Body weight of newborn and suckling piglets affects their intestinal gene expression

Modern hyperprolific sows must deal with large litters (16–20 piglets) which reduce piglet birthweight with a concomitant increase in the proportion of small and intrauterine growth retarded piglets. However, larger litters do not only have a greater variation of piglet weights, but also a greater variation in colostrum and milk consumption within the litter. To further understand the impact that body weight has on piglets, the present study aimed to evaluate the degree of physiological weakness of the smallest piglets at birth and during the suckling period (20 d) compared to their middle-weight littermates through their jejunal gene expression. At birth, light piglets showed a downregulation of genes related to immune response (FAXDC2, HSPB1, PPARGC1α), antioxidant enzymes (SOD2m), digestive enzymes (ANPEP, IDO1, SI), and nutrient transporter (SLC39A4) (P < 0.05) but also a tendency for a higher mRNA expression of GBP1 (inflammatory regulator) and HSD11β1 (stress hormone) genes compared to their heavier littermates (P < 0.10). Excluding HSD11β1 gene, all these intestinal gene expression differences initially observed at birth between light and middle-weight piglets were stabilized at the end of the suckling period, when others appeared. Genes involved in barrier function (CLDN1), pro-inflammatory response (CXCL2, IL6, IDO1), and stress hormone signaling (HSD11β1) over-expressed compared to their middle-weight littermates (P < 0.05). In conclusion, at birth and at the end of suckling period, light body weight piglets seem to have a compromised gene expression and therefore impaired nutrient absorption, immune and stress responses compared to their heavier littermates.     

小麦重要农艺性状QTL研究方法及研究进展

小麦的许多重要农艺性状都是数量性状,研究小麦数量性状遗传对小麦育种及其杂种优势具有十分重要的意义。近年来,分子生物学特别是分子标记技术的飞速发展,使得我们可以更深入地进行数量性状的研究。本文综述了近年来小麦QTL的研究进展,包括QTL定位原理及前提条件,常用的分子标记,QTL定位常用的作图群体,QTL定位的方法,QTL定位的统计软件和阈值,QTL的作图精度及小麦QTL定位的研究进展。讨论了小麦QTL定位存在的问题,展望了该领域的发展前景。     

静原鸡let-7a-5p的靶基因预测及组织表达分析

【目的】了解let-7a-5p的生物学信息,初步探索其在静原鸡肌肉组织中的功能作用。【方法】利用生物信息学方法对转录组测序获得的静原鸡let-7a-5p的成熟序列进行保守性分析,使用miRDB、TargetScan和miRanda在线软件预测let-7a-5p的靶基因,取其交集进行GO功能和KEGG通路富集分析,并利用实时荧光定量PCR检测let-7a-5p在静原鸡公鸡和母鸡各组织中的表达水平。【结果】let-7a-5p的成熟序列在各物种间高度保守,共预测得到38个基因集合。在生物过程、细胞组分和分子功能中靶基因富集较多的GO条目有细胞过程、生物调节、细胞、结合和催化活性;靶基因显著富集于聚酮糖单元生物合成、AGE-RAGE信号通路在糖尿病并发症中的作用、泛素介导的蛋白水解、TGF-β信号通路和加压素调节的水重吸收信号通路,且富集最多的是代谢途径、AGE-RAGE信号通路在糖尿病并发症中的作用、泛素介导的蛋白水解和MAPK信号通路。let-7a-5p-靶基因互作主要通过作用于靶mRNA的3′-UTR抑制表达或使其降解。组织表达发现,let-7a-5p在静原鸡公、母鸡的心脏、肝脏、脾脏、...     

广灵驴FTO基因克隆、序列分析及组织差异表达

【目的】对广灵驴脂肪和肥胖相关基因(fat mass and obesity-associated gene, FTO)进行克隆及序列分析,同时检测其在广灵驴各组织中的表达差异,以探究广灵驴FTO基因结构对其生理代谢功能的影响。【方法】运用RT-PCR技术扩增并克隆广灵驴FTO基因CDS序列,进行基因及蛋白质功能分析,同时运用实时荧光定量PCR方法检测FTO基因在广灵驴7种组织(心脏、肝脏、脾脏、肺脏、肾脏、背最长肌及皮下脂肪)中的差异表达。【结果】广灵驴FTO基因CDS区序列长1 518 bp,编码505个氨基酸,序列提交至NCBI,登录号:MZ169553。广灵驴FTO基因与马、猪、牛、人、羊驼、绵羊和山羊的相似性为99.3%、90.3%、89.5%、90.8%、90.7%、89.2%和89.2%;系统进化树分析发现,广灵驴与马的亲缘关系最近。FTO蛋白分子质量为58.35 ku,理论等电点为5.07,脂肪系数为80.36,不稳定系数为48.82,平均疏水指数为-0.550,为不稳定的酸性亲水蛋白。FTO蛋白无信号肽和跨膜区,主要定位于细胞质中,具有34个磷酸化位点与5个糖基化位点...     

抑制差减杂交法(SSH)及其在植物中的应用

简述了抑制差减杂交法的基本原理、方法及优缺点,并对其在植物中的应用进行了综述。     

Penetration, Development and Emigration of Juveniles of the Nematode Meloidogyne arenaria in Myrobalan Plum (Prunus cerasifera) Clones Bearing the Ma Resistance Genes

Penetration, development and emigration of M. arenaria in the roots of three Myrobalan plum (Prunus cerasifera) clones genetically characterized for their resistance to root-knot nematodes (RKN) were studied during the 10 (penetration) and 15 (emigration) days following the date of inoculation (D) of 2500 juveniles (J2s) per plant into the soil. Miniaturized tests were conducted on the two resistant clones P.2175 (Ma1 gene) and P.1079 (Ma2 gene) and the susceptible clone P.2032 (recessive for both genes), obtained from micropropagated plantlets and grown in mini-containers under controlled conditions at 25°C in a growth chamber. For penetration and development studies, nematodes in the roots were recovered by the acid fuchsin-lactophenol staining technique. Equivalent numbers of J2s were recovered in all the clones at D+1 and D+2. Subsequently, the numbers increased rapidly in P.2032 and were significantly different from those in P.1079 and P.2175 that remained at a low level. No swollen larvae were observed in the resistant clones. In P.2032, the first swollen larvae were observed at D+4, the first females were observed at D+12, whereas the first females with attached egg sacs and the first new-generation J2s were obtained between D+21 and D+28. Our data suggest that the resistance phenomenon does not act on the very early nematode penetration but acts later by preventing feeding-site induction and development into the third-stage. For emigration studies, plants in which J2s had been allowed to penetrate for two days (from D to D+2) were washed free of soil, repotted and then, after various periods of growth, soil-free roots were placed under a mistifier to evaluate the numbers of emigrating individuals. Emigration of J2s from the roots occured mainly from D+2 to D+4 in all the genotypes and was very limited from D+4 to D+10. There was no significant differences in the number of emigrated juveniles between the resistant and susceptible clones, indicating that emigration cannot explain the difference in the numbers of nematodes recovered in the roots.     

中国条锈菌新小种条中30、31号的研究

本文报道了1991年以来对新小种条中30、31号鉴定与致病性的研究。继1991年发现对绵阳系成株小麦有致病力的、对Hybrid46有毒的新致病类型91—1,1993年又发现了新的致病类型93—1。根据它们对我国鉴别寄主的反应,命名为条中30、31号。与条中28、29号相比,新小种具有更宽毒性基因组成和更高的相对寄生适合度值,它们对我国生产品种、高代品系和重要抗源有更广的致病范围。证实两个新小种的出现和发展是绵阳系小麦抗条锈变异的主要因素,建议加强对新小种抗病育种和流行预测的研究。     

BBTV两个株系DNA组分1的克隆及序列分析

 对在生物学特性特别是寄主范围上存在明显差异的NSP株系和NS株系的代表分离物(广州天河分离物和高州分离物)的DNA组分1进行了克隆和序列分析,结果表明:2个代表分离物的DNA组分1全序列、ORF及其编码的氨基酸序列的变异率分别为3.2%、3.1%和2.8%,从而进一步确证了可以用寄主范围来作上述2个株系的鉴定。此外,这2个株系的DNA组分1、ORF及其编码的氨基酸序列分别与肖火根等报道的中国(广东)分离物、以及亚洲组和南太平洋组各分离物进行比较,结果表明:NS株系与肖火根等报道的中国(广东)分离物的亲缘关系很密切;这2个株系与亚洲组各分离物的差异均较小,而与南太平洋组各分离物的差异均较大,它们应属亚洲组。     

金针菇单核体DAN3和M与其杂交双核体G1菌丝阶段基因表达差异的转录组初步分析

以金针菇(Flammulinavelutipes)单核菌株DAN3的基因组为参考,完成单核体DAN3和M及其杂交双核体G1在菌丝阶段的转录组测序与数据分析,比较两个样本间的差异基因,并对差异基因进行GO功能分析和KEGG pathway分析.结果表明:两个样本中共有显著性差异表达的基因86个,其中,在G1中呈上调、下调表达的基因数分别为41、45个,有2个基因在G1中特异表达.GO功能分析结果表明,86个差异基因中有40个基因比对上了GO功能注释,其中18个基因在G1中呈上调表达;单一生物过程和催化活性为显著性富集的功能,相关基因在G1中呈上调表达.KEGG pathway分析结果表明,22个差异基因被定位到17条Pathway,其中10个基因在G1中呈上调表达,包括赖氨酸代谢途径对应基因,3_M和G1菌丝样品中赖氨酸含量分别为1.70×103 ng/mg和1.06×103 ng/mg,说明G1中上调的基因可能与之降解相关;DNA复制是显著性富集的代谢途径,相关基因在G1中呈下调表达.     

利用CAPS标记辅助辣椒PVY抗性基因PVr4转育的研究

利用国外报道的与PVr4基因紧密连锁的CAPS标记,对辣椒抗PVY基因PVr4的转育进行了研究和探讨。采用与报道的相同抗源材料CdM334为回交的供体亲本,与5个自交系77013、75-7-3-1、83077、83078、83-163进行回交,在BC1代进行了分子标记的选择。从5个BC1群体75-7-3-1×(CdM334×75-7-3-1)、77013×(CdM334×77013)、83077×(CdM334×83077)、83078×(CdM334×83078)、83-163×(CdM334×83-163)中,分别检测出含有抗病连锁标记的单株21株、15株、10株、11株、12株。