Bare-patches, a new sex-linked gene in the mouse, associated with a high production ofXOfemales: II. Investigations into the nature and mechanism of theXOproduction

Abstract

SUMMARYThe highXOproduction inBpa+ mouse stocks appears to be due, not toBpaitself, but to a closely linked factor for highXOproduction (Fxo) which may be a gene or a chromosomal aberration. The change ofBpa FxotoBpanon-Fxooccurs with a frequency of about 6%; the reciprocal change fromBpa FxotoFxonon-Bpahas not been found. There is some evidence thatFxomight involve a structural alteration such as an inversion or a deletion. TheX-chromosome loss is due to non-disjunction which occurs in about one-third of the oocytes, probably mainly at meiosis I. Frequencies of other chromosomal abnormalities found in the stocks are given.