黑鲷DMRT1基因cDNA片段的克隆和序列分析

根据其他鱼类DMRT1基因中的保守序列设计了一对简并引物 ,利用反转录 多聚酶链式反应 (RT PCR)的方法克隆了黑鲷 (Acanthopagrusschlegeli)DMRT1基因cDNA的一个片段 .该片段长 13 8bp ,推导的氨基酸序列由 45个氨基酸残基组成 .同源性分析表明 ,该cDNA片段与其他鱼类DMRT1基因序列具有较高的同源性     

许氏平鲉(Sebastes schlegelii)TRAF基因的鉴定及其响应杀鱼爱德华氏菌侵染的表达模式研究

TRAF是机体内一种具有信息传导作用的胞内因子, 承担多个受体家族的信号转导工作, 在固有免疫以及获得性免疫方面都发挥出重要作用。TRAF作为一类胞内接头蛋白, 对多条信号途径的活化具有一定的影响, 包括细胞的增殖、生存、凋亡、炎症反应、免疫反应等。目前已有研究表明鱼类中的TRAF基因也发挥重要的免疫防疫作用。以许氏平鲉为研究对象, 基于基因组和转录组的数据库, 进行了许氏平鲉TRAF基因家族的系统鉴定。在许氏平中共鉴定到9个TRAF基因, 并对这些TRAF基因的长度和氨基酸个数进行了统计分析。同时, 分析了这9个TRAF基因的结构特征。选取了包括许氏平鲉在内的6种鱼类进行了TRAF基因的共线性分析。结果显示, TRAF基因在硬骨鱼类中具有保守的共线性。通过系统发育分析, 更好地解析了TRAF家族基因的进化关系, 同时也证明了对其鉴定及命名的准确性。此外, 还进行了TRAF家族基因的蛋白质相互作用网络预测以及表达模式分析。通过蛋白质相互作用的网络分析, 得到TRAF基因与其互作蛋白的关联状况。在杀鱼爱德华氏菌侵染许氏平鲉后的不同时间点, 探究TRAF基因在杀鱼爱德华氏菌刺激下的表达模式。定量结果显示, 除TRAF4.1外, 其他TRAF基因在感染后均存在不同程度的上调。综上所述, 从分子水平上揭示了许氏平鲉TRAF家族基因的结构和功能, 揭示了TRAF可能依赖的免疫通路, 为进一步探究TRAF家族基因在许氏平先天免疫过程中的作用奠定了基础。     

许氏平鲉(Sebastes schlegelii)速生选育群体的生长性能与遗传特征分析

本研究目的为开展许氏平鲉(Sebastes schlegelii)遗传改良和优质新品系选育,选取荣成(R)和长岛(C)的野生许氏平鲉为基础群体,采用群体选育(群体内和群体间)和家系选育相结合的方法,获得R-F1、RC-F1两个群体选育群体和R-F2、RC-F2、R-F3、RC-F3四个家系选育群体。对4个选育家系的生长性能进行比较分析,并利用20对高多态性的微卫星标记对8个群体进行遗传多样性检测。结果表明:(1)群体内和群体间家系选育子3代比家系选育子2代生长速度分别提高21.59%和30.99%。4个选育家系后代的绝对增重率随着天数的增加而上升,群体内家系选育(R-F3)的生长速度、绝对增重率显著大于群体间的杂交选育系(RC-F3),杂交系未表现出生长的杂种优势。(2)20对微卫星位点在所有群体中均表现出较高多态性,8个群体的平均有效等位基因数(Νe)为2.9849—7.9598,平均观测杂合度(oH)和期望杂合度(He)分别为0.7230—0.8405和0.6315—0.8716,平均多态信息含量(PIC)为0.6472—0.8478。经两代家系选育的R-F3和RC-F3平均等位基因数显著降低,但观测杂合度(Ho)和期望杂合度(He)均值仍达到0.7230、0.7549和0.6527、0.6315,还有维持了较高的遗传多样性水平,遗传潜力较大。Hardy-Weinberg平衡检测结果和遗传偏离指数(d)表明各群体在大约10个位点上表现出一定程度的杂合子缺失现象。群体间平均遗传分化系数(Fst)为0.1279,各群体间存在中等遗传分化程度。R与R-F1分别与RC-F3遗传距离最远(0.9959、0.9848),预测利用两组群体中生长优良个体分别进行杂交育种有可能获得杂种优势。     

许氏平鲉消化道形态学和组织学的初步研究

许氏平鲉Sebastes schlegeli (Hilgendorf)消化 道短,具有肉食性鱼类的典型特征。 可分为口咽腔、食道、胃、小肠、直肠和肛门。口咽 腔上皮为复层上皮,上皮内有味蕾分布。咽后消化道的管壁可分为四层：粘膜层、粘膜下层 、肌层和浆膜层。其中变化最大的是粘膜层上皮。食道为复层上皮,部分区域具有由单层柱 状上皮细胞构成的突起。胃Y形,粘膜表层为单层柱状上皮,胃贲门部和盲囊部都具有发达 的皱襞和胃腺,胃幽门部无胃腺。小肠上皮为单层柱状上皮,小肠绒毛发达。小肠与直肠连 接处有瓣膜。直肠粗短,其上皮为假复层柱状上皮。     

Use of calcein and alizarin red S for immersion marking of black rockfish Sebastes schlegelii juveniles

Black rockfi sh Sebastes schlegelii juveniles(30–40 mm total length) were immersed in a range of calcein(CAL) solutions at concentrations ranging from 50 to 250 mg/L and alizarin red S(ARS) solutions at concentrations ranging from 100 to 500 mg/L in fi ltered seawater(salinity 30) for 24 h. Fluorescent marks were detected in otoliths(sagittae, asteriscus), scales, fi n rays(dorsal, pectoral, ventral, anal, and caudal fi n rays), and fi n spines(dorsal, ventral, and anal fi n spines) after a 60-d growth experiment. With the exception of 50–100 mg/L CAL, acceptable marks were produced in the otoliths and fi n spines by all concentrations of CAL and ARS. In particular, marks were clearly visible under normal light in the sagittae, asteriscus, and fi n spines of fi sh immersed in 200–500 mg/L, 300–500 mg/L, and 200–500 mg/L ARS, respectively. Scales and fi n rays had acceptable marks at much higher concentrations(≥50 mg/L CAL, ≥300 mg/L ARS for scales and ≥50 mg/L CAL, ≥200 mg/L ARS for fi n rays). The mark quality was highest(i.e., acceptable marks were observed in all sampled structures after immersion marking) in fi sh immersed in 150–250 mg/L CAL or 300–500 mg/L ARS. In addition, there was no signifi cant difference in survival and growth of marked fi sh compared with controls 60 d post-marking( P 0.05).     

Histological Observation of Germ Cell Development and Discovery of Spermatophores in Ovoviviparous Black Rockfish（Sebastes schlegeli Hilgendorf） in Reproductive Season

Black rockfish（Sebastes schlegeli） is an important species for culture; however, its reproductive characteristics have not been fully documented. In this study, we investigated the morphology and developmental process of germ cells in this ovoviviparous rockfish in reproductive season（October 2011–November 2012） with histological methods. We found that the gonad of mature fish showed notable seasonal changes in developmental characteristics and morphological structure. The sperm cells matured during a period lasting from October to December, significantly earlier than the oocytes did. A large number of spermatozoa and other cells occurred in testis at different developmental stages. Vitellogenesis in oocytes began in October, and gestation appeared in April next year. Spermatophores were discovered for the first time in Sebastes, which assembled in testis, main sperm duct, oviduct and genital tract, as well as ovarian cavity in October and April. These organs may serve either as production or hiding places for spermatophores and spermatozoa which were stored and transported in form of spermatophores. Testicular degeneration started from the distal part of testis in April, with spermatophores assembled in degenerating testis and waiting for transportation. The copulation probably lasted for a long period, during which the spermatozoa were discharged in batches as spermatophores. These spermatophores were coated with sticky materials secreted from the interstitial areas of testis and the main sperm duct, then transported into ovary.