鲤WISP基因家族的克隆、表达及系统进化树的构建

Wnt1诱导分泌蛋白(WISP)基因家族与CYR61、CTGF、NOV基因共同构成了CCN家族。研究通过鲤基因组序列与斑马鱼WISP基因编码区全序列的比对获得WISP1a、WISP1b、WISP2、和WISP3等4条序列。经过克隆、测序、比对拼接得到其开放阅读框,分别是1 089、1 077、1 038和1 026 bp,它们都是由5个外显子和4个内含子构成,分别编码362、358、345和341个氨基酸。分子系统学分析表明,鲤4个WISP基因具有高度同源性,其中WISP1a、WISP1b和WISP2均含有4个模块,WISP3缺少第2个模块。通过RT-PCR检测WISP基因在鲤组织中的表达,结果表明,WISP1a鲤在13个组织中均有表达,皮肤中表达最高,脾、肠、卵巢次之,其他组织中表达较低。WISP1b在精巢、脑、皮肤、卵巢中表达较高。WISP2在血液、鳃中表达较高。WISP3在血液、脑、肝中表达较高。实时荧光定量PCR法分析WISP基因在鲤胚胎发育时期的表达,结果表明,除WISP3外,WISP1a、WISP1b和WISP2在前期表达较高,36 h表达最低,随后逐渐升高至第6天开始下降。     

锦鲤墨蝶呤还原酶基因的克隆、表达和定位分析

为探究SPR在锦鲤体色形成中的作用,实验利用RACE技术获得spr cDNA全长序列,并分析其时空表达模式,同时利用Western blot和免疫组织化学方法检测SPR蛋白在皮肤、鳍条和鳞片中的分布和表达情况。结果显示,spr cDNA全长879 bp,包含132 bp和134 bp的5′和3′非编码区,开放阅读框510 bp,编码170个氨基酸残基。氨基酸序列比对和系统进化树分析显示,锦鲤SPR具有保守的adh_short_C2结构域,与金鱼相似性高达97.7%。spr在各组织中均有表达,其中皮肤的表达量最高。spr在锦鲤个体发育的4个阶段表现为先降后升。纯红、纯白及红白3种体色锦鲤皮肤、鳞片和鳍条中spr mRNA和蛋白表达水平基本一致,在纯红锦鲤皮肤中表达量最高,红白锦鲤白色皮肤、鳞片和鳍条的表达量最低。SPR组织定位分析显示,红色锦鲤和白色锦鲤皮肤中均检测到阳性信号,其中红色皮肤阳性信号强度高于白色皮肤。研究表明,spr可能与锦鲤红/黄色素细胞的分化和形成具有一定相关性,参与了锦鲤体色的形成。     

Growth and water quality for growing-out of juvenile spotted Babylon, Babylonia areolata, at different water-exchange regimes in a large-scale operation of earthen ponds

Growth and water quality for growing-out of juvenile spotted Babylon, Babylonia areolata, were determined at three water-exchange regimes of 7-, 15- and 30-day intervals in large-scale operation of earthen ponds over a 5-month period. Results showed that growth was significantly different among the water-exchange treatments (P < 0.05). The higher body weight gains and shell length increments were observed in snails held at water exchange of 7- and 15-day intervals when compared with those held at water exchange of 30-day intervals. At the end of the experiment, average body weight gains were 4.22, 3.73 and 2.77 g for snails held in water-exchange treatments of 7-, 15- and 30-day intervals, respectively, and 16.63, 15.04 and 13.78 mm for those of shell length increments, respectively, The average final survivals were 83.60, 80.90 and 74.20% for snails held in water-exchange treatments of 7-, 15- and 30-day intervals, respectively. Seawater temperature, salinity, pH, dissolved oxygen, nitrite–nitrogen and ammonia–nitrogen had gradually changed throughout the culture period for all water-exchange treatments. With one exception, the total alkalinity showed the greatest changes during the culture period for all water-exchange treatments ranging from 58.67–97.50 mg/l.     

不同糖及糖水平对松浦镜鲤养殖过程中糖代谢相关基因表达的影响

为探讨在养殖不同阶段,不同糖及糖水平对松浦镜鲤肝脏糖酵解酶(GK和HK)、糖异生酶(G6Pase和PEPCK)和糖代谢相关基因(IGF-Ⅰ和GHR)m RNA表达水平的影响,实验采用2×2双因素设计实验,选择淀粉和葡萄糖2种糖源,2个糖水平(25%和50%),共4个实验组,分别为低淀粉组(LS)、高淀粉组(HS)、低葡萄糖组(LG)和高葡萄糖组(HG)。选用初始体质量为(8.30±0.15)g的松浦镜鲤420尾,随机分为4组,每组3个重复,每个重复35尾鱼。实验周期为7周。结果显示,不同养殖阶段,HK基因和IGF-Ⅰ基因在不同实验组中的表达趋势基本一致,HK基因在养殖1周时表达量显著升高,之后开始降低,IGF-Ⅰ基因在养殖3周时表达量显著升高。在不同养殖阶段,GK、PEPCK、G6Pase和GHR基因的表达趋势受糖水平和糖种类的影响。在低糖水平下(LS组和LG组),这些基因表现了相同的变化趋势,GK和GHR基因在1周时表达量最高,之后开始下降;PEPCK基因在3周时表达量最高;G6Pase在1周时表达量升高,之后下降,在7周时表达量又有上升趋势。在高糖水平下,HS组的GK基因的表达量在各个养殖阶段差异不显著,而HG组的GK基因则在1周时表达量显著升高;HS组和HG组的PEPCK基因的表达量在各个养殖阶段差异不显著;HS组的G6Pase基因的表达量在各个养殖阶段差异不显著,而HG组的G6Pase基因则在3周时表达量显著升高;HG组的GHR基因的表达量在各个养殖阶段差异不显著,而HS组的GHR基因则在3周时表达量显著升高。在养殖初期(1周),高糖饲料显著促进了HK基因的表达,并抑制了PEPCK、G6Pase和GHR基因的表达。     

Comparison of food selection and growth performance of koi carp, Cyprinus carpio L., and goldfish, Carassius auratus (L.) in mono- and polyculture rearing in tropical ponds

To compare the effect of polyculture against conventional monoculture on ornamental carp production, investigations on food selection and growth performance of koi carp (K), Cyprinus carpio L. and goldfish (G), Carassius auratus (L.) were conducted in a 11‐week rearing experiment in two monoculture (100% K and 100% G) and five polyculture (90% K–10% G, 70% K–30% G, 50% K–50% G, 30% K–70% G and 10% K–90% G) conditions in tropical ponds. There were three replicates for each treatment. Environmental conditions and food availability were similar in all the treatments. Ivlev's electivity index showed that both fish species avoided phytoplankton and preferred cladocerans to other zooplankton groups (copepods and rotifers) in monotypic conditions. However, in the polyculture treatments, the positive electivity of goldfish towards cladocerans reduced significantly (P<0.05), while the percentage of copepods, rotifers and phytoplankton in the gut content increased. No significant differences in weight gain, specific growth rate and deformities were recorded at harvest for koi carp between the different treatments (P>0.05). Even the survival rate of koi carp recorded above 90% in all the treatments. However, the goldfish recorded significantly better weight gain, specific growth rate and survival in monoculture (100% G), compared with the polyculture treatments (P<0.05). Goldfish deformities were lowest (P<0.05) in the monoculture treatment (2.42%). The number of marketable fish above a set size limit of 4 g total weight was significantly higher in the two monoculture treatments, compared with the five polyculture treatments (P<0.05). Keeping in view of the dietary similarities of koi carp and goldfish, and the aggressive nature of koi carp in polyculture, it is suggested to refrain from polyculture of goldfish and koi carp until further documentations relating to optimum stocking density and management of polyculture of ornamental carps are available.     

Characterization of water quality in shrimp ponds of different sizes and with different management regimes using multivariate statistical analysis

Coastal shrimp aquaculture in Bangladesh is mostly practiced in an agricultural unit called a Gher, which is a special type of agricultural field with elevated surrounding embankments/borders situated by the side of a river that is used to grow rice in winter and shrimp in summer. Ghers of different sizes are managed in different ways. An on-farm project was carried out to study the effects of Gher size and their related management practices on water quality, shrimp production and the economic returns of shrimp farming in the Southwest coastal region of Bangladesh. We present here the results of this project with respect to water quality as explored through factor analysis, which was applied as a way to understand the nature and extent of the effects of different variables. For the majority of the variables and factors, one-half to two-thirds of their variability was explained by changes over time (months), and a further one-quarter to one-third was explained by Gher size and associated management practices. The alternating dry/monsoon season and water management practices determined long-term and large-scale (annual) water exchange in the Ghers that mainly affected processes related to live and dead particles suspended in the water column. Processes related to decomposition and nitrification were more dependent on short-term (days) water circulation in the Ghers, which is turn was reliant on the time span between the exchanges of water in the Ghers and river. Our results show that improved management leads to higher natural and shrimp productivity in the smaller Ghers and strongly support the argument put forward by the policy makers and scientific community in Bangladesh that the smaller the Gher, the better they can be managed and the better the possibility of increased shrimp survival and production.     

A comparison of the growth and survival of two freshwater crayfish species, Astacus leptodactylus Eschscholtz and Pacifastacus leniusculus (Dana), under different temperature and density regimes

Growth experiments carried out with two juvenile crayfish species, Astacus leptodactylus Eschscholtz and Pacifastacus leniusculus (Dana), at different temperatures and densities highlighted the problem of cannibalism under conditions aimed at intensifying crayfish production. Cannibalism proved to be much lower in A. leptodactylus than P. leniusculus, suggesting that the former might be the better candidate for astaciculture. In the first of two population survival trials, A. leptodactylus showed a higher survival rate than P. leniusculus, with 26% of P. leniusculus surviving in the first replicate, compared to 42.3% of P. leniusculus, and 40.76% surviving in the second replicate, compared to 47.6% of P. leniusculus. The same trend was observed in the second experiment, with P. leniusculus showing survival rates of 48.5 and 55.3% (first and second replicates, respectively) in comparison to 65.2 and 68.2%, respectively, for A. leptodactylus. It is therefore highly likely that if P. leniusculus were to become established in Turkey, it would outcompete the native A. leptodactylus even if it were not to be devastated by the crayfish plague that has decimated the native species. The experiments also highlighted the problem of differential growth, with some juveniles hardly growing at all while others reached a relatively large size. The range in carapace length (CL) was 9–18 mm for A. leptodactylus and 8.5–18.5 mm CL for P. leniusculus at the end of the first experiment. While both species grew quickly, P. leniusculus hatched earlier, giving it an advantage over A. leptodactylus; consequently, by the end of the summer, the juveniles of the former were larger than those of A. leptodactylus. Specific growth rate values showed that the juveniles of the two species had similar growth rates. The results also revealed that growth was not significantly affected by density in both species at 15°C, but at 25°C, growth was significantly better at a density of 234 juveniles m⁻² than at 468 juveniles m⁻², and better at 468 juveniles m⁻² than at 937 juveniles m⁻² (P < 0.01 and P < 0.001, respectively). We conclude that P. leniusculus is a good candidate for aquaculture as it has a rapid growth rate and early hatching and maturity; however, its aggressive behavior may make it a less attractive proposition than A. leptodactylus, which is also fast growing but less aggressive. This study is a part of PhD study of M.M. Harlıoğlu, who is supported by Fırat University Elazığ, Turkey.