Comparative studies on X-autosome translocations in the mouse. II. Inactivation of autosomal loci, segregation, and mapping of autosomal breakpoints in five T (X;1) S.
Comparative studies on X-autosome translocations in the mouse. II. Inactivation of autosomal loci, segregation, and mapping of autosomal breakpoints in five T (X;1) S.
复制标题
小鼠 X 常染色体易位的比较研究。
作者：
L. B. Russell;C. Montgomery
nine X-autosome translocations observed in the mouse possess distinctive Tyftures that give each certain advantages and certain disadvantages in studies of gene action connected with X-chromosome inactivation. Thus, for T (X; ?) 16H, the translocation reported by SEARLE ( 1962), both genetic (LYON, SEARLE, FORD and OHNO 1964) and cytological ( OHNO and LYON 1965) evidence indicates that X inactivation, at least in certain adult cells and tissues, is nonrandom, affecting almost invariably the nonrearranged X. While this situation provides a tool for determining gene inactivation in the normal X chromosome (LYON 1966) it lacks the opportunities, offered by the other translocations, of studying inactivation in autosomal genes. The fact that the autosome involved in this translocation is not known becomes less important when one realizes that its genes would presumably behave no differently in the rearranged chromosome (which is virtually always active) than they normally do. In the two X;8 translocations (RUSSELL RUSSELL, the five X;1 translocations to be described in this paper (RUSSELL and the flecked translocation (CATTANACH 1961), nonrandomness appears not to be a factor. The flecked translocation, ,which is probably an insertion of about one-third of LGI into the X (OHNO and CATTANACH 1962), has certain distinctive features, one of which is that one class of unbalanced segregants (autosomal duplication) is viable, providing the opportunity for studying autosomal dosage phenomena. Furthermore, the unbalanced males are fertile, in contrast to males carrying any of the
