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1.
The molecular basis of color polymorphism in the shells of the pearl oyster Pinctada fucata is largely unknown. We developed a red-shelled family line and used suppression subtractive hybridization (SSH) to screen for differentially expressed genes in red- and non-red-shelled pearl oysters. We constructed forward and reverse cDNA subtractive libraries consisting of 2 506 and 797 clones, respectively. Among 343 randomly selected clones in the forward library, 304 sequences were identified in GenBank using BLASTx and BLASTn. Of the 304 sequences, 13 showed no similarity to known sequences and 291 were matched with known genes of the pearl oyster, including shematrin-1, shematrin-2, shematrin-6, shematrin-7, nacrein, nacrein-like protein, aspein for shell matrix protein, glycine-rich protein, mantle gene 5, 28S, EST00031, EST00036, 16S, and COΙ. In the reverse library, 7 clones were sequenced and analyzed by BLAST. Two sequences shared similarity with EST00036 from the P. fucata subtraction cDNA library, four with the P. fucata mitochondrial gene for 16S rRNA and 1 with P. fucata shematrin-2. We evaluated the expression of 12 genes from the forward library using RT PCR. Two sequences matched with 16S and COΙ so were considered to be false positives. The remaining 10 sequences were differentially expression in the red-shelled pearl oysters. Our results suggest that differential expression of these genes may be related to color variation in the red-shelled family line of the pearl oyster.  相似文献   

2.
3.
The high phenotypic plasticity in the shell of oysters presents a challenge during taxonomic and phylogenetie studies of these economically important bivalves. However, because DNA can exhibit marked differences among morphologically similar species, DNA barcoding offers a potential means for oyster identification. We analyzed the complete sequences of the cytochrome oxidase subunit I (COI) of five common Crassostrea species in China (including Hong Kong oyster C. hongkongensis, Jinjiang oyster C. ariakensis, Portuguese oyster C. angulata, Kumamoto oyster C. sikamea, and Pacific oyster C. gigas) and screened for distinct fragments. Using these distinct fragments on a high-resolution melting analysis platform, we developed an identification method that does not rely on species-specific PCR or fragment length polymorphism and is efficient, reliable, and easy to visualize. Using a single pair of primers (Oyster- COI-1), we were able to successfully distinguish among the five oyster species. This new method provides a simple and powerful tool for the identification of oyster species.  相似文献   

4.
研究雷州半岛自然生活条件、养殖条件下的野生贝和全人工养殖条件下的养殖贝主要污损及寄居生物。结果表明:大珠母贝主要污损及寄居生物共46种,其中自然生活条件下野生贝的污损及寄居生物有24种,养殖条件下野生贝的污损与寄居生物42种,养殖贝的污损及寄居生物有31种;根据附着或寄居部位可将大珠母贝污损及寄居生物可分为4种类型:贝壳表面附生型、贝壳层寄居型、贝壳内侧寄居型、外套腔寄居型;海绵、缨鳃虫、龙介沙蚕、长鳃树蛰虫为贝壳表面附生型主要种类,砗磲江珧虾为外套腔寄居型种类,对大珠母贝危害较小;石蛏、开腹蛤、厥目革囊星虫、有盾海扇虫、才女虫、钻穿裂虫为贝壳层寄居型的主要种类;吻蛇稚虫为贝壳内侧寄居型,对大珠母贝危害较大。自然生活条件下野生贝主要危害种类为石蛏、开腹蛤、厥目革囊星虫、才女虫、钻穿裂虫,养殖条件下野生贝主要危害种类有石蛏、开腹蛤、厥目革囊星虫、有盾海扇虫、吻蛇稚虫、才女虫、钻穿裂虫;养殖贝受寄居生物危害较小。  相似文献   

5.
The effects of high pressure(HP) treatment on spoilage characteristic and shelf life extension of Pacific oysters(Crassostrea gigas) during refrigerated storage were studied.Results showed that HP treatment of 275 MPa for 3 min or 300 MPa for 2 min could achieve 100% full release of oyster adductor muscle,pressures higher than 350 MPa caused excessive release as the shells of oysters were broken,thus use of higher pressures should be cautious in oyster processing industry because of its adverse impact on the appearance of shells.HP treatment(300 MPa,2 min) was proper for the shucking of Pacific oyster(Crassostrea gigas) in China.This treatment caused no organoleptic disadvantage.Moreover,HP treatment resulted in obvious differences in biochemical spoilage indicators(p H,TVB-N and TBARS) changes and volatile compounds profile determined by electronic nose during storage.HP treatment(300 MPa,2 min) also led to a reduction of aerobic bacterial count(APC) by 1.27 log cycles.Furthermore,the APC values of oysters treated by HP were always lower than those of the control samples during storage.Based on the organoleptic,biochemical and microbiological indicators,shelf life of 6-8 d for control and 12 d for HP-treated oysters could be expected.HP treatment showed great potential in oyster processing and preservation.  相似文献   

6.
以印度尼西亚引进大珠母贝亲本繁育的子代F1群体进行植核育珠,育珠贝数量8086只,在海区休养20d后,统计育珠母贝的成活率与留核率,比较3月与4月植核手术育珠贝的育珠性状差异。结果表明:休养期结束后,育珠贝的成活率与留核率分别为97.57%和90.69%;育珠期3个月时(6月17日)育珠贝的成活率为81.22%;4月植核育珠母贝的留核率与成活率明显高于在3月的植核育珠母贝,但两者之间差异不具统计学意义(P〉0.05)。  相似文献   

7.
企鹅珍珠贝人工养殖及育珠的研究   总被引:1,自引:0,他引:1  
在幼贝中间养成中采用柱形笼养殖法,母贝的养成中采用穿耳开放式养殖法,与全程采用锥形笼的传统式养殖方法相比较,进行企鹅珍珠贝人工养殖。结果表明:采用本技术养殖企鹅珍珠贝,在幼贝中间养成阶段,比传统养殖的壳高生长速率提高32·1%(P<0·05),壳长生长速率提高30·3%(P<0·01),成活率提高36%(P<0·01);母贝养成阶段,比传统养殖的壳高生长速率提高28·1%(P<0·05),壳长生长速率提高26·7%(P<0·01),成活率提高18·3%(P<0·01)。同时进行企鹅珍珠贝人工培育游离珠实验,植核贝在休养期和育珠期存活率分别为71·2%和54·3%,留核率分别为29·6·6%和21·0%,成珠率58·6%,优质珠比例为26·7%。  相似文献   

8.
Microsatellites are a ubiquitous component of the eukaryote genome and constitute one of the most popular sources of molecular markers for genetic studies. However, no data are currently available regarding microsatellites across the entire genome in oysters, despite their importance to the aquaculture industry. We present the fi rst genome-wide investigation of microsatellites in the Pacifi c oyster Crassostrea gigas by analysis of the complete genome, resequencing, and expression data. The Pacifi c oyster genome is rich in microsatellites. A total of 604 653 repeats were identifi ed, in average of one locus per 815 base pairs(bp). A total of 12 836 genes had coding repeats, and 7 332 were expressed normally, including genes with a wide range of molecular functions. Compared with 20 different species of animals, microsatellites in the oyster genome typically exhibited 1) an intermediate overall frequency; 2) relatively uniform contents of(A)n and(C)n repeats and abundant long(C)n repeats(≥24 bp); 3) large average length of(AG)n repeats; and 4) scarcity of trinucleotide repeats. The microsatellite-fl anking regions exhibited a high degree of polymorphism with a heterozygosity rate of around 2.0%, but there was no correlation between heterozygosity and microsatellite abundance. A total of 19 462 polymorphic microsatellites were discovered, and dinucleotide repeats were the most active, with over 26% of loci found to harbor allelic variations. In all, 7 451 loci with high potential for marker development were identifi ed. Better knowledge of the microsatellites in the oyster genome will provide information for the future design of a wide range of molecular markers and contribute to further advancements in the fi eld of oyster genetics, particularly for molecular-based selection and breeding.  相似文献   

9.
LCDV-cn是分离自中国养殖牙鲆的淋巴囊肿病病原,给中国牙鲆养殖业带来了严重危害。通过PCR、克隆和测序,获得了LCDV-cn部分基因的序列,证明LCDV-cn与LCDV-C的基因组序列是一致的。比较基因组学分析发现,LCDV-cn基因组中有137个ORF是其独有的、与LCDV-1及其它虹彩病毒无同源区域。对LCDV-cn基因组进行生物信息学分析发现,在LCDV-cn独有的ORF中,有的编码与宿主同源的蛋白,有的编码与DNA复制相关的蛋白,某些ORF编码的蛋白含有跨膜区等。LCDV-cn的独有基因或许对其毒力和宿主范围有关。  相似文献   

10.
按照常规技术进行马氏珠母贝插核育珠,在手术后第1、3、7、15、20、30和60天解剖剪取珍珠囊,利用H E染色等组织化学方法研究马氏珠母贝珍珠囊形成过程中的组织学和组织化学变化。结果表明:珍珠囊表皮细胞来自于移植细胞小片的表皮细胞;在水温27℃条件下,插核后1~3 d来自育珠贝的游走细胞逐渐将细胞小片包围;插核后7~15 d,珠核表面密集来自育珠贝的游走细胞;插核后15~20 d,细胞小片外表皮细胞增殖形成珍珠囊,珍珠囊表皮细胞和细胞核均呈扁平状;插核后20~30 d,扁平状珍珠囊表皮细胞逐渐转变为高柱型,并分泌形成透明的壳皮层物质;在插核后第60天,已形成具有分泌珍珠质功能的扁平状珍珠囊表皮细胞,细胞核呈椭圆形或近圆形。  相似文献   

11.
Glycogen is important not only for the energy supplementary of oysters, but also for human consumption. High glycogen content can improve the stress survival of oyster. A key enzyme in glycogenesis is glycogen synthase that is encoded by glycogen synthase gene GYS. In this study, the relationship between single nucleotide polymorphisms(SNPs) in coding regions of Crassostrea gigas GYS(Cg-GYS) and individual glycogen content was investigated with 321 individuals from five full-sib families. Single-strand conformation polymorphism(SSCP) procedure was combined with sequencing to confirm individual SNP genotypes of Cg-GYS. Least-square analysis of variance was performed to assess the relationship of variation in glycogen content of C. gigas with single SNP genotype and SNP haplotype. As a consequence, six SNPs were found in coding regions to be significantly associated with glycogen content(P 0.01), from which we constructed four main haplotypes due to linkage disequilibrium. Furthermore, the most effective haplotype H2(GAGGAT) had extremely significant relationship with high glycogen content(P 0.0001). These findings revealed the potential influence of Cg-GYS polymorphism on the glycogen content and provided molecular biological information for the selective breeding of good quality traits of C. gigas.  相似文献   

12.
The changes in the contents of adenosine 5’-triphosphate (ATP) and its related breakdown compounds were investigated in the adductor muscle, mantle, gill and body trunk of oyster (Crassostrea gigas) during frozen storage at -20℃ and -30℃ and compared with that of the fresh oyster. The investigation was performed using an HPLC system. Different extents of ATP decomposi- tion were found in various tissues frozen at the two temperatures. The K, K’ and A.E.C values were calculated as the chemical fresh- ness indices. Considering the results of sensory evaluation, the A.E.C. value in body trunk at -20℃ and -30℃ could be used as the best freshness index for frozen oyster.  相似文献   

13.
Shell color is regarded as an economic trait in many breeding programs of bivalve mollusks, but the relationship between shell color and production traits remains controversial. In our breeding program of Crassostrea gigas, solid white, black, and orange shell lines were obtained, and second-generation(F2) and testcross families with segregating shell colors were constructed by crossing these three lines. These segregating families provided ideal samples for investigating the relationship between shell color and production traits in C. gigas. The growth and survival of 7-month-old oysters with different shell colors sampled within the same families were compared in seven F2 families and 13 testcrosses. In addition, the growth and survival of oysters from the three shell color lines were compared at 4 and 16 months of age. The growth and survival rates of the orange shell line were significantly lower than those of the white and black shell lines. However, no significant difference in growth between oysters with different shell colors was observed within segregating families, except the testcrosses produced by crossing orange-and white-shelled grandparents, and no significant difference in survival was observed in any family. Overall, no significant correlation was observed between shell color and production traits in C. gigas. These results suggest that shell color cannot be used as a marker to guide the selection of growth and survival traits. Thus shell color and production traits should be selected independently in oyster breeding programs.  相似文献   

14.
利用线粒体16S rRNA基因和线粒体细胞色素氧化酶亚基Ⅰ(cytochrome oxidaseⅠ,COⅠ)基因片段初步研究钦州湾牡蛎(Ostrea)的物种组成。以特异引物进行PCR扩增,对扩增产物进行纯化、测序,分析表明,16S rRNA基因部分长度为413bp,COⅠ基因部分长度为535bp,2种牡蛎序列的碱基组成均显示出较高的A+T比例:16S rRNA基因59.8%;COⅠ基因60.5%。对位排序比较表明,16S rRNA片段种内个体间变异较小,存在7个变异位点,4种单倍型,其中包括5个转换位点突变,2个颠换位点突变;COⅠ片段有30个碱基存在变异,7种单倍型,其中包括16个转换位点突变,14个颠换位点突变。运用MEGA4软件计算出不同个体间的遗传距离,并构建了NJ和UPGMA系统树。香港牡蛎(Crassostrea hongkongensis)16S rRNA和COⅠ序列与白肉牡蛎的遗传距离均为0.000,有明巨牡蛎(Crassostrea ariakensis)16S rRNA和COⅠ序列和红肉牡蛎(red meat ostrea)的遗传距离分别为0.000和0.011,白肉牡蛎16S rRNA和COⅠ序列和红肉牡蛎之间的遗传距离分别为0.035和0.146。结果表明,钦州湾牡蛎分为2个不同的种,线粒体16S rRNA和COⅠ基因在种间存在明显的多态性,证实了16S rRNA和COⅠ基因序列适用于牡蛎的系统学分析。  相似文献   

15.
Heavy metal pollution can affect the immune capability of organisms.We evaluated the effect of cadmium(Cd) on the defense responses of the Pacific oyster Crassostrea gigas to Listonella anguillarum challenge.The activities of several important defensive enzymes,including superoxide dismutase(SOD),glutathione peroxidase(GPx),acid phosphatase(ACP),Na+,K+-ATPase in gills and hepatopancreas,and phenoloxidase-like(POL) enzyme in hemolymph were assayed.In addition,the expression levels of several genes,including heat shock protein 90(HSP90),metallothionein(MT),and bactericidal/permeability increasing(BPI) protein were quantified by fluorescent quantitative PCR.The enzyme activities of SOD,ACP,POL,and GPx in hepatopancreas,and the expression of HSP90 were down-regulated,whereas GPx activity in the gill,Na+,K+-ATPase activities in both tissues,and MT expression was increased in Cdexposed oysters post L.anguillarum challenge.However,BPI expression was not significantly altered by co-stress of L.anguillarum infection and cadmium exposure.Our results suggest that cadmium exposure alters the oysters’ immune responses and energy metabolism following vibrio infection.  相似文献   

16.
以勒氏笛鲷(Lutjanus russellii)基因组DNA为模板,采用同源克隆的方法,获得2 887 bp的肌肉生长抑制素(myostatin,MSTN)基因组序列,该MSTN序列具有3个外显子和2个内含子,包括101 bp的5′-UTR、385bp的外显子1、354 bp的内含子1、370 bp的外显子2、761 bp的内含子2、381 bp的外显子3和1 932 bp的3′-UTR。整个开放阅读框编码了378个氨基酸,前面的22个氨基酸为信号肽,具有9个保守的半胱氨基酸及一个RVRR的蛋白酶解加工位点。氨基酸序列分析发现,该基因编码的蛋白质与其他鱼类的I型同源性较高,与其他鱼类的2型MSTN同源性较低,且与鲈形目的同源性最高,与鲤形目的同源性较低,与人、鼠和鸡的同源性最低。采用邻接法(Neighbor-Joining)构建的MSTN的系统发育树表明,勒氏笛鲷MSTN与鲈形目鱼类的狼鲈属亲缘关系较近,且与鱼类的MSTN-1聚为1支。这表明该基因属于Ⅰ型MSTN基因。  相似文献   

17.
对企鹅珍珠贝稚贝、中贝和成贝在降低盐度的海水中存活状态进行了观察和研究。在水温20~23℃,以不同盐度梯度(8、12、16、20、242、8、30和33)的海水暂养稚贝并定时检查,在广东的四个海区,对盐度变化时中贝及成贝的养殖成活率进行了观察。结果表明:盐度低于16的3个组,稚贝在60h内全部死亡,盐度20~24海水中,稚贝虽只有部分死亡,但活力较差;稚贝在14的海水中4h后转入正常海水,可全部存活,而超过8h后再移入正常海水的稚贝会陆续死亡;在盐度18海水中,稚贝一直未分泌足丝附着,而移入正常海水,6h就有小苗附着;大万山岛附近海域在雨季盐度可降至20以下,6~9月不适合养殖,而其它实验点可以通过深吊避免海水盐度变化造成企鹅珍珠贝死亡。  相似文献   

18.
A muscle cDNA library of Chinese shrimp (Fenneropenaeus chinensis) was constructed with the SMARTTM cDNA Li- brary Construction Kit. The titer of optimal primary library was 7.7×105 pfu mL-1 and that of the amplified library was 3.0×109 pfu mL-1. The percentages of the recombinant clones of primary and amplified libraries were over 98%. The insert sizes were longer than 400 bp with an average of 1000 bp. A positive clone containing a 794 bp insert was sequenced and identified encoding fast skeletal troponin Ⅰ gene. This library provided a useful resource for the functional genomic research ofE chinensis.  相似文献   

19.
利用线粒体16SrRNA基因和线粒体细胞色素氧化酶亚基Ⅰ(cvtocllrome oxidase Ⅰ,COI)基因片段初步研究钦州湾牡蛎(Ostxea)的物种组成。以特异引物进行PCR扩增,对扩增产物进行纯化、测序,分析表明,16SrRNA基因部分长度为413bp,COI基因部分长度为535bp,2种牡蛎序列的碱基组成均显示出较高的A+T比例:16SrRNA基因598%;COI基因605%。对位排序比较表明,16SrRNA片段种内个体间变异较小,存在7个变异位点,4种单倍型,其中包括5个转换位点突变,2个颠换位点突变;COI片段有30个碱基存在变异,7种单倍型,其中包括16个转换位点突变,14个颠换位点突变。运用MEGA4软件计算出不同个体间的遗传距离,并构建了NJ和UPGMA系统树。香港牡蛎(Crassostrea hongkongensis)16SrRNA和COI序列与白肉牡蛎的遗传距离均为0000,有明巨牡蛎(Crassostrea ariakensis)16SrRNA和COI序列和红肉牡蛎(redmeatostxea)的遗传距离分别为0000和0011,白肉牡蛎16SrRNA和COI序列和红肉牡蛎之间的遗传距离分别为0035和0146。结果表明,钦州湾牡蛎分为2个不同的种,线粒体16SrRNA和COI基因在种间存在明显的多态性,证实了16SrRNA和COI基因序列适用于牡蛎的系统学分析。  相似文献   

20.
【目的】了解巨砺属牡蛎的系统关系和种类区分。【方法】对我国沿海分布的7种巨砺属牡蛎(香港牡蛎、有明牡蛎、熊本牡蛎、岩牡蛎、艾氏牡蛎、太平洋牡蛎、葡萄牙牡蛎)的线粒体DNA片段(COI、12S、16S和tRNAs),以及核糖体RNA基因转录间隔子序列(ITS-1、ITS-2和ITS)进行分子系统学研究。【结果】无论种间或种内,tRNAs序列差异最大,亚种内TS1序列差异最大;tRNAs和COI序列较其它序列变异更快,种间变异与种内变异之间有明显的条形码间隙;12S、16S、ITS和ITS2的种间变异与种内变异无重叠及条形码间隙;ITS1的种间变异与种内变异出现重叠。在亚种层面,12S、ITS、ITS1和ITS2的亚种间变异与亚种内变异出现重叠;16S的亚种间变异与亚种内变异无重叠及条形码间隙;tRNAs与COI序列亚种间变异与亚种内变异之间有明显的条形码间隙,有利于区分亚种。【结论】tRNAs和COI序列可用于种及亚种的鉴定。  相似文献   

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