演者： Andrew Murray 博士
Harvard University&s_comma; Boston&s_comma; USA
演題：Looking after your chromosomes: an intrinsic bias to biorient in mitosis and meiosis
日時：12月 10日 （月） 1 6:00~17:00
The spindle checkpoint is a regulatory circuit that keeps chromosomes from segregating until they have been correctly lined up on the spindle. In mitosis&s_comma; the chromosomes that segregate from each other are sisters&s_comma; and in meiosis I they are homologs (paternal and maternal chromosomes). In both divisions&s_comma; the binding of microtubules to kinetochores (the proteinaceous structure that assembles on the centromere) attaches the chromosomes to the spindle. A new experiment suggests that tension is detected at the linkage between sister kinetochores rather than the linkage between kinetochores and microtubules
Down Syndrome occurs when both maternal and paternal copies of chromosome 21 segregate to the same spindle pole in meiosis I. These chromosomes have fewer recombination events (cross-overs) near the centromere and more far away from it than the chromosomes in normal infants. In a budding yeast spindle checkpoint mutant&s_comma; an artificial tether near the centromere rescues the meiotic segregation of chromosomes whose cross-overs are far from the centromere.
1) Indjeian&s_comma; V. and Murray&s_comma; A.W. The Centromeric Protein Sgo1 Signals Lack of Tension on Mitotic Chromosomes. Science 307&s_comma; 130-133 (2005). 2) Indjeian V.B.&s_comma; Murray A.W. Budding Yeast Mitotic Chromosomes Have an Intrinsic Bias to Biorient on the Spindle. Curr Biol. 2007 Oct 31; [Epub ahead of print]). 3) Lacefield&s_comma; S. and Murray&s_comma; A.W. The spindle checkpoint rescues the meiotic segregation of chromosomes whose crossovers are far from the centromere. Nat. Genet. 39&s_comma; 1273-1277 (2007).
世話人：東大分生研・染色体動態研究分野 渡邊嘉典 ( 内21466)
主催 東京大 学分子細胞生物学研究所、グローバルCOE