Effects of melatonin on maturation,histone acetylation,autophagy of porcine oocytes and subsequent embryonic development

Melatonin (MLT) is an endogenous hormone with roles in animal germ cell development. However, the effect of MLT on porcine oocyte maturation and its underlying mechanisms remain largely unknown. Here, we investigated the effects of exogenous MLT on oocyte maturation, histone acetylation, autophagy and subsequent embryonic development. We found that 1 nmol/L MLT supplemented in maturation medium was the optimal concentration to promote porcine oocyte maturation and subsequent developmental competence and quality of parthenogenetic embryos. Interestingly, the beneficial effects of 1 nmol/L MLT treatment on porcine oocyte maturation and embryo development were mainly attributed to the first half period of in vitro maturation. Simultaneously, MLT treatment could also improve maturation of small follicle‐derived oocytes, morphologically poor (cumulus cell layer ≤1) and even artificially denuded oocytes and their subsequent embryo development. Furthermore, MLT treatment not only could decrease the levels of H3K27ac and H4K16ac in metaphase II (MII) oocytes, but also could increase the expression abundances of genes associated with cumulus cell expansion, meiotic maturation, histone acetylation and autophagy in cumulus cells or MII oocytes. These results indicate that MLT treatment can facilitate porcine oocyte maturation and subsequent embryonic development probably, through improvements in histone acetylation and autophagy in oocytes.     

禽霍乱蜂胶灭活疫苗对雏鸡免疫试验

本文报告不同剂量禽霍乱蜂胶灭活疫苗对雏鸡免疫的安全性和效果，按雏难的日龄分成Ⅰ组，Ⅱ组，Ⅲ组，Ⅳ组共４组。结果，Ⅰ组接种０．３ｍｌ，０．４ｍｌ，０．５ｍｌ苗的鸡反应率分别为１６．７４％，１６．７６，１７．７９％，免疫后３个月统计，死亡率分别为３．０９％，２．８５％，２．８９％。Ⅱ组接种０．３ｍｌ，０．５ｍｌ，０．７ｍｌ苗的反应率分别为１２．８２％，１３．８３％，１６．２６％，死亡率分别为４．２９％     

茶黄酮对无角多赛特羊生长和呼吸道疾病的影响

选择平均体重为26．6kg的无角多赛特断奶大羔羊22只．平均体重为49．3kg的无角多赛特育成羊48只，分别分为对照组和试验组，试验组羊只精料补充料中添加300mg／kg的茶黄酮，研究茶黄酮对羊只生长和呼吸道疾病的影响。结果表明，添加茶黄酮可提高羔羊和育成羊的增重效果．和对照组比较羔羊提高增量9．8%（P〉0．05），育成羊提高增重6．1%（P〉0．05）；在饲料中添加茶黄酮可使羔羊呼吸道疾病发病率降低64%，使育成羊呼吸道疾病发病率降低50%，可有效预防羊的呼吸道疾病。     

姜堰市桑园虫害多发原因及防治对策

近几年,姜堰市桑园害虫发生面广、量大、种类多,为害重,主要害虫有桑尺蠖、桑毛虫、桑象虫、野蚕、桑叶螨、桑蓟马、天牛等。从发生量看,这几年害虫属于偏重发生,并且各种害虫发生世代重桑较严重,发生为害时间延长,给养蚕生产带来了一定的威胁。为此,我们对桑园害虫发生的原因作调查分析并对今后的防治工作提出几点看法。     

CRISPR/Cas9介导的基因组编辑技术及应用研究进展

成簇的规律间隔的短回文重复序列及其相关蛋白系统(Clustered regularly interspaced short palindromic repeats,CRISPR/CRISPR-associated nuclease system,CRISPR/Cas)是广泛存在于细菌和古细菌的适应性免疫系统,其中由Ⅱ型CRISPR/Cas系统改造而来的第三代基因组编辑技术——CRISPR/Cas9系统已广泛应用于生命科学研究的多个领域。本文主要从CRISPR/Cas9系统的发现、作用原理、应用进展及与其他新兴的基因组编辑技术的对比等四个方面进行阐述,重点介绍其最新研究进展,并展望了CRISPR/Cas9系统的应用前景。     

盐城地区养猪生产中易发疾病的病因及防治措施

本文对盐城地区养猪生产中常发猪病猪链球菌病、附红细胞体病、弓形体病、高热病等四种疾病的分类、临床症状、病理变化以及防治措施进行了总结;同时结合当地猪病发病率高的情况,从养殖业生产的生物安全、疾病防疫、养殖观念以及动物保健等四个方面给予合理建议。     

维生素C对快大型黄羽肉鸡肺动脉高压综合征的影响

采取分组对比的方法(对照组,肺动脉高压综合征(PHS)发病组,维生素C治疗组)分别检测试验鸡只肝组织、肠黏膜、心肌线粒体中的NO含量和NOS的活性。结果显示,对于发生PHS的快大型黄羽肉鸡,其肝脏、心肌和肠黏膜线粒体NO含量呈现先显著上升后显著下降的变化趋势(P<0.05)。线粒体NOS活力的变化趋势则与NO一致。与对照组相比,维生素C治疗组各指标则呈现相反的变化,说明其能有效地阻止快大型黄羽肉鸡发生PHS这一过程。     

鸭副黏病毒的分离与鉴定

从广东省某鸭场的病死番鸭肝脏中分离一株病毒,该病毒对雏鸭、种鸭、蛋鸭均可引起发病。接种鸭胚传至第6代时病毒对鸡红细胞的血凝性稳定,通常在72h开始致死非免疫鸭胚,死亡率为80%。经磷钨酸负染电镜观察,病毒粒子多呈现椭圆形,长轴为167～264nm,短轴为131～139nm,病毒外表有囊膜,囊膜外层有排列整齐的纤突。病毒与禽流感病毒无抗原相关性,能被禽副黏病毒I型阳性血清所中和。根据试验结果,初步将分离的病毒判定为鸭副黏病毒。     

响应面法优化鸡α干扰素工程菌发酵培养基

本研究采用单因素试验和响应面法相结合的方式优化毕赤酵母重组菌的发酵培养基,以提高毕赤酵母发酵液的生物量。首先,通过单因素试验确定最优碳、氮源分别为甘油和NH4H2PO4;然后,采用Plackett-Burman试验、最陡爬坡试验及Box-Behnken响应面分析并结合Design Expert统计分析软件构建响应方程。利用该方程预测得到最佳培养基配方:甘油46g/L,NH4H2PO414g/L,K2SO418g/L,MgSO415g/L,CaSO41.0g/L,KH2PO45g/L,KOH1.5g/L,初始pH6.96,PTM1盐4.4mL/L。此条件下毕赤酵母发酵后湿重具有最高值为175.54g/L,生物量比优化前提高了50%,并且培养基成本低廉,成分简单,方便调控,适合大规模发酵生产。     

Effect of chicken egg yolk immunoglobulins on serum biochemical profiles and intestinal bacterial populations in early‐weaned piglets

This study was conducted to test the hypothesis that dietary supplementation with anti‐E. coli, chicken egg yolk immunoglobulins (IgY), may affect early weaned piglet (EWP) intestinal functions and enteric micro‐organisms. One hundred and forty‐eight ([Landrace × Yorkshire] × Duroc) piglets, weaned at age day 21, were randomly assigned to receive one of three diets for 14 days. Treatment group one (control group) was fed the base diet. Treatment group two (antibiotics group) was fed the base diet which was supplemented with 100 ppm colistin sulphate and 15 ppm enramycin; treatment group three (IgY group) was fed the base diet which was supplemented with 500 mg/kg anti‐E. coli IgY. The study evaluated the effects on EWPs of IgY on growth, serum biochemical, inflammatory profiles and also digestion content intestinal bacterial populations. Results showed no significant difference in diarrhoea rates between IgY‐fed EWPs and antibiotic‐treated EWPs. Serum biochemical analysis showed that EWPs fed an IgY‐containing diet had both lower (p < 0.05) cholesterol and low‐density lipoprotein compared to antibiotic‐treated EWPs. Escherichia coli populations measured in IgY‐fed EWP ileal contents, compared to the control group, were significantly reduced (p < 0.05). Enterococcus, Lactobacillus, Clostridium and Bifidobacterium populations were unaffected by the IgY treatment. Larger (p < 0.05) Enterococcus populations and lower (p < 0.05) expression levels of heat‐stable enterotoxin b (STb) were observed in IgY‐fed EWP caecal digesta compared to the control group. Enteric Lactobacillus significantly decreased (p < 0.05) in EWPs fed antibiotics while it was unaffected by IgY treatment. Dietary supplementation with anti‐E. coli IgY has the potential to suppress enteric E. coli growth, but not Lactobacillus, Clostridium and Bifidobacterium. This promotes and maintains a healthy EWP intestinal environment. These findings suggest that IgY may be used as an alternative to antibiotics in EWP diets.