Novel mutations in ubiquitin-specific protease 26 gene might cause spermatogenesis impairment and male infertility.
OBJECTIVE
To study the incidence of single nucleotide polymorphisms in ubiquitin-specific protease 26 (USP26) gene and its involvement in idiopathic male infertility in China.


METHODS
Routine semen analysis was performed. Infertility factors such as immunological, infectious and biochemical disorders were examined to select patients with idiopathic infertility. DNA was isolated from peripheral blood of the selected patients and control population, which were examined for mutations using polymerase chain reaction-single strand conformation polymorphism analysis. Furthermore, nucleotide sequences were sequenced in some patients and controls.


RESULTS
Of 41 infertile men, 9 (22.0%, P = 0.01) had changes in USP26 gene on the X chromosome. A compound mutation (364insACA; 460G right triple arrow A) was detected in 8 patients (19.5%, P = 0.01) and a 1044T right triple arrow A substitution was found in 1 patient (2.4%, P > 0.05). All three variations led to changes in the coding amino acids. Two substitutions predict some changes: 460G right triple arrow A changes a valine into an isoleucine, and 1044T right triple arrow A substitutes a leucine for a phenylalanine. Another insertion of three nucleotides ACA causes an insertion of threonine. No other changes were found in the remaining patients and fertile controls.


CONCLUSIONS
The USP26 gene might be of importance in male reproduction. Mutations in this gene might be associated with male infertility, and might negatively affect testicular function. Further research on this issue is in progress.
Zhang
Jie
J
Department of Anatomy, Histology and Embryology, Medical College of Xi'an Jiaotong University, Xi'an 710061, China.
Qiu
Shu-Dong
SD
Li
Sheng-Bin
SB
Zhou
Dang-Xia
DX
Tian
Hong
H
Huo
Yong-Wei
YW
Ge
Ling
L
Zhang
Qiu-Yang
QY
D044466:Asian People / Q000208:ethnology / Q000235:genetics; D016022:Case-Control Studies; D002681:China; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism; D010450:Endopeptidases / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D015994:Incidence; D007248:Infertility, Male / Q000208:ethnology / Q000235:genetics*; D007985:Leydig Cells / Q000378:metabolism; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012708:Sertoli Cells / Q000378:metabolism; D013091:Spermatogenesis / Q000235:genetics*; D013737:Testis / Q000378:metabolism; D064570:Ubiquitin-Specific Proteases
D012333:RNA, Messenger; C501866:USP26 protein, human; D010450:Endopeptidases; D064570:Ubiquitin-Specific Proteases; D003546:Cysteine Endopeptidases