This work was funded by the National Natural Science Foundation of China (Nos. 81370748 and 30971598). The authors have no conflicts of interest.

Non-obstructive azoospermia (NOA) is a complex, multifactorial disease. Recent genome-wide association studies (GWAS) have identified eight NOA susceptibility loci at genome-wide significance of P < 5.0 × 10(-8) in Han Chinese from southeastern, northern, and central China. To better understand the role of the variants in conferring NOA risk, we selected four GWAS loci (HLA-DRA rs3129878, PRMT6 rs12097821, SOX5 rs10842262, and PEX10 rs2477686) that were reported before 2014 to investigate their association with NOA and their potential effects on sperm production in 1177 Han males from southwest China, including 545 patients with idiopathic NOA and 632 controls with normozoospermia. The results confirmed that the HLA-DRA rs3129878 was an NOA susceptibility locus in the present population. Along with our data, meta-analyses supported the association of the four GWAS-linked loci with NOA, whereas an additive effect of the four loci on NOA susceptibility was not found. Interestingly, the normozoospermic males with the risk genotypes of rs12097821 and rs3129878 + rs10842262 + rs12097821 were observed to have higher total sperm counts relative to non-risk genotypes, suggesting that the risk alleles of the genetic loci may not be via impairing spermatogenic ability to express susceptibility to NOA. These findings may advance our understanding of the role of the NOA susceptibility loci, although the results need to be confirmed in larger samples.

Testis-specific protein Y-linked 1 (TSPY1) is expressed predominantly in adult human spermatogonia and functions in the process of spermatogenesis; however, our understanding of the underlying mechanism is limited. Here we observed that TSPY1, as an interacting partner of TSPY-like 5 (TSPYL5), enhanced the competitive binding of TSPYL5 to ubiquitin-specific peptidase 7 (USP7) in conjunction with p53. This activity, together with its promotion of TSPYL5 expression by acting as a transcription factor, resulted in increased p53 ubiquitylation. Moreover, TSPY1 could decrease the p53 level by inducing the degradation of ubiquitinated USP7. We demonstrated that the promotion of p53 degradation by TSPY1 influenced the activity of p53 target molecules (CDK1, p21, and BAX) to expedite the G2/M phase transition and decrease cell apoptosis, accelerating cell proliferation. Taken together, the observations reveal the significance of TSPY1 as a suppressor of USP7-mediated p53 function in inhibiting p53-dependent cell proliferation arrest. By simulating TSPY1 function in Tspy1-deficient spermatogonia derived from mouse testes, we found that TSPY1 could promote spermatogonial proliferation by decreasing the Usp7-modulated p53 level. The findings suggest an additional mechanism underlying the regulation of spermatogonial p53 function, indicating the significance of TSPY1 in germline homeostasis maintenance and the potential of TSPY1 in regulating human spermatogonial proliferation via the USP7-mediated p53 signaling pathway.

Kawasaki disease (KD) is a dominant cause of acquired heart disease in children due to frequent complicating coronary artery lesions (CALs). Genome-wide association study and linkage analysis have recently identified 6 susceptibility loci at genome-wide significance of P < 5.0 × 10(-8) in subjects of Japanese, Taiwanese and European. In present study, we analysed the variants of 6 single nucleotide polymorphisms (SNPs) in the genetic loci to investigate their potential effect on KD susceptibility and outcomes in Han Chinese population. As a result, the risk alleles of rs1801274 and rs2254546 were observed significant effect on KD with higher frequencies in 358 patients than those in 815 controls. The significant role of rs1801274, rs2857151 and rs2254546 in KD was found in the multi-variable logistic regression analysis of the SNPs. Two 2-locus and one 3-locus combinations of the SNPs showed significant effect on KD with stronger association with KD relative to comparable single SNP or 2-locus combinations. Significant susceptibility to CALs was found in KD patients with high-risk genotypes at both rs1801274 and rs2857151. The meta-analyses first revealed significant risk for CALs in KD patients carrying risk allele of rs11340705, and the association of rs28493229 with KD was not observed in the Han Chinese. In conclusion, the findings demonstrated that 5 of the 6 genetic loci influence the risk for KD and 3 of them may be involved in secondary CALs formation in Han Chinese. The additive effects of 3 multi-locus combinations on KD/CALs imply that some loci may participate together in certain unknown gene networks related to KD/CALs. Further function studies of the genetic loci are helpful for better understanding the pathophysiology of KD.

AZFc deletions cause a significant phenotypic heterogeneity with respect to spermatogenesis; however, the reason for this is poorly understood. Recently, testis-specific protein Y-encoded 1 (TSPY1) copy number variation (CNV) was determined to be a potential genetic modifier of spermatogenesis. We performed a large-scale cohort study to investigate the effect of TSPY1 CNV on spermatogenesis and to elucidate the possible contribution of TSPY1 genetic variation to the phenotypic expression of AZFc deletions. Haplogrouping of the Y-chromosome and quantification of the TSPY1 copy number were performed in 2272 Han Chinese males with different spermatogenic statuses (704 males with the b2/b4 or gr/gr deletion and 1568 non-AZFc-deleted males). Our data revealed that the TSPY1 copy number distributions were significantly different among non-AZFc-deleted males with different spermatogenic phenotypes. Lower sperm production and an elevated risk of spermatogenic failure were observed in males with fewer than 21 TSPY1 copies and in those with more than 55 copies relative to men with 21-35 copies. Similar results were observed in males with the gr/gr deletion. These findings indicate that TSPY1 CNV affects an individual's susceptibility to spermatogenic failure by modulating the efficiency of spermatogenesis and strongly suggest that there is a significant quantity effect of the TSPY1 copy number on the phenotypic expression of the gr/gr deletion. To our knowledge, this CNV is the first independent genetic factor that has been clearly observed to influence the spermatogenic status of gr/gr deletion carriers. A combined genetic analysis of the TSPY1 copy number and the gr/gr deletion could inform the clinical counselling of infertile couples.