Efficacy of anticoagulant-free alternative bait products against house mice (Mus musculus) and brown rats (Rattus norvegicus)

The attractiveness and efficacy of four anonymous anticoagulant-free alternative rodenticides (active ingredients cellulose or plaster) were tested on wild strain groups of house mice (Mus musculus Linnaeus) and brown rats (Rattus norvegicus Berkenhout) in laboratory choice and no-choice experiments. In no-choice tests, the rodenticide product was offered ad libitum to the animals for 21 days (mice) and 10 days (rats), respectively. In choice tests, the rodenticide product and non-poisoned food were offered for 28 days (mice) and 14 days (rats). Two products with cellulose (C1 and C2) as the active ingredient were tested against both mice and rats. In two no-choice tests with mice, all animals died within 14 days (C1) and 21 days (C2); in a third no-choice test, 11% (2/18) of mice survived (C1: 21 days). In all three tests, numerous incidents of cannibalism were observed. The attractiveness of cellulose baits was tested for one product (C1) in three trials against normal food pellets. In all trials, bait consumption was low and all mice survived (15–34 days). Two no-choice trials with cellulose baits (C1) were conducted on groups of Rattus norvegicus; 11 of 12 rats survived the bait feeding period and no cannibalism or sign of aggression between conspecifics was observed. Two plaster-based (CaSO₄·0.5H₂O) products (P1 and P2) were tested against both mice and rats; in no-choice tests, only one mouse (n= 20) and no rats (n= 8) were killed, although the baits proved to be attractive for rats and mice in choice tests. The results of these experiments suggest that neither cellulose-based nor plaster-based rodenticides are suitable agents for the control of Mus musculus and Rattus norvegicus.     

社鼠褐色脂肪组织和器官总蛋白及线粒体蛋白的季节变化

对社鼠(Rattus nivivenler confucianus)的褐色脂肪组织(BAT)、肝脏、心脏和后肢肌肉组织总蛋白和线粒体蛋白含量的季节性变化进行测定和分析。结果表明：BAT的平均鲜质量和相对质量从春季到冬季逐渐增加，各季节之间存在权显著差异；BAT组织总蛋白各季节无显著差异，线粒体蛋白以春季最高，夏季最低，各季节之间有显著差异；肝脏组织总蛋白和线粒体蛋白含量均呈冬春季高、夏季低的特点，各季节之间的差异分别达到权显著和显著水平；心脏组织总蛋白无季节性差异，线粒体蛋白的季节变化与BAT的线粒体蛋白相似；后肢肌肉组织总蛋白在各季节问无显著差异，线粒体蛋白表现为春秋季高、夏冬季低，有显著差异。社鼠的BAT、肝脏、心脏与产热有密切的关系，而后肢肌肉与产热的关系尚难以定论。栖于亚热带地区的社鼠常年生活在较为温暖的环境中，低温并不是影响社鼠生存的决定因子，因此BAT、肝脏、心脏和后肢肌肉的组织总蛋白、线粒体蛋白含量的季节变化较高寒地区鼠类更为温和。     

6天龄与10天龄大鼠的睾丸组织的基因差异表达

通过基因芯片技术,利用Roche-NimbleGen公司制作的大鼠12×135K全基因组表达谱芯片,对日龄为6d和10d的大鼠睾丸组织进行全基因组表达差异分析。结果显示：具有2倍以上的差异表达基因有4298个,其中表达上调的基因共1878个,表达下调的基因共2420个。这些差异表达的基因中有3154个基因具有基因本体注释,参与了154个生物学通路。进一步分析表明具有8倍以上差异表达的基因有13个,这些基因参与了生物学过程、细胞组分和分子功能等基因本体分类,进一步选择3个差异表达的基因,LOC686076、Cxcl6和Trib3,做了实时定量RT-PCR检测。其结果趋势与芯片数据一致。因此,我们初步认为精原干细胞的发生与增殖在大鼠早期的发育过程中已经有大量的基因参与,是一个多基因协调表达的过程。     

Trawl catch composition in relation to Norway lobster (Nephrops norvegicus L.) abundance on the Farn Deeps grounds, NE England

Management of fisheries directed at a particular species (the target) is often complicated by the capture of other species (the bycatch), each of which may be subject to competing management objectives. Optimal management depends upon a good understanding of how catches of the target species vary in relation to bycatch of other species of commercial and conservation concern. This paper considers the composition of trawl catches taken on a Norway lobster (Nephrops norvegicus) ground off the NE coast of England, examining the factors that determine catch rates of Nephrops and various commercial finfish species taken as bycatch. We describe the results of a trawl survey undertaken using four commercial vessels deploying standard commercial gear. Only about 19% of the variance in Nephrops catch rates could be accounted for by variations in local density, as measured independently by underwater television survey of Nephrops burrows. Variations in Nephrops catch rates were dominated by changes over time, particularly in relation to tidal state. Five commercial bycatch species were taken alongside Nephrops in significant quantities. Catch rates of haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus) and lemon sole (Microstomus kitt) varied independently of Nephrops, whereas catches of cod (Gadus morhua) and plaice (Pleuronectes platessa) were inversely related to Nephrops. We conclude that it is possible for the commercial Nephrops fishery to use spatial and temporal targeting to maximise catches of N. norvegicus whilst minimising the bycatch of some fish species. If catch statistics are used to identify Nephrops-directed fishing métiers for fishery management purposes it is vital that data are examined at the level of individual hauls or fishing trips. Aggregation of data at a higher level risks obscuring the effectiveness with which the fishery is targeted at Nephrops.     

RNA Interference-Mediated Downregulation of sAC Gene Inhibits Sperm Hyperactivation in Male Rats （Rattus norvegicus）

Hyperactivation is one of the most critical parts for fertilization, cAMP generated by soluble adenylyl cyclase （sAC） is necessary to activate sperm and is a prerequisite for sperm hyperactivation. The aim of this study is to investigate the function of sAC in hyperactivation in male rats. Four siRNAs of sAC gene were designed and separately transformed into rat sperm using electrotransformation method. Cultured for 12 and 24 h, physiological and biochemical indexes of these sperm were analyzed, and the expressions of some hyperactivation-related genes were detected using real-time PCR. We demonstrated 26.3-30.8% and 49.1-50.5% reduction in sAC at the protein by Western blot and mRNA levels by real-time PCR, respectively. The results showed that two siRNAs, Actb-717 and Actb-4205, were the best RNAi sites for silencing sAC. The VCL （curvilinear velocity） and ALH （amplitude of lateral head displacement） of RNA interference （RNAi）-transfected sperm were reduced, cAMP and protein phosphorylation in RNAi transfected sperm were also decreased. The hyperactivation-related genes, such as CatSper2, LDHC and PKA, were downregulated in the sperm, which sAC was knockdown. These findings demonstrated that sAC might play a critical role in cAMP signaling in the rat sperm hyperactivation, and downregulated sAC gene might prevent the expression of these hyperactivation-ralated genes resulting in sperm dysfunction. These findings suggest that these hyperactivation-ralated genes and sAC are functionally related in sperm hyperactivation and sAC falls into an expanding group of sperm proteins that appear to be promising targets for the development of male contraceptives.     

警惕鄱阳湖区滨湖农田害鼠暴发成灾

2015年6月、9月和12月在鄱阳湖湖滩草洲和滨湖农田进行了鼠类密度调查,结果表明,农田总捕获率为11.22%,湖滩草洲总捕获率为3.98%,其中水稻田鼠密度非常高,6月、9月、12月合计捕获率分别为6.02%、16.73%和14.94%。尤其在本应该鼠密度较低的冬季,恒湖垦殖场水稻田生境的鼠密度却高达33.54%,说明目前鄱阳湖滨湖农田鼠密度已达较高水平,其中优势鼠种黄毛鼠(Rattus losea)和黑线姬鼠(Apodemus agrarius)的繁殖能力强,在冬季保持了较高的密度,且亚成体以下个体比例较高,如不加控制,有进一步暴发成灾的可能。从鼠种组成看,黑线姬鼠为湖滩生境第一优势种(占比为59.46%),黄毛鼠(32.43%)次之;在滨湖农田黄毛鼠(52.63%)已替代黑线姬鼠(44.41%)成为第一优势种群。由于黄毛鼠体型更大、密度高,其成为第一优势种后的发展动态需密切关注。     

应用胴体重指标鉴定贵州省褐家鼠的年龄

为完善贵州省农区主要害鼠种群年龄鉴定划分标准体系建设内容。对2002~2009年贵州省余庆、息烽、三都、关岭、大方5个县捕获的441只褐家鼠(雌鼠201只,雄鼠240只)胴体重统计分析表明,褐家鼠平均胴体重为(69.16±30.45)g,雌、雄鼠之间胴体重差异不显著。根据胴体重的频次分配特征,参照繁殖状况,本研究将褐家鼠划分为5个年龄组,并制定了各年龄组胴体重划分标准:幼年组(Ⅰ)(≤40.0 g),亚成年组(Ⅱ)(40.1~80.0 g),成年Ⅰ组(Ⅲ)(80.1~120.0 g),成年Ⅱ组(Ⅳ)(120.1~160.0 g),老年组(Ⅴ)(160.0 g以上)。研究表明,不同年龄组胴体重、体重、体长、尾长、后足长、耳长之间具有极显著差异,随着种群年龄的增长而不断增加;胴体重与体重、体长、尾长、后足长、耳长之间具有极显著的正相关关系;不同年龄组种群繁殖力存在显著差异,随着种群年龄的增长,种群繁殖力不断增加;参与种群繁殖的主要群体为成年Ⅰ组、成年Ⅱ组和老年组,平均怀孕率为51.39%,平均睾丸下降率为93.51%,平均繁殖指数为2.583 9。种群年龄组成具有明显的季节变化特征。     

息烽县褐家鼠形态特征、种群数量动态及预测研究

采用夹夜法调查逐月捕获率,用捕获率表示种群数量,对贵州省息烽县1986～2009年褐家鼠种群数量进行系统监测。结果表明:褐家鼠是当地家栖鼠优势种,占总鼠数的47.68%,为监测和防治的主要对象。年均捕获率为(3.73±0.70)%,最高为(9.26±4.49)%,最低为(1.09±0.30)%。全年种群数量在3月、7月、10月出现3个数量高峰期,平均捕获率分别为(4.74±3.39)%、(4.67±4.33)%、(4.01±3.42)%;1月和12月为数量低谷期,平均捕获率分别为(3.36±1.54)%、(2.67±1.92)%。在不同季节,种群数量变化以夏季(6～8月)最高,平均捕获率为(4.33±3.71)%,冬季(12～2月)最低为(2.75±2.19)%。以此建立以捕获率为单因子指标的预测方程式为:Y1=0.508 2X1+2.459 5,Y2=1.017 1X2+0.849 6,Y3=1.315 8X3-0.263 4,Y4=1.055 7X4+0.866 3,其相关性极显著,可提前1～3个月对褐家鼠种群数量高峰期进行预测。