近日,，中科院遺傳與發(fā)育生物學(xué)研究所程祝寬課題組在水稻中鑒定出了HEI10基因，研究分析發(fā)現(xiàn)，HEI10基因突變導(dǎo)致交叉結(jié)的數(shù)目顯著減少，而剩余交叉隨機(jī)分布于不同染色體上。該研究結(jié)果于7月5日在線發(fā)表于PloS Genetics上,。
減數(shù)分裂是維持生物體染色體數(shù)恒定，導(dǎo)致遺傳重組產(chǎn)生的基礎(chǔ),。減數(shù)分裂缺陷是導(dǎo)致不孕,、不育和出生障礙的主要原因。絕大多數(shù)減數(shù)分裂基因在不同物種中有著高度保守的功能,。
HEI10基因最初在人類體細(xì)胞中分離,，并證明有調(diào)控細(xì)胞周期的功能。在小鼠中的研究表明,，HEI10基因的突變會(huì)導(dǎo)致減數(shù)分裂異常并最終導(dǎo)致不育,，但是HEI10在減數(shù)分裂過程中的具體生物學(xué)功能目前仍然不清楚,。
但是HEI10的突變并不影響重組早期蛋白的定位以及聯(lián)會(huì)復(fù)合體的形成。令人驚奇的是,，HEI10蛋白在染色體上呈現(xiàn)一種動(dòng)態(tài)的定位：最初呈現(xiàn)為明顯的點(diǎn)狀而且與重組蛋白MER3高度共定位,，隨著減數(shù)分裂聯(lián)會(huì)的進(jìn)行，HEI10沿著染色體軸逐漸連成線狀信號(hào),，在聯(lián)會(huì)復(fù)合體解體之后,，線狀信號(hào)逐漸消失，只有大的點(diǎn)狀信號(hào)維持在染色體上,，而這些點(diǎn)狀信號(hào)恰好對(duì)應(yīng)于交叉結(jié)的位置,。
HEI10是水稻中分離的第一個(gè)可以用于指示重組位置的標(biāo)記蛋白，相關(guān)研究為在水稻中進(jìn)一步深入研究重組機(jī)制提供了堅(jiān)實(shí)基礎(chǔ),。
程祝寬實(shí)驗(yàn)室王克劍,、王莫和唐丁為該工作的共同第一作者。該項(xiàng)工作受到科技部及國(guó)家自然科學(xué)基金委項(xiàng)目的資助,。（生物谷Bioon.com）
doi:10.1371/journal.pgen.1002809
PMC:
PMID:
The Role of Rice HEI10 in the Formation of Meiotic Crossovers
Kejian Wang1#, Mo Wang1#, Ding Tang1#, Yi Shen1, Chunbo Miao1, Qing Hu1, Tiegang Lu2, Zhukuan Cheng1*
HEI10 was first described in human as a RING domain-containing protein that regulates cell cycle and cell invasion. Mice HEI10mei4 mutant displays no obvious defect other than meiotic failure from an absence of chiasmata. In this study, we characterize rice HEI10 by map-based cloning and explore its function during meiotic recombination. In the rice hei10 mutant, chiasma frequency is markedly reduced, and those remaining chiasmata exhibit a random distribution among cells, suggesting possible involvement of HEI10 in the formation of interference-sensitive crossovers (COs). However, mutation of HEI10 does not affect early recombination events and synaptonemal complex (SC) formation. HEI10 protein displays a highly dynamic localization on the meiotic chromosomes. It initially appears as distinct foci and co-localizes with MER3. Thereafter, HEI10 signals elongate along the chromosomes and finally restrict to prominent foci that specially localize to chiasma sites. The linear HEI10 signals always localize on ZEP1 signals, indicating that HEI10 extends along the chromosome in the wake of synapsis. Together our results suggest that HEI10 is the homolog of budding yeast Zip3 and Caenorhabditis elegans ZHP-3, and may specifically promote class I CO formation through modification of various meiotic components.
