灰海马染色体制备及核型分析  

Chromosome preparation and karyotype of the lined seahorse(Hippocampus erectus)

作　　者：刘鑫[1] 张东[1] 林听听[1] 周丽青[2] LIU Xin;ZHANG Dong;LIN Tingting;ZHOU Liqing(Key Laboratory of East China Sea Fishery Resources Exploitation,Ministry of Agriculture and Rural Affairs,East China Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences,Shanghai 200090,China;Key Laboratory of Sustainable Development of Marine Fisheries,Ministry of Agriculture and Rural Affairs,Yellow Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences,Qingdao 266071,China)

机构地区：[1]中国水产科学研究院东海水产研究所,农业农村部东海渔业资源开发利用重点实验室,上海200090 [2]中国水产科学研究院黄海水产研究所,农业农村部海洋渔业可持续发展重点实验室,山东青岛266071

出　　处：《水产学报》2020年第6期907-914,共8页Journal of Fisheries of China

基　　金：农业农村部农业行业标准制订专项(2428-L-2019);中国水产科学研究院基本科研业务费专项(2017HY-ZD04,2019ZY12);中国水产科学研究院东海水产研究所基本科研业务费专项(2019M05);中国水产科学研究院黄海水产研究所基本科研业务费专项(206030222018004)。

摘　　要：为了解灰海马的细胞遗传学特征,便于今后开展灰海马的种质评价与鉴定、规模化人工繁育、亲缘关系研究及人工选育等工作,实验以雌雄灰海马的背鳍为材料,采用秋水仙素浸泡和常规热滴片法制备染色体标本。借助Photoshop图像软件,将同源染色体配对、拼贴,做出染色体核型图。采用Image J软件的自定义曲线测量功能,以着丝粒的中心位置为起点,顺着染色体弯曲的形态,到染色体臂末端为终点,测量线段长度,得出图片中染色体的臂长,根据相同放大倍数下标尺的测量值,换算出染色体的实际臂长。根据臂比值,将染色体进行配对、分类后,得出灰海马的染色体核型公式。结果显示,灰海马的背鳍组织可作为其染色体制备的理想材料,实验选用的染色体制备方法能获得图像清晰、形态良好的细胞分裂相。此法简单、效果好,解决了海龙科鱼类染色体制备的难题;灰海马具有22对染色体,二倍体染色体数目2n=44,雄鱼的染色体核型公式为2n=2sm+20st+22t,雌鱼的染色体核型公式为2n=1m+2sm+20st+21t,雌鱼存在性染色体异型的现象,因此灰海马的性染色体为ZW/ZZ型。Since the lined seahorse Hippocampus erectus was introduced into China in 2009,it has become the major aquacultured seahorse species in China.With the development of its aquaculture,the genetic quality of the species should be evaluated to provide fundament for artificial breeding study.The karyotype is varied among species,and is directly related to the genetic quality.Thus karyotype is the basis for identifying taxonomic status and study on phylogeny of a certain species.Study on karyotype would contribute to the studies on the genetic identification and community analysis.In order to explore the cytogenetical characters of the lined seahorse H.erectus,the metaphase chromosome was obtained from the dorsal fin of six-month old fish by colchicine incubation and hot air drying methods.Clear images of the chromosomes indicate the dorsal fin is an appropriate tissue for chromosomal investigation in seahorses.There were 22 pairs of chromosomes in diploid(i.e.n=22,and 2 n=44).The karyotypes of both sexes were examined separately.There were significant differences in karyotype between males and females,male karyotype formula is 2 n=2 sm+20 st+22 t,and female karyotype formula is 2 n=1 m+2 sm+20 st+21 t.Heterotypic sex chromosome was found in female H.erectus,so its sex chromosome belongs to ZW/ZZ type.The preparation of chromosome,karyotype and heterotypic sex chromosome in the lined seahorse were reported for the first time.The present study lays a good foundation for studies on cytogenetics,genetic breeding and protection of genetic resources of the lined seahorse.

关 键 词：灰海马 染色体 鳍 核型 

分 类 号：S917.4[农业科学—水产科学]