title: Altered bivalent positioning in metaphase I human spermatocytes from Robertsonian translocation carriers.
abstract: OBJECTIVE
  The study aims to determine whether there is an altered bivalent positioning in metaphase I human spermatocytes from Robertsonian translocation carriers.
  
  
  METHODS
  Metaphase I human spermatocytes from three 45,XY,der(13;14)(q10;q10) individuals and a 45,XY,der(14;15)(q10;q10) individual were analyzed. Proximity relationships of bivalents were established by analyzing meiotic preparations combining Leishman staining and multiplex-FISH procedures. Poisson regression model was used to determine proximity frequencies between bivalents and to assess associations with chromosome size, gene density, acrocentric morphology, and chromosomes with heterochromatic blocks. The hierarchical cluster Ward method was used to characterize the groups of bivalents with preferred proximities in a cluster analysis. Bivalent groups obtained were individually compared with those obtained in normal karyotype individuals evaluated in a previous study.
  
  
  RESULTS
  A total of 1288 bivalents were examined, giving a total of 2289 proximity data. Only four positive significant proximities were detected for each type of Robertsonian translocation. Significant bivalent associations were only observed by small-size chromosomes for MI,22,XY,III(13q14q). These results were clearly divergent from 46,XY individuals. Moreover, cluster analysis revealed that about 30 % of the bivalents showed changes in their proximity relationships in metaphase I.
  
  
  CONCLUSIONS
  The territorial organization of bivalents in metaphase I human spermatocytes changes in the presence of a Robertsonian translocation.
authors.affiliation: Genetics of Male Fertility Group. Unitat de Biologia Cel·lular. Departament de Biologia Cel·lular, Fisiologia i Immunologia. Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, (Cerdanyola del Vallès), 08193, Spain.
authors.forename: Mireia
authors.initials: M
authors.lastname: Solé
authors.affiliation: Genetics of Male Fertility Group. Unitat de Biologia Cel·lular. Departament de Biologia Cel·lular, Fisiologia i Immunologia. Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, (Cerdanyola del Vallès), 08193, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Blanco
authors.affiliation: Servei d'Estadística Aplicada, Universitat Autònoma de Barcelona, Bellaterra, (Cerdanyola del Vallès), 08193, Spain.
authors.forename: Oliver
authors.initials: O
authors.lastname: Valero
authors.affiliation: Genetics of Male Fertility Group. Unitat de Biologia Cel·lular. Departament de Biologia Cel·lular, Fisiologia i Immunologia. Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, (Cerdanyola del Vallès), 08193, Spain.
authors.forename: Laia
authors.initials: L
authors.lastname: Vergés
authors.affiliation: Genetics of Male Fertility Group. Unitat de Biologia Cel·lular. Departament de Biologia Cel·lular, Fisiologia i Immunologia. Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, (Cerdanyola del Vallès), 08193, Spain.
authors.forename: Francesca
authors.initials: F
authors.lastname: Vidal
authors.affiliation: Genetics of Male Fertility Group. Unitat de Biologia Cel·lular. Departament de Biologia Cel·lular, Fisiologia i Immunologia. Facultat de Biociències, Universitat Autònoma de Barcelona, Bellaterra, (Cerdanyola del Vallès), 08193, Spain. Zaida.Sarrate@uab.cat.
authors.forename: Zaida
authors.initials: Z
authors.lastname: Sarrate
mesh_terms: D059786:Abnormal Karyotype; D000328:Adult; D002875:Chromosomes / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007248:Infertility, Male / Q000235:genetics* / Q000473:pathology; D007621:Karyotyping / Q000379:methods; D008297:Male; D008540:Meiosis / Q000235:genetics; D008677:Metaphase; D013090:Spermatocytes / Q000473:pathology*; D013094:Spermatozoa / Q000473:pathology; D014178:Translocation, Genetic
keywords: Chromosome territories; Meiosis; Metaphase I; Robertsonian translocation; Spermatocytes