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中国农学通报 ›› 2025, Vol. 41 ›› Issue (25): 153-164.doi: 10.11924/j.issn.1000-6850.casb2025-0057

• 水产·渔业 • 上一篇    

基于基因组Survey数据的深海尾鳗微卫星特征及系统发育关系分析

郑昀凯(), 刘鹏辉, 牛世洋, 杨天燕()   

  1. 浙江海洋大学水产学院,浙江舟山 316022
  • 收稿日期:2025-01-16 修回日期:2025-06-03 出版日期:2025-09-05 发布日期:2025-09-16
  • 通讯作者:
    杨天燕,女,1982年出生,湖北武汉人,副教授,博士,研究方向:渔业资源学。通信地址:316022 浙江省舟山市定海区临城街道海大南路1号,E-mail:
  • 作者简介:

    郑昀凯,男,2003年出生,浙江衢州人,研究方向:海洋资源与环境。通信地址:316022 浙江省舟山市定海区临城街道海大南路1号,E-mail:

  • 基金资助:
    浙江省自然科学基金项目“东海蛇鳗科鱼类线粒体基因组重排模式与分类系统演化研究”(LMS25D060002); 舟山市科技计划项目“东海重要海洋鱼类种质资源保护技术研究”(2022C41022); 国家级大学生创新创业训练计划项目“两种深海鳗鲡目鱼类基因组Survey及微卫星分布特征分析”(202410340014)

Analysis of Microsatellites Characterization and Phylogenetic Relationship for Bathyuroconger vicinus Based on Genomic Survey Data

ZHENG Yunkai(), LIU Penghui, NIU Shiyang, YANG Tianyan()   

  1. Fishery College of Zhejiang Ocean University, Zhoushan, Zheijiang 316022
  • Received:2025-01-16 Revised:2025-06-03 Published:2025-09-05 Online:2025-09-16

摘要: 为探究深海尾鳗对极端环境的基因组适应机制及系统演化地位,本研究首次对其开展全基因组Survey测序与系统分析。采用Illumina NovaSeq 6000平台进行基因组测序,结合SOAPdenovo2组装基因组草图,利用MISA筛选微卫星位点,基于线粒体蛋白质编码基因串联序列构建系统发育树。结果显示,深海尾鳗基因组大小约为1414 Mb,杂合率、重复序列比例分别为0.66%、54.93%。筛选得到总长度为10936848 bp的微卫星位点共计1221434个,分布在698950条序列上,发生频率、出现频率和相对丰度分别为19.18%、33.53%和857.57个/Mb。在6种完整型微卫星中,二碱基重复类型占比最大(804493个,65.86%)、出现频率最高(22.08%)且相对丰度最大(564.84个/Mb)。在1484种微卫星重复基元中,种类最多的为六碱基重复基元(668种),其次为五碱基重复(583种)、四碱基重复(231种)、三碱基重复(60种)、二碱基重复(12种)和单碱基重复(4种)。其优势碱基类别分别为A(128843,43.40%)、CA(239966,29.83%)、AAT(9533,12.30%)、AAAT(2663,8.16%)、CATTA(316,5.40%)和CACACT(268,6.56%)。基于线粒体蛋白质编码基因串联序列构建的最大似然树显示,深海尾鳗与尖尾鳗属鱼类的亲缘关系较近。本研究揭示了深海尾鳗基因组的复杂特征及丰富的多态性微卫星位点,为其深海适应机制研究提供了分子基础;筛选的微卫星位点可用于种群遗传学分析;系统发育结果支持其与尖尾鳗属鱼类的近缘关系,明确了其在康吉鳗亚科中的演化地位,并提示康吉鳗科可能为多系群。

关键词: 深海尾鳗, 基因组测序, 微卫星标记, 系统发育, 鳗鲡目

Abstract:

In order to explore the genomic adaptation mechanism and phylogenetic status of Bathyuroconger vicinus to extreme environments, this study carried out whole genome Survey sequencing and systematic analysis for the first time. The Illumina NovaSeq 6000 platform was used for genome sequencing, combined with the SOAPdenovo2 assembly genome sketch, MISA was used to screen microsatellite loci, and a phylogenetic tree was constructed based on the mitochondrial protein-coding gene tandem sequence. K-mer analysis revealed that the genome size of B. vicinus was approximately 1414 Mb, with the heterozygosity rate and repeat sequence proportion of 0.66% and 54.93%, respectively. A total of 1221434 microsatellite loci were identified, with an overall length of 10936848 bp. These microsatellites were randomly distributed across 698950 sequences, with the occurrence frequency, appearance frequency and relative abundance of 19.18%, 33.53%, and 857.57 loci/Mb, respectively. Among the six perfect microsatellite types, the dinucleotide repeat was the most prevalent (804493, 65.86%), with the highest appearance frequency (22.08%) and the greatest relative abundance (564.84 loci/Mb). There were 1484 repeat motifs in all, of which hexanucleotide repeat was the most diverse (668), followed by pentanucleotide repeat (583), tetranucleotide repeat (231), trinucleotide repeat (60), dinucleotide repeat (12), and mononucleotide repeat (4). The dominant repeat motifs were A (128843, 43.40%), CA (239966, 29.83%), AAT (9533, 12.30%), AAAT (2663, 8.16%), CATTA (316, 5.40%), and CACACT (268, 6.56%). The phylogenetic tree based on the concatenated sequences of mitochondrial protein-coding genes was constructed by using the maximum likelihood (ML) method. The topology indicated a close relationship between B. vicinus and the species from genus Uroconger. This study revealed the complex characteristics of B. vicinusis genome and numerous highly polymorphic microsatellite loci, which provided a molecular basis for the study of its deep-sea adaptation mechanism. The selected microsatellite loci can be used for population genetics analysis. The phylogenetic results supported its close relationship with the fish of the genus Uroconger, clarified its evolutionary status in the subfamily Congrinae, and suggested that Congridae may be a polyphyletic group.

Key words: Bathyuroconger vicinus, genome sequencing, microsatellite loci, phylogenetic, Anguilliformes