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1.
ImeIOWThe nathead lobster, Thenus orientalis, is widely distributed in the trOPical and subtIDPical indO - West Pacific region. T. orientalis is one of the most eCOnondcally significantspecies among scyllarids althoUgh its catch is nowhere large. In addition to its eCOnondc value,T. Orientalis is also of great scientific value because it represents a fdrily wfor reproductivebiology is ~ly studied. It is important to clarify the structures of ovary and Ovarian follicle inT. Orientalis.…  相似文献   

2.
Differential expression of genes is crucial to growth and development of fish. To select the appropriate genes for gene normalization during Cynoglossus semilaevis early developmental process, eight candidate reference genes (ACTB, B2M, EF1A, GADPH, RPL7, TUBA, UBCE and 18S) were tested for their adequacy by using quantitative real-time PCR. The results showed that the expression of all the examined genes exhibited tissue dependent variations in the mature C. semilaevis. EF1A was listed as the most stable reference among the 14 tissues by RefFinder. Furthermore, the recommended comprehensive ranking of the stability determined by RefFinder showed that 18S was the most stable gene during the early developmental stages (from oosphere to 90 days old) in this study. However, when divided the Ct value data of the above mentioned early developmental stages into two separate periods (embryo and post-hatching periods), TUBA and 18S represented the most stable references of these two developmental periods, respectively. Consequently, the reference gene should be carefully and accurately chosen even for studies of the same species at various developmental processes. The relevant data may help in selecting appropriate reference genes for mRNA expression analysis, and is of great value in the studies of fish growth and development.  相似文献   

3.
The present investigation focuses on population structure analysis of the purple sea urchin Paracentrotus lividus across the African Mediterranean coast, with the main aim of assessing the influence of the Siculo-Tunisian Strait on gene flow disruption in this highly dispersive echinoid species. For this purpose, patterns of morphological and genetic variation were assessed among its populations from the western and eastern Mediterranean coasts. A total of 302 specimens from seven Tunisian sites were collected and examined for morphometric variability at twelve morphometric traits. Concordant results, inferred from CDA (canonical discriminant analyses), pairwise NPMANOVA (non parametric multivariate analysis of variance) comparisons and MDS (multidimensional scaling) plot, unveiled significant inter-population differences in the measured traits among the studied populations. Furthermore, the combined use of the one way ANOSIM (analysis of similarities) and the Discriminant/Hotelling analysis allowed unravelling two morphologically differentiated groups assigned to both western and eastern Mediterranean basins. The SIMPER (similarity percentages) routine analysis showed that total dry weight, test diameter and spine length were major contributors to the morphometric separation between locations and between groups. Pattern of phenotypic divergence discerned in P. lividus across the Siculo-Tunisian Strait is interestingly in congruence with that inferred from the genetic investigation of the purple sea urchin populations from the same region based on the analysis of the mtDNA COI (cytochrome oxidase I) gene in 314 specimens from nineteen locations covering a wider geographic transect, streching westward to the Algerian coast and eastward to the Libyan littoral. The specific haplotypic composition characterizing each Mediterranean basin, as inferred from the minimum spanning network, confirmed the geographic partioning of genetic variation, as revealed by F-statistics and AMOVA (analysis of molecular variance) analyses, yielding significant genetic differentiation between eastern and western Mediterranean populations. The newly detected phylogeographic patterns, observed for the first time in P. lividus throughout the explored distribution range, suggest the involvement of different biotic and abiotic processes in shaping such variation, and provide evidence that a large and geographically exhaustive dataset is necessary to unveil phylogeographic structure within widespread marine species, previously cathegorized as panmictic in part of their distribution range.  相似文献   

4.
The estimation of genetic parameters has played an important role in animal selective breeding for growth traits.Recently studies show that molecular markers can be incorporated into genetic evaluations. In order to improve the performance of an incomplete pedigree(i.e, only parents are known) in the genetic evaluations, 12 microsatellite markers have been applied in the estimation of the genetic parameters for body weight in a farmed population(n=1 890) of juvenile turbot(Scophthalmus maximus L.). A new relatedness called parental molecular relatedness(PMR) is estimated based on results of genotyping of 48 parents(31 males, 17 females) with microsatellites markers. The feasibility of PMR in estimation of genetic parameters is verified by comparison with pedigree related(PR) which is obtained from a complete pedigree. The results demonstrate that a high correlation(0.872) between them is found. Heritabilities are estimated using the PMR(0.52±0.13) and PR(0.55±0.22) with the same animal model. A cross-validation shows that the predictive abilities of models using the PMR and the PR are identical(0.81). From that, a conclusion can be made that PMR and PR predicted genetic values equally well in a population of juvenile turbot. Therefore PMR can be applied as an alternative of the PR when only parents are known. However, for a better performance, more markers and more families should be included in a further study.  相似文献   

5.
Halimeda is one of the major reef-building algas in the middle Miocene of Xisha, and one of the significant reefbuilding algas in the algal reef oil and gas field of the South China Sea. However, there have been few reports regarding the characteristics of mineral rocks, reservoir porosity and permeability layers, and sedimentationdiagenetic-evolution of fossil Halimeda systems. The present paper briefly introduces the relevant studies on chlorophyta Halimeda and the research status of oil and gas exploration. Through the 1 043 m core of the Xichen-1 well, we studied the characteristics of the mineral rocks and porosity and permeability of the middle Miocene Halimeda of the Yongle Atoll, identified and described the segments of fossil Halimeda, and pointed out that most of the segment slides are vertical sections in ovular, irregular or long strips. The overwhelming majority of these fossil Halimeda found and studied are vertical sections instead of cross sections. In this paper, knowledge regarding the cross sections of fossil Halimeda is reported and proven to be similar with the microscopic characteristics of modern living Halimeda; fossil Halimeda are buried in superposition; it is shown that there are different structures present, including typical bio-segment structure, and due to its feature of coexisting with red alga, tying structure, twining structure and encrusting structure are all present; and finally, it is suggested to classify the fossil Halimeda into segment algal reef dolomites. In addition, all of the studied intervals are moderately dolomitized. Secondary microcrystalline-dolosparite dominates the original aragonite raphide zones,and aphanitic-micrite dolomite plays the leading role in the cortexes and medullas; in the aragonite raphide zones between medulla and cysts, secondary dissolved pores and intercrystalline pores are formed inside the segments, and algal frame holes are formed between segments; therefore, a pore space network system(dissolved pores + intragranular dissolved pores—intercrystalline pores + algal frame holes) is established. Segment Halimeda dolomite has a porosity of 16.2%–46.1%, a permeability of 0.203×10–3–2 641×10–3 μm2, and a throatradius of 23.42–90.43 μm, therefore it is shown to be a good oil and gas reservoir. For the reasons mentioned above, we suggest building the neogene organic reef-modern reef sedimentation-diagenetic-evolution models for the Xisha Islands.  相似文献   

6.
In this study, we assess coral health by detecting the severity of coral diseases and compromised health states on massive Porites. Field surveys are conducted at twenty-two sites covering the eastern, inner and western Gulf of Thailand as well as the Andaman Sea during 2010-2015. A total of nine coral diseases and signs of compromised health are observed in the waters of Thailand, consisting of pigmentation responses (pink lines, pink patches, pink spots and pink borers), white syndromes (white patches, white bands and ulcerative white spots), growth anomalies, and unusual bleaching patterns. The highest severity of all observed coral diseases and signs of compromised health are found at Ko Khang Khao in the inner Gulf of Thailand, while that observed in the Andaman Sea is relatively low. Composition of the diseases vary across the study sites. Four groups of study sites, in which there is an 80% similarity of diseases or signs of compromised health composition, are clustered and detected based on the Bray-Curtis similarity. The canonical analysis of principal coordinates reveal that most study sites in the Gulf of Thailand, especially the inner Gulf of Thailand, tend to show a high severity of the diseases. The association of disease severity and composition and the level of human impact are also detected. The study sites located near the shores and/or the areas with intensive tourism tend to have higher human impact, especially on poor water quality, which may be linked to the higher severity and composition of coral diseases and signs of compromised health in the Gulf of Thailand. Fish bites are also observed in many study sites. The severity of fish bites in the Gulf of Thailand is much lower compared to the Andaman Sea. Ko Rawi exhibits the highest severity, following by Ko Surin Nua and Ko Butang. The study sites within marine national park boundaries have a significantly higher severity of fish bites than those outside of the marine national park boundaries. This study suggests that higher coral diseases and signs of compromised health severity might be linked to anthropogenic disturbances on coral communities in the waters of Thailand.  相似文献   

7.
The seasonal variabilities of a latent-heat flux (LHF), a sensible-heat flux (SHF) and net surface heat flux are examined in the northern South China Sea (NSCS), including their spatial characteristics, using the in situ data collected by ship from 2006 to 2007. The spatial distribution of LHF in the NSCS is mostly controlled by wind in summer and autumn owing to the lower vertical gradient of air humidity, but is influenced by both wind and near-surface air humidity vertical gradient in spring and winter. The largest area-averaged LHF is in autumn, with the value of 197.25 W/m 2 , followed by that in winter; the third and the forth are in summer and spring, respectively. The net heat flux is positive in spring and summer, so the NSCS absorbs heat; and the solar shortwave radiation plays the most important role in the surface heat budget. In autumn and winter, the net heat flux is negative in most of the observation region, so the NSCS loses heat; and the LHF plays the most important role in the surface heat budget. The net heating is mainly a result of the offsetting between heating due to the shortwave radiation and cooling due to the LHF and the upward (outgoing) long wave radiation, since the role of SHF is negligible. The ratio of the magnitudes of the three terms (shortwave radiation to LHF to long-wave radiation) averaged over the entire year is roughly 3:2:1, and the role of SHF is the smallest.  相似文献   

8.
The precise and accurate knowledge of genetic parameters is a prerequisite for making efficient selection strategies in breeding programs.A number of estimators of heritability about important economic traits in many marine mollusks are available in the literature,however very few research have evaluated about the accuracy of genetic parameters estimated with different family structures.Thus,in the present study,the effect of parent sample size for estimating the precision of genetic parameters of four growth traits in clam M.meretrix by factorial designs were analyzed through restricted maximum likelihood(REML) and Bayesian.The results showed that the average estimated heritabilities of growth traits obtained from REML were 0.23–0.32 for 9 and 16 full-sib families and 0.19–0.22 for 25 full-sib families.When using Bayesian inference,the average estimated heritabilities were0.11–0.12 for 9 and 16 full-sib families and 0.13–0.16 for 25 full-sib families.Compared with REML,Bayesian got lower heritabilities,but still remained at a medium level.When the number of parents increased from 6 to 10,the estimated heritabilities were more closed to 0.20 in REML and 0.12 in Bayesian inference.Genetic correlations among traits were positive and high and had no significant difference between different sizes of designs.The accuracies of estimated breeding values from the 9 and 16 families were less precise than those from 25 families.Our results provide a basic genetic evaluation for growth traits and should be useful for the design and operation of a practical selective breeding program in the clam M.meretrix.  相似文献   

9.
The shell traits and weight traits are measured in cultured populations of bay scallop, Argopecten irradians. The results of regression analysis show that the regression relationships for all the traits are significant (P<0.01). The correlative coefficients between body weight, as well as tissue weight with shell length, shell height and shell width are significant (P<0.05). But the correlative coefficients between the anterior and posterior auricle length with body weight as well as tissue weight are not significant (P>0.05). The multiple regression equation is obtained to estimate live body weight and tissue weight. The above traits except anterior and posterior auricle length are used for the growth and production comparison among three cultured populations, Duncan's new multiple range procedure analysis shows that all the traits in the Lingshuiqiao (LSQ) population are much more significant than those of the other two populations (P<0.01), and there is no significant difference between the Qipanmo (  相似文献   

10.
The aim of the present study is to detect the potential of the base population from diallel crosses of eight introduced strains of the Pacific white shrimp(Litopenaeus vannamei) for improving the yield. Heterosis and heritability were estimated for pond survival at commercial farm conditions for the base population that included 207 full-sib families from a nested mating design by artificial insemination. Among all the hybrids,the heterosis ranged from –11.37%(UA1×UA2) to 20.53%(UA3×SIN) with an average of 0.953%. The results showed that more than half of the hybrids(51.85%) have negative heterosis for survival rate, but most of the hybrids with positive heterosis have high estimates. The high proportion of negative heterosis for survival rate reminders us that the survival trait also should be considered in the crossbreeding program to avoid yield decrease. However, high positive heterosis manifested in most of the hybrids for survival indicates the usefulness of these hybrids for improving the survival to obtain higher yield by crossbreeding in this breeding program. The heritability estimate for pond survival was 0.092±0.043 when genetic groups were included in the pedigree, and it was significantly different from zero(P0.05). The results from this study also indicated that significant improvement for survival is possible through selection in L. vannamei.  相似文献   

11.
用于紫菜无性系种质鉴定的计算机化DNA指纹的建立   总被引：6，自引：1，他引：6  
研究用RAPD技术对条斑紫菜(Porphyra yezoensis)、坛紫菜(P.Haitanensis)、半叶紫菜(P.Katadai var.Hemiphylla)和少精紫菜(P.Oligospermatangia)的15个无性系丝状体进行了遗传多样分析,用120个Operon引物进行了筛选,从中选用来自OPJ-18和OPN-02扩增出的8条多态性条带构建了这15个紫菜无性系的DNA指纹图谱,在该图谱中每个紫菜无性系均有各自特异的DNA指纹.用1和0分别表示DNA带的出现和缺失,将各个无性系的DNA指纹用计算机语言表示,建立了15个紫菜无性系的计算机化DNA指纹;在此基础上设计了紫菜无性系种质鉴定的计算机软件PhGI.  相似文献   

12.
几种紫菜种质资源遗传多样性的RAPD分析   总被引：10，自引：0，他引：10  
用随机多态DNA(RAPD)标记方法对11个紫菜(Porphyra)样品进行遗传多样性检测,从46个随机引物中筛选出27个有效引物,共扩增出282条DNA带,其中多态位点224个,占79．4％。用类间平均链锁法对各样品间的遗传距离进行聚类分析。结果显示,2个条斑紫菜之间的亲缘关系很近,遗传相似系数达98．1％,和坛紫菜的亲缘关系较远;坛紫菜不同样品间的遗传相似系数在75．8％～90．6％之间,表明坛紫菜种质资源具有丰富的遗传多样性,是良种选育的遗传基础。  相似文献   

13.
条斑紫菜高纯度总DNA及其质粒状DNA的提取   总被引：11，自引：2，他引：9  
提取条斑紫菜高纯度总DNA及其质粒状DNA的新方法。先用海螺酶处理紫菜叶状体制备细胞,然后用SDS-蛋白酶K裂解细胞提取总DNA,再用玻璃粉浆(glassmilk)对其纯化,经纯化后的总DNA能被EcoRI,Dral与HaeⅢ等限制酶完全酶切,并在酶切图谱上形成明显的DNA带型。当用异硫氰酸胍一十二烷基肌氨酸钠裂解紫菜细胞时,在总DNA提取物中直接发现有一条质粒状DNA带(2.3Kb),即建立了一种极简便的质粒状DNA提取方法。  相似文献   

14.
现代生物技术在紫菜属中的应用   总被引：2，自引：0，他引：2  
本文综述了近十年来国内外紫菜生物技术的发展与研究。在细胞生物学方面，介绍了紫菜原生质体制备、组织培养和细胞融合等技术，及其在新种质创建，工业苗种生产、单细胞活饵料开发和基因组操作等研究中的广泛应用，而细胞分光光度技术（MSP）和流式细胞技术（FCM）的加盟使得对紫菜细胞DNA的了解达到量化，快速分选细胞并实现对其生理代谢动态 观测，在生物化学方法中，讨论了用同工酶电泳技术来评价紫菜群体遗传结构、鉴别种质和描述系统发育等研究，以及利用生化方法对糖类等其它化合物进行提纯与测定等工作，在分子生物学方面；总结了如何获得高纯度DNA，并将其应用于DNA分析研究，RFLP、RAPD和DNA-序列测定等分子标记技术所揭示的紫菜的多态性，以及利用DNA-指纹和消减DNA文库的技术来构建紫菜的质体基因图谱和cDNA文库，并进行紫菜比较基因组学的研究，此外还介绍了紫菜基因转移方面的工作。  相似文献   

15.
紫菜(Porphyra遗传差异的ISSR分析   总被引：2，自引：0，他引：2       下载免费PDF全文
采用ISSR标记技术对来自不同产地的6个坛紫菜(Porphyra haitanensis)无性系和两个条斑紫菜(P.yezoensis)无性系进行了遗传差异的分析。结果表明,7条ISSR引物在8个紫菜系中共扩增出59条片段,全部表现出多态性。根据Nei等的相似性系数得出8个紫菜系间的遗传距离在0.274—0.746之间。用UPGMA方法作出的系统树中各紫菜基本上是按照产地进行聚类,从而推测紫菜的遗传差异可能与地域分布相关。本文结果也证明了ISSR与RAPD、AFLP等标记技术一样适用于紫菜的遗传多样性分析。  相似文献   

16.
I~ODWrIONExtraction of DNA from Porphyra po~nsis is very difficult due tO its high content ofpolysaccharides. TO avoid the interference Of POlysaccharides, HOng et al. (1992) used LiCI tosoften Porphyra thalli cells to release DNA directly without lysing the thalli, hoWever, the procedure is problematic in the isolation of high-quality DNA. Kitade et al. (1996) established a complicated procedure which includes the grindiflg of material in liquid nitrogen, lysing of material inextra…  相似文献   

17.
对羊栖菜(Hizikia fusiformis (Harv) Okamura)养殖中常见的3个品系进行了DNA指纹分析及遗传变异的研究,构建了其遗传指纹图谱,分析了不同种群的遗传关系,为羊栖菜的种质鉴定及选育提供了理论依据.运用RAPD分子标记技术,对5个羊栖菜的种群中共125个个体进行了分析,从300个引物中筛选出12条随机扩增引物共扩增135个位点,多态位点比率为84.4%.从中选择了4个多态性位点,构建了DNA指纹图谱.相关结果对羊栖菜遗传选育和种质鉴定等有参考价值.  相似文献   

18.
坛紫菜品系间遗传差异的RAPD分析   总被引：10，自引：1，他引：9  
利用RAPD技术对六个坛紫菜品系进行了研究,从107条随机引 物中筛选10条随机引物,一共扩增出93条可重现的片段。经统计分析,六个品系间的遗传相 似系数在0.246～0.636之间。其中浙江北部沿海栽培品系间的相似系数最高为0.636.地 域间品系的遗传相似系数最低为0.246。六个品系用UPGMA方法得到的聚类关系符合传统的地 域和表型关系。通过对照品系间有稳定差异的DNA条带,表明RAPD标记是坛紫菜品系鉴定和 遗传多样性分析的有效手段。  相似文献   

19.
Intermsoftheresearchingermplasmandgeneticsofmarineanimals,Chinaseemsquiteweakincomparisonwithotherdevelopedcountries,fortherelevantresearchprogramswereonlyinitiatedinthe1980's.Inrecentyears,moreattentionhasbeendrawntothegermplasmsourcesofmarinevaluableanimalsandsomeresearchprogramshavebeenplannedorundertakeninChina.Abroad,thetechniquessuchaselectrophoresispatternsofisoenzym,RAPDandRFLPhavebeenappliedtotherelevantstudiesongeneticvariationandevolutionaryrelationshipswithinagroupofPenaeidshri…  相似文献   

20.
RSAP标记技术在紫菜遗传多样性检测及种质鉴定中的应用   总被引：4，自引：0，他引：4  
限制性位点扩增多态性（restriction site amplification polymorphism，RSAP）是根据基因组内普遍存在的酶切位点来设计特殊的引物，通过简单的梯度PCR反应来产生多态性。本研究首次将RSAP标记技术成功应用于紫菜遗传多样性检测和种质鉴定。利用所建立的适合于紫菜RSAP分析的PCR反应体系和反应条件，使用30对引物对15个紫菜系DNA进行了PCR扩增，经过3次重复验证，有12对引物能够扩增出清晰且稳定的条带。这12对引物共扩增出413条带，其中408条为多态性条带，多态性比例96％，平均每对引物产生34条多态性条带，片段大小在50-500bp之间。利用这413条带进行聚类分析，产生了这15个紫菜系的进化树。15个紫菜系在0.69相似系数水平上分为两大类：一类包括坛紫菜；另一类包括条斑紫菜和少精紫菜。选2对引物R1／R6和R3／R4所扩增的10条稳定且重复性好的条带，构建了这15个紫菜系的RSAP-DNA指纹图谱。在该指纹图谱中，每个紫菜系都有其独一无二的指纹模式，能够很容易地与其它紫菜系相区分。  相似文献   

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