不育症影响着全球10-15％的育龄夫妇，生殖细胞形成异常是造成不育的重要原因之一。复旦大学发育生物学研究所的最新发现，“SUN1”蛋白变异是生殖细胞形成异常的关键因素。
每个人从父母那儿所获得的遗传信息，决定了个体的生物性状。当个体把来自父母双亲的一半遗传信息再传给子女时，这些遗传信息会重新组合(称为遗传重组)，以使后代获得更多的生物多样性，促进生物的进化。那么，到底是“谁”来启动遗传信息减半传递和遗传重组的呢？
复旦大学发育生物学研究所的韩珉教授、徐人尔所带领的科研小组发现，“SUN1”蛋白能够帮助父母双亲来源的染色体结合到核膜上启动染色体配对(遗传信息减半传递的第一步)和遗传重组。而根据通过对小鼠的实验，如果“SＵN1”基因突变，就会使染色体配对和遗传重组受阻而不能产生成熟的精子和卵子，造成突变小鼠不育。
据介绍，该项成果已刊登于6月4日出版的《Developmental Cell》杂志上，并即将被新一期的《Science》杂志选为“值得关注的论文”作专门介绍。（生物谷援引东方网）
原始出处:
Developmental Cell, Vol 12, 863-872, 05 June 2007
Article
SUN1 Is Required for Telomere Attachment to Nuclear Envelope and Gametogenesis in Mice
Xu Ding,1,5 Rener Xu,1,5, Juehua Yu,1 Tian Xu,1,2 Yuan Zhuang,1,3 and Min Han1,4,
1 Institute of Developmental Biology and Molecular Medicine and School of Life Science, Fudan University, Shanghai 200433, China
2 Howard Hughes Medical Institute and Department of Genetics, Yale University School of Medicine, New Haven, CT 06536, USA
3 Department of Immunology, Duke University Medical Center, Durham, NC 27708, USA
4 Howard Hughes Medical Institute and Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
Corresponding author
Rener Xu
rener_xu@fudan.edu.cn
Corresponding author
Min Han
mhan@colorado.edu
Summary
Prior to the pairing and recombination between homologous chromosomes during meiosis, telomeres attach to the nuclear envelope and form a transient cluster. However, the protein factors mediating meiotic telomere attachment to the nuclear envelope and the requirement of this attachment for homolog pairing and synapsis have not been determined in animals. Here we show that the inner nuclear membrane protein SUN1 specifically associates with telomeres between the leptotene and diplotene stages during meiotic prophase I. Disruption of Sun1 in mice prevents telomere attachment to the nuclear envelope, efficient homolog pairing, and synapsis formation in meiosis. Massive apoptotic events are induced in the mutant gonads, leading to the abolishment of both spermatogenesis and oogenesis. This study provides genetic evidence that SUN1-telomere interaction is essential for telomere dynamic movement and is required for efficient homologous chromosome pairing/synapsis during mammalian gametogenesis.
