title: Meiotic arrest at the midpachytene stage in a patient with complete azoospermia factor b deletion of the Y chromosome.
abstract: OBJECTIVE
  To study the meiosis of a patient with complete azoospermia factor (AZF)b deletion of the Y chromosome.
  
  
  METHODS
  Case report.
  
  
  METHODS
  La Conception University Hospital, Marseille, France.
  
  
  METHODS
  One azoospermic patient.
  
  
  METHODS
  Yq deletion testing, testicular sperm extraction, and meiotic study with immunocytochemistry.
  
  
  METHODS
  Abnormal synapsis rates in spermatocytes.
  
  
  RESULTS
  We found that most spermatocytes were at an early stage of meiosis. Half of the meiotic germ cells analyzed showed asynapsis, which was mostly extended or total. Discontinuity in the synaptonemal complex was seen in one third of the meiotic cells analyzed. An unusually small number of normal pachytene nuclei were found, all at early pachytene substages.
  
  
  CONCLUSIONS
  This is the first demonstration that the synaptic process is impaired in a man with complete deletion of the AZFb interval. Our findings provide evidence that the pachytene checkpoint is situated at the midpachytene substage in humans.
authors.affiliation: Laboratoire de Biologie de la Reproduction, Assistance Publique of Marseille (AP-HM) La Conception, Marseille, France.
authors.forename: Jeanne
authors.initials: J
authors.lastname: Perrin
authors.forename: Catherine
authors.initials: C
authors.lastname: Metzler-Guillemain
authors.forename: Gilles
authors.initials: G
authors.lastname: Karsenty
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Grillo
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mitchell
authors.forename: Marie-Roberte
authors.initials: MR
authors.lastname: Guichaoua
mesh_terms: D000328:Adult; D041322:Chromosomes, Human, Y; D017353:Gene Deletion; D056426:Genetic Loci; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008540:Meiosis; D009845:Oligospermia / Q000235:genetics* / Q000473:pathology*; D029589:Seminal Plasma Proteins / Q000235:genetics*; D012729:Sex Chromosome Aberrations; D013094:Spermatozoa / Q000473:pathology
chemical_list: D029589:Seminal Plasma Proteins