中国水产科学研究院长江水产研究所(简称"长江所") 是隶属于国家农业农村部的科研事业单位,于1958年成立,经过60 年的发展,已成为我国淡水渔业综合性的重点研究机构. 经人力资源和社会保障部、全国博士后管理委员会批准, 根据 "人社部发〔2010〕60号"文件,长江所于2010年9月正式设立工作站,2011年6月与华中农业大学签订联合招收博士后协议,当年11月招收首个博士后,工作站在2015年度博士后综合评估中被评为良好级.长江所工作站设站至今共招收博士后8人, 其中5人已出站,3人在站, 经过数年的建设,已经形成了一套行之有效的运行机制,获得了一定的经验,也发现了一些具有公益事业单位特点的问题.

我国实行博士后制度始于1985年,招收的平台主要是博士后科研流动站和博士后科研工作站两类,其中博士后科研工作站(简称"工作站")是指在企业、科研生产型事业单位和特殊的区域机构内,经批准可以招收和培养博士后研究人员的组织.我国首个工作站于1994年在上海宝山钢铁公司成立,经过多年的发展,工作站已成为我国推动人才强国战略和创新驱动发展战略的重要平台.本文以中国水产科学研究院长江水产研究所博士后科研工作站为研究对象,在总结经验的基础上,通过与合作导师、博士后、兄弟单位专职人员交流获取第一手信息,对科研事业单位的博士后培养工作进行了较为深入的总结思考,介绍了一些经验做法.

The present study aims to uncover the relationship between the phenotypic sex and genotypic sex and the growth rate of male and female half-smooth tongue sole and to select the excellent families with high female proportion.In this paper,we firstly established 22 half-smooth tongue sole families which were cultured in the same pond.Secondly,we identified the offspring's phenotypic sex and genotypic sex of 5 normal male families and 5 neo-male families.This study shows that there are significant differences not only in growth rate but also in proportion of male to female.Two fast-growing families(No.16 and No.61)whose relative weight gain rate were 0.81 g/d and 0.56 g/d and 4 relatively fast-growing families(No.21,No.28,No.57 and No.63),the relative weight gain rate ranges from 0.48 g/d to 0.53 g/d were selected;12 commonly-growing and 4 slow-growing families were selected also.The average ratios of genotypic female and phenotypic female of the 5 normal male(ZZ)families were 51.87% and 42.94%,and the ratio of genotypic female reversing to phenotypic male was 14.08%.Instead,the average genotypic female and phenotypic female ratio of the 5 neo-male(ZW)families was 49.34% and 4.45%,respectively,and the ratio of genotypic female reversing to phenotypic male was 91.41%.In the present study we found for the first time that there were significant differences in phenotypic sex ratio between different families.We also found that the genotypic females in neo-male families were more easily reversed to phenotypic males,which increased the number of phenotypic males in cultured populations.It initially showed that the families with high female proportion and fast growing rate could be selected via family selection,which could provide theories and new technical methods for the breeding and the production of high quality seeding of half-smooth tongue sole.

本研究克隆了半滑舌鳎（Cynoglossus semilaevis）AMH基因并对其进行表达分析。该基因cDNA序列开放阅读框长为1 563 bp,编码蛋白含520个氨基酸。该蛋白含有TGF-β超家族的特征序列,包含1个AMH-N区域和TGF-β结构域,并在C端生物活性区含有9个保守的半胱氨酸残基。系统进化分析表明,半滑舌鳎AMH和所有鱼类AMH聚为一簇,与鲽形目相似性最高。实时定量结果表明,AMH基因在半滑舌鳎不同组织中有差异表达,在正常雄鱼和伪雄鱼性腺中表达量最高。胚后不同时期性腺的实时定量结果表明,性腺分化之前AMH在精巢中相对表达量较低,70 dph（days post hatching）达到最高峰,而在卵巢中呈现先升高后下降的趋势,预示AMH基因可能在半滑舌鳎性腺发育中起重要作用。较正常雄鱼后代而言,AMH基因在伪雄鱼后代的雄鱼和伪雄鱼性腺中的表达都有升高的趋势,而在雌鱼中无明显差异,也预示其可能参与半滑舌鳎的性反转过程。

为研究HIRA基因在半滑舌鳎胚胎发育中的作用及其组织差异表达,以半滑舌鳎为研究对象,采用同源克隆策略从其精巢中分离了长度为764bp的HIRA部分cDNA序列,该片段编码254个氨基酸,具有5个WD结构域.对氨基酸进行比较发现,半滑舌鳎HIRA与比较物种的氨基酸序列具有很高的同源性,与红鳍东方鲀亲缘关系最近.实时定量PCR分析发现,HIRA mRNA在多细胞期到原肠胚期的表达量较高,表明HIRA对胚胎发育起重要作用;HIRA在不同组织中表达差异显著,其中在性腺中表达最高,推测HIRA在维持性腺的功能方面有一定作用.

Anti-Mullerian hormone(AMH),also known as Mullerian inhibiting substance(MIS),is a glycoprotein belonging to the transforming growth factor β superfamily,which plays a major role during reproductive development in vertebrates.We isolated and characterized AMH cDNA in the half-smooth tongue-sole,Cynoglossus semilaevis.The open reading frame(ORF) of this gene spans a region of 1 563 bp and codes 520 amino acids. Sequence alignment analysis revealed that the AMH of half-smooth tongue-sole and pleuronectiformes shared 61.7% homology.We evaluated the pattern of AMH mRNA expression in 14 tissues of the half-smooth tongue-sole.Expression level was highest in male and neo-male gonads,followed by the blood,skin,and brain. AMH expression was low prior to 70 dph(days post hatching) but was highest in the testis 70 dph.In the ovary, AMH expression increased then decreased,suggesting it plays a role during reproductive development.Furthermore, in contrast with normal offspring,the gonad of male and neo-male non-normal offspring exhibited an increased in expression,but there was no change in females.This suggests that the AMH gene is required for sex reversal.

We detected the genetic sex and the occurrence of sex reversal in eight normal families and their male parents in the half-smooth tongue sole(Cynoglossus semilaevis Gunther) using the SSR female-specific marker scaffold 1128_343 and a gonad slice.The proportion of females in eight normal families(28,30,38,39,40,44,57, and 69) ranged from 37.93 to 55.00%.The genetic sex of four of the eight normal families(28,39,44,57) was detected twice,and the proportion of femalesdid not exibit significant difference between two tests(P0.05).We detected both the genetic sex and physiological sex in four of the eight normal families(28,39,44,and 57) and in all the male parents.The proportion of physiological females ranged from 18.75%.46.88% among the four families, and was lower than the proportion of genetic females.Our results suggest there are inter-family differences in the proportion of females undergoing sex-reversal.The present study also suggests that a significant number of male parent fishes(28.42%) are neo-males.Our results suggest that sex reversal is a natural phenomenon in the half-smooth tongue sole breeding population.Furthermore,we reveal the pedigrees of different physiological spawner ratio have significant differences.Our observations provide a theoretical basis for developing methods to culturing families that have a high proportion of female larvae.

[Objective]This research aimed to understand the cultured genetic gender proportion and the female vs. male gonadal development process of Cynoglossus semilaevis groups in order to provide reference for high proportion female breeding. [Method]The sex linkage microsatellite markers scaffold1128_343 was used to detect the juvenile female proportion variation characteristics of the two groups of half-smooth tough sole; combined with the genetic sex identification and paraffin section technique, the gonad sexual maturity development was also observed through tracking the two groups from 25 days old to 2 years old. [Result]From the results of genetic sex identification performed on the two breeding groups of half-smooth tough sole aged 12 to 76 days,the average genetic female percentage of group I and group II was respectively 50.00 and 50.23%, which coincided with the 1∶1 distribution. The female and male gonadal structure of early half-smooth tough sole gonad development (25 days old) had no significant difference, but starting from the age of 56 days, the female and male gonadal structure started to display visible differences. At 76 days of age, the female and male gonadal structure showed obvious visible differences. At 106 days of age, the female and male gonads appeared to be obviously differentiated, which, though the gonadal biopsy meothd, the female and male gender could be identified. [Conclusion]The female vs. male ratio of Cynoglossus semilaevis accorded with the 1∶1 distribution. The female gonad development and differentiation were faster than those of the male gonad development, but the development processes were more complex.

The taxonomy of Symphysodon is mainly based on morphology,however,there has been some disagreement on whether one species or two about this genus.In order to study the phylogenetic relationship of Symphysodon and probe into its taxonomy status on molecular level,we sequenced and compared 276 base pairs of mitochondrial D-loop gene sequences from S.aequifasciata aequifasciata,S.a.axelrodi and S.discus,phylogenetic trees were constructed with neighbor-joining method and unweighted pair group method and obtained the same topology.The results showed that: The genetic distance of the 276 bp D-loop gene sequence was 0.004-0.015 among individuals of S.discus;0.042-0.050 between S.a.aequifasciata and S.discus,0.034-0.038 between S.a.axelrodi and S.discus,and 0.050 between S.a.aequifasciata and S.a.axelrodi.The difference between two species of S.discus and S.aequifasciata was close to that of two subspecies between S.a.aequifasciata and S.a.axelrodi,which indicated that S.discus perhaps had not evolved to the level of species.

Mitochondrial cytochrome b(cytb) gene complete sequences of Symphysodon aequifasciata aequifasciata,S. a. axelrodi and S. discus were amplified with PCR technique and sequenced. By comparing with the same gene sequence of S. a. haraldi recorded in the GenBank,the sequences of 1137 bp DNA had 23 nucleotide sites substituted (2.02%),among of them 22 base substitutions were transition and only one was transversion,most of the base substitution happened in the third locus of the codon. The genetic distance of the cytb gene sequence was ~0.005 -0.01 between S. discus and the other three S. aequifasciata,and 0.012-0.014 among S. a. aequifasciata、S. a. axelrodi and S. a. haraldi,which indicated that S. discus perhaps did not evolve to the level of species. Phylogenetic trees were constructed with neighbor-joining method and unweighted pair group method using arithmetic average method.