title: Three dimensional reconstruction of quadrivalents and mapping of translocation breakpoints of the mouse translocations T(2;8) 26H and T(9;17)138Ca.
abstract: Three dimensional reconstruction from electron micrographs of serial sections reveals 18 synaptonemal complexes and a cross-shaped quadrivalent in the mouse pachytene oocytes of the heterozygous reciprocal translocations T(2;8)26H and T(9;17)138Ca. The unambiguous identification of translocation breakpoints on the quadrivalents has allowed the mapping of the translocation breakpoints on the chromosomes. The translocation breakpoints of T(2;8)26H are mapped at 73% and 45% from the telocentric centromeres of chromosomes 2 and 8, while those of T(9;17)138Ca are mapped at 41% and 45% from the telocentric centromeres of chromosomes 9 and 17 respectively. This report represents the first study of serial section reconstruction of a mammalian oocyte.
mesh_terms: D000818:Animals; D002874:Chromosome Mapping; D002875:Chromosomes / Q000648:ultrastructure*; D005260:Female; D008297:Male; D008540:Meiosis; D051379:Mice; D008854:Microscopy, Electron; D009865:Oocytes / Q000648:ultrastructure; D013090:Spermatocytes / Q000648:ultrastructure; D014178:Translocation, Genetic