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鄱阳湖区黄鳝体长、体重与性比关系初步研究 总被引:3,自引:0,他引:3
通过对不同季节在黄鳝市场随机购得的569尾黄鳝体重、体长测量及解剖取性腺观察鉴定性别,统计、分析得出:569尾黄鳝雌性占76.8%,间性占6.5%,雄性占16.7%.春季122尾黄鳝中雌性占85.2%,间性2.5%,雄性12.3%;夏季95尾黄鳝中,雌性占84.2%,间性8.4%,雄性7.4%;秋季231尾黄鳝中,雌性68.4%,间性8.2%,雄性23.4%;冬季121尾黄鳝中雌性78.5%,间性5.8%,雄性15.7%.体长25 cm以下全为雌性,未见雄性;体长25~30 cm,雌性:间性,为1:0.017;初步认为体长30 cm左右为性逆转的起点;体长30~50 cm是间性黄鳝出高峰期,但50 cm以上仍有部分雌性个体.40cm范围以下雌性占多数,45 cm以上雄性占多数.体重25 g以下个体很少见到性转化个体,雌性:间性,为1:0.012;初步认为体重25 g左右为性逆转的起点.25~150 g是间性黄鳝出现高峰期,但黄鳝体重150 g以上仍有部分雌性个体.黄鳝人工繁殖选择野生黄鳝规格为体重75 g以下,体长40cm以下,可基本保证雌鳝占大部分;黄鳝体重75 g以上,体长45cm以上,可基本保证雄鳝占大部分. 相似文献
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6-甲氨基嘌呤诱导栉孔扇贝三倍体的细胞学机理 总被引:12,自引:1,他引:11
以60mg/L的6-甲氨基嘌呤(简称6-DMAP)诱发栉孔扇贝三倍体时,在荧光显微镜下观察受精卵的染色体行为以及核相组成,对照三倍体率和孵化率,探讨了不同减数分裂期6-DMAP处理对染色体倍数性的影响。结果表明,处理5 ̄15min可见3种类型图像,第1种图像可见第一极体和一个雌性原核及雄性原核;第2种图像可见第一极体和两雌性原核及一个雄性原核;第3种图像可见两个雌性原核和一个雄性原枋,随着处理时间 相似文献
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黄鳝是一种具有天然单向性逆转特性的动物.雌性成熟发育的第一个周期内黄鳝个体全部表现为雌性,性成熟产卵后,卵巢内卵细胞败育,卵巢结构逐渐退化,与此同时雄性细胞开始发育,通过雌雄间性发育过渡到雄性发育.芳香化酶是细胞色素P450家族中的一员,催化某些雄激素转化为雌激素,是雌激素生物合成中的关键酶和限速酶,广泛存在于大多数脊椎动物的脑和垂体中.芳香化酶调节神经内分泌和繁殖功能以及性行为,并参与非哺乳动物性腺分化的调控.芳香化酶与黄鳝的性逆转可能存在着潜在的联系并参与黄鳝的性逆转. 相似文献
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为了解不同体色黄鳝的性别与体长、体重的差异,2011年5-7月,于洞庭湖地区随机采集灰色及黄色2种体色共208尾野生黄鳝,并对体长、体重及性别进行测量鉴定。样本中,雌性146尾,雄性62尾,雌雄比例为2.35∶1。其中黄色黄鳝83尾,灰色黄鳝125尾。分析结果表明,黄色黄鳝雌雄个体体重及肥满度均高于灰色群体;黄色黄鳝雌性体长大于灰色雌性,雄性小于灰色雄性。雌雄个体体重与体长的相关系数,黄色黄鳝分别为0.914、0.945,灰色黄鳝分别为0.567、0.438。黄色雌鳝比例随着体长的增加逐渐降低,雄性比例随体长的增加逐渐升高,雄鳝在35 cm以上占优势,40 cm之上雄性仅1尾。灰色雌鳝在40 cm以下占优势。2种体色黄鳝雌性比例与体重变化无明显规律。 相似文献
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为了揭示芳香化酶与黄鳝(Monopterus albus)性逆转之间的内在联系和作用机理,以不同性别黄鳝的性腺和脑组织为试验材料,采用免疫组化方法检测芳香化酶在不同性别黄鳝的性腺和脑组织上的定位及其变化趋势。免疫组化结果显示:在雌性黄鳝性腺中,芳香化酶主要分布在成熟卵母细胞的胞质上,卵膜、胞核和不成熟的卵母细胞呈阴性;在雌雄间性黄鳝性腺中,芳香化酶主要分布在的退化卵母细胞膜和纵隔上;在雄性黄鳝性腺中,芳香化酶主要分布在各级精母细胞上。芳香化酶在脑组织中均有分布,并且其染色程度随着黄鳝由雌性转换为雄性而趋于减弱。这意味着黄鳝性腺和脑组织中的芳香化酶可能参与黄鳝的性逆转过程,且与其性别转化密切相关。 相似文献
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通过雌核发育和用紫外线光照过和精子与卵受精及随后用CB处理和抑制PBⅡ的释放都成功地诱导生产雌的和三倍体的矮小蛤。进一步处理结果显示矮小蛤可能有Y显性化的xx-雌,xy-雄的性别确定,与二倍体相比,三倍体有一定的生殖力,雌性为59%,雄性为80%,三倍体雌性产生的卵的容量比二倍体雌性的卵容量大53%(P〈0.001)。 相似文献
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黄鳝是一种具有性逆转特性的动物,如对其进行雄化育苗可加快生长速度,提高增重率。黄鳝在雌性阶段的生长速度只是逆变成雄性阶段的30%左右,即雄黄鳝的生长速度及增重率是雌性的一倍以上。据此,如在商品鳝的催肥中,给黄鳝喂服甲基睾丸素进行雄化,即可取得良好的效果和经济效益。 相似文献
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B. Breton T. Mikolajczyk C. Weill J. M. Danger H. Vaudry 《Fish physiology and biochemistry》1990,8(4):339-346
The action of neuropeptide Y (NPY) and gonadotropin releasing hormone (s-GnRH) have been compared on the release of gonadotropin
(GtH) by perifused rainbow trout pituitary glands sampled from freshly ovulated female rainbow trout. We have already demonstrated
that NPY stimulated the secretion of GtH in vitro.
The pituitary responses to s-GnRH and NPY were similar either after repeated 10 min infusions or a one hour prolonged application.
In both cases, after the first application, the pituitary did not responded to subsequent secretagogues stimulations, and
appeared to be desensitized. The stimulatory action of s-GnRH was partly inhibited (60%) by LH-RH antagonist (DpGlu1, DPhe2, DTrp3–6) LH-RH, which completely inhibited the response to NPY in perifused pituitary glands sampled from freshly ovulated females,
but did not modify the response of pituitaries taken from vitellogenic animals in which NPY induced a transient inhibition
of the GtH secretion. These results may indicate that the mode of action of NPY would differ between vitellogenic and matured
animals. NPY also stimulated the GtH secretion from perifused pituitary dispersed cells prepared from pituitaries taken from
freshly ovulated rainbow trout, indicating that NPY may act directly on the pituitary gonadotropic cells to stimulate GtH
secretion. 相似文献
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根据已发表的H5N1亚型禽流感病毒的HA基因全序列,设计了1对引物,对禽流感病毒新疆株A/Goose/XJYL/10/2003(H5N1)提取RNA,经RT-PCR扩增后将其克隆到pMD18-T载体上,获得长为1758bp的HA全基因序列。序列测定后,分析结果表明,本试验株与广东、香港和东南亚等不同地区的H5N1禽流感病毒HA的核甘酸序列的同源率很高,其氨基酸切割位点附近具有高致病性禽流感病毒的特征。系统进化树分析表明,新疆株为独立分支,属于欧亚种系。 相似文献
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锯缘青蟹脑内5-HT和NPY的免疫细胞化学定位 总被引:4,自引:0,他引:4
为探讨5-羟色胺和神经肽Y在锯缘青蟹脑内的存在与否和分布状况,应用免疫细胞化学技术,在光学显微镜下观察5-羟色胺和神经肽Y阳性细胞和神经髓质的形态和分布。结果表明:在锯缘青蟹脑中共12个胞体群和11个神经髓质中,前脑和中脑中有4个细胞群和6个神经髓质检出5-HT免疫阳性反应;中脑和后脑中有7个细胞群和3个神经髓质具有NPY免疫阳性反应。5-羟色胺和神经肽Y在锯缘青蟹脑内的特异性分布,为其参与神经牛理活动提供了形态学证据。 相似文献
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厚颌鲂(Megalobrama pellegrini)神经肽Y cDNA克隆和序列分析 总被引:1,自引:1,他引:0
利用RT-PCR的方法获得了厚颌鲂(Megalobrama pellegrini)NPY基因的编码序列。结果显示:厚颌鲂NPY基因长度为302 bp,包含了NPY基因291 bp的整个开放阅读框,共编码96个氨基酸,其分子量预测值为10987.4,理论等电点为5.72。通过ClustalX软件,将厚颌鲂与21个物种NPY的氨基酸序列进行比对,再结合Blastp分析的结果发现,厚颌鲂NPY氨基酸序列与鲤、中华倒刺鲃、鲫、斑马鱼、岩原鲤等鲤科鱼类的同源性最高,其同源性分别为100%、97%、95%、93%、93%。根据包括厚颌鲂在内的22个物种的NPY氨基酸序列的同源性构建进化树,其同源性与各鱼种分类地位一致。 相似文献
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Effect of fasting and feeding on growth,intestinal morphology and enteroendocrine cell density in Rhamdia quelen juveniles 下载免费PDF全文
David Roque Hernández Carlos Eduardo Barrios Juan José Santinón Sebastián Sánchez Bernardo Baldisserotto 《Aquaculture Research》2018,49(4):1512-1520
This study was carried out to assess the effect of fasting and feeding on growth, intestinal morphology and density of cholecystokinin (CCK‐) and neuropeptide Y (NPY‐) immunoreactive cells in Rhamdia quelen. Fish were fed during 30 days with three commercial feeds containing different protein levels (T1 = 25%, T2 = 30% and T3 = 45%) while one group remained food deprived (T0). Our results show that the T3 group presented higher final mean weight and specific growth rate, while food‐deprived group showed a significant weight loss. Histological analyses showed that the epithelial area of the intestine was significantly affected by fasting. Also, immunohistochemical analyses showed changes in enteroendocrine cells density, according to nutritional status. Cholecystokinin cell density was higher in T2 and T3 groups, while no differences in NPY cell density were observed between fed groups. Neuropeptide Y and CCK cell densities decreased in fasted group. Nevertheless, this group presented a higher NPY:CCK cell ratio (5:1) compared to fed groups (1–1.5:1), suggesting NPY acts as a peripheral orexigenic factor. These results show that the structure and endocrine functions of R. quelen intestine respond with a downregulation mechanism to endure long‐term starvation. 相似文献
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Konrad Ocalewicz Igor Babiak Barbara Kasprzycka Stefan Dobosz Henryk Kuzminski Krzysztof Goryczko 《Aquaculture (Amsterdam, Netherlands)》2007,270(1-4):546-551
Morphologically differentiated sex chromosomes are found in only few salmonid species. Some populations of rainbow trout, Oncorhynchus mykiss, exhibit chromosomal polymorphism related to sex. We found sex-related chromosomal polymorphism in fish from the synthetic Rutki strain, Poland, in approximately 85% (n = 22) of examined males (XY-like) whereas the remaining males (n = 4) possessed chromosomes similar to these observed in females (XX-like). To investigate whether males possessing XX-like chromosomes were genotypic males or genotypic females with altered phenotypic sex, androgenetic progeny of four males (representing both XY-like and XX-like forms, n = 2 + 2) was examined. Androgenetic progeny (F1) of all four fathers consisted of both phenotypic females and males. F1 male progeny of two fathers showed XX-like chromosomes whereas F1 male progeny of the other two fathers possessed YY-like (supermale) chromosomes. F1 were reared further until they were sexually mature. Two males from each of four F1 families were used to produce F2 androgenetic and control F2 generation. All F2 individuals, androgenetics and control, were phenotypic males at sexual maturation. The results indicate that males possessing XX-like chromosomes are genetic males and they are not sex-reversed females. Thus, the Y chromosome can exist in different morphological forms in farmed rainbow trout. The YS chromosome (shorter form, unlike the X chromosome) has a shorter or absent p-arm and lacks the pericentromeric cluster of AT-rich chromatin and the 5S rDNA sequences that are found in the YL chromosome (longer form, like the X chromosome). 相似文献
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为研究刺鼠相关蛋白(AGRP)和神经肽Y(NPY)基因在团头鲂幼鱼应答饥饿与再摄食过程中所起的调控作用,本研究采用RACE PCR技术首次克隆了团头鲂AGRP和NPY基因全长cDNA序列,通过设置正常对照组(control,体质量3%持续投喂4周)、饥饿再投喂组(F/refeeding,饥饿2周+3%再投喂2周)、饥饿过量投喂组(F/excessive refeeding,饥饿2周+8%再投喂2周)和饥饿组(fasted,持续饥饿4周)4个处理组,采用qRT-PCR技术分析团头鲂在脑和肠道组织中这两种基因在饥饿再投喂过程中的表达变化特征。结果显示,(1)组织学分析表明,持续饥饿组肠道黏膜下层出现明显的白细胞浸润现象。(2)团头鲂AGRP和NPY基因cDNA序列全长分别为770 和557 bp,其中有5’非编码区77和101 bp以及3’非编码区315和120 bp,开放阅读框为378和336 bp,共编码了125个氨基酸和111个氨基酸。系统进化树分析表明,团头鲂的AGRP和NPY基因分别与其他鲤科鱼类聚类一支,具有最近的亲缘关系。(3)qRT-PCR分析显示,AGRP和NPY基因在所有检测组织中均有表达,二者均在脑组织中表达量最高,其次是肝脏和肠道。(4)饥饿再投喂处理对团头鲂脑和肠道中AGRP和NPY基因表达影响显著,饥饿组团头鲂脑和肠道组织AGRP基因表达量均呈先升后降趋势,第28天,饥饿再投喂组能够显著上调团头鲂AGRP基因在脑组织中的表达,但饥饿过量投喂组能够显著上调AGRP基因在肠道中表达量。持续饥饿组团头鲂脑和肠道组织NPY基因表达呈先上升后下降趋势,且饥饿组脑和肠道组织中NPY表达量在28 d均显著高于其余3组。上述结果表明,AGRP和NPY基因在团头鲂摄食调控中发挥重要作用,且在脑和肠道组织具有不同表达模式。 相似文献
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采用PCR方法扩增了皱纹盘鲍(4个群体)和九孔鲍(1个群体)共5个群体(53个样本)16S rRNA基因片段(16S),测序获得了1000 bp核苷酸序列,其中669 bp核苷酸序列用于遗传差异分析,旨在评估我国皱纹盘鲍不同群体间及其与九孔鲍间的遗传差异。从52个序列中共检测到17种单倍型,其中皱纹盘鲍4个群体有13种单倍型,九孔鲍1个群体(9个样本)有4种单倍型。单倍型核苷酸序列比对显示,变异位点占比对位点的20.5%,基于单倍型的皱纹盘鲍4个群体间的遗传距离为0.002~0.011,平均为0.005;九孔鲍群体内的平均遗传距离为0.004,两种鲍间的平均遗传距离为0.218;两种鲍间的遗传分化系数 F‐统计量 FST平均为0.982,皱纹盘鲍4群体间的 FST值为0.0051~0.0065。本研究显示2种鲍群体内16S变异很小。系统发育分析鲍属11种鲍的聚类关系,显示皱纹盘鲍与盘鲍、日本鲍交叉聚为一支,九孔鲍与杂色鲍也交叉聚为一支,4个种类未聚成单系支。 相似文献
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采用皱纹盘鲍大连群体与盘鲍日本群体进行杂交育苗试验和鲍苗种生产。结果表明,皱纹盘鲍和盘鲍正、反交组合的受精率和孵化率均低于两亲本自交组,而其苗种成活率高于两亲本自交组(提高达20%以上);皱纹盘鲍和盘鲍的正、反交组合鲍苗的生长情况是,其平均壳长明显高于两亲本自交组鲍苗的平均壳长,最长达2.01 cm ;皱纹盘鲍与盘鲍作为亲本进行鲍苗种生产,经160 d培育,共培育出鲍苗种2020.75万只(平均壳长2.01 cm ),鲍出苗量平均4345.7只/m2。通过鲍种内杂交的育种方法,可以达到改良和优化鲍种质的目的。 相似文献