Ghrelin对莎能奶山羊垂体催乳素和生长激素mRNA表达的影响

垂体催乳素和生长激素对雌性哺乳动物泌乳的启动和维持以及乳腺的发育都发挥着重要的调节作用.为探讨ghrelin对奶畜泌乳的调节作用,10只泌乳期莎能奶山羊随机分为2组(试验组和对照组),每组5只.试验组羊静脉注射ghrelin(3.0μg/kg)3 h后检测垂体催乳素(Prolactin,PRL)和生长激素(Grouth hormone,GH)mRNA的表达,结果显示一定剂量的ghrelin对催乳素mRNA的表达具显著上调作用(P<0.01);对生长激素mRNA的表达也有显著促进作用(P<0.01).结果表明,ghrelin在垂体水平上对催乳素和生长激素mRNA的表达具有上调作用,提示ghrelin可能通过对这些激素的作用参与了对奶畜泌乳的调节.     

家鸡催乳素放射免疫测定法的建立

本文建立了测定鸡血浆样品中催乳素(chPRL) 的放射免疫测定方法。所用试剂为标准chPRL( AFP 10328B) ,碘标chPRL( AFP 4444B) ,一抗为免抗chPRL(AFP 151040789) 抗血清,二抗驴抗免IgG 抗血清。碘标采用氯胺T 改进法,减少了氯胺T 的用量,并省略了偏重亚硫酸钠的使用,碘标chPRL 比放射性为29μCi/ug 。测定的灵敏度为0-34ng/ ml, 标准曲线的ED75 、ED50 和ED25 分别为1-30 ,3-71 和10-60ng/ ml。样品批内和批间变异低于15 % 。母鸡血浆样品倍比稀释产生的结合抑制曲线与标准曲线平行;测定不同繁殖状态母鸡血浆样品chPRL 显示出显著差异且变化规律符合繁殖活动的变化。证明本方法可用于测定家鸡血浆chPRL 浓度。     

高邮鸭PRL基因内含子1的SNP检测及其与产蛋性状的相关分析

利用PCR—RFLP技术对高邮鸭催乳素（Prolactin，PRL）基因内含子1进行了SNP检测和测序分析，并对该基因与高邮鸭产蛋性状的相关性进行了研究。结果表明：PRL基因内含子1存在两个Dra Ⅰ酶切位点，其中1个位点具有DraⅠ多态性。该位点由于在1326位点发生了T→C的碱基突变，产生了AA、AB和BB3种基因型。基因型BB和等位基因B的频率最高；BB基因型个体30周龄蛋重极显著高于AB基因型个体（P〈0．01）；AB基因型个体的双黄率显著高于BB基因型个体（P〈0．05）；3种基因型间产蛋数、最长连产天数和开产体重无显著差异。     

番鸭就巢期生殖激素水平的变化规律

对番鸭就巢期不同时间的血浆生殖激素水平进行测试,揭示了不同就巢时间血浆生殖激素浓度变化的规律,并对就巢与激素之间的相关性进行分析。结果表明:(1)抱窝期血浆PRL含量(0.68±0.11ng/mL)极显著高于醒抱期的含量(0.33±0.04ng/mL)(P<0.01);(2)醒抱前后血浆LH含量差异很大,醒抱后LH含量(33.17±15.49mIU/mL)极显著高于抱窝期含量(5.56±1.99mIU/mL)(P<0.01);(3)抱窝期血浆E2含量(0.9±0.65ng/mL)极显著低于醒抱期含量(1.9±1.17ng/mL)(P<0.01);(4)PRL与LH、PRL与E2、LH与E2之间的相关系数分别为-0.923、-0.666和0.641。     

泌乳奶山羊非繁殖季节诱发发情研究

奶山羊具有明显的季节性发情的特点,在非繁殖季节里,泌乳母羊体内的催乳素水平要高于繁殖季节,从而抑制了卵巢的生理机能。本研究采用具有抑制催乳素分泌作用的溴隐亭(CB-154,Parlodel)药物来降低母羊体内的催乳素水平,配合使用促性腺激素,提高泌乳母羊的诱发发情率,使配种后不返情率达到80％(28/35)。     

罗非鱼催乳素I基因的组织分布及盐胁迫对其表达的影响

采用同源克隆方法从橙色莫桑比克罗非鱼（Oreochromis mossambicus）、荷那龙罗非鱼（O.hornorum）及其正反交子代垂体中克隆了催乳素Ⅰ基因（PRLⅠ）,并对其核苷酸序列和推导的氨基酸序列进行了比对分析。结果显示,4种罗非鱼的PRLⅠ基因序列长度均为798 bp,ORF长639 bp,共编码212个氨基酸;橙色莫桑比克罗非鱼和荷那龙罗非鱼仅在31号位点存在一个氨基酸残基差异。用qPCR方法分析橙色莫桑比克罗非鱼和荷那龙罗非鱼PRLⅠ基因在不同组织或器官中的表达,结果表明罗非鱼PRLⅠ基因在垂体中的表达量最高,在其他组织中的表达量较低;盐胁迫后4种罗非鱼垂体中的PRLⅠmRNA水平均显著降低,而在其他组织中的表达变化不大。由此可知PRLⅠ基因主要在垂体表达,参与罗非鱼的渗透压调节。     

Effects of photoperiod on salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relation between salsolinol (SAL)‐induced prolactin (PRL) release and photoperiod in goats. A single intravenous (i.v.) injection of SAL was given to adult female goats under short (8 h light, 16 h dark) or long (16 h light, 8 h dark) photoperiod conditions at two different ambient temperatures (20°C or 5°C), and the PRL‐releasing response to SAL was compared to that of thyrotropin‐releasing hormone (TRH) or a dopamine (DA) receptor antagonist, sulpiride. SAL, as well as TRH or sulpiride, stimulated the release of PRL promptly after each injection in both 8‐ and 16‐h daily photoperiods at 20°C (P < 0.05). The area under the response curve (AUC) of PRL for the 60‐min period after injections of saline (controls), SAL, TRH and sulpiride in the 16‐h daily photoperiod group was greater than each corresponding value in the 8‐h daily photoperiod group (P < 0.05). There were no significant differences in the AUC of PRL among the values produced after the injection of SAL, TRH and sulpiride in 16‐h daily photoperiod group; however, the values produced after the injection of TRH were smallest among the three in the 8‐h daily photoperiod group (P < 0.05). The PRL‐releasing responses to SAL, TRH and sulpiride under a short and long photoperiod condition at 5°C resembled those at 20°C. These results show that a long photoperiod highly enhances the PRL‐releasing response to SAL as well as TRH or sulpiride in either medium or low ambient temperature in goats.     

Effects of photoperiod on secretory patterns of growth hormone in adult male goats

The aim of the present study was to clarify the effect of photoperiod on secretory patterns of growth hormone (GH) in male goats. Adult male goats were kept at 20°C with an 8‐h or 16‐h light photoperiod, and secretory patterns of GH secretion were compared. In addition, plasma profiles of prolactin (PRL), insulin‐like growth factor‐I (IGF‐I) and testosterone (T) were also examined to characterize GH secretion. GH was secreted in a pulsatile manner. There was no significant difference in pulse frequency between the 8‐h and 16‐h photoperiods. However, GH pulse amplitude tended to be greater in the group with the 16‐h photoperiod (P = 0.1), and mean GH concentrations were significantly greater in the 16‐h photoperiod (P < 0.05). The GH‐releasing response to GH releasing hormone was greater in the 16‐h than 8‐h photoperiod (P < 0.05). Plasma PRL and IGF‐I levels were higher in the 16‐h than 8‐h photoperiod (P < 0.05). In contrast, plasma T levels were lower in the 16‐h photoperiod (P < 0.05). These results show that a long light photoperiod enhances the secretion of GH as well as PRL and IGF‐I, but reduces plasma T concentrations in male goats.     

基于连接酶检测反应的PRL基因多态与清远麻鸡繁殖性能的相关性研究

旨在建立一个基于聚合酶链反应-连接酶检测反应的基因多态性并行检测系统,探讨鸡催乳素(PRL)基因的多态性,并分析其对优良地方鸡种——清远麻鸡繁殖性能的遗传效应。本研究应用PCR-LDR方法检测PRL8052T/C和PRL8113G/C基因型,并使用SAS软件进行最小二乘分析。结果,在8052T/C位点上,CT基因型个体的52周产蛋数显著高于TT型个体;在8113G/C位点上,CG基因型个体的开产日龄显著低于GG型个体,而其52周龄产蛋数却显著高于GG型个体。2个位点的单倍型对开产日龄和52周产蛋数也存在显著的效应,CTCG型个体具有较早的开产日龄和最高的52周龄产蛋数。结果表明,PRL基因多态性与清远麻鸡繁殖性状有相关关系,PRL 8052T/C和PRL 8113G/C杂合基因型可能是提高鸡繁殖性能的分子标记,利用单倍型进行标记辅助选择可能会获得更大的遗传进展。     

金水乌鸡PRL基因多态性研究

[目的]研究金水乌鸡PRL基因多态性,为金水乌鸡的保种和持续选育与提高积累分子基础数据。[方法]采用PCR-RFLP方法研究金水乌鸡白羽丝毛系165只乌鸡PRL基因多态性,分别采用HaeⅢ和HhaⅠ2种内切酶对各DNA样品的PCR产物进行单酶切,分析基因型与产蛋数的相关。[结果]金水乌鸡PRL基因的PCR产物的HhaⅠ酶切片段未出现多态性。金水乌鸡PRL基因的PCR产物的HaeⅢ酶切片段呈现RFLP多态性,有AA、AB、BB3种基因型,A基因频率较高。相关分析结果表明,不同基因型的产蛋数差异不显著。[结论]A基因可能是影响产蛋数的优势基因。