Department of Genetics at Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
J Assist Reprod Genet. 2013 Jul;30(7):923-31. doi: 10.1007/s10815-013-0027-9. Epub 2013 Jun 19.
The human X chromosome is enriched with testis-specific genes that may be crucial for male fertility. Mutations in USP26 gene have been proposed to be associated with male infertility. Moreover, the importance of the ubiquitin pathway during different stages of mammalian fertilization and even embryo development has been addressed. Some mutations and haplotypes on this gene have been proposed to be associated with male infertility. In this study, five different mutations on USP26 were investigated: 1737 G > A, 1090 C > T, 370-371ins ACA, 494 T > C and 1423 C > T.
The study included 166 infertile men with non-obstructive azoospermia, 72 male partners of couples who had previously experienced ≥3 clinical first trimester spontaneous abortions and 60 fertile men. Besides family history of reproduction, hormonal evaluation and semen analysis were performed. DNA was extracted from blood samples. PCR-SSCP, PCR-RFLP and PCR Product Cloning methods were used and resumed by sequencing to insure about the mutations. Moreover, USP26 gene expression was studied by Real-Time PCR after RNA extraction followed by cDNA synthesis from 24 testis biopsies in obstructive and non-obstructive azoospermia patients.
The results indicate that there is a haplotype between three observed mutations in Iranian population include: 370-371insACA, 1423C > T and 494 T > C. This haplotype was seen in control group as well. Surprisingly, total frequency of mutations in men with history of idiopathic RPL and azoospermic cases were significantly higher than that of in control groups (p < 0.05). Serum testosterone concentrations and testicular volume did not differ in the mutation positive group compared with the non-mutation group. About the USP26 gene expression, there is a significant difference between the expression levels of obstructive azoospermia, complete maturation arrest samples and SCO samples (P < 0.05).
According to our results, the USP26 gene may play an important role in male reproduction. The alterations of this gene may be involved in male infertility and RPL in Iranian population and may negatively affect testicular function.
人类 X 染色体富含睾丸特异性基因，这些基因可能对男性生育能力至关重要。USP26 基因突变被认为与男性不育有关。此外，在哺乳动物受精的不同阶段甚至胚胎发育过程中，泛素途径的重要性已经得到了阐述。该基因的一些突变和单倍型被认为与男性不育有关。在这项研究中，我们研究了 USP26 上的五个不同突变：1737G > A、1090C > T、370-371insACA、494T > C 和 1423C > T。
这项研究包括 166 名非梗阻性无精子症的不育男性、72 名曾经历过≥3 次临床早期自然流产的夫妇中的男性伴侣和 60 名生育能力正常的男性。除了生育史外，还进行了激素评估和精液分析。从血液样本中提取 DNA。使用 PCR-SSCP、PCR-RFLP 和 PCR 产物克隆方法，并通过测序进行了重新分析，以确保突变的存在。此外，从 24 例梗阻性和非梗阻性无精子症患者的睾丸活检中提取 RNA 并合成 cDNA 后，通过实时 PCR 研究了 USP26 基因的表达。
结果表明，在伊朗人群中，三个观察到的突变（370-371insACA、1423C > T 和 494T > C）之间存在单倍型。该单倍型也存在于对照组中。令人惊讶的是，有不明原因习惯性流产史和无精子症患者的突变总频率明显高于对照组（p < 0.05）。与非突变组相比，突变阳性组的血清睾酮浓度和睾丸体积无差异。关于 USP26 基因的表达，在梗阻性无精子症、完全成熟阻滞样本和 SCO 样本之间存在显著差异（P < 0.05）。
根据我们的结果，USP26 基因可能在男性生殖中发挥重要作用。该基因的改变可能与伊朗人群中的男性不育和习惯性流产有关，并可能对睾丸功能产生负面影响。
