Chromosome dynamics during the G2/M transition in meiosis

在精子和卵子的产生过程中，细胞的染色体数量必须减少一半，否则产生的胎儿就会含有过多的染色体。这需要一种特殊的细胞分裂，染色体首先找到它们的伴侣，然后与之分离——结婚后离婚。细胞如何确保每个卵子或精子恰好包含一套完整的染色体，人类是23条？染色体在序列相同的基础上配对，形成称为交叉的特殊连接，在显微镜下看起来像希腊字母chi。配对和交叉的形成是由一种叫做突触复合体的结构促进的；当交叉形成时，突触复合体被分解，细胞准备分裂成对的染色体。我们正在研究突触复合体的分解是如何促进的，以及它是如何与交叉的形成协调的。为此，我们使用面包酵母作为模式生物。贝克酵母为交叉和突触复合体的形成提供了有价值的见解，我们希望控制其分解的一些基本原则也适用于人类。

During the production of sperm and eggs, cells have to half the number of chromosomes, otherwise the resulting foetus will contain too many. This requires a specialized cell division where chromosomes first find their partner and then split from them- a marriage followed by divorce. How do cells ensure that each egg or sperm contains exactly one full set of chromosomes, 23 in the case of humans? Chromosomes pair on the basis of sequence identity and form specialized connections called chiasmata that look like the Greek letter chi under the microscope. Pairing and the formation of chiasmata is facilitated by a structure called the synaptonemal complex; when chiasmata form the synaptonemal complex is broken down and cells get ready to split up the chromosome pairs. We are investigating how the breakdown of the synaptonemal complex is facilitated and how is it coordinated with formation of chiasmata. To this end, we use baker‘s yeast as a model organism. Baker‘s yeast has provided valuable insight into how chiasmata and the synaptonemal complex are formed and we expect that some of the basic principles that govern its breakdown will also be relevant in humans.