title: Meiotic recombination, synapsis, meiotic inactivation and sperm aneuploidy in a chromosome 1 inversion carrier.
abstract: Disrupted meiotic behaviour of inversion carriers may be responsible for suboptimal sperm parameters in these carriers. This study investigated meiotic recombination, synapsis, transcriptional silencing and chromosome segregation effects in a pericentric inv(1) carrier. Recombination (MLH1), synapsis (SYCP1, SYCP3) and transcriptional inactivation (γH2AX, BRCA1) were examined by fluorescence immunostaining. Chromosome specific rates of recombination were determined by fluorescence in-situ hybridization. Furthermore, testicular sperm was examined for aneuploidy and segregation of the inv(1). Our findings showed that global recombination rates were similar to controls. Recombination on the inv(1) and the sex chromosomes were reduced. The inv(1) associated with the XY body in 43.4% of cells, in which XY recombination was disproportionately absent, and 94.3% of cells displayed asynapsed regions which displayed meiotic silencing regardless of their association with the XY body. Furthermore, a low frequency of chromosomal imbalance was observed in spermatozoa (3.4%). Our results suggest that certain inversion carriers may display unimpaired global recombination and impaired recombination on the involved and the sex chromosomes during meiosis. Asynapsis or inversion-loop formation in the inverted region may be responsible for impaired spermatogenesis and may prevent sperm-chromosome imbalance.
authors: Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, BC, Canada V6H-3N1.
authors: Gordon
authors: G
authors: Kirkpatrick
authors: Victor
authors: V
authors: Chow
authors: Sai
authors: S
authors: Ma
mesh_terms: D000328:Adult; D000782:Aneuploidy; D002843:Chromatin / Q000378:metabolism; D007446:Chromosome Inversion; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D015321:Gene Rearrangement; D020868:Gene Silencing; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007248:Infertility, Male / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D008540:Meiosis; D008856:Microscopy, Fluorescence / Q000379:methods; D008875:Middle Aged; D011995:Recombination, Genetic; D013094:Spermatozoa / Q000473:pathology*
chemical_list: D002843:Chromatin