetics in recent years that spermatogenesis is controlled by correlative genes. There is a gene family (azoospermia factor, AZF) on Yq11,23, deletions of many genes of which can cause severe spermatogenesis im- pediment. DAZ gene is considered as the most important candidate and its deletion can lead to spermatogenesis impediment from azoospermia to oligozoospermia. The sub- ject is to study the critical effect of DAZ gene on spermato- genesis and the correlation of DAZ gene and idiopathic azoo- spermia or oligozoospermia.Methods: Peripheral blood samples were got from 27 azoospermia patients, 13 idiopathic oligozoospermia patients and 40 normal fertile men. There were 3 azoospermia pa- tients diagnosed Klinefelter's sydrome and other 3 azoo- spermia patients had abnormal karyotypes. The diagnoses ofazoospermia were according to the standard of WHO. The oligozoospermia is that whose sperm number is not up to 10 million per ml. The genomic DNA of every sample was obtained, then DAZ gene was amplified through polymerase chain reaction. The primers are SY277. The product was visualized using ultraviolet transillumination, the size of which was 275 bp. The deletion of DAZ gene was considered by three successive negative results. The negative samples were tested again by multiple polymerase chain reaction. Two pairs of primers of SY277 and SY 14 were added to the reaction system. SY14 gene was an inside control, the size of which was 472bp. The two genes were amplified stenuously. Thus any factor influcing PCR had effect on the two genes' amplification stinuously. Through this method the influence of genomic DNA, reaction system and odd error could be excluded. The results of the subject were more faithful.Results: three patients with DAZ gene deleted were found, who are all idiopathic azoospermia with normal karyotype. It accounted for 14.3%(3/21) of idiopathic azoo- spermia, which was in accordance with the public reports (5~16%). There was no deletion of DAZ gene in 40 normal fertile men. It was indicated that DAZ gene might play a role during the course of spermatogenesis and the deletion of DAZ gene could cause idiopathic azoospermia, which was an important reason of azoospermia. The testis biopsy of one patient with DAZ gene deleted was defective spermatogene-sis with lack of spermatocyte, which tallied with public reports and indicated the relationship of DAZ gene and the spermatogenesis function of testis. It is reported that there are deletions of DAZ gene in idiopathic oligozoospermia, but it is only in severe oligozoospermia, the deletion rates is 6~14.3%. In our subject 13 oligozoospermia was only in- cluding 3 severe oligozoospermia and no DAZ deletion was detected, which demonstrated that there was no deletions in gently or moderately defective spermatogenesis. The study of Tateno indicates that it is not the microdeletions of Yq but many mechanisms and many factors that arouse the severe spermatogenesis impediment in Klinefelter's syndrome. No deletions of DAZ gene were found in our three Klinefelter's sydromes. The number of sample was so small that there was no significance by itself, but it supported the conclusion of Tateno.Conclusions: The subject detected the DAZ gene in idiopathic azoospermia by PCR. The result was many deletions in them and no deletions in normal fertile men. It posted that DAZ gene play an important role during the course of spermatogenesis, which is a critical conditions of spermatogenesis and one of the reasons for infertility of men. Detecting DAZ gene of idiopathic azoospermia can help them find their pathogeny in case that they search for treatment blindfoldly doing damages not only in econom...
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