Abnormal synapses and recombination in an azoospermic male carrier of a reciprocal translocation t(1;21).
OBJECTIVE
To study the meiotic abnormalities during prophase I in an azoospermic man with t(1;21) reciprocal translocation.


METHODS
Analysis of synapses, recombination, and transcription inactivation in a testicular biopsy sample.


METHODS
Research laboratory.


METHODS
One azoospermic patient with t(1;21) and five men with normal spermatogenesis.


METHODS
Immunostaining for SCP3, MLH1, and gamma-H2AX/BRCA1 was performed on biopsy to identify synapses, recombination, and transcriptional inactivation, respectively.


METHODS
Synapses, recombination, and transcriptional inactivation in meiosis I.


RESULTS
The t(1;21) carrier had a larger number of synaptonemal complexes with gaps and a lower rate (46%) of XY pairs with MLH1 foci than the controls (78%). The asynapsed quadrivalents, which were often associated with an XY body (84%), were frequently observed (96%) in pachytene cells of the translocation carrier. The variant histone gamma-H2AX and BRCA1 proteins were found to be located at the asynapsed quadrivalents.


CONCLUSIONS
These results suggest that impaired synaptic integrity of translocated chromosomes may affect synapses, recombination frequency of XY pairs, and transcriptional activation of asynapsed areas, and consequently may impair fertility in men.
Leng
Mei
M
Laboratory of Molecular and Cell Genetics, Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, People's Republic of China.
Li
Guangyuan
G
Zhong
Liangwen
L
Hou
Heli
H
Yu
Dexin
D
Shi
Qinghua
Q
D000328:Adult; D053713:Azoospermia / Q000235:genetics*; D016022:Case-Control Studies; D023902:Chromosome Pairing / Q000235:genetics; D002878:Chromosomes, Human, Pair 1; D002891:Chromosomes, Human, Pair 21; D006579:Heterozygote; D006801:Humans; D008297:Male; D049469:Meiotic Prophase I / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics; D014178:Translocation, Genetic