Fatty acid profile as affected by fat depot and the sex category of Polish Holstein-Friesian × Limousin fattening cattle fed silage ad libitum

This study was designed to compare the fatty acid profiles of four types of fat depots from bulls, steers, and heifers. All animals were Polish Holstein-Friesian and Limousin crossbreds fattened semi-intensively—silage at libitum and concentrate in the amount corresponding to 30% of their net energy requirements. The fatty acid profile in intramuscular, intermuscular, and external and internal fat was determined. The intramuscular fat of bulls was most abundant in total PUFAs and n-6 PUFAs, and functional fatty acids C 18:2, C 20:4, and C 22:5 in comparison with steers and heifers. Regardless of sex category, intramuscular and external fat were characterized by higher levels of UFAs and a more desirable MUFA/SFA ratio than the remaining fat types. It should also be noted that external fat was more abundant in CLA than other fat types, and that the highest CLA content was found in bull fat, compared with the remaining sex categories of cattle.     

Effect of mixed rearing of barrows and gilts on backfat thickness and serum metabolite profiles of the Kagoshima-Kurobuta (Berkshire) pig

We investigated the effect of mixed rearing of barrows and gilts on the backfat thickness and the serum metabolite profiles of Kagoshima-Kurobuta (Berkshire) pigs. A total of 149 pigs with an average body weight of 35 kg were divided into the following groups: 100%, 90%, 70%, 50%, 30%, 10%, and 0% groups consisting of 10 barrows (1 pen), 9 barrows + 1 gilt (3 pens), 7 barrows + 3 gilts (2 pens), 5 barrows + 5 gilts (3 pens), 3 barrows + 7 gilts (2 pens), 1 barrow + 9 gilts (3 pens), and 9 gilts (1 pen), respectively. All pigs were raised to a shipping weight of 120 kg. Mixed rearing significantly reduced (p < 0.001) backfat thickness, and the optimum mixing ratio of barrows and gilts was 7:3 (the 70% group). Four types of circulating sex steroids were found in both the barrows and gilts in the 50% group but were not detected in barrows from the 100% group. These results indicated that mixed rearing of barrows and gilts was effective for reducing the backfat thickness of barrows, and induced sex steroid hormones may influence the backfat thickness of barrows in mixed-reared groups.     

中华卵索线虫人工室内培养技术

为室内大量繁殖中华卵索线虫Ovomermis sinensis,采用个体由大到小的斜纹夜蛾Spodoptera litura、棉铃虫Helicoverpa armigera和黏虫Mythimna separata作为宿主,测定被中华卵索线虫寄生后3种宿主的体长和体重,研究宿主种类对中华卵索线虫有效率、雌雄比和体长的影响以及寄生强度对线虫雌雄比的影响。结果显示,被中华卵索线虫寄生后,斜纹夜蛾、棉铃虫和黏虫生长减缓。在相同感染比例下（除宿主与线虫比为1∶15外）,3种宿主的线虫有效率之间差异不显著。当寄生强度为5时,3种宿主体内脱出的中华卵索线虫均为雌线虫;当寄生强度从10增到40时,斜纹夜蛾、棉铃虫和黏虫所脱出的雌性比分别由100.0%、90.0%、83.9%降为0;相同寄生强度下,从斜纹夜蛾体内脱出的雌性比显著高于从棉铃虫与黏虫体内脱出的雌性比。斜纹夜蛾、棉铃虫和黏虫体内脱出雌线虫和雄线虫平均体长分别为14.8、13.8、12.8 cm和8.0、7.5和7.5 cm。当中华卵索线虫与宿主按照比例20∶1～25∶1侵染斜纹夜蛾、按照15∶1侵染棉铃虫和黏虫时,能获得线虫最适雌雄比（1∶1...     

光源、性别及光处理时间对草地贪夜蛾趋光行为的影响

为研发高效、精准的监测防控设备,利用八臂行为选择装置系统测定不同光源、性别和光处理时间下草地贪夜蛾Spodoptera frugiperda的趋光行为。结果显示,在紫外光（波长365 nm）、紫光（波长420～430 nm）、蓝光（波长465～475 nm）、绿光（波长525～535 nm）、黄光（波长585～595 nm）和红光（波长655～665 nm）6种波长光源下,草地贪夜蛾混合种群（雌雄成虫比为1∶1）对紫外光光源的趋光选择率最高,为25.61%,显著高于其他处理,其次为紫光和蓝光光源,趋光选择率分别为16.30%和8.82%,对红光的趋光选择率最低,为4.76%。在紫外光刺激下,草地贪夜蛾雌成虫的趋光选择率显著高于混合种群（雌雄成虫比为1∶1）,在红光刺激下,雄成虫的趋光选择率显著高于雌成虫。另外,在紫外光刺激下,光处理时间60 min草地贪夜蛾雌成虫的趋光选择率显著高于其他处理。表明光源与性别因素均影响草地贪夜蛾的趋光行为,光处理时间对草地贪夜蛾的趋光行为影响较小,且与光源及性别因素有关。     

利用shRNA真核表达载体干涉雌性鸡胚性腺中芳香化酶基因(CYP19A1)的表达

本研究通过把构建的短发夹结构RNA(shRNA)真核表达载体导入鸡胚,检测鸡胚性腺分化期质粒载体在鸡胚体内代谢情况及雌性鸡胚性腺中芳香化酶基因(CYP19A1)mRNA表达效率,进而探讨利用该方法在鸡胚体内进行特定基因干涉的可行性.实验针对CYP19A1基因构建了4条特异性表达载体,一条非特异性表达载体.每个实验组选取45个新鲜种蛋作为实验材料进行胚盘下腔注射,并设立空白对照组.鸡胚发育12d时,检测各处理组鸡胚肝脏组织中质粒存在情况,并取其左侧性腺组织进行目标基因的荧光定量分析.研究结果表明,导入组在12日胚龄时所有鸡胚基因组中均可检测到绿色荧光蛋白基因(EGFP);荧光定量结果显示,导入特异性表达载体cyp-580、cyp-1083和cyp-1295后,对应雌性鸡胚性腺CYP19A1 mRNA表达效率显著低于空白对照组,干涉效率分别为:73％、52％和85％;特异性表达载体cyp-1403组CYP19A1mRNA表达效率与空白对照组相比有所降低但无显著性差异.本实验为诱导鸡胚性反转提供了新方法并建立了鸡胚发育期特定基因体内干涉新平台.     

先锋植物沙棘Ⅲ——生活史分析

就沙棘生态习性,应归属r-型生态对策型。沙棘的生活史具两型性(有性和无性繁殖),是对有限资源权衡利用与分配在生命维持-生长-繁殖-扩散上的不均衡结果,是长期自然选择,进化的结果。固氮与克隆生长有利与扩大了r-型生态对策。雌雄异株的进化,避免了近交衰退和提高了沙棘的适合度。沙棘的花序分化受多种同源异型基因调控,而性别决定则受Y性染色体上性基因连锁决定。沙棘繁殖力很高,但衰老较快,是一种生命期(20年左右)较短的灌木。     

一种快速鉴别草地贪夜蛾蛹及成虫雌雄的简易方法

草地贪夜蛾Spodoptera frugiperda(J.E.Smith)是新近入侵我国的重大迁飞性害虫。本研究通过比较草地贪夜蛾雌、雄蛹及成虫的外部形态差异,总结出一种快速鉴别草地贪夜蛾蛹及成虫性别的方法。结果表明:草地贪夜蛾雄蛹在第9腹节腹面中央有一纵裂缝,并连接两个半圆形瘤状突起,且纵裂离肛门的距离较近,腹部末端较尖,分节较为明显;雌蛹在第8腹节腹面近前缘有一短纵裂缝,两侧平滑且无突起结构,裂缝离肛门的距离较远,腹部末端钝圆,分节不明显。雄蛾腹部狭长,腹部末端有一圈黄色长毛簇;雌蛾腹部较雄蛾浑圆,腹部末端黄色毛簇较短。经检测,该鉴定方法的准确率高达100%。对草地贪夜蛾蛹及成虫性别的快速鉴定,将有助于改进后期草地贪夜蛾室内饲养方法,并为田间草地贪夜蛾的预测预报提供参考。     

黏虫蛹性别的快速鉴别方法

根据黏虫Mythimna separata(Walker)蛹生殖孔的位置、腹部腹节的外部形态学特征、生殖孔(产卵孔)至排泄孔之间的距离,快速、准确鉴别黏虫蛹性别。雌蛹第8腹节腹面中央的生殖孔与第9腹节的产卵孔连接形成一纵裂缝,裂缝两侧平坦,无突起。生殖孔下端与第9腹节的前缘连接、产卵孔下端与第10腹节的前缘连接,形成2个明显的"人"字纹。雄蛹第8腹节无纵裂缝,在第9腹节腹面中央的生殖孔呈现的纵裂缝连接第10腹节,裂缝两边各有一个半圆形瘤状突起。雌雄蛹排泄孔均在第10腹节腹面,雌蛹产卵孔下端至排泄孔上端之间的距离为(400.85±151.10)μm,雄蛹生殖孔下端至排泄孔上端之间的距离为(178.21±93.59)μm,约为雌蛹相应距离的一半。采用该方法观察的270头羽化蛹的性别鉴别准确率100%。该方法对于快速鉴别黏虫蛹的性别、开展黏虫相关的生物学研究以及预测预报等具有重要的参考价值。