数字经济背景下南泥湾家庭农场发展的研究

在数字经济发展背景下,为探究应用可溯源技术的家庭农场在南泥湾地区发展的可行性,并制定合理的家庭农场发展战略,文章首先结合SWOT分析法对南泥湾区域家庭农场发展的优势、劣势、机会、威胁4方面独立和联合分析,进而对家庭农场的发展战略进行定位,总结出该地的家庭农场的发展要以SO扩张型的发展战略为主、以WO防御型的发展战略为辅。农场要借助南泥湾地区的自然优势和旅游产业优厚条件,吸引政府的投资及企业合作融资,不断优化技术和管理方案,以期提高当地农民收入,实现产业联动发展,推动经济高速高质量发展。     

Bactrian camel (Camelus bactrianus) integrins αvβ3 and αvβ6 as FMDV receptors: Molecular cloning, sequence analysis and comparison with other species

Integrins are heterodimeric adhesion receptors that participate in a variety of cell–cell and cell–extracellular matrix protein interactions. Many integrins recognize RGD sequences displayed on extracellular matrix proteins and the exposed loops of viral capsid proteins. Four members of the αv integrin family of cellular receptors, αvβ3, αvβ6, αvβ1 and αvβ8, have been identified as receptors for foot-and-mouth disease virus (FMDV) in vitro, and integrins are believed to be the receptors used to target epithelial cells in the infected animals. To analyse the roles of the αv integrins from a susceptible species as viral receptors, we have cloned Bactrian camel αv, β3 and β6 integrin cDNAs and compared them to those of other species. The coding sequences for Bactrian camel integrin αv, β3 and β6 were found to be 3165, 2289 and 2367 nucleotides in length, encoding 1054, 762 and 788 amino acids, respectively. The Bactrian camel αv, β3 and β6 subunits share many structural features with homologues of other species, including the ligand binding domain and cysteine-rich region. Phylogenetic trees and similarity analyses showed the close relationships of integrin genes from Bactrian camels, pigs and cattle, which are each susceptible to FMDV infection, that were distinct from the orders Rodentia, Primates, Perissodactyla, Carnivora, Galliformes and Xenopus. We postulate that host tropism of FMDV may in part be related to the divergence in integrin subunits among different species.     

细胞凋亡的常用调控基因研究近况

细胞凋亡主要受基因的控制，现已发现许多基因对细胞凋亡均有直接或间接的调控作用。通常将这些基因分为两大类，即细胞生存基因和细胞死亡基因。一般认为与细胞生存有关的基因包括C－myc,C-abl,Ras,V-src,Bcl-2,EIB,LMW5-HL,C-kit和Bcl-x等；与细胞死亡有关的基因包含P^35,P^53,RB,DCC,WT-1,CpGv,Bcr-abl,V-erb-A,tats20,DAD1,ADO/Fas,TGF-β，TRP－2，RP－8，TRPM－2，SGP－2，TIA，Bax,ICE,C-rel,irrecrst等。本文对目前使用较多研究较深入的几种凋亡调控基因，即C－myc基因，Bcl-2基因，P^53基因，ICE基因，Fas基因及FasL和Cdc2基因的来源，作用和相互间关系的研究近况，予以综述，做一简介。     

家蚕葡萄糖-甲醇-胆碱氧化还原酶家族基因BmGMCβ2的克隆及序列与表达分析

葡萄糖-甲醇-胆碱氧化还原酶(glucose-methanol-choline oxidoreductases,GMC)家族是昆虫体内一大类以黄素腺嘌呤二核苷酸(FAD)为辅酶的氧化还原酶类,家蚕基因组中含有43个GMC家族基因。以家蚕5龄幼虫cDNA为模板克隆到一个家蚕GMC家族基因,命名为BmGMCβ2(GenBank登录号:JQ965926)。该基因cDNA全长1 875 bp,编码624个氨基酸,预测蛋白质分子质量为69.3 kD,pI为6.21,定位于家蚕16号染色体的nscaf3058上,编码蛋白质含GMC家族共有的ADP-bindingβ-α-β折叠结构域。系统发育分析表明该基因是家蚕GMC家族β亚家族基因成员。RT-PCR检测家蚕不同发育时期和5龄第3天幼虫不同组织中BmGMCβ2基因mRNA转录水平,以5龄盛食期最高,并且主要在表皮、脂肪体和气管中转录表达;Westernblotting分析BmGMCβ2蛋白主要在5龄第3天幼虫的脂肪体中表达。将BmGMCβ2克隆到原核表达载体pET-28a(+)中,转化E.coli BL21表达菌株,IPTG诱导表达BmGMCβ2融合蛋白,通过His-亲和层析得到纯化的融合蛋白并制备多克隆抗体,为后续研究该蛋白在家蚕生长发育过程中的功能奠定了基础。     

我国家庭农场的生成机制、发展现状与现实约束

基于相关历史与现实背景,从经济性激励与社会环境改善两大视角研究家庭农场的生成机制,对家庭农场经营规模、发展速度、经营收益、经营方式、宜机化程度等现状进行探讨,得出经营者文化程度低、融资难、品牌与合作意识不强、现代信息技术应用不足等结论,并从人才培养、政策扶持、规范管理、配套服务等方面为家庭农场未来发展提供建议,以期助力乡村振兴。     

团头鲂Hox基因家族的鉴定、进化与表达分析

Hox基因家族在调控动物早期胚胎发育、组织和器官生长起重要作用,因此这类基因家族被广泛应用到物种进化和发育调控的研究中。为了探究Hox基因在团头鲂中分布,进化及表达调控作用,同时为了探究Hox基因与团头鲂肌间刺发育的关系,研究基于团头鲂全基因组数据,结合生物信息学分析方法对其Hox基因家族进行鉴定、染色体分布、系统进化和表达模式分析。结果显示,在团头鲂基因组中共鉴定出49个Hox基因,根据系统进化分析分为5个亚类;其中49个Hox基因不均匀的分布在5条染色体上,并分为7个基因连锁群（HoxAa、HoxAb、HoxBa、HoxBb、HoxCa、HoxCb和HoxDa）;表达模式分析结果表明,团头鲂Hox基因家族成员具有不同的表达模式;团头鲂和斑马鱼所有Hox基因在肌肉中的表达水平存在显著差异。此外,团头鲂不同发育阶段及不同组织转录组结果显示,HoxA基因群集中,HoxA2a、HoxA3a在幼鱼阶段高表达,其他基因在肌肉、肌间刺及结缔组织中表达量低甚至不表达;HoxB基因群集中,HoxB9a、HoxB3a、HoxB8a、HoxB1b、HoxB5a、HoxB5b在幼鱼阶段高表达;HoxB7a、HoxB10a、HoxB9a在成鱼肌肉、结缔组织及肌间刺中高表达;HoxC基因群集中,HoxC3a、HoxC4a在幼鱼阶段高表达,HoxC3a、HoxC8a在成鱼的3个组织都有表达;HoxD基因群集中,HoxD9a、HoxD10a和HoxD11a在胚胎S2期表达量较高。研究表明,Hox基因在团头鲂早期胚胎时期和肌间刺的形成中有表达,提示团头鲂肌间刺的形成可能受Hox基因家族调控。     

Aux/IAA基因家族鉴定及对大豆茎尖发育的调控作用分析

Aux/IAA基因家族在植物茎尖发育过程发挥重要作用.为了探究大豆Aux/IAA基因家族在大豆茎尖发育过程的调控作用,本文以拟南芥Aux/IAA基因家族蛋白序列为参照鉴定了大豆全基因组Aux/IAA家族基因,包括63个成员;然后以拟南芥、鹰嘴豆和大豆的Aux/IAA家族为研究对象,比对这些基因全长氨基酸序列并构建进化树...     

Developmental temperature stress and parental identity shape offspring burst swimming performance in sockeye salmon (Oncorhynchus nerka)

Abstract – The persistent effects of embryonic temperature stress and individual parentage on fry swimming performance were examined in a cross‐fertilisation experiment using sockeye salmon (Oncorhynchus nerka). A fixed‐velocity test of burst swimming was used to assess the endurance capacity and behavioural performance of individual fry from 10 offspring families incubated at 12, 14 or 16 °C to hatch and then reared through yolk absorption and exogenous feeding stages in a common posthatch environment (average 6.9 °C). Fry burst swim time (BST) was influenced by an interaction between incubation temperature and family identity. Average BST was longer for fry from the 12 °C prehatch treatment compared to 14 and 16 °C, although differences were largely attributable to temperature effects on average fry size. Behavioural observations revealed that fish incubated at 16 °C performed more poorly, having a larger proportion of individuals that required stimulation to swim, fatigued more frequently or were classified as ‘nonswimmers’. Within all three incubation temperature treatments, mean BST varied significantly among offspring families, independent of fry mass and length. An interesting relationship was observed within the 16 °C treatment, whereby families with higher survivorship were characterised with lower mean BSTs. Collectively, these findings demonstrate that exposure to high temperatures in early sockeye salmon development can result in persistent, parentally mediated effects on fry performance. As such, these results provide important insight into how elevated temperature events during egg incubation may affect early life history selection processes and survival in stages beyond when the stressor is experienced.     

可可泛素结合酶基因家族的生物信息学初步分析

泛素结合酶(E2s)促进底物泛素化或者与E3s链接,是靶蛋白泛素化的关键酶,在泛素-蛋白酶体途径中起重要作用。利用可可(Theobroma cacao L.)全基因组测序数据,共鉴定出45个E2s基因家族成员,包括39个UBC和6个UEV基因。通过生物信息学方法,对可可E2s家族的基本理化性质、基因结构、二级结构预测、亚细胞定位、进化关系等方面进行初步分析。结果表明:可可E2s基因CDS长度在441(Tc UEV3)~3 651 bp(Tc UBC7)之间,对应的编码蛋白氨基酸数目在146(Tc UEV3)~1 216 aa(Tc UBC7)之间,编码蛋白分子量在16.39~134.71 ku之间。E2s基因外显子在1~11之间,多数基因外显子数目在5~7之间。E2s基因在10条染色体上均有分布,1号染色体为7个,数量最多;6号染色体2个基因,数量最少。可可E2s蛋白大多为不稳定蛋白,且均为亲水性蛋白,其二级结构以α-螺旋和无规则卷曲为主要构成元件。大多数可可E2s蛋白定位在细胞核,少数定位在内质网或者细胞质。进化树分析表明:可可E2s蛋白被分为20个亚家族,包括16个UBC亚家族和4个UEV亚家族,第Ⅵ亚家族E2s数目最多为9个;E2s家族蛋白在物种进化过程中具有高度保守性。     

孵化后温度调控对虹鳟全雌家系早期生长性能的影响

本研究以建立的虹鳟（Oncorhynchus mykiss）全雌全同胞家系为研究对象,受精卵在12℃避光孵化至上浮,上浮后设置了四个温度处理组进行饲育,分别为12℃、15℃、18℃、20℃和水温4～7℃之间（平均水温约为6℃）常规涌泉水流水养殖对照组。30d后,所有处理组均转入与对照组相同条件的流水养殖。生长性能数据采...