双三倍体银鲫超数微小染色体的基因组特征  

GENOMIC CHARACTERIZATION OF SUPERNUMERARY MICROCHROMOSOMES IN AMPHITRIPLOID GIBEL CARP

作　　者：石倩 丁苗[2] 汪洋[2,3] 周莉 王忠卫[2,3] 张晓娟 李志[2] 李熙银 桂建芳[2,3] SHI Qian;DING Miao;WANG Yang;ZHOU Li;WANG Zhong-Wei;ZHANG Xiao-Juan;LI Zhi;LI Xi-Yin;GUI Jian-Fang(College of Fisheries and Life Science,Dalian Ocean University,Dalian 116023,China;State Key Laboratory of Freshwater Ecology and Biotechnology,Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture,Hubei Hongshan Laboratory,the Innovative 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]大连海洋大学水产与生命学院,大连116023 [2]中国科学院水生生物研究所淡水生态与生物技术国家重点实验室,水产品种创制与高效养殖重点实验室,湖北洪山实验室,中国科学院种子创新研究院,武汉430072 [3]中国科学院大学,北京100049

出　　处：《水生生物学报》2023年第11期1816-1826,I0003,I0004,共13页Acta Hydrobiologica Sinica

基　　金：国家重点研发计划“农业生物种质资源挖掘与创新利用”(2021YFD1200804);中国科学院战略先导专项(XDA24030104);中国科学院青年创新促进会(2020334);国家自然科学基金(32202923和31873036);国家现代农业产业技术体系(CARS-45-07);国家重点实验室自主课题(2019FBZ04);国家博士后科学基金会(2022M713322)资助。

摘　　要：为了揭示双三倍体银鲫超数微小染色体基因组特征,利用银鲫超数微小染色体富集的卫星序列及染色体荧光原位杂交,鉴定了银鲫基因组数据库中超数微小染色体序列,并对这些序列进行了基因组解析。研究发现在银鲫基因组数据库中存在15个scaffold为潜在超数微小染色体序列,这些序列中的22.28%与其祖先种双二倍体鲫的常规染色体存在同源性。双三倍体银鲫超数微小染色体重复序列含量明显高于双二倍体鲫和双三倍体银鲫的常规染色体,且重复序列组成也存在差异。随后,研究发现在银鲫中扩张的与减数分裂相关的8个基因家族,有6个在超数微小染色体序列上含有扩增拷贝,且这些扩增拷贝在银鲫卵子发生过程中具有转录活性。此外,根据超数微小染色体扩增拷贝的特异性序列开发了3个超数微小染色体特异的SCAR标记,可以用来区分双二倍体鲫和双三倍体银鲫。研究结果表明,双三倍体银鲫超数微小染色体起源于常规染色体,演化过程中积累了大量重复序列和部分活性基因,且大多数减数分裂相关基因的扩张通过超数微小染色体完成。研究结果不仅解析了双三倍体银鲫超数微小染色体基因组特征,也为超数染色体在单性生殖演化中的作用提供了创新见解。Supernumerary microchromosomes are non-essential chromosomes in addition to regular chromosomes,and it always believed that they have no biological functions.With the rapid development of sequencing technology,more and more evidence show that supernumerary microchromosomes have active genes and play important role in organism.Amphitriploid gibel carp(Carassius gibelio) and amphidiploid crucian carp(Carassius auratus) are belonged to the polyploid Carassius complex,and previous studies have shown that amphitriploid C.gibelio contain regular chromosomes and supernumerary microchromosomes while amphidiploid C.auratus are consist of regular chromosomes.To reveal genomic characteristics of the supernumerary microchromosomes in amphitriploid C.gibelio,we identified the potential sequences of supernumerary microchromosomes by supernumerary microchromosome-enriched satellite sequences and fluorescence in situ hybridization,and performed genomic characterization of these sequences.In this study,a total of 15 scaffolds were identified to be derived from supernumerary microchromosomes in the genome database of a female gibel carp,and 22.28% of these sequences had homologous to the regular chromosomes of amphidiploid C.auratus,which was the ancestral of gibel carp.The repetitive sequence proportion of supernumerary microchromosomes in amphitriploid C.gibelio was obviously higher than that of regular chromosomes in amphidiploid C.auratus and amphitriploid C.gibelio,and the contents of repetitive sequences were also different among them.Subsequently,we found that 6 of the 8 expanded meiosis-related gene families in C.gibelio had duplicated copies in the sequences of supernumerary microchromosomes,and these duplicated copies displayed transcriptional activity during oogenesis.In addition,we developed 3 SCAR markers specific to supernumerary microchromosomes based on these amplified copies,and these markers also could be used to distinguish amphidiploid C.auratus and amphitriploid C.gibelio.These results indicated that the super

关 键 词：单性生殖 超数微小染色体 重复序列 性染色体 减数分裂 银鲫 

分 类 号：Q344.1[生物学—遗传学]