MiR‐330‐5p negatively regulates ovine preadipocyte differentiation by targeting branched‐chain aminotransferase 2

The differentiation of preadipocytes into adipose tissues is tightly regulated by various factors including microRNAs and cytokines. This article aims to study the effect of miR‐330‐5p on expression of BCAT2 in ovine preadipocytes. Ovine preadipocytes were isolated, and we found that the miR‐330‐5p expression decreased gradually during the early differentiation of ovine preadipocytes, while BCAT2 expression increased. BCAT2 was identified as a direct target of miR‐330‐5p, ectopic expression of miR‐330‐5p could change the expression of both BCAT2 mRNA and protein. Silencing BCAT2 had the same inhibition effects as overexpressing miR‐330‐5p on the preadipocyte differentiation, but overexpressing BCAT2 had the converse effects. Taken together, we demonstrated that miR‐330‐5p is a negative regulator of differentiation by targeting BCAT2, and clarified the role of BCAT2 and miR‐330‐5p during preadipocyte differentiation.     

Replication of neurovirulent equine herpesvirus type 1 (EHV-1) in CD172a+ monocytic cells

Equine herpesvirus type 1 (EHV-1) is responsible for respiratory disorders, abortion and myeloencephalopathy (EHM) in horses. Two pathotypes of EHV-1 strains are circulating in the field: neurovirulent (N) and non-neurovirulent (NN). For both strains, CD172a⁺ monocytic cells are one of the main carrier cells of EHV-1 during primary infection, allowing the virus to invade the horse’s body. Recently, we showed that EHV-1 NN strains showed a restricted and delayed replication in CD172a⁺ cells. Here we characterize the in vitro replication kinetics of two EHV-1 N strains in CD172a⁺ cells and investigate if the replication of these strains is similarly silenced as shown for EHV-1 NN strains. We found that EHV-1 N replication was restricted to 7–8% in CD172a⁺ cells compared to 100% in control RK-13 cells. EHV-1 N replication was not delayed in CD172a⁺ cells but virus production was significant lower (10^3.0 TCID₅₀/10⁵ inoculated cells) than in RK-13 cells (10^8.5 TCID₅₀/10⁵ inoculated cells). Approximately 0.04% of CD172a⁺ cells produced and transmitted infectious EHV-1 to neighbour cells compared to 65% of RK-13 cells. Unlike what we observed for the NN strain, pretreatment of CD172a⁺ cells with histone deacetylases inhibitors (HDACi) did not influence the replication of EHV-1 N strains in these cells. Overall, these results show that the EHV-1 replication of N strains in CD172a⁺ cells differs from that observed for NN strains, which may contribute to their different pathogeneses in vivo.     

植物miR172家族成员进化与分子特性分析

为了解植物miR172家族成员的进化与分子特性,对mi Rbase数据库中37个物种的161个miR172前体序列和196个miR172成熟体序列进行进化规律分析,并对植物miR172家族的保守基序、二级结构和靶基因进行预测分析。结果表明:miR172家族成员分布的37个物种都是被子植物,被子植物很可能是miR172家族进化来源的祖先。进化分析表明,植物miR172家族成员序列相似性是其聚类的首要影响因素,其次才是物种差异的影响。植物miR172家族成员成熟体序列分析表明,5p臂上形成的成熟体序列特异性较大,3p臂上形成的成熟体序列保守性较高。二级结构分析发现,植物miR172家族成员具有典型的茎环二级结构,且茎序列的保守性较环序列高。植物miR172前体序列包含1个UNCG环。靶基因预测分析发现,同一物种不同miR172成员的靶基因可能不同;不同物种miR172的靶基因也可能不同,AP2或AP2-like出现频率最高,其次还有arginine decarboxylase 1、Pathogenesis-related、MYB84等靶基因,表明其靶基因功能的多样性。     

拟南芥晚花突变体fve-1和fca-1营养生长时相转变

拟南芥胚后发育经历了营养生长和生殖生长两个主要阶段,在营养生长的过程中,由幼龄期向成熟期的转变称为营养生长时相转变。有关这个转变的基因调控网络仍不清楚。本文对拟南芥晚花突变体fca-1、fve-1的营养生长时相转变过程进行了形态学观察和基因表达分析。结果表明：与野生型相比,fve-1、fca-1植株幼龄期延长,导致营养生长时相转变延迟。自主开花基因FVE、FCA参与了植物营养生长时相转变的调控。     

杂交水稻新组合特优172的高产制种技术

特优172是容县农科所选育出的感温型杂交稻新组合,2006年通过广西区种子审查委员会审定,该组合制种高产的主要经验是：掌握好父母本的播错期及抽穗期;重施父本肥,使父本早生快发,穗大粒多,花粉充足;适时适量喷施九二0。     

超量表达胡杨peu-MIR156j基因增强拟南芥耐盐性

Micro RNAs（miRNAs）是一类内源性的非编码小分子RNA。本文克隆了miR156j的前体（peu-MIR156j）,并将其转入拟南芥获得35S：MIR156j转基因植株。对转基因植株的鉴定表明,过量表达miR156j增加了拟南芥莲座叶的发生,导致叶片浓密及开花延迟。这一结果表明：同拟南芥、水稻等物种类似,胡...