一种独特的无减数融合生殖方式的发现及一条合成不育异源多倍体高效路径的创建  

An efficient approach to synthesize sterile allopolyploids through the combined reproduction mode of ameiotic oogenesis and sperm-egg fusion in the polyploid Carassius complex

作　　者：鲁蒙 张勤灿 朱子彧 彭芳 李志 汪洋 李熙银 王忠卫 张晓娟 周莉 桂建芳 Meng Lu;Qin-Can Zhang;Zi-Yu Zhu;Fang Peng;Zhi Li;Yang Wang;Xi-Yin Li;Zhong-Wei Wang;Xiao-Juan Zhang;Li Zhou;Jian-Fang Gui(State Key Laboratory of Freshwater Ecology and Biotechnology,Hubei Hongshan Laboratory,The Innovation Academy of Seed Design,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]State Key Laboratory of Freshwater Ecology and Biotechnology,Hubei Hongshan Laboratory,The Innovation Academy of Seed Design,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Science Bulletin》2023年第10期1038-1050,M0004,共14页科学通报（英文版）

基　　金：supported by the National Key Research and Development Program of China(2022YFD2400101);the National Natural Science Foundation of China(31930111 and 32102785);the Strategic Priority Research Program of Chinese Academy of Sciences(XDA024030104);the China Agriculture Research System of Ministry of Finance and Ministry of Agriculture and Rural Affairs;the Special Research Assistant Project CAS;the China Postdoctoral Science Foundation(2021M693344);the Excellent Young Talents program of Wuhan。

摘　　要：多倍化与生殖方式转换之间的联系作为进化遗传学的热点,能被开拓为农业生物遗传改良的新路径.最近我们通过整合雌核生殖银鲫和有性生殖鲫的基因组,创制了一个新双三倍体群体,发现它们中的大部分雌性恢复了单性雌核生殖能力.在本研究中,我们发现少数雌性获得了一种定义为“无减数融合生殖”的独特生殖方式.具有这种生殖方式的新双三倍体雌性不仅从单性雌核生殖银鲫遗传了无减数分裂产生不减数卵子的能力,还从有性生殖鲫遗传了卵核与精核融合形成受精卵的能力.随后我们将这种新双三倍体与二倍体团头鲂进行交配,直接创制了一个合成异源七倍体群体.它们的染色体组由来自其母本新双三倍体鲫的全套染色体组和来自父本二倍体团头鲂的一套染色体组构成.此外,我们还在一尾异源七倍体的部分体细胞中,检测到鲫与团头鲂染色体间相互易位的现象.随后我们追踪了异源七倍体生殖细胞在减数分裂过程中的染色体行为,揭示了它们不育的细胞学机制.结果表明,在减数第一次分裂(减Ⅰ)前期,染色体联会异常以及DNA双链断裂无法被完全修复,导致异源七倍体初级卵母细胞严重凋亡.尽管其初级精母细胞在减Ⅰ前期表现出与初级卵母细胞相似的染色体行为,但它们可以发育到减Ⅰ中期,并最终由于同源染色体分离失败而发生凋亡.最后,我们建立了一个可持续大规模生产具有无减数融合生殖能力的新双三倍体克隆系,还将其与多种鲤科鱼类进行交配快速创制出多种整合有不同鲤科鱼类基因组的不育异源多倍体群体,由此研发出一条高效的育种技术路径.本研究不仅拓宽了我们对脊椎动物生殖方式转换的认识,还为多倍体育种和杂种优势固定提供了一个可行的策略.The association between polyploidy and reproduction transition,which is an intriguing issue in evolutionary genetics,can also be exploited as an approach for genetic improvement in agriculture.Recently,we generated novel amphitriploids(NA3n)by integrating the genomes of the gynogenetic Carassius gibelio and sexual C.auratus,and found gynogenesis was recovered in most NA3n females(NA3n$I).Here,we discovered a unique reproduction mode,termed ameio-fusiongenesis,which combines the abilities of both ameiotic oogenesis and sperm-egg fusion,in a few NA3n females(NA3n$II).These females inherited ameiotic oogenesis to produce unreduced eggs from gynogenetic C.gibelio and sperm-egg fusion from sexual C.auratus.Subsequently,we utilized this unique reproduction mode to generate a group of synthetic alloheptaploids by crossing NA3n$II with Megalobrama amblycephala.They contained all chromosomes of maternal NA3n$II and a chromosomal set of paternal M.amblycephala.Intergenomic chromosome translocations between NA3n$II and M.amblycephala were also observed in a few somatic cells.Primary oocytes of the alloheptaploid underwent severe apoptosis owing to incomplete double-strand break repair at prophase I.Although spermatocytes displayed similar chromosome behavior at prophase I,they underwent apoptosis due to chromosome separation failure at metaphase I.Therefore,the alloheptaploid females and males were all sterile.Finally,we established a sustainable clone for the large-scale production of NA3n$II and developed an efficient approach to synthesize diverse allopolyploids containing genomes of different cyprinid species.These findings not only broaden our understanding of reproduction transition but also offer a practical strategy for polyploidy breeding and heterosis fixing.

关 键 词：Polyploid Carassius complex Reproduction transition Polyploidy breeding Synthetic allopolyploid Ameio-fusiongenesis 

分 类 号：Q492[生物学—生理学]