生物谷：生殖細(xì)胞中的染色體異常,，會引發(fā)新生嬰兒的許多疾病,，包括不孕癥（infertility）、流產(chǎn)（miscarriage）,、染色體數(shù)目不規(guī)則（非整倍體,；aneuploidy），等等,。一項來自卡羅林斯卡研究所（Karolinska Institute）的新的研究報告向我們展示了,，生殖細(xì)胞形成的時候，染色體紊亂的發(fā)生機(jī)制,。
生殖細(xì)胞中通常有一套“控制站”（control station）,，用于監(jiān)測 一個確保正確分配染色體到子細(xì)胞的機(jī)制?？茖W(xué)家發(fā)現(xiàn),，在雌性生殖細(xì)胞中還存在另外一套分配機(jī)制，這套機(jī)制會引起染色體紊亂,。變異的染色體可以將它們自身 “裝扮”成正常的染色體,，這種擁有兩種身份的本領(lǐng)讓它們躲避了控制站的監(jiān)測。
“我們相信這個根本的機(jī)制,，可以用于解釋為何磁性生殖細(xì)胞中更容易發(fā)生染色體紊亂,，”研究的主持者Christer Höög教授介紹說。此項研究可能最終有助于醫(yī)療技術(shù)的研發(fā),，從而降低胎兒畸形的概率,。
超過0.3%的兒童都患有一定程度的染色體紊亂。當(dāng)中絕大多數(shù)患有唐氏綜合癥（Downs Syndrome）,，或因為獲得錯誤數(shù)量的性染色體而患有特納綜合征（Turner’s syndrome）或克蘭費爾特氏綜合癥（Klinefelter’s syndrome）,。唐氏綜合癥只發(fā)生在女性當(dāng)中，是因為兩條X染色體中缺失了一條引起的,?；加刑丶{綜合征的女孩會停滯發(fā)育,，如果沒有接受合適的治療的話，將不會進(jìn)入青春期,?？颂m費爾特氏綜合癥是因為男性額外接受了一條X染色體引起的，癥狀有注意力不集中,、運(yùn)動技能差和不育等,。（援引生命經(jīng)緯）
圖：Univalents in Sycp3-/- oocytes are bi-oriented in a mitotic manner and evade the SAC.
資料來源：Karolinska Institutet
原始出處:
Brief Communication abstract
Nature Genetics
Published online: 8 July 2007 | doi:10.1038/ng2065
Bi-orientation of achiasmatic chromosomes in meiosis I oocytes contributes to aneuploidy in mice
Anna Kouznetsova1, Lisa Lister2, Magnus Nordenskjöld3, Mary Herbert2 & Christer Höög1
Abstract
The spindle assembly checkpoint guards against chromosomal missegregation but does not induce arrest in oocytes that contain a few achiasmatic chromosomes (univalents). We followed the fate of univalents in oocytes during the first meiotic division, and although these preserved a meiotic kinetochore structure, they were also bi-oriented in a mitotic manner. The hybrid chromosomal configuration attained by univalents allows them to evade the spindle assembly checkpoint and contribute to aneuploidy in oocytes.
Department of Cell and Molecular Biology, Karolinska Institutet, S-171 77, Stockholm, Sweden.
Newcastle Fertility Centre, Institute of Human Genetics and North East England Stem Cell Institute, Newcastle University, Bioscience Building, International Centre for Life, Newcastle upon Tyne NE1 4EP, UK.
Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska University Hospital, 171 76 Solna, Sweden.
Correspondence to: Christer Höög1 e-mail: [email protected]
