褪黑素的作用及其在畜牧生产上的应用

褪黑素(MLT)是哺乳动物和人类的松果体分泌的一种激素,具有抗肿瘤、抗氧化、改善睡眠、调控生殖活动、改善免疫功能等作用。本文对褪黑素的作用及其在动物生产上的应用作一综述。     

Effects of melatonin on oocyte developmental competence and the role of melatonin receptor 1 in juvenile goats

Melatonin enhances in vitro embryo development in several species by improving the oocyte developmental competence during in vitro maturation (IVM). Melatonin has a wide range of actions, from scavenging reactive oxygen species (ROS) to regulating gene expression, and it can also act by way of melatonin receptors. The aim of this study was to determine the mechanism of action of melatonin during the IVM of juvenile goat oocytes and the role of the membrane receptors. Melatonin receptor 1 was immunolocalized in cumulus cells and oocytes before and after 24 hr of IVM. The effect of melatonin on oocyte developmental competence was tested in three experimental IVM groups: (a) control, (b) 10^?7 M melatonin, and (c) 10^?7 M melatonin +10^?7 M luzindole (an inhibitor of both melatonin receptors). After IVM oocytes were assessed for ROS levels, mitochondrial activity, adenosine 5′‐triphosphate (ATP) concentration and relative gene expression (ACTB, SLC1A1, SOD1, GPx1, BAX, DNMT1, GCLC and GDF9). IVM‐oocytes were in vitro fertilized and cultured under conventional conditions. Blastocyst rate and quality (differential cell count) were assessed at 8 days post‐fertilization. Melatonin decreased ROS levels, increased mitochondrial activity and ATP content and increased blastocyst quality compared to control group (55.8 vs. 30.4 inner cell mass ICM, p < 0.05). There was no effect on the relative gene expression due to treatment with melatonin. In conclusion, we have showed that melatonin improves oocyte developmental competence in juvenile goats by reducing ROS levels and improving mitochondrial activity.     

我国香根草繁殖方法的研究进展

针对香根草Vetiveria zizanioides需求量较大和种苗供不应求的现状,综述了我国香根草繁殖方法的研究进展.认为整合组织培养法和种子繁殖法的独特优势,大力开展以种子为材料的组织培养研究,使香根草组织培养工作系统化和产业化,并诱导提高香根草的结籽率,是解决目前我国香根草繁殖慢、种苗供不应求的难题和进一步推广应用的有效途径.     

紫花苜蓿在内蒙古草地畜牧业发展中的作用及利用方式

阐述了紫花苜蓿Medicago sativa在内蒙古草地畜牧业发展中的作用,分析了紫花苜蓿利用方式,旨在有效地解决内蒙古自治区草地畜牧业发展及紫花苜蓿利用过程中存在的问题,促进内蒙古畜牧业健康、持续、稳定发展.     

褪黑素对体外培养绵羊卵泡颗粒细胞分泌雌二醇和孕酮的影响

采集绵羊卵泡颗粒细胞进行体外培养,根据试验设计加入褪黑素(MLT)和HCG,分别于不同培养时间收集细胞培养液,用放射免疫测定法(RIA)测定细胞培养液中雌二醇(17β-E2)和孕酮(P4)含量。结果表明:卵泡颗粒细胞在无血清培养体系中可体外培养,并能够分泌相应17β-E2;用MLT或MLT与HCG共同处理卵泡颗粒细胞,能促进细胞分泌17β-E2,并呈时间和剂量的依赖性,但对P4的分泌没有影响。     

Triennial reproduction symposium: L. E. Casida Award for Excellence in Graduate Education: mentoring graduate students in animal science

Graduate education in animal science prepares students to enhance the understanding of biology and to utilize this knowledge to increase animal productivity. The mentor is instrumental in the development of scientists and must be dedicated to success of students. The approach used to guide an inquisitive student into a productive researcher and educator is formulated from the experiences of the mentor. The training program that the mentor was exposed to, as well as experiences to identify activities that are successful, can result in a unique program to nurture and stimulate students. A dedication to a productive research program is essential for mentoring. Participation in research early in a graduate program is important and it helps students realize that their research can be innovative and exciting. Frequent meetings between students and mentors are essential and participation in data collection and analyses by the student and mentor are great teaching events. Students must have knowledge of the basic sciences and the discipline as well as their focused research area. A demanding and comprehensive graduate education is essential to expand the scientific development of the future generation of researchers and educators.     

Development of novel intracytoplasmic sperm injection and somatic cell nuclear transfer techniques for animal reproduction

Animal biotechnology has made new biological experiments possible and new discoveries are being made on an almost daily basis. Among these discoveries is a method for directly injecting a spermatozoa or somatic nucleus into an oocyte that has brought a revolution in the world of micromanipulators. Experiments that were unfeasible until now have become possible, and normal offspring can be generated from infertile cells, such as using dead sperm or a dead frozen body. In this review, I will introduce the progress of animal reproductive biotechnology, including our current research.     

瘦素在动物生殖调控中的作用(续)

6 结论 由以上可以得出:瘦素对动物的初情期启动有重要作用,是发情周期得以维持正常的代谢信号,可以通过激活卵巢,引起性激素分泌增加,对卵巢内分泌功能有一定促进作用,在早期胚胎发育中也起重要作用,对新生儿生长发育起调节作用,也可促进乳腺发育和乳汁的分泌.     

瘦素在动物生殖调控中的作用（续）

由以上可以得出：瘦素对动物的初情期启动有重要作用，是发情周期得以维持正常的代谢信号，可以通过激活卵巢，引起性激素分泌增加，对卵巢内分泌功能有一定促进作用，在早期胚胎发育中也起重要作用，对新生儿生长发育起调节作用，也可促进乳腺发育和乳汁的分泌。     

微生物脂肪酶概况及其动物营养效应的研究进展

微生物脂肪酶是工业用脂肪酶的重要来源,是生物技术和有机化学应用中广泛使用的酶类之一。文章从微生物脂肪酶来源、酶学特性、在动物消化道中的营养效应和作用机理方面进行综述,主要介绍国内外关于脂肪酶应用在动物饲料方面所取得的一些研究成果,为微生物脂肪酶在饲料中的开发与应用提供参考。     

小肠上皮细胞的培养及在动物营养上的研究进展

小肠是动物消化吸收的主要场所,体外分离培养小肠黏膜上皮细胞(intestinal epithelial-cells,IEC)为研究小肠消化吸收、物质转运及肠道免疫等生物学功能提供了重要手段,文章综述了体外培养小肠上皮细胞的有关方法及鉴定,简要介绍了小肠上皮细胞培养在动物研究中的应用概况。     

动物源性食品中糖皮质激素残留检测方法的研究进展

糖皮质激素常用于治疗家畜的炎症反应、免疫性疾病、牛的酮病等,并且能提高饲料的转化率,促进畜禽的生长,因而广泛用于畜牧业中。然而,动物生长过程中过量使用糖皮质激素会导致其在动物源性食品中残留,给人体健康带来极大的危害。世界各国对动物源性食品中糖皮质激素残留实施愈来愈严格的监控,对各种检测方法也提出了越来越高的要求。本文介绍了糖皮质激素在畜牧业中的应用、糖皮质激素残留的危害,并对其残留检测方法进行综述。     

抗菌药物对动物免疫调节机能影响的研究进展

对常见抗菌药物的分类及其对动物免疫机能造成的影响进行了综述,并对其应对措施进行了初步探讨。抗菌药物除了具有清除体内微生物作用外,尚可直接或间接地调节机体的免疫功能。认识和阐明抗菌药物相关免疫调节机能,对临床上选择抗菌药物治疗具有积极意义。     

丝兰提取物在动物饲粮中应用的研究进展

丝兰提取物(YE)由于生理结构的特殊性,其含有的丝兰皂苷等活性成分具有吸附性,可降低畜舍氨气、硫化氢等有害气体的浓度,改善动物饲养环境,维持动物健康,还可提高动物生产性能。因此,本文就丝兰提取物的营养特点与其在反刍动物和单胃动物饲粮中的应用及对畜禽有害减排的影响进行综述,以期为丝兰提取物在动物生产中的应用提供参考。     

醋酸铅对小鼠卵巢组织结构和卵巢颗粒细胞凋亡的影响

将40只20日龄雌性昆明系小鼠随机分成3个处理组和1个对照组,每组10只。给3个处理组小鼠分别连续2d腹腔按体质量注射醋酸铅10,20,40mg/kg,对照组小鼠注射等体积的生理盐水。于注射后24,72h分离卵巢,用原位末端标记法(TUNEL)测定卵巢颗粒细胞的凋亡率,研究卵巢组织结构及卵巢颗粒细胞凋亡的变化。结果显示,醋酸铅可使小鼠卵巢组织结构发生病变,加速卵巢颗粒细胞的凋亡,且凋亡率随着攻毒剂量的增加和时间的延长而升高,与对照组相比,差异极显著(P0.01);表明醋酸铅对小鼠卵巢具有毒性作用,可诱导卵巢颗粒细胞发生凋亡,并呈现一定的剂量-时间依赖关系。     

醋酸铅对小鼠卵巢颗粒细胞凋亡基因p53、Bax、Bcl-2表达的影响

将40只未成年雌性昆明系小鼠随机分成3个处理组和1个对照组,每组10只。处理组小鼠分别连续2 d腹腔注射铅10、20、40 mg/kg（按体质量给药）,对照组小鼠注射等体积的生理盐水。于注射后24、72 h分离卵巢,用原位末端标记法（TUNEL）测定卵巢颗粒细胞的凋亡率,同时用半定量RT-PCR方法检测凋亡基因p53、Bax、Bcl-2mRNA表达。结果表明,铅可促进颗粒细胞凋亡,且随剂量的增加和作用时间的延长,颗粒细胞中p53、Bax基因表达量逐渐增加,与对照组相比差异显著或极显著（P〈0.05或P〈0.01）;而Bcl-2基因表达量则逐渐减少（P〈0.05或P〈0.01）;表明铅可通过上调促细胞凋亡基因p53、Bax基因表达量,下调Bcl-2基因表达量,诱导卵巢颗粒细胞的凋亡。     

青蒿素及其衍生物在动物生产中的应用研究

青蒿素是一种倍半萜内酯类化合物,其特殊的过氧基团结构使其具有抗疟疾、抗菌、抗炎、抗氧化、抗寄生虫、免疫调节、缓解热应激、促进生长等作用.青蒿素及其衍生物应用于动物生产中可以替代抗生素,具有广阔的应用前景.文章对青蒿素及其衍生物的生理功能、主要提取方式及在动物生产中的应用进行论述.     

单细胞转录组测序技术及其在动物繁殖中的应用进展

动物繁殖在动物种群发展和生命进化的过程中起到群落延续、物种演化、进化变异等至关重要的作用。繁殖是各种生殖细胞的动态变化和互作效应的结果,对生殖细胞动态变化机制进行解析是了解动物繁殖过程的基础。单细胞转录组测序技术在群体细胞中以单细胞维度深入解读信息,逐步成为解读细胞类群异质性、关键基因筛选、相关通路表达、细胞互作等具有复杂性、多样性、动态性的生物学问题的首要选择。目前,单细胞转录组测序技术已经开始从动物生殖细胞的角度对动物繁殖的相关机制进行更深入的探究,以此进一步研究动物繁殖的相关过程。因此,本文主要对单细胞转录组测序技术的相关内容以及其在动物繁殖中的相关应用进行总结。     

C型尿钠肽的作用机制及其对动物生殖调控的研究进展

C型尿钠肽(CNP)属于尿钠肽家族,其结构较为保守,在各种动物体内分布广泛,主要通过自分泌和旁分泌方式发挥生物学作用.C型尿钠肽受体NPR-B通过第二信使cGMP传递信号.CNP在动物生殖中发挥重要作用.在雄性动物中,CNP通过CNP/NPR-B/cGMP级联效应调节精子活力、促进生殖细胞发育、对阴茎勃起具有调节作用;...     

The bovine oviduct and its role in reproduction: a review of the literature

The bovine oviduct provides the environment for sperm transport and capacitation, oocyte transport and maturation, fertilization and early embryonic cleavage. Gamete interactions in the tube occur in contact with both the tubal epithelium and the oviduct fluid secreted by these cells. Current research continues to reveal the active role of the oviduct and its products play in normal fertilization and embryo development. This paper reviews the anatomy and physiology of the oviduct of the cow, including the specific events of reproduction which occur in this organ.