硒的生物学功效及富硒果品研究进展

综述硒的重要生物学功能、硒与疾病的关系、人体对硒的安全摄入量以及富硒果品的研究现状及其开发。     

Effect of exercise on serum concentration of cartilage oligomeric matrix protein in Thoroughbreds

OBJECTIVE: To evaluate changes in serum cartilage oligomeric matrix protein (COMP) concentrations in response to exercise in horses. ANIMALS: 15 horses in experiment 1 and 27 horses in experiment 2. PROCEDURES: In experiment 1, 15 Thoroughbreds free of orthopedic disease underwent a standardized exercise protocol. Running velocity and heart rate (HR) were recorded, and blood samples were collected immediately before (baseline) and 1, 5, and 24 hours after a single episode of exercise. In experiment 2, 27 horses underwent 9 stages of a training program in which each stage consisted of 4 to 8 consecutive daily workouts followed by a rest day. Blood samples were collected immediately before the first and final daily workouts in each stage. Serum COMP concentrations were measured via inhibition ELISA with a monoclonal antibody (14G4) against equine COMP. RESULTS: In experiment 1, mean serum COMP concentration was significantly higher than baseline 1 and 5 hours after exercise and returned to baseline concentrations 24 hours after exercise. Mean serum baseline COMP concentration increased as the velocity of running at maximum HR and at an HR of 200 beats/min increased, being significantly higher during the third and fourth exercise tests than during the first. In experiment 2, mean baseline COMP concentration at the final workout of each stage was significantly higher than that at the first workout, beginning with stage 3. CONCLUSIONS AND CLINICAL RELEVANCE: Serum COMP concentrations changed significantly in response to exercise. Exercise may enhance movement of COMP into the circulation as well as change the basal turnover rate of COMP.     

两种灯笼果生物学特性观察

通过对外地种和本地种两种灯笼果相关性状的观测,发现将东北的灯笼果引种到海南能够正常生长,并从多方面详细描述了本地种和外地种灯笼果在海南栽培的性状表现。     

Possible involvement of phosphatidylinositol 3-kinase in the maintenance of metaphase II attest in porcine oocytes matured in vitro

It has been reported that phosphatidylinositol 3-kinase (PI3K)-protein kinase B (PKB) pathway plays a crucial role in the meiotic resumption and progression to the metaphase II (MII) stage of oocytes. However, the role of this pathway in meiotic arrest at the MII stage (cytostatic activity) is not well understood. In this study the effect of a PI3K inhibitor, LY294002, on the MAPK and p34^cdc2 kinase activities of matured porcine oocytes was examined. After maturation culture, both the MAPK and p34^cdc2 kinase activities in the oocytes were gradually decreased in a time-dependent manner. Although 25 µmol/L LY294002 did not affect either the MAPK or p34^cdc2 kinase activities, 50 µmol/L LY294002 suppressed the PKB phosphorylation and slightly decreased MAPK activity, but not the p34^cdc2 kinase activity. Therefore the effect of 10 µmol/L Ca²⁺ ionophore which was reported as inducing a transient decrease of p34^cdc2 kinase but not MAPK activities, was also examined in LY294002-treated oocytes. By additional treatment with LY294002 after Ca²⁺ ionophore, both the MAPK and p34^cdc2 kinase activities were decreased in a time-dependent manner, concomitantly with improvement of pronuclear formation. Therefore, we concluded that PI3K is involved in the maintenance of MAPK activity in matured porcine oocytes.     

The effect of M‐phase stage‐dependent kinase inhibitors on inositol 1,4,5‐trisphosphate receptor 1 (IP3R1) expression and localization in pig oocytes

At fertilization, inositol 1,4,5‐trisphosphate receptor type 1 (IP₃R1) has a crucial role in Ca²⁺ release in mammals. Expression levels, localization and phosphorylation of IP₃R1 are important for its function, but it still remains unclear which molecule(s) regulates IP₃R1 behavior in pig oocytes. We examined whether there was a difference in localization of IP₃R1 after in vitro or in vivo maturation of pig oocytes. In mouse oocytes, large clusters of IP₃R1 were formed in the cortex of the oocyte except in a ring‐shaped band of cortex adjacent to the spindle. However, no such clusters of IP₃R1 were observed in pig oocytes and there was no difference in its localization between in vitro and in vivo matured oocytes. We next tried to clarify which factor(s) regulates IP₃R1 localization, phosphorylation and expression using M‐phase stage‐dependent kinase inhibitors. Our results show that treatments with roscovitine (p34^cdc2 kinase inhibitor) or U0126 (mitogen‐activated protein kinase inhibitor) did not affect IP₃R1 expression or localization in pig oocytes, although the latter strongly inhibited phosphorylation. However, treatment with BI‐2536, an inhibitor of polo‐like kinase 1 (Plk1), dramatically decreased the expression level of IP₃R1 in pig oocytes in a dose‐dependent manner. From these results, it is suggested that Plk1 is involved in the regulation of IP₃R1 expression in pig oocytes.     

国内外肉牛遗传评估体系概况

种公牛的选育是肉牛育种工作的核心。传统选育肉用种公牛需要经过后裔测定进行选择,其优点是准确性高,但存在周期长、屠宰和肉质性状难以收集、成本高等问题,致其选择效率低。自2001年全基因组选择概念提出后,该技术迅速成为动植物育种领域研究的热点。利用全基因组选择进行肉用种公牛的选育,进行早期选择从而大幅度缩短世代间隔,可以提高繁殖性状等低遗传力性状的选择准确性,加快遗传进展,并大大降低育种成本。2014年,美国安格斯协会开始应用全基因组选择技术,其他欧美发达国家也陆续使用,肉牛育种进入基因组时代。中国自2017年开始使用全基因组选择技术选择青年肉用种公牛,并于2020年在全国范围内使用该技术进行基因组遗传评估。本文综述了国内外肉牛遗传评估现状,以期为我国肉牛育种工作提供参考和借鉴。     

Phospholipase Cζ (PLCζ) versus postacrosomal sheath WW domain‐binding protein (PAWP): Which molecule will survive as a sperm factor?

During mammalian fertilization, sperm is fused with the oocyte's membrane, triggering the resumption of meiosis from the metaphase II arrest, the extrusion of the second polar body, and the exocytosis of cortical granules; these events are collectively called 'oocyte activation.' In all species studied to date, the transient rise in the cytosolic level of calcium (in particular, the repeated calcium increases called 'calcium oscillations' in mammals) is required for these events. Researchers have focused on identifying the factor(s) that can induce calcium oscillations during fertilization. Sperm‐specific phospholipase C, i.e., PLC zeta (PLCζ), is a strong candidate of the factor(s), and several research groups using different species obtained evidence that PLCζ is a sperm factor that can induce calcium oscillations during fertilization. However, postacrosomal sheath Tryptophan‐Tryptophan (WW)—domain‐binding protein (PAWP) was recently shown to have a pivotal role in inducing calcium oscillations in some species. In this review, we focus on PLCζ and PAWP as sperm factors, and we discuss this controversy: Which of these two molecules survives as a sperm factor?     

杧果MADS-box基因保守区片段的克隆与序列分析

为从杧果中克隆新的MADS-box基因,利用MADS-box转录因子的保守特征设计简并引物,应用RT-PCR从杧果花序中成功分离出14条MADS-box基因cDNA片段。片段长度在138~147bp之间,推导的氨基酸序列与已知的杧果MADS-box基因的同源性为65.2%~82.6%。用推导的氨基酸序列与已知的杧果和拟南芥MADS-box基因进行系统发育分析,可将这些片段归入MADS-box的不同亚家族中。表明杧果花序中存在多种MADS-box转录因子,参与杧果花器官的发育及开花时间的调节。     

ctsd、ctsl基因的多态性与雪龙黑牛胴体性状相关性研究

为了提高雪龙黑牛的胴体性状,进行新品种选育,本研究以组织蛋白酶D、L(Cathepsin D, Cathepsin L)基因为候选基因,利用PCR-RFLP方法对114头雪龙黑牛F1代商品牛进行多态性检测,应用SAS 9.2软件采用最小二乘拟合线性模型进行分析,结果表明,ctsd,c581t位点与雪龙黑牛的经济性状无明显的相关性,ctsl基因xma I位点与雪龙黑牛的三角牛腩厚显著相关,且AB型个体三角牛腩厚与AA和BB型个体三角牛腩厚差异显著。     

高原家养动物环境适应性的研究进展

青藏高原环境主要体现为低氧低压、寒冷干燥、紫外线强、食物匮乏等,而高原家养动物经历了长期的选择和培育后能够生活在此环境下,其机体已经形成了独特的高原适应性特征。由于高原畜禽机体适应进化体系的复杂性,全面系统的适应性分子机制解析尚未完善。随着分子生物学和生物信息学的发展,高原家养动物基因组组装和功能注释完成,然后逐步开展了基因组、转录组和蛋白质组等组学层面的工作,挖掘到一系列高原动物环境适应性关键候选基因,为解析高原家养动物环境适应性分子机制研究提供了强有力支撑。本文以世居在青藏高原的藏鸡(Gallus gallus)、藏猪(Sus scrofa)、牦牛(Bos grunniens)、藏山羊(Capra hircus)、藏绵羊(Ovis aries)、藏马(Equus caballus)和藏獒(Canis lupus familiaris)等高原土著畜禽资源作为分类单元,分别从组织器官的解剖学结构、血液生理生化指标和分子遗传机制解析3个方面进行论述,并对高原适应性进化的研究趋势进行展望,以期为下一步培育高原高寒低氧地区新品种奠定基础。