title: A case of spontaneous trisomy in the spermatocytes of Microtus arvalis.
abstract: A triple synaptomal complex was observed between 3 small-sized chromosomes in 4 spermatocytes closely connected by intercellular bridges, of the common vole (Microtus arvalis L.). Other spermatocytes from the same and from 2 other males had a normal chromosome complement and pairing patterns. This finding was interpreted as the result of a single act of non-disjunction taking place in a spermatogonium. These data suggest that chromosome non-disjunction in premeiotic germ cells can be considered one of the causes of aneuploidy in mammals.
authors.affiliation: Institute of Cytology and Genetics, Academy of Sciences of the U.S.S.R. Siberian Department, Novosibirsk.
authors.forename: P M
authors.initials: PM
authors.lastname: Borodin
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000235:genetics*; D002467:Cell Nucleus / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D009630:Nondisjunction, Genetic; D013090:Spermatocytes / Q000648:ultrastructure; D013573:Synaptonemal Complex; D014314:Trisomy