青海湖裸鲤肠道显微结构及基于宏条形码的食性分析  

INTESTINAL MICROSTRUCTURE AND DIETARY ANALYSIS BASED ON MACROBARCODE OF GYMNOCYPRIS PRZEWALSKII

作　　者：蔡伟杰 张存芳 李柯懋 郝佳慧 覃敏欣 关弘弢 高强 刘丹 聂苗苗 贾军梅 祁得林 CAI Wei-Jie;ZHANG Cun-Fang;LI Ke-Mao;HAO Jia-Hui;QIN Min-Xin;GUAN Hong-Tao;GAO Qiang;LIU Dan;NIE Miao-Miao;JIA Jun-Mei;QI De-Lin(State Key Laboratory of Plateau Ecology and Agriculture,Qinghai University,Xining 810016,China;College of Eco-Environmental Engineering,Qinghai University,Xining 810016,China;Qinghai Provincial Fishery Technology Promotion Center(Qinghai Provincial Fishery Environment Monitoring Center),Xining 810012,China)

机构地区：[1]青海大学省部共建三江源生态与高原农牧业国家重点实验室,西宁810016 [2]青海大学生态环境工程学院,西宁810016 [3]青海省渔业技术推广中心(青海省渔业环境监测中心),西宁810012

出　　处：《水生生物学报》2023年第12期1954-1964,共11页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金(31960098);青海省应用基础研究项目(2021-ZJ-728)资助。

摘　　要：研究利用扫描电镜和HE染色技术来观察青海湖裸鲤(Gymnocypris przewalskii)的肠道显微结构,并通过DNA宏条形码技术,对其食性特点进行分析。研究结果表明,青海湖裸鲤前、中、后肠的组织结构层次清晰且差异明显,从内向外依次由黏膜层、黏膜下层、肌层和浆膜层四层组成,因缺乏黏膜肌,光镜下仅有三层膜结构清晰可见,从前肠至后肠肠腔逐渐减小,黏膜皱褶高度显著降低(P<0.05),宽度显著增加(P<0.05),杯状细胞、分泌孔及分泌物颗粒的数量也相对减少;18S rDNA和rbcL基因DNA宏条形码测序分析结果显示:青海湖裸鲤肠道内容物测序获得51656个OTU,剔除鱼类自身序列、细菌、古菌及真菌的序列后共39031个OTU注释为43门、114纲、282目和435科。在门水平上主要以链型植物门(53.73%)、硅藻门(23.19%)、p_unclassified_d_Eukaryota(11.14%)、丝足虫门(6.67%)、p_unclassified(1.93%)和轮虫动物门(0.67%)为主,纲水平上,主要以真藓纲(35.79%)、硅藻纲(23.05%)、双子叶植物纲(18.03%)和金藻纲(3.36%)为主。由此可见青海湖裸鲤主要食物组成为真藓类、硅藻类、双子叶植物类、金藻类、丝足虫类、轮虫类及未确定分类的物种。综上所述,青海湖裸鲤的肠道组织结构具有特异性和杂食性鱼类肠道结构的共性,且DNA宏条形码食性分析结果也证实青海湖裸鲤属于杂食性鱼类,其中还有许多未知种类的食物。研究阐明了青海湖裸鲤肠道结构和食性的特点,为青海湖裸鲤的人工繁育和进一步保护提供了基础的科学依据。As a national second-class protected animal,Gymnocypris przewalskii is a unique indigenous fish that plays an extremely important role in maintaining the biodiversity and ecosystem stability of Qinghai Lake.After long-term adaptation to plateau extreme environment,Gymnocypris przewalskii has formed the characteristics of tolerance to hypoxia,low temperature,high salt and poor nutrition,however,due to the global temperature rises,the temperature of Qinghai Lake has been gradually increasing year by year,which causing changes of the habitat of fish.In this study,scanning electron microscopy and hematoxylin-eosin staining(HE) were used to observe the intestinal microstructure of Gymnocypris przewalskii,and its dietary characteristics were analyzed by DNA metabarcoding.The results showed that the histological structure of the foregut,midgut and hindgut of Gymnocypris przewalskii was clear and the difference was obvious.From inside to the outside,it was composed of four layers:mucous membrane layer,submucosa layer,muscularis and serosa layer,however,due to the lack of muscularis mucosae,only three layers of membrane structure were visible under the light microscope.The researchers observed that intestinal cavity gradually decreased from foregut to the hindgut.The height of mucosal fold decreased significantly(P<0.05),and the width of mucosa fold increased significantly(P<0.05).The number of goblet cells,secretory pores and secretory granules also decreased.The results of 18S rDNA and rbcL gene DNA metabarcoding sequencing showed that 51656 OTU were obtained from the intestinal contents of Gymnocypris przewalskii.After removing the sequences of fish,bacteria,archaea and fungi,a total of 39031 OTU were identified,representing 43 phyla,114 classes,282 orders and 435 families.At the phylum level,the main phyla are Streptophyta(53.73%),Bacillariophyta(23.19%),p_ unclassified_ d_ Eukaryota(11.14%),Cercozoa(6.67%),p_ unclassified(1.93%) and Rotifera(0.67%).At the class level,the main classes were Bryopsida(35.79%),Bacillario

关 键 词：肠道结构 扫描电镜 HE染色 宏条形码 食性 青海湖裸鲤 

分 类 号：Q174[生物学—水生生物学]