title: Altered segregation pattern and numerical chromosome abnormalities interrelate in spermatozoa from Robertsonian translocation carriers.
abstract: The aim of this study was to assess whether there is a relationship between numerical chromosome abnormalities and certain segregation modes in spermatozoa from Robertsonian translocation carriers. A sequential fluorescence in-situ hybridization protocol based on two successive hybridization rounds was performed on sperm samples from one t(13;22) and ten t(13;14) carriers. Patient inclusion criteria included the presence of a positive interchromosomal effect (ICE). In the first round, numerical abnormalities for chromosomes 15/22, 18, 21, X and Y were analysed. In the second round, the segregation outcome of the rearranged chromosomes was evaluated in the numerically abnormal spermatozoa detected in the first round, as well as in randomly assessed spermatozoa. Aneuploid spermatozoa showed statistical differences in all segregation modes when compared with randomly assessed spermatozoa: alternate (50.7% versus 84.3%), adjacent (36.6% versus 14.6%) and 3:0 (10.2% versus 1%). Diploid/multiple disomic spermatozoa showed differences in alternate (3.7% versus 84.3%) and 3:0 (67.6% versus 1%). We concluded that in Robertsonian translocation carriers that exhibit ICE, numerically abnormal spermatozoa preferentially contain unbalanced segregation products. This might be explained by heterosynapsis acting as a rescue mechanism that would lead to aberrant recombination, which is a predisposing factor for non-disjunction events.
authors.affiliation: Genetics of Male Fertility Group, Unitat de Biologia Cel⋅lular (Facultat de Biociències), Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Godo
authors.affiliation: Genetics of Male Fertility Group, Unitat de Biologia Cel⋅lular (Facultat de Biociències), Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Blanco
authors.affiliation: Genetics of Male Fertility Group, Unitat de Biologia Cel⋅lular (Facultat de Biociències), Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain.
authors.forename: Francesca
authors.initials: F
authors.lastname: Vidal
authors.affiliation: Reprogenetics Spain, Carrer Tuset, 23, 08006 Barcelona, Spain.
authors.forename: Mireia
authors.initials: M
authors.lastname: Sandalinas
authors.affiliation: Reprogenetics Spain, Carrer Tuset, 23, 08006 Barcelona, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Garcia-Guixé
authors.affiliation: Genetics of Male Fertility Group, Unitat de Biologia Cel⋅lular (Facultat de Biociències), Universitat Autònoma de Barcelona, 08193 Bellaterra, Cerdanyola del Vallès, Spain. Electronic address: ester.anton@uab.cat.
authors.forename: Ester
authors.initials: E
authors.lastname: Anton
mesh_terms: D000782:Aneuploidy; D002869:Chromosome Aberrations; D020090:Chromosome Segregation; D002877:Chromosomes, Human / Q000378:metabolism; D006579:Heterozygote; D006801:Humans; D007248:Infertility, Male / Q000235:genetics; D008297:Male; D013094:Spermatozoa / Q000648:ultrastructure*; D014178:Translocation, Genetic
keywords: ICE; Robertsonian translocation; segregation pattern; sequential FISH; spermatozoa