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1.
橄榄蛏蚌性腺发育与生长 总被引：1，自引：0，他引：1
2008年8月—2009年10月,每月采集一批橄榄蛏蚌,分别进行可量性状的测定和年龄鉴定,并研究了其肥满度周年变化规律。为了揭示其繁殖特性,取繁殖季节性腺制作石蜡切片,经苏木精和伊红染色后在显微镜下观察其形态结构,并测量性腺细胞的直径。结果表明,橄榄蛏蚌的肥满度在每年的5月出现最高峰,且一年只有一个高峰,因而橄榄蛏蚌繁殖为一年产卵一次、繁殖一次。橄榄蛏蚌性腺细胞直径为49.3～70.2μm。随着水温的升高,橄榄蛏蚌的摄食活性增强。统计学数据分析表明,橄榄蛏蚌体质量与壳长、壳宽和壳高均呈指数关系,而后三者之间呈线性关系。对体质量影响最大的指标是壳高,最小的指标为壳长。 相似文献
2.
三角帆蚌稚蚌形态发育与生长特性 总被引：4，自引：1，他引：3
在人工繁育现场,水温为26.5～32.0 ℃的条件下,对三角帆蚌钩介幼虫寄生期结束至发育到呈三角形的稚蚌阶段的形态变化过程进行了连续观察。结果发现三角帆蚌稚蚌形态发育过程根据其变化特点可分为4个阶段。刚脱落的稚蚌平均壳长221.88 μm,此时帆没有形成,全高等于壳高;前4 d里稚蚌增厚显著,为贝壳增厚期。5 d后到第23天,壳顶开始突起,为壳顶突出期;此期出现了一个显著的变化,到15 d时,壳顶后端生长速度超过了前端。23 d后到第34 天,翼开始出现,为两翼形成期。34 d后到第60 天,帆开始形成,为帆生长期;此期全高和壳高的比例加大,壳顶不再是稚蚌的最高点。从第60天开始,外型与成体相似,稚蚌发育阶段完成。三角帆蚌稚蚌发育过程中最明显的变化是壳顶位置的变化。对三角帆蚌稚蚌生长特性的研究表明：壳长与日龄的关系式为L=329.39e0.059t（r=0.968）,全高与壳长的关系式为H=0.776L-103.36（r=0.997）。 相似文献
3.
舟山渔场银鲳和灰鲳繁殖特性的比较 总被引：16，自引：3，他引：16
用常规的生物学调查方法对舟山渔场银鲳和灰鲳进行了周年的取样调查分析，并对其性腺做石蜡切片，观察性腺发育情况，对银鲳和灰鲳的繁殖特性进行比较研究。结果表明：银鲳和灰鲳在繁殖季节性比为1∶1；两者的性腺发育和卵母细胞发育没有显著差异（P>0.05），Ⅴ时相的卵母细胞卵径都为700～870 μm，油球1个，油球径260～400 μm，初级卵膜厚度12～19 μm；都为一个繁殖期内多次产卵类型的鱼类；繁殖期内银鲳、灰鲳雌性生殖群体的平均叉长分别为22.5 cm、29.0 cm，银鲳雄性生殖群体叉长主要集中在14.0～17.0 cm，灰鲳雄性生殖群体叉长为23.0～25.5 cm；银鲳的繁殖季节在每年的4月初至6月初，繁殖高峰在4月中旬到5月中旬，银鲳卵巢成熟系数最高可达25%；而灰鲳的繁殖期在每年的6月初至8月中旬，繁殖高峰在6月下旬到7月下旬，灰鲳的卵巢成熟系数最高只有12.6%。银鲳繁殖期的水温为18～24 ℃，灰鲳为24～28 ℃；其他环境条件差异不大。另外还对银鲳和灰鲳卵母细胞发育的特征、繁殖期内卵巢成熟系数的变动以及繁殖期内环境因子的变动对产卵群体的数量影响进行了讨论。 相似文献
4.
鸭绿沙塘鳢繁殖习性的观察及性腺发育周期的组织学研究 总被引：5，自引：0，他引：5
周年调查了鸭绿沙塘鳢的繁殖习性,观察了其性腺发育的周年组织学变化.试验结果表明,鸭绿沙塘鳢Ⅰ龄性成熟,分批产卵,雄鱼护卵,繁殖旺季为4-6月,补充群体6月开始繁殖.1、2月雌雄鱼的比例为1 : 2,3月至繁殖季节急剧增至1 : 2～3,10-12月约1 : 1.1-5月雌鱼的成熟系数急剧增加,5-6月急剧下降,7月后上升后又逐渐下降.11月至翌年3月,雄鱼的成熟系数最低, 3-4月急剧上升,5-6月略有下降,7-9月又略上升后而降低.破膜后40 d为Ⅰ期精巢; 60～70 d为Ⅱ期,精原细胞呈束排列;约130 d发育至Ⅲ期;约230 d发育至Ⅳ期,精巢内除精原细胞、精母细胞外,还有少量直径3.15～4.20 μm的精子细胞;约360 d(翌年4-6月)为Ⅴ期,有少量长径为2.10 μm的精子.7月Ⅵ期的壶腹内,部分精子排出,但仍有大量残留.破膜后53 d雌鱼的卵巢为Ⅰ期,卵原细胞直径9.1～10.1 μm,同步发育;150 d发育至Ⅱ期,卵母细胞直径83.3～124.3 μm,细胞核直径71.0～97.2 μm,细胞质嗜碱性,核膜内侧有多个核仁,卵母细胞外有一层滤泡细胞,放射膜不明显.约220 d发育至不同步的Ⅲ期,有Ⅰ、Ⅱ期的卵细胞,滤泡膜和放射膜明显.约280 d(翌年3月)卵巢发育至第Ⅳ期,初级卵母细胞体积增大,充满卵黄颗粒,辐射带增厚.滤泡膜、放射膜和细胞膜厚度分别为7.8、13.0、13.2 μm.约370 d(4-5月)发育至Ⅴ期.雌、雄鱼分别以Ⅲ期和Ⅳ期性腺越冬. 相似文献
5.
长江口纹缟虾虎鱼繁殖季节的性腺组织学 总被引：2，自引：0，他引：2
采用常规组织切片法研究了长江口纹缟虾虎鱼各期卵巢和精巢的组织学结构特征.结果表明,每年的4、5、6月为长江口纹缟虾虎鱼的繁殖季节.进入繁殖季节的卵巢以Ⅳ期为主,4-6月的Ⅳ期卵巢分别占当月总数的62.32%、71.43%和48.41%.Ⅲ期卵巢只占当月总数的24.55%、12.33%、6.28%;Ⅴ期卵巢占13.13%、10.45%和26.67%;5、6月份Ⅵ期卵巢占5.89%、18.10%.Ⅲ～Ⅵ期的性腺指数(GSI)分别为4.49%±2.07%、31.75%±7.08%、38.33%±6.24%和7.78%±3.18%.4-6月精巢均处于Ⅳ、Ⅴ、Ⅵ期,4月以Ⅳ期为主,5、6月以Ⅴ期为主.Ⅳ～Ⅵ期精巢的GSI分别为0.66%±0.07%、0.96%±0.14%和0.43%±0.06%.纹缟虾虎鱼卵母细胞发育可以分为5个时相.Ⅲ期卵巢以第Ⅲ时相卵母细胞为主,这时期液泡、卵黄颗粒出现,同时含有少量Ⅰ时相和Ⅱ时相的卵母细胞;Ⅳ期卵巢以第Ⅳ时相卵母细胞为主,Ⅳ时相晚期卵母细胞开始出现油球,细胞核偏移和变形,放射带明显;Ⅴ期卵巢的卵细胞游离,卵膜外的二层滤泡膜脱落;Ⅵ期卵巢主要由第Ⅱ、Ⅲ时相卵母细胞和大量的空滤泡外膜组成.纹缟虾虎鱼精巢为小叶型,精巢内生殖细胞分为初级精母细胞、次级精母细胞、精细胞和精子,各期生殖细胞和支持细胞组成了精小囊,同一精小囊中的生精细胞发育同步.精子成熟后,精小囊破裂释放精子进入小叶腔,完成发育过程. 相似文献
6.
采用组织学方法系统研究了人工养殖条件下半滑舌鳎亲鱼卵巢的组织发育周年变化特征.结果表明,卵母细胞发育可分为6个时相,卵巢发育分为6期.卵巢不同发育时期都由不同类型的卵母细胞组成,半滑舌鳎为非同步分批多次产卵类型.周年发育过程中,6月龄前的鱼卵巢发育处于第Ⅰ期;9～12月龄卵巢可发育至第Ⅱ期;12月龄半滑舌鳎性腺可发育达到Ⅲ期,并一直保持至24月龄.3龄雌鱼达到性成熟,卵巢可发育至第Ⅳ期;随着水温和光周期的调控,卵巢发育进入成熟期(Ⅴ期),发生水合现象是卵母细胞成熟并准备排卵的信号;产卵结束后卵巢退化至第Ⅵ期,排出的卵母细胞退化吸收,以Ⅲ期卵巢越冬后,卵巢退化至Ⅱ期并持续至下一个繁殖周期.人工养殖条件下,卵巢内存在卵母细胞闭锁现象.性腺周年发育过程中,性腺指数(GSI)在性腺达到成熟期时达到峰值,产卵结束后性腺快速退化,GSI值各月份差异显著(P<0.05),亲鱼性腺重量在卵巢发育成熟过程中一直处于生长状态.亲鱼肝脏指数(HSI)在产卵前7～8月份(性腺达到成熟期前30 d左右)达到最大,表明7～8月份是性腺进行卵子发育、卵黄能量储备的重要时期,亲鱼在产卵前通过积极摄食储备体内能量,肝脏在卵母细胞卵黄积累方面具有重要的生理作用.肥满度(CF)值在繁殖盛期10～11月份达到最大,表现出与GSI类似的变化趋势. 相似文献
7.
2013年4月–2014年3月,采用组织学和实验生态学方法研究了山东莱州湾海域小刀蛏(Cultellus attenuatus)的性腺发育、生殖周期、胚胎及幼虫发育。结果显示,在繁殖季节,小刀蛏性别可通过性腺颜色区分,雌性为白色,雄性为黄色;1个生殖周期为1年,性腺发育经历增殖期、生长期、成熟期、排放期和休止期5个阶段;莱州湾繁殖期为6月中旬–7月上旬。小刀蛏受精卵卵径为50–55 μm,在水温26℃、盐度28的条件下,经24 h发育至D形幼虫,10 d后幼虫发育变态为稚贝。对莱州湾小刀蛏繁殖生物学的研究,可为该海域小刀蛏的人工育苗和增养殖提供科学依据。 相似文献
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摘要：采用常规组织切片法研究了长江口纹缟虾虎鱼各期卵巢和精巢的组织学结构特征。结果表明,每年的4、5、6月为长江口纹缟虾虎鱼的繁殖季节。进入繁殖季节的卵巢以Ⅳ期为主,4～6月份的Ⅳ期卵巢分别占当月总数的62.32%、71.43%和48.41%。Ⅲ期卵巢只占当月总数的24.55%、12.33%、6.28%;Ⅴ期卵巢占13.13%、10.45%和26.67%;5、6月份Ⅵ期卵巢占5.89%、18.10%。Ⅲ～Ⅵ期的性腺指数（GSI）分别为4.49%±2.07%、31.75%±7.08%、38.33%±6.24%和7.78%±3.18%。4～6月精巢均处于Ⅳ、Ⅴ、Ⅵ期,4月份以Ⅳ期为主,5、6月份以Ⅴ期为主。Ⅳ～Ⅵ期精巢的GSI分别为（0.66±0.07）%、（0.96±0.14）%和（0.43±0.06）%。纹缟虾虎鱼卵母细胞发育可以分为5个时相。Ⅲ期卵巢以第Ⅲ时相卵母细胞为主,这时期液泡、卵黄颗粒出现,同时含有少量Ⅰ时相和Ⅱ时相的卵母细胞;Ⅳ期卵巢以第Ⅳ时相卵母细胞为主,Ⅳ时相晚期卵母细胞开始出现油球,细胞核偏移和变形,放射带明显;Ⅴ期卵巢的卵细胞游离,卵膜外的二层滤泡膜脱落;Ⅵ期卵巢主要由第Ⅱ、Ⅲ时相卵母细胞和大量的空滤泡外膜组成。纹缟虾虎鱼精巢为小叶型,精巢内生殖细胞分为初级精母细胞、次级精母细胞、精细胞和精子,各期生殖细胞和支持细胞组成了精小囊,同一精小囊中的生精细胞发育同步。精子成熟后,精小囊破裂释放精子进入小叶腔,完成发育过程。 相似文献
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This study was conducted to gain insight into the characteristics of algal blooms in relation to the marine environment of
Gamak Bay. From the first known occurrence of algal blooms in 1984 until 2006, 23 causal species have been identified, the
most common ones being Prorocentrum sp., Cochlodinium polykrikoides, Chaetoceros sp., Skeletonema costatum, and Heterosigma akashiwo. A principal component analysis indicated that blooms of these species develop under different conditions in terms of water
temperature, salinity, precipitation, and insolation. Field data showed Cochlodinium polykrikoides to be favored by high temperatures and to be euryhaline, whereas Skeletonema costatum appeared to be eurythermal and euryhaline. Prorocentrum sp. and Chaetoceros sp. appeared to be stenothermal and stenohaline. Finally, Heterosigma akashiwo appeared at the lowest temperature and highest salinity of the five species and was classified here as stenothermal and stenohaline. 相似文献
12.
Garth L. Fletcher Madonna J. King Ming H. Kao Margaret A. Shears 《Fish physiology and biochemistry》1989,6(2):121-127
Several species of marine teleosts have evolved blood plasma antifreeze polypeptides which enable them to survive in ice-laden seawater. Four distinct antifreeze protein classes differing in carbohydrate content, amino acid composition, protein sequence and secondary structure are currently known. Although all of these antifreezes are relatively small (2.6–33 kd) it was generally thought that they were excluded from the urine by a variety of glomerular mechanisms. In the present study antifreeze polypeptides were found in the bladder urine of winter flounder (Pseudopleuronectes americanus), sea raven (Hemitripterus americanus), ocean pout (Macrozoarces americanus) and Atlantic cod (Gadus morhua). Since the plasma of each of these fish contains a different antifreeze class it would appear that all four classes of antifreeze can enter the urine. The major antifreeze components in the urine of winter flounder were found to be identical to the major plasma components in terms of high performance liquid chromatography retention times and amino acid composition. It is concluded that plasma antifreeze peptides need not be chemically modified before they can enter the urine. 相似文献
13.
G. Immanuel T. Citarasu V. Sivaram M. Michael Babu A. Palavesam 《Aquaculture International》2007,15(2):137-152
One of the major problems in the shrimp culture industry is the difficulty in producing high-quality shrimp larvae. In larviculture,
quality feeds containing a high content of highly unsaturated fatty acids (HUFA) and ingredients that stimulate stress and
disease resistance are essential to produce healthy shrimp larvae. In the present study, Penaeus monodon postlarvae (PL15) were fed for 25 days on an unenriched Artemia diet (control; A) or on a diet of Artemia enriched with either HUFA-rich liver oil of the trash fish Odonus niger (B), probionts [Lactobacillus acidophilus (C1) or yeast-Saccharomyces cerevisiae (C2)] or biomedicinal herbal products (D) that have anti-stress, growth-promoting and anti-microbial characteristics. P. monodon postlarvae fed unenriched Artemia exhibited the lowest weight gain (227.9 ± 8.30 mg) and specific growth rate (9.95 ± 0.05%), while those fed the HUFA-enriched
Artemia (B) exhibited the highest weight gain and specific growth rate (362.34 ± 12.56 mg and 11.77 ± 0.08%, respectively). At the
end of the 25-day rearing experiment, the shrimp postlarvae (PL40) were subjected to a salinity stress study. At both low
and high (0 and 50‰) salinities, the group fed the control diet (A) experienced the highest cumulative mortality indices (CMI)
935.7 ± 2.1 and 1270.7 ± 3.1, respectively. Those fed diet D showed the lowest stress-induced mortality, and CMI were reduced
by 31.1 and 32.3% under conditions of low and high salinity stress, respectively. A 10-day disease challenge test was conducted
with the P. monodon postlarvae (PL40–PL50) by inoculating the shrimp with the pathogen Vibrio harveyi at the rate of 105–107 CFU/ml in all rearing tanks. P. monodon postlarvae fed probiont-encapsulated Artemia diets (C1 and C2) exhibited the highest survival (94.3 and 82.3%, respectively) and lowest pathogen load (V. harveyi) in hepatopancreas (5.2 × 102 ± 9.0 × 10 and 4.6 × 102 ± 9.0 × 10 CFU g−1, respectively) and muscle (2.0 × 102 ± 6 × 10 and 1.7 × 102 ± 8.6 × 10 CFU g−1, respectively) tissues. The shrimp that were fed the unenriched Artemia (Control; A) showed the lowest survival (26.33%) and highest bacterial load in the hepatopancreas (1.0 × 105 ± 5 × 103 CFU g−1) and muscle (3.6 × 104 ± 6 × 102 CFU g−1). The shrimp fed the herbal product (D)-enriched Artemia also exhibited enhanced survival and reduced V. harveyi load in the tissues tested compared to the control diet (A) group. The results are discussed in terms of developing a quality
larval feed to produce healthy shrimp larvae. 相似文献
14.
Bacillus subtilis isolated from the intestine of Cirrhinus mrigala (Hamilton) was incorporated into the rearing water of Poecilia reticulata (Peters), Poecilia sphenops (Valenciennes), Xiphophorus helleri (Heckel) and Xiphophorus maculatus (Gunther) at four different concentrations (5 × 108 cells ml−1, 5 × 107 cells ml−1, 5 × 106 cells ml−1 and 5 × 105 cells ml−1) and its effect on fish growth performance and survival, water quality parameters and bacterial population of water were
assessed. The results showed that the addition of bacterial cells in the rearing water resulted in greater survival and a
faster growth rate and, hence, greater length and weight increments of the livebearers. The use of a bioaugmentor in the rearing
water of the livebearing fishes resulted in significantly lower (P < 0.05) concentrations of dissolved organic matter and total ammonium nitrogen. The counts of motile aeromonads and total
coliforms recorded in the water of bioaugmented tanks were also lower than that in the control tank. Bioaugmentation between
106 and 108 cells ml−1 in the rearing water is sufficient in establishing a bioaugmentor and the use of a higher concentration of bacterial cells
did not always lead to significantly better results. 相似文献
15.
T. Citarasu K. Venkatramalingam M. Micheal Babu R. Raja Jeya Sekar M. Petermarian 《Aquaculture International》2003,11(6):581-595
The indiscriminate use of antibiotics and chemicals in shrimp hatcheries has led to biomagnification and that in turn could
lead to rejection of a whole consignment. The application of the bioencapsulation technique as a tool for curative treatment
in shrimp larvae was investigated. Herbs having antibacterial properties such as Solanum trilobatum, Andrographis paniculata and Psoralea corylifolia (methanolic extracts) were bioencapsulated in Artemia and fed to Penaeus monodon post larvae PL 1–25. The post larvae were reared in a medium inoculated with pathogenic bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi and Vibrio sp. Post larvae reared in the non-inoculated water and fed with non-enriched Artemia exhibited 90% survival, highest specific growth rate (12.43%) and reduced bacterial load. P. monodon reared in the bacterial inoculated water and fed with the non-enriched Artemia exhibited the lowest survival (10–30%), specific growth rate (8.42–9.1%) and increased bacterial load (2.86 × 103 to 3.76 × 105 cfu/g). The methanolic extracts of the herbs helped to increase survival and specific growth rate and reduced bacterial load
in the P. monodon culture system. Among the three herbal extracts, P. corylifolia enriched Artemia fed post larvae showed the tendency to higher survival (>50%), growth rate (11.5 averaged) and low bacterial load (1.12 × 105 cfu/g).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
16.
基于线粒体COⅠ和Cytb基因序列的北太平洋柔鱼种群遗传结构研究 总被引：2，自引：1，他引：1
为准确掌握柔鱼的种群遗传结构,拟通过线粒体DNA的COI和Cytb基因序列分析方法对柔鱼不同产卵季节群体的遗传多样性和遗传结构进行研究。经PCR扩增与测序分别获得600 bp COI与481 bp Cytb基因序列。基于COI基因序列分析得到的单倍型数、单倍型多样性指数、核苷酸多样性指数及平均核苷酸差异数分别为24、(0.729 ±0.033)、(0.005 70 ± 0.003 25)和3.421。基于Cytb基因序列分析得到的单倍型数、单倍型多样性指数、核苷酸多样性指数及平均核苷酸差异数分别为28、(0.852 ± 0.016)、(0.006 45 ± 0.003 73)和3.101。分析认为, 北太平洋柔鱼2个产卵季节群体均具有较高的单倍型多样性指数和较低的核苷酸多样性指数。单倍型邻接树、两两群体间的Fst值以及AMOVA分析结果均表明, 北太平洋柔鱼2个产卵季节群体间的遗传差异不显著, 不存在显著的群体遗传结构。初步认为, 该海域因缺乏地理上的障碍, 加之北太平洋海流的作用以及柔鱼个体较强的游泳能力, 使得群体之间具有较强的基因流。 相似文献
17.
Tetsushi Kageyama Tetsuya Yanagida Kenichi Ohara Hiroshi Yokoyama 《Fisheries Science》2009,75(3):657-663
Two types of infection with myxosporean parasites, which were different in cyst size, were found from the gill of Rhinogobius sp. OR collected from the Nagara River, Gifu Prefecture, Japan. A myxosporean forming large-type cysts in the gill filament
was morphologically identified as Henneguya rhinogobii. Another myxosporean forming small-type cysts was found to be parasitic in the gill lamella. Average spore sizes of the latter
myxosporean were 15.8 (range 14.2–17.8) μm in length, 5.3 (4.7–5.8) μm in width, 6.5 (5.9–7.6) μm in polar capsule length
and 34.9 (25.3–42.9) μm in caudal appendage length, which were almost identical to those of H. rhinogobii. However, the two were distinguishable by the location in the gill (intrafilamental or intralamellar) and by the difference
in the sequence of SSU rDNA (about 96% similarity). We propose the myxosporean forming intralamellar small-type cysts as Henneguya pseudorhinogobii n. sp. and redescribe H. rhinogobii by morphological and molecular studies. 相似文献
18.
东太平洋公海茎柔鱼种群遗传结构初步研究 总被引：8，自引：1，他引：7
根据2009年7月到10月我国大型鱿钓渔船在东太平洋(81.9°～94.9°W,8.9°N～11.3°S)秘鲁和哥斯达黎加外海作业期间采集的样本,利用线粒体DNA细胞色素b基因的724 bp部分序列,分析了采自秘鲁7个采样点和哥斯达黎加3个采样点的155个个体的序列多样性与种群遗传结构.结果显示,724 bp片段中发现了16个变异位点,155个个体出现43个单倍型.序列多样性分析结果揭示,155个个体的平均单倍型多样性指数为0.873,核苷酸多样性指数为0.003 69.群体间共享6个单倍型,秘鲁外海茎柔鱼群体享有最多特有单倍型(20个).分子方差分析揭示,82.70％的遗传变异性出现在种群内;群体间的FST分析揭示部分秘鲁群体与哥斯达黎加群体,部分秘鲁群体间存在着显著的遗传分化;而哥斯达黎加群体内部不存在显著的遗传分化. 相似文献
19.
抑食金球藻对翡翠贻贝抗氧化酶系统的影响 总被引：1，自引：0，他引：1
本研究以单种抑食金球藻及其与亚心形四爿藻的混合藻为实验组,以亚心形四爿藻为对照,探究抑食金球藻对翡翠贻贝超氧化物歧化酶(SOD)活性、丙二醛(MDA)和谷胱甘肽(GSH)含量的影响。结果显示,抑食金球藻显著影响翡翠贻贝的SOD活性、MDA和GSH含量,各实验组均表现出诱导升高与抑制降低交替出现的规律。单种高、中浓度的抑食金球藻在短期(3 h)内即可对翡翠贻贝的SOD活性产生影响,混合藻组中的SOD活性上升较慢,说明亚心形四爿藻可以延滞氧化还原系统的反应时间。各实验组翡翠贻贝GSH含量在2 d内均显著低于对照组,且混合藻组与单种抑食金球藻组相差不大,提示亚心形四爿藻对抗氧化还原损伤并未起到明显的缓解作用。 相似文献
20.
为了研究对虾免疫致敏过程中Dscam基因的表达规律,实验采用同源克隆和RACE技术获得了中国明对虾Dscam基因c DNA全长序列,并对该序列进行生物信息学分析。结果显示,中国明对虾Dscam基因的c DNA全长为6 624 bp,其中包括171 bp的5′端非编码区,459 bp的3′端非编码区,开放阅读框的长度为5 994 bp,编码1 996个氨基酸。推测该基因编码的蛋白含有一个信号肽、10个Ig结构域、6个FNIII功能区、1个胞质尾区和1个跨膜结构域。同源性分析及系统进化分析表明,Dscam基因与节肢动物的Dscam基因首先聚为一类,且与凡纳滨对虾的同源性最高,为92.4%。连续投喂6 d热灭活白斑综合征病毒(white spot syndrome virus,WSSV)饵料来诱导免疫致敏反应,在0、6和12 d及二次感染后的12、24、48、72和168 h分别取样,用RT-PCR的方法检测中国明对虾Dscam的相对表达量。结果显示,诱导感染组Dscam基因在第12天开始上调,且与阴性对照组和未诱导感染组差异显著;二次感染后24 h,Dscam基因的相对表达量达到最大值,与阴性对照组和未诱导感染组差异显著;48 h后基因表达量开始下降,但表达量仍高于阴性对照组和未诱导感染组。实验表明,中国明对虾存在Dscam基因,并在免疫致敏过程中发挥重要作用。 相似文献