2002 年 17 巻 2 号 p. 1-7
The genetic basis of infertility remains unclear in a majority of infertile men. In this study, Y chromosome long arm involving DAZ (Deleted in Azoospermia) was screened in order to evaluate the occurrence of microdeletion in Japanese infertile men. 197 infertile Japanese men with azoospermia and oligozoospermia were analyzed for microdeletions of the Azoospermia factor (AZF) c region of the Y chromosome by using polymerase chain reaction with sequence-tagged site markers. The 16 sets of oligonucleotides primer were synthesized for polymerase chain reaction, and southern blot analysis was also performed. All analyzed infertile men were divided into 5 categories on the basis of sperm concentration: functional azoospermia (A) 28, azoospermia due to obstruction (AO) 20, oligozoospermia I (OI) (less than 1×105/ml) 49, oligozoospermia II (OII) (less than 1×106/ml) 50 and oligozoospermia III (OIII) (less than 1×107/ml) 50. 30 fertile men with sperm concentration of more than 2×107/ml were also analyzed as control. In 15 (7.6%) of 197 infertile men, microdeletions were identified as follow: 1 in category A, 1 in category AO, 6 in category OI, 6 in category OII and 1 in category OIII. On the other hand, no deletion was identified in fertile men. One common region around sY240 was identified through 14 infertile men with microdeletions. This locus might contain specific genes for spermatogenesis. Sperm concentrations of 13 oligozoospermic men with microdeletions were below 1×106/ml. There was no correlation between the severity of spermatogenesis and the extent of microdeletions. These results suggested that genes in the AZFc region of the Y chromosome might be important roles for spermatogenesis.
