| 摘要: |
| 于1994-1996年，分别在威海海洋渔业捕捞公司（石岛）和鸿洋实业总公司龙须岛育苗场采集人工培育的3－5龄牙鲆亲鱼，采用紫外线照射法使牙鲆精子遗传物质失活，并用冷休克法抑制受精卵第二极体释放，从而获得雌核发育二倍体牙好。原肠期采用空气干燥法、Giemsa染色，得到雌核发育二倍体、正常二倍体及单倍体的染色体制片，进行染色体和核型的分析。结果表明，牙鲆的雌核发育二倍体和正常二倍体的染色体数均为2n=48，核型为48t，即48条端部着色点染色体，臂数NF=48，两者的核型设有明显差异；单倍体为24条端部着丝点染色体；在3个组别中，第一号染色体上都有一明显的次缢痕。雌核发育二倍体牙鲆的诱导率为98％。 |
| 关键词: 牙鲆 雌核发育 二倍体 单倍体 核型 染色体 |
| DOI： |
| 分类号: |
| 基金项目:国家“863”计划资助资助项目，963052号 |
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| CHROMOSOME AND KARYOTYPE EVIDENCE OF ARTIFICIAL-INDUCED GYNOGENESIS IN THE OLIVE FLOUNDER PARALICHTHYS OLIVACEUS (T. ET S.) |
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LIU Jing, YOU Feng, WANG Xin-cheng, XU Yong-li, ZHANG Pei-jun
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Institute of Oceanology,the Chinese Academy of Sciences,Qingdao,266071
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| Abstract: |
| Since there exist obvious growth differences between the male and female olive flounder, i.e., the female grows faster than the male, and the number of the female is smaller than the male, the production of the olive flounder is limited. Gynogenesis is considered to be an efficient method to solve these problems. For this purpose, gynogenetic induction of the olive flounder was carried out by cold shock 3–4 min after activation of the eggs with sperm which had been inactivated with UV irradiation during 1994 to 1996. The normal diploidy, gynogenetic diploidy and haploidy olive flounder were obtained and cultured under normal conditions. Chromosome samples of the three groups were prepared by air-dried method. Observations and analyses of chromosome spreads show that there are 48 acrocentric chromosomes in both normal and gynogenetic diploid. Their karyotype formula were 48t, NF=48. In haploid there were 24 acrocentric chromosomes. A secondary constriction was observed in No.1 chromosomes in all groups. There was no obvious difference in karyotype between normal and gynogenetic diploid.
The sex determination in olive flounder is of the female homogametic (XX) and male heterogametic (XY) type. Manipulation of such a system using gynogenesis gives diploid fish that are both genetically and phenotypically female, because the homogametic haploid gynogenetics is produced when the irradiated sperm is used to fertilize eggs, and diploidisation of the gynogenetic genome is achieved by temperature shocks. The present study also shows that the induction rate of the gynogenetic diploid in olive flounder was 98%; elsewhere, it was reported that a 100% production of all-female gynogenesis was obtained in the same species in Japan. The failure to produce 100% gynogenesis might be due to the limited conditions of treatment of sperm. By the optimization of inducing conditions, the results may be further improved. |
| Key words: Paralichthys olivaceus (T. et S.), Gynogenesis, Diploid, Haploid, Karyotype, Chromosome |
