Abnormal synapses and recombination in an azoospermic male carrier of a reciprocal translocation t(1;21)
Received 9 August 2008; received in revised form 27 November 2008; accepted 10 December 2008. published online 09 February 2009.
Objective
To study the meiotic abnormalities during prophase I in an azoospermic man with t(1;21) reciprocal translocation.
Design
Analysis of synapses, recombination, and transcription inactivation in a testicular biopsy sample.
Setting
Research laboratory.
Patient(s)
One azoospermic patient with t(1;21) and five men with normal spermatogenesis.
Intervention(s)
Immunostaining for SCP3, MLH1, and γ-H2AX/BRCA1 was performed on biopsy to identify synapses, recombination, and transcriptional inactivation, respectively.
Main Outcome Measure(s)
Synapses, recombination, and transcriptional inactivation in meiosis I.
Result(s)
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 γ-H2AX and BRCA1 proteins were found to be located at the asynapsed quadrivalents.
Conclusion(s)
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.
aLaboratory 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
bDepartment of Urology, the First Affiliated Hospital, Anhui Medical University, Hefei, Anhui, People's Republic of China
Reprint requests: Qinghua Shi, Ph.D., 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, Hefei, Anhui 230027, China (FAX: +86-551-3600344).
M.L. has nothing to disclose. G.L. has nothing to disclose. L.Z. has nothing to disclose. H.H. has nothing to disclose. D.Y. has nothing to disclose. Q.S. has nothing to disclose.
Supported by the National Basic Research Program (2006CB504003, 2007CB947401) of China (973), the Program of “One Hundred Talented People” (KJ207004) of Chinese Academy of Sciences and the Program of Knowledge Innovation (KSCX1-YW-R-51) of Chinese Academy of Sciences.
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