Differential gene expression of Eph‐ephrin A1 and LEPR‐LEP with high or low number of embryos in pigs during implantation

The objective of this study was to ascertain whether mRNA and protein expressions of implantation‐related genes (erythropoietin‐producing hepatocellular receptor–ligand A1, Eph‐ephrin A1 and leptin receptor–leptin, LEPR‐LEP) differed between pigs with high and low number of embryos, and whether these differences in gene expression might affect embryo implantation. Experimental pig groups (n = 24) for high and low number of embryos were prepared by altering the number of eggs ovulated in pre‐pubertal gilts treated with 1.5 × (High) or 1.0 × (Low) PG600 ([400 IU PMSG + 200 IU hCG]/dose, AKZO‐NOBEL). Gilts expressing oestrus were artificially inseminated twice and maintained in breeding and gestation until the reproductive tract was collected on day 22 of pregnancy. At slaughter, the reproductive tracts from each pregnant gilt from each treatment were immediately processed to collect samples for RNA and protein analysis. Within each gilt, three conceptus points were sampled, one from each horn and then a random conceptus within the tract. At each conceptus point, endometrial attachment site, chorion–allantois and embryo were collected and immediately frozen in liquid nitrogen. Number of corpus luteum (CL) (35.4 vs. 12.6) and total embryo number (18.8 vs. 10.2) were greater in the high‐embryo compared to the low‐embryo group, respectively (p < .05). Real‐time qPCR results showed that Eph‐ephrin A1 mRNA expression was less in the high‐embryo (p < .05) compared to the low‐embryo group. In addition, Western blotting analysis indicated that Eph‐ephrin A1 and LEP protein expression at endometrial attachment site in high‐embryo was less (p < .05) compared to low‐embryo group. It was also noted that mRNA expression of Eph‐ephrin A1 and LEPR‐LEP was greater in pregnant than non‐pregnant gilts (p < .05). Moreover, mRNA expression of Eph‐ephrin A1 (p < .05) and LEPR‐LEP was greatest at endometrial attachment site among all three tissues. There was a positive correlation between expressions of Eph‐ephrin A1, LEPR‐LEP and embryo length with the correlation coefficient 0.31–0.59. For Eph‐ephrin A1, the highest correlation coefficient appeared between Eph A1 expression and normal embryo number, between ephrin A1 expression and embryo length. For LEPR‐LEP, the highest correlation coefficient appeared between LEPR‐LEP expression and ovary weight (0.79 for both, p < .05), followed by embryo length and weight. The results of this study suggest that low expression of Eph‐ephrin A1 and LEPR‐LEP is somehow related to increased embryo number during implantation and that endometrial attachment site might be the main target tissue of these gene products. Yet, the increased expression of Eph‐ephrin A1 and LEPR‐LEP appeared associated with increased embryo growth (length and weight) and ovary weight, Eph‐ephrin A1 and LEPR‐LEP might play roles in the regulation of embryo implantation in pigs.     

紫茎泽兰对萨能奶山羊血常规及重要脏器病理学的影响

紫茎泽兰(Eupatorium adenophorum)在中国作为入侵物种,可造成食草动物中毒死亡,并给畜牧业带巨大的损失。为研究反刍动物采食紫茎泽兰后的中毒机理,本研究探讨了日粮中添加不同剂量的紫茎泽兰对萨能奶山羊(Saanen goat)血常规及肝、脾、肾的病理学影响。选择16只5~6月龄健康萨能奶山羊,随机分成对照组(日粮中未添加紫茎泽兰)和试验Ⅰ、Ⅱ、Ⅲ组(日粮配比中分别添加紫茎泽兰40%、60%和80%),每组4只。试验Ⅰ、Ⅱ、Ⅲ组分别饲喂含40%、60%和80%紫茎泽兰的混合日粮3个月,每两周检测一次血常规,试验末屠宰奶山羊,并观察其肝、肾、脾的病理学变化。结果表明,与对照组相比,各试验组血液中的白细胞(white blood cell,)和中性粒细胞(neutrophil,NEUT)均显著升高(P0.05),试验后期极显著高于对照组(P0.01);而各试验组血液中淋巴细胞(lymphocyte,LY)与血红蛋白(hemoglobin,HGB)均呈下降趋势,试验后期均极显著低于对照组(P0.01)。肝和脾肿大,肝组织出现淤血,肝细胞发生水泡变性及脂肪变性等,肾组织伴有出血、坏死、颗粒变性及水泡样变性的现象。因此,本研究结果说明紫茎泽兰对萨能奶山羊血液指标有显著影响,且长期摄入紫茎泽兰可引起动物肝、肾、脾等主要实质器官不同程度的损伤。     

盐碱胁迫下植物生理和钙信号通路分子机制的研究进展

土壤的盐化和碱化往往伴随发生,在盐碱胁迫下,植物会遭受许多类型的非生物胁迫,严重影响植物的正常生长发育.本综述首先介绍了盐碱土的分类;其次从四个方面对植物在盐碱胁迫下体内产生相应生理机制进行详细介绍;接下来以植物在盐碱胁迫下产生的钙信号为重点进行阐述,包括植物首个非离子通道型盐胁迫下离子感受器GIPCs的发现、盐碱胁迫...     

30%爱苗乳油防治水稻纹枯病的研究

用生长速率法测定了30%爱苗对水稻纹枯病菌(Rhizoctonia solani Kuhn)菌丝生长的抑制作用,结果表明,爱苗对水稻纹枯病菌抑制能力较强,其毒力回归式为:y=4.026 5 0.788 1 x,EC50=17.19 μL·L-1;田间试验表明,爱苗乳油用量为225 mL·hm-2,对水稻纹枯病的防效可达62.4%,与对照相比增产13.4%.     

基于有限混合模型的山东海域口虾蛄群体体长结构分析

个体大小是渔业资源种群的重要结构特征,一般研究中采用平均个体体长或平均体质量等分析指标,难以充分反应具有多年龄结构和个体生长速度差异的种群组成差异。为研究口虾蛄个体大小组成的时空变化,实验根据山东海域2016年10月和2017年1、5、8月的底拖网调查数据,应用有限混合模型分析了不同性别、不同时间、不同水深口虾蛄个体大小的频率分布特征。结果发现,除秋季外,山东海域口虾蛄均可区分为高、低两个年龄组,同时雌雄体长分布具有一定的差异。从冬季到夏季,雌性口虾蛄中低龄组个体比例先下降后上升,雄性口虾蛄低龄比例则逐渐下降。就不同水深而言,口虾蛄低龄组个体主要集中在近海海域,其比例由近海向远海逐渐减小。各年龄组的近远海分布表现出季节性差异,春季高龄口虾蛄在近海比例最大,由近海向远海比例逐渐减小;夏季高龄组口虾蛄在20～30 m水深比例最大;冬季高龄组口虾蛄比例则由近海向远海逐渐增加。有限混合模型能够较好地对口虾蛄的体长结构进行分析,解析口虾蛄不同年龄组在山东海域的时空分布,对于深入了解口虾蛄种群分布动态和科学的渔业管理具有重要意义。     

75%甲嘧磺隆水分散粒剂防除非耕地杂草试验

应用75%甲嘧磺隆水分散粒剂对非耕地杂草进行防除试验。结果表明,试验剂量在45～75g/667m2范围内,防治效果达100%。     

华北棉区棉铃虫对三种杀虫剂的抗性监测

为明确华北棉区棉铃虫Helicoverpa armigera田间种群对3种常用杀虫剂的抗性,于2014—2015年和2018—2019年分别采集河南、河北、山东和山西4个省的棉铃虫田间种群,采用浸叶法于室内测定棉铃虫对辛硫磷、三氟氯氰菊酯和甲维盐的抗性水平。结果表明,各监测点棉铃虫对辛硫磷处于中等水平抗性,在2014—2015年和2018—2019年的抗性倍数分别为13.0~58.5倍和21.1~55.3倍,棉铃虫对辛硫磷的抗性发展相对缓慢;各监测点棉铃虫种群对三氟氯氰菊酯已产生中等至高水平抗性,并呈现逐年上升的趋势,其中河北沧县、河南安阳、山西盐湖种群的抗性倍数由2014年的61.0倍、22.5倍和24.0倍上升至2019年的91.1倍、44.7倍和61.3倍,山东夏津种群的抗性最高,2019年抗性倍数达到216.3倍;棉铃虫种群对甲维盐表现为低至中等水平抗性,河北沧县、河南安阳、山西盐湖和山东夏津种群的抗性倍数分别为8.2~40.4倍、5.8~16.6倍、5.5~23.4倍和11.0~36.6倍。表明4个监测地区的棉铃虫田间种群对3种杀虫剂已经产生了不同程度的抗性,建议减少这3种杀虫剂的使用频次,并注意与其他杀虫剂交替轮换使用,以延缓棉铃虫抗药性的发展。     

番茄早疫病菌抗啶酰菌胺菌株细胞膜透性变化

为探究番茄早疫病菌Alternaria solani对啶酰菌胺产生抗性后膜透性的变化,采用菌丝生长法、可见分光光度法、电导率法和荧光猝灭法分别测定了抗、感菌株对NaCl渗透压的敏感性、胞内可溶性蛋白和糖的含量、膜渗透率及对啶酰菌胺的吸收量。结果表明:抗性(R-Bos)菌株在2.5 g/L NaCl浓度中生长最快,敏感(S-Bos)菌株则在5 g/L NaCl浓度中生长最快;在0~10 g/L NaCl浓度下,R-Bos菌株的生长明显快于S-Bos菌株,在20~80 g/L NaCl浓度下生长无显著差异;R-Bos菌株的可溶性蛋白和可溶性糖含量显著增高,分别达61.9%~105.2%和133.1%~161.9%;用啶酰菌胺处理菌株后,所有菌株的渗透率上升,膜透性增大,但R-Bos菌株的渗透率始终低于S-Bos菌株;且R-Bos菌株对啶酰菌胺的吸收量明显减少,为48.3%~49.9%。推测番茄早疫病菌对啶酰菌胺产生抗性后,胞内保水能力提高,对渗透压表现出耐受性,同时膜透性降低使得对药剂的吸收能力下降。     

莲子草假隔链格孢的寄主范围及对空心莲子草的控制作用

 空心莲子草(Alteranthera philoxeroides)由于具有繁殖迅速、适应性强等特点,于20世纪50年代被引人我国江苏和浙江等地作为牲畜饲料植物栽培,随后相继传人全国各地并引起危害,成为我国大部分省区旱地和水域的恶性杂草之一。其微生物防治目前仍处于生物防治物的调查筛选阶段,已发现的病原真菌有假隔链格孢菌(Nimbya alternantherae)、炭疽菌(Colletotrichum gloeosporioides)、立枯丝核菌(Rhizoctonia solani)及链格孢(Alternaria sp.)等。