中国科学院水生生物研究所机构知识库
Advanced  
IHB OpenIR  > 中科院水生所知识产出(2009年前)  > 学位论文
题名: 鱼类远缘杂交后代同工酶基因表达和调控的研究
作者: 傅洪拓
答辩日期: 1988
导师: 吴清江
专业: 遗传学
授予单位: 中国科学院水生生物研究所
授予地点: 中国科学院水生生物研究所
学位: 硕士
摘要: 鲤鱼(♀)* 鲫鱼、草鱼(♀)* 团头鲂和草鱼(♀)* 鲤鱼是三个有代表性的远缘杂交组合,它们的发育成功性依次降低,鲤鲫杂种能正常发育至成体,且雌性可育;草团杂交能得到成体杂种,但成活率不高,且完全不育;而草鲤杂种在孵出期前后全部死亡,是一个致死杂种。本人观察三个杂种发育过程的形态学变化,并对草团杂种的胚胎和成体染色体进行了比较研究,发现早期胚胎(原肠胚)的大多数细胞为二倍体(其中也存在三倍体),而成活的草团杂种都是三倍体。在自然条件下,形成三倍体的机率很小。杂种发育过程的同工酶分析发现:草团杂种中,LDH和EST表现了双亲的共表达,但EST的一条带提前表达而LDH的A基因推迟表达;在草鱼、团头鲂及草团杂种的胚胎发育过程中均未检测到ADH的活性;而草团杂种的MDH和G6PDH在发育过程中表现为单方(母本)表达。草鲤杂种胚胎发育过程中,MDH和EST也表现为仅母本单方基因表达。草团杂种成体组织同工酶分析发现;LDH、SOD;ADH、MP都显示了随体重减小而活性依次降低的规律性变化,但MDH没有这种相关性变化。此外,本人也对二倍体鲤鲫杂种(含一套鲤鱼染色体和一套鲫鱼染色体)和三倍体鲤鲫杂种(含两套鲤鱼染色体和一套鲫鱼染色体)的同工酶表达进行了对比,发现LDH和EST在二倍休种和三倍体杂种中皆为双亲基因的共表达,二倍体和三倍体没有区别;MDH和SOD则表现了明显的基因剂量效应,父本(鲫鱼)的MDH和SOD在二倍体中表达,而在三倍体中没有表达;IDH的情况比较特殊,出现了双亲所没有的“新带”。由此可知,草团杂种之所以成活率低,是由于大部份杂种的染色体未能加倍,仍处于“双单倍体”状态。在这些二倍体杂种的发育过程中,双亲某些位点因缺乏亲和性而出现单方(母本)表达(降低了酶活性),另一些具有部分亲合性的位点则因发生相互作用而改变了表达时间(扰乱了酶的正常表达时间),结果发育不能正常进行,最终全部死亡。但是那些母本基因组加倍而形成了三倍体的少数杂种,不但弥补了不足的基因剂量,而且可不同程度地抑制异源父本基因的表达(这可由鲤鲫杂种的同工酶分析结果得知),克服父本基因的干扰,因此能成活下来。草鲤杂种则因父本染色体逐步丢失和母本染色体未能加倍而全部死亡。另一方面,根据Whitt的“阈值说”可以解释杂种发育过程中出现的各种基因异常表达的分子机制。此外,由染色体和同工酶的分析结果可以推断,在草鱼和团头鲂杂交时,如用适当的方法抑制草鱼的第二极体排出,或者先诱导草鱼四倍体,再与团头鲂杂交,可能会大大提高草团杂种的成活率。
英文摘要: Among freshwater fish distant hybridizations, Cyprinus carpio (Cy) X Carassius auratus(Ca), Ctenopharyngodon idellus(Ct) X Megalobrama amblycephala(Meg) and Ctenopharyngodon idellus X Cyprinus carpio are three representative combinations, their development abilities decrease in a continued series. The hybrid of Cy X Ca can normally develop into adult, and the female hybrid is fertile; only few survivals can be obtained from Ct X Meg,a nd they are all sterile; hybrid between Ct and Cy is all died at hatching period. The morphological characteristics of these three hybrid embryos were observed, and the chromosome number of Ct X Meg hybrid were also investigated. The chromosome number is 72 in all fingerings of hybrid between Ct and Meg, but 48 in most of gastral cells. The isozyme analysis during embryogenesis showed that: in Ct X Meg hybrid, LDH and EST were the co-expression of both parents, but EST-8 of Ct was previously expressed in the hybrid, and LDH-A locus was delayed; no activity of ADH was detected during embryogenesis of hybrid and its parents; MDH and G-6-PDH of hybrid were only maternally expressed. During the embryogenesis MDH and EST of hybrid between Ct and Cy were only maternally expressed too. In the fingerling of hybrid between Ct and Meg, activities of LDH, SOD, ADH and MP but MDH were dependent on body size, i.e. the lighter the body-weight, the lower the enzyme activities. Comparisons between the diploid and triploid isozymes of carp and goldfish hybrid showed that: LDH and EST were the co-expression of both parents, and no difference between diploid and triploid. But there were obvious gene-dosage effects for MDH and SOD, the MDH and SOD of goldfish were expressed in diploid but not in triploid; on the other hand, only IDH of goldfish was expressed in the dipoloid and a "new pattern" of IDH appeared in the triploid, its mobility was faster than the diploid's and either of both parents. From above results we were led to the conclusion and the distinct low survival rate of hybrid between Ct and Meg was caused by "double haploid". In the embryogenesis of these hybrids some isozyme loci which were deficient in affinity between both parent alleles were only maternally expressed (reduce the activity of enzyme), other loci which were partial compatible between both parent alleles presented mutual interactions (disturb the normal expression of enzyme). Both the reductions of enzyme activity and disturbances of spatial and temporal expression of enzymes, would bring about distinct abnormal development, were caused cessation from development and died at last. On the other hand, among the hybrid between Ct and Meg in the triploid which obtains two maternal genomes, the insufficient dosage of gene in the diploid hybridis compensated by the maternal double genomes and the expression of paternal heterogenetic genes are possibly inhibited by the maternal double genomes (this phenomenon was also observed in the hybrid between carp and goldfish), as a result, the triploid can develop normally and survive. However, the hybrid between Ct and Cy all die during hatching period, the observation of chromosome indicates that no any triploid hybrid is found an in the embryogenetic process carp chromosome are continually excluded. These results suggests that employing artificially induced triploid (inhibiting the exclusion of the second polar body), fish distant hybridizations might achieve greater success.
语种: 中文
内容类型: 学位论文
URI标识: http://ir.ihb.ac.cn/handle/342005/12732
Appears in Collections:中科院水生所知识产出(2009年前)_学位论文

Files in This Item:
File Name/ File Size Content Type Version Access License
鱼类远缘杂交后代同工酶基因表达和调控的研究001.pdf(1650KB)----暂不开放-- 联系获取全文

Recommended Citation:
鱼类远缘杂交后代同工酶基因表达和调控的研究.傅洪拓[d].中国科学院水生生物研究所,1988.20-25
Service
Recommend this item
Sava as my favorate item
Show this item's statistics
Export Endnote File
Google Scholar
Similar articles in Google Scholar
[傅洪拓]'s Articles
CSDL cross search
Similar articles in CSDL Cross Search
[傅洪拓]‘s Articles
Related Copyright Policies
Null
Social Bookmarking
Add to CiteULike Add to Connotea Add to Del.icio.us Add to Digg Add to Reddit
所有评论 (0)
暂无评论
 
评注功能仅针对注册用户开放,请您登录
您对该条目有什么异议,请填写以下表单,管理员会尽快联系您。
内 容:
Email:  *
单位:
验证码:   刷新
您在IR的使用过程中有什么好的想法或者建议可以反馈给我们。
标 题:
 *
内 容:
Email:  *
验证码:   刷新

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.

 

 

Valid XHTML 1.0!
Copyright © 2007-2016  中国科学院水生生物研究所 - Feedback
Powered by CSpace