Generation and Analysis of Expressed Sequence Tags （ESTs） from Muscle Full-Length cDNA Library of Wujin Pig

Porcine skeletal muscle genes play a major role in determining muscle growth and meat quality. Construction of a full-length cDNA library is an effective way to understand the expression of functional genes in muscle tissues. In addition, novel genes for further research could be identified in the library. In this study, we constructed a full-length cDNA library from porcine muscle tissue. The estimated average size of the cDNA inserts was 1 076 bp, and the cDNA fullness ratio was 86.2%. A total of 1 058 unique sequences with 342 contigs （32.3%） and 716 singleton （67.7%） expressed sequence tags （EST） were obtained by clustering and assembling. Meanwhile, 826 （78.1%） ESTs were categorized as known genes, and 232 （21.9%） ESTs were categorized as unknown genes. 65 novel porcine genes that exhibit no identity in the TIGR gene index of Sus scrofa and 124 full-length sequences with unknown functions were deposited in the dbEST division of GenBank （accession numbers： EU650784-EU650788, GE843306, GH228978-GH229100）. The abundantly expressed genes in porcine muscle tissue were related to muscle fiber development, energy metabolism and protein synthesis. Gene ontology analysis showed that sequences expressed in porcine muscle tissue contained a high percentage of binding activity, catalytic activity, structural molecule activity and motor activity, which involved mainly in metabolic, cellular and developmental process, distributed mainly in intracellular region. The sequence data generated in this study would provide valuable information for identifying porcine genes expressed in muscle tissue and help to advance the study on the structure and function of genes in pigs.     

狭闭空间内苗盘物流化搬运机器人运动规划与试验

针对植物工厂狭小密闭工作空间(狭闭空间)内大范围作业需求,提出了一种应用于植物工厂内部的物流化搬运机器人。采用D-H法建立连杆坐标系,通过求解运动学正解对机器人运动空间进行分析,在此基础上,采用边界追踪法规划了一种满足植物工厂立体式培育特点的滑切式搬运最优轨迹,提取轨迹上若干点,求解提取点运动学逆解,采用三次样条插值拟合机械手臂关节变量随时间变化函数,并在实验室中搭建育秧环境可自动调控的立体式育秧平台进行试验,控制机器人按照最优轨迹运动,应用高速摄像技术对实际运动轨迹进行记录,试验结果表明,实际轨迹和最优轨迹最大绝对误差为8 mm,在误差允许范围内,可以完成植物工厂内所需的搬运作业功能。     

南方红豆杉转录组SSR挖掘及分子标记的研究

 利用Trinity软件对NCBI公共数据库中公布的南方红豆杉（Taxus chinensis var. mairei）根、茎和叶的转录数据进行转录组的重新拼接。通过对13 737 528条序列组装得到96 279条Unigenes（38 Mb）,通过SSR检测程序从96 279条Unigenes中得到2 160个SSR位点（2.24%）,其平均发生率为1/18.01 kb,基序长度为14 ~ 25 bp之间。优势重复基序为六核苷酸和三核苷酸,分别占总SSR位点的38.56%和37.08%。2 160个SSR位点由703种重复基序构成,其中六核苷酸占60.96%,主要分布在3 ~ 4重复;二、三核苷酸占总SSR位点的44.81%,其中以（AG/CT）_n、（AT/AT）_n、（AAG/CTT）_n、（AGC/CTG）_n、（AGG/ CCT）_n 和（ATC/ATG）_n重复基序最为丰富,合占总SSR重复类型的34.73%,并出现少量的（CG/CG）_n和（CCG/CGG）_n重复。通过L₉（3⁴）正交试验得到最优的SSR-PCR体系,10 μL PCR体系中含DNA 20 ng,1× PCR缓冲液,MgCl₂ 20 mmol,dNTPs 0.35 mmol,引物0.25 μmol,Taq酶0.45 U。随机挑选62对SSR引物进行8个南方红豆杉株系的SSR扩增,有效扩增率为53.23%,多态性比率为38.71%。这些多态性转录组SSR引物的开发为红豆杉遗传多样性的分析、分子标记辅助育种、遗传图谱构建和功能基因的挖掘提供了更丰富的标记。     

模拟降雨条件下土壤结皮的发展和聚丙烯酰胺对黄土上结皮形成的影响

This study evaluated the morphological characteristics and dynamic variation in characteristics of soil crust and iden-tified the relationships between soil crust and splash erosion under simulated rainfall.The effect of polyacrylamide (PAM) on soil aggregate stabilization and crust formation was also investigated.A laboratory rainfall simulation experiment was carried out using soil sample slices.The slices were examined under a polarized light microscopy and a scanning electron microscope (SEM).The results revealed that the soil crusts were thin and were characterized by a greater density,higher shear strength,finer porosity,and lower saturated hydraulic conductivity than the underlying soil.Two types of crusts,i.e.,structural and depositional crusts,were observed.Soil texture was determined to be the most important soil variable influ-encing surface crust formation;depositional crust formation was primarily related to the skeleton characteristics of the soil and happened when the soil contained a high level of medium and large aggregates.The crust formation processes observed were as follows:1) The fine particles on the soil surface became spattered,leached,and then rough in response to raindrop impact and 2) the fine particles were washed into the subsoil pores while a compact dense layer concurrently formed at soil surface due to the continual compaction by the raindrops.Therefore,the factors that influenced structural crust formation were a large amount of fine particles in the soil surface,continual impact of raindrops,dispersion of aggregates into fine particles,and the formation of a compact dense layer concurrently at the soil surface.It was concluded that the most important factor in the formation of soil crusts was raindrop impact.When polyacrylamide (PAM) was applied,it restored the soil structure and greatly increased soil aggregate stabilization.This effectively prevented crust formation.However,this function of PAM was not continuously effective and the crust reformed with long-term rainfall.In conclusion,this study showed that soil micromorphological studies were a useful method for evaluating soil crust formation.     

用玉米圆斑病菌毒素筛选抗病单倍体胚性细胞无性系研究初报

本试验用圆斑病菌（Helminthosporium carbonum）的粗提毒素处理单倍体玉米胚性细胞团，以未处理的细胞团为对照，用HC-毒素和活菌的 分子孢子接种细胞团鉴定，初步筛选出抗圆斑病菌毒素和抗圆斑菌的细胞团。在筛选体系中，初步认为用高浓度毒素（20-25%毒素处理）体系的效果较理想。通过组织培养技术诱发玉米抗病突变体可能为玉米抗病育种开辟新的途径。     

An Evaluation Attempt Based on Rational Investigation and Analysis - Taking Sanxia Plaza, Chongqing for Example

In this paper, an attempt of rational estimation is made, in which the authors evaluated a specified object by taking a given theory as basis, using some given methods, the given items about the object are studied and analyzed. The evaluation object in this paper is the Sanxia Plaza in Chongqing. The purpose is to promote the well development of specialty evaluation system.     

TLR7/8 signalling affects X-sperm motility via the GSK3α/β-hexokinase pathway for the efficient production of sexed dairy goat embryos

Background:Goat milk is very similar to human milk in terms of its abundant nutrients and ease of digestion.To derive greater economic benefit,farmers require more female offspring(does);however,the buck-to-doe offspring sex ratio is approximately 50%.At present,artificial insemination after the separation of X/Y sperm using flow cytometry is the primary means of controlling the sex of livestock offspring.However,flow cytometry has not been successfully utilised for the separation of X/Y sperm aimed at sexing control in dairy goats.Results:In this study,a novel,simple goat sperm sexing technology that activates the toll-like receptor 7/8(TLR7/8),thereby inhibiting X-sperm motility,was investigated.Our results showed that the TLR7/8 coding goat Xchromosome was expressed in approximately 50%of round spermatids in the testis and sperm,as measured from cross-sections of the epididymis and ejaculate,respectively.Importantly,TLR7/8 was located at the tail of the Xsperm.Upon TLR7/8 activation,phosphorylated forms of glycogen synthase kinaseα/β(GSK3α/β)and nuclear factor kappa-B(NF-κB)were detected in the X-sperm,causing reduced mitochondrial activity,ATP levels,and sperm motility.High-motility Y-sperm segregated to the upper layer and the low-motility X-sperm,to the lower layer.Following in vitro fertilisation using the TLR7/8-activated sperm from the lower layer,80.52±6.75%of the embryos were XX females.The TLR7/8-activated sperm were subsequently used for in vivo embryo production via the superovulatory response;nine embryos were collected from the uterus of two does that conceived.Eight of these were XX embryos,and one was an XY embryo.Conclusions:Our study reveals a novel TLR7/8 signalling mechanism that affects X-sperm motility via the GSK3α/β-hexokinase pathway;this technique could be used to facilitate the efficient production of sexed dairy goat embryos.