Study of AZFc partial deletion gr/gr in fertile and infertile Japanese males

Abstract

A recurrent partial azoospermia factor C (AZFc) deletion, called gr/gr, has been reported to be a male infertility risk factor. A specific type of Y chromosome observed in approximately 30% of Japanese males (haplogroup D derived at YAP+) is believed to have a fixed gr/gr deletion. A recent study claimed that spermatogenic failure is more likely in males with D Y chromosomes, because of the gr/gr deletion, the presence of which is not well characterized among D haplogroup chromosomes. We therefore decided to perform a systematic study of the frequency of the gr/gr deletion in the Japanese. We studied fertile and infertile males to investigate the possibility of different gr/gr frequencies. The deletions were detected by use of single tagged-sequences (STSs) and the D haplogroup sub-lineages typing were done by use of the biallelic markers M174, M64, M116.1, 12f2.2, M15, M151, and M125. Analysis of gr/gr deleted Y chromosomes showed that all are classified as haplogroup D2, suggesting a lineage association. The subtype D2b1 was most frequent among the Japanese, in control and infertile samples. The haplogroups D2b2, D*, and D1 were not found in any population group. Remarkably, we observed no statistical difference between haplogroup D sub-lineages of the infertile and control groups, although the statistical power of this study is low. This study suggests lack of significant evidence of increased infertility risk in haplogroup D Japanese males. We were also able to establish the ancestral chromosome that suffered a gr/gr deletion, and propose a new Y chromosome phylogeny for haplogroup D and its derivatives. In summary, we were able to define the frequency of gr/gr deletion in Japanese males and show that the gr/gr deletion was probably present in the ancestral Y chromosome that entered Japan at least 12,000 years ago.

Climatic influence on the reproductive characteristics of Japanese males

“…1 In a previous report, it was found that the 12f2.2 and M125 markers belong to the same lineage. 17 Our data analysis produced the same results (data not shown). Therefore, we considered the 12f2.2 allele to represent the D2a1 lineage ( Figure 1).…”

Investigation of AZF microdeletions in patients with Klinefelter syndrome

“…(2004) found that in France, the deletion rate of gr/gr was 6% in male infertility patients and was 3.5% in controls, but no significant difference between groups was observed (P > 0.05). Chinese (Wu et al, 2007) and Japanese (de Carvalho et al, 2006) researchers reached the same conclusion, while studies in India revealed that the gr/gr deletion was a risk factor for spermatogenic failure (Shahid et al, 2011). b2/b3 deletion is another common type of partial AZFc deletion; the length of the deleted DNA is 1.8 Mb, and the deleted DNA includes 12 testis-specific expression genes and transcripts.…”

“…There are 3 types of gr/gr deletions: the g1/g2 deletion involving a missing a DAZ copy (DAZ1/DAZ2), whereas the r1/r3 and r2/r4 deletions involve DAZ1/ DAZ2 deletions, even more sophisticated copy deletions, and all 3 types contains deletion of SY1291. According to previous studies, the rate of gr/gr deletion may differ among population groups (Machev, 2004;de Carvalho et al, 2006;Wu et al, 2007;Shahid et al, 2011). The association between the gr/gr deletion and male infertility is not well understood.…”

Molecular Characterization of Some Genetic Factors Controlling Spermatogenesis in Egyptian Patients with Male Infertility

“…The AZFc rearrangement analysis results were interpreted according to Table 2. [11][12][13][14] Detailed sequences of the all primers that used in molecular studies were given in Table 3.…”