[Abnormalities of meiotic recombination in Han Chinese azoospermic patients].
OBJECTIVE
To analyze defective homologous chromosomal recombination in Han Chinese azoospermic patients.


METHODS
Testicular biopsy samples from 7 healthy controls and 7 Han Chinese azoospermic patients including 2 obstructive azoospermia (OA group) and 5 non-obstructive azoospermia (NOA group) were analyzed. Immunofluorescence staining was performed to categorize early stage cells at meiosis prophase and to analyze chromosome pairing and recombination of pachytene spermatocyte. Newly developed meiotic proteins antibodies (anti-SCP3, anti-synaptonemal complex proteins 3, anti-MLH1, anti-Mut-L Homolog 1, anti-CREST, chromosome centromere antibody) were used to identify synaptonemal complex (anti-SCP3), recombination sites (anti-MLH1) and centromere (anti-CREST), respectively. Staging of spermatocyte was determined according to SCP3 formation progression. Qualitative data were compared by a Chi-square test, and ANOVA was used to analyze quantitative data.


RESULTS
Respectively, 2346 and 2932 spermatocytes were categorized in the controls and azoospermic patients. The proportions of zygotene cells in both OA group and NOA group were significantly higher than that of the control group. Investigation of 1967 pachytene cells from the controls and 354 pachytene cells from azoospermic patients indicated that the mean MLH1 foci per pachytene cell of NOA group was statistically lower than that of the controls. Compared with the controls, incomplete synaptonemal complexes cells (containing gap and/or split) were significantly increased in the NOA group.


CONCLUSIONS
Delayed meiosis prophase is relatively common in azoospermic patients, and changes in quantity and distribution of recombination foci may be the cause for spermatogenesis arrest in Han Chinese population.
Reproductive Medicine Center, the First Affiliated Hospital, Anhui Medical University, Hefei, Anhui 230022, P. R. China.
Xiao-jin
XJ
He
Qing-ling
QL
Yang
Zhen-zhen
ZZ
Pan
Huan
H
Wu
Liu
L
Wang
Qing-hua
QH
Shi
Ji-hua
JH
Zhao
Yun-xia
YX
Cao
D000328:Adult; D044466:Asian People; D053713:Azoospermia / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008297:Male; D008540:Meiosis / Q000235:genetics*; D008875:Middle Aged; D011995:Recombination, Genetic; D013090:Spermatocytes / Q000378:metabolism; D013573:Synaptonemal Complex / Q000235:genetics; D055815:Young Adult