title: Meiotic studies of translocations causing male sterility in the mouse. II. Double heterozygotes for Robertsonian translocations.
abstract: Unusual meiotic behavior of the XY chromosome pair was observed in sterile male mice doubly heterozygous for two Robertsonian translocations, Rb(16.17)7Bnr and Rb(8.17)1Iem. Nonrandom association between the X chromosome and the translocation configuration, ascertained from the frequencies of relevant C-band contacts, was found in 9 of 10 sterile males. Besides the nonrandom association, the XY chromosomes showed signs of impaired condensation, as judged by measurement of their lengths at diakinesis/MI of the first meiotic division. In contrast, neither nonrandom contact nor decondensation of the XY chromosomes pair was found in fertile males heterozygous for a single Robertsonian translocation, Rb1Iem or Rb7Bnr. The present observations lend indirect support to the working hypothesis advanced previously, the assumption that interference with X-chromosome inactivation is a possible cause of spermatogenic breakdown in carriers of various male-sterile chromosomal transloations. Alternative explanations of the available data, which cannot be ruled out, are briefly discussed.
mesh_terms: D000818:Animals; D006579:Heterozygote; D007248:Infertility, Male / Q000235:genetics*; D008297:Male; D008540:Meiosis; D051379:Mice; D013091:Spermatogenesis; D014178:Translocation, Genetic