基于胆汁酸代谢网络分析绞股蓝总皂苷降脂作用的机制

绞股蓝总皂苷具有显著的降低血脂的作用,然而其机制尚未明确。课题组在前期研究的基础上,将33只C57BL/6J雄性小鼠随机分为3组,对照组(ND组)、模型组(HFD组)和绞股蓝皂苷组(HFD+GP组),分别给予维持饲料和高脂饲料,从16周开始,每日分别灌胃给予绞股蓝总皂250 mg/kg和等体积的空白溶剂,至38周,收集小鼠的血清和肝脏样本。通过HE染色观察肝脏组织的病理变化,检测血清总胆固醇和低密度脂蛋白水平,利用UPLC-MS/MS技术对小鼠肝脏14种胆汁酸含量进行分析,采用实时荧光定量PCR检测Cyp7a1、Cyp8b1、Fxr、Shp、Lrh1、Hnf4α基因表达水平。与对照组比较,模型组有明显的脂肪泡结构,给予绞股蓝总皂苷可以明显减轻肝脏组织的病理改变。与模型组比较,绞股蓝总皂苷可以显著降低血清中TC和LDL-C含量,显著降低肝脏中牛磺熊去氧胆酸(TUDCA)、甘氨鹅去氧胆酸(GCDCA)和甘氨脱氧胆酸(GDCA)含量,显著升高肝脏中鹅去氧胆酸(CDCA)、脱氧胆酸(DCA)和牛磺脱氧胆酸(TDCA)含量,并在上调肝脏Cyp7a1、Cyp8b1、Fxr和Lrh1基因表达的同时下调Shp的基因表达。绞股蓝总皂苷降脂作用的潜在靶点可能与FXR介导的胆汁酸代谢通路有关,为进一步深入探讨绞股蓝总皂苷降脂作用及其机制提供了参考。     

利用微卫星标记分析不同鹅种的遗传变异

应用微卫星标记技术以6个品种鹅(东北白鹅、籽鹅、皖西白鹅、豁眼鹅、莱茵鹅、朗德鹅)为实验材料分析不同品种鹅的遗传多样性。利用等位基因频率计算出各群体的平均遗传杂合度(H)多态信息含量(PIC)和群体间的遗传距离D_S, 结果表明: 7个微卫星位在6种鹅群体中均表现为高度多态性, 可作为有效的遗传标记来分析各鹅群体的遗传多样性和系统发生关系。实验各群体的杂合度均较高, 平均杂合度在0.6617(莱茵鹅)~0.8814(籽鹅)之间。各品种的PIC值变动大小在0.6145(莱茵鹅)~0.7846(籽鹅)这与杂合度的高低一致。依据D_S遗传聚类进行UPGMA聚类分析结果6个品种被分为2类: 国内地方品种东北白鹅、籽鹅、豁眼鹅及皖西白鹅为一类; 外来鹅种莱茵鹅与朗德鹅为一类。表明微卫星标记可准确地反映6个品种的亲缘关系及其所在地域分布上的差异, 适宜于群体遗传结构及遗传关系的研究, 是畜禽遗传多样性研究与保护的有效分析手段。     

Establishment of a highly efficient hematopoietic differentiation model from human embryonic stem cells for functional screening

Human embryonic stem cells(hESCs)have been successfully differentiated into hematopoietic progenitor cells with colony formation capacity and further into various kinds of blood cells including erythrocytes,megakaryocytes,neutrophils,nature killer cells and T lymphocytes[1 7].Nevertheless,the differentiation efficiency is extremely low.     

Complete genome sequence of methicillin-sensitive Staphylococcus aureus containing a heterogeneic staphylococcal cassette chromosome element

Staphylococcus aureus is a common human bacterium that sometimes becomes pathogenic,causing serious infections.A key feature of S.aureus is its ability to acquire resistance to antibiotics.The presence of the staphylococcal cassette chromosome(SCC) element in serotypes of S.aureus has been confirmed using multiplex PCR assays.The SCC element is the only vector known to carry the mecA gene,which encodes methicillin resistance in S.aureus infections.Here,we report the genome sequence of a novel methicillin-sensitive S.aureus(MSSA) strain:SCC-like MSSA463.This strain was originally erroneously serotyped as methicillin-resistant S.aureus in a clinical laboratory using multiplex PCR methods.We sequenced the genome of SCC-like MSSA463 using pyrosequencing techniques and compared it with known genome sequences of other S.aureus isolates.An open reading frame(CZ049;AB037671) was identified downstream of attL and attR inverted repeat sequences.Our results suggest that a lateral gene transfer occurred between S.aureus and other organisms,partially changing S.aureus infectivity.We propose that attL and attR inverted repeats in S.aureus serve as frequent insertion sites for exogenous genes.     

A New Species of the Genus Tylototriton （Urodela： Salamandridae） from Northeastern Hunan Province,China

We describe a new species from the family Salamandridae from northeastern Hunan Province of China based on morphological and molecular genetic evidences.The new species,Tylototriton liuyangensis,is a member of the T.asperrimus group,and shares a number of similarities with T.wenxianensis and T.broadoridgus.The dorsal surface of the new Tylototriton species is completely black,with nodule-like warts distributed evenly along the lateral margin of dorsal body,and there is no transverse striae between the warts.There are several diagnostic characters of the new species that differ from those of T.wenxianensis and T.broadoridgus as follows：（1）the interorbital space（IOS）is comparatively wide;（2）there is a bony ridge present on the dorsal head surface,running along the upper eyelids;（3）the space between axilla and groin（AGS）is comparatively large,with the mean male AGS approximately equal to 50%of the snout-vent length（SVL）and the mean female AGS being 53%of SVL;and（4）there is a small genital armature on the anterior angle of labial folds present inside the anal fissure of adult males during the breeding season.The result from the molecular phylogenetic analysis of the genus Tylototriton（including the type specimen of the new species）based on the complete DNA sequence of the mitochondrial ND2 gene（1035 bp）indicated that the new species was similar to T.wenxianensis,T.dabienicus,and T.broadoridgus,but formed an independent clade.This result was consistent with the morphological analysis above,supporting that the Liuyang Population represented a distinct species.     

Asymmetric or diffusive co-evolution generates meta-populations in fig-fig wasp mutualisms

Co-evolutionary theory assumes co-adapted characteristics are a positive response to counter those of another species,whereby co-evolved species reach an evolutionarily stable interaction through bilateral adaptation.However,evidence from the fig-fig wasp mutualistic system implies very different co-evolutionary selection mechanisms,due to the inherent conflict among interacted partners.Fig plants appear to have discriminatively enforced fig wasps to evolve"adaptation characteristics"that provide greater benefit to the fig,and fig wasps appear to have diversified their evolutionary strategies in response to discriminative enforcement by figs and competition among different fig wasp species.In what appears to be an asymmetric interaction,the prosperity of cooperative pollinating wasps should inevitably lead to population increases of parasitic individuals,thus resulting in localized extinctions of pollinating wasps.In response,the sanctioning of parasitic wasps by the fig should lead to a reduction in the parasitic wasp population.The meta-populations created by such asymmetric interactions may result in each population of coevolved species chaotically oscillated,temporally or evolutionarily.     

Characteristics of dental morphology in the Xinjiang Uyghurs and correlation with the EDARV370A variant

Teeth are one of the most important materials for anthropological studies because they are likely to be preserved in ancient remains.While the frequencies of dental characteristics can provide clues to the phylogeny of populations,genetic studies at the individual level can further reveal the biological mechanisms and evolutionary context of dental characteristics.In this study,by analyzing 38 dental characteristics of 242 Xinjiang Uyghur individuals,we found that(i)the dental characteristics of the Uyghurs showed evidence of admixture between European and East Asian populations.The admixture proportions were in line with those previously reported in population genetic studies;(ii)the Xinjiang Uyghur dental characteristics formed three clusters in pairwise correlation analysis.One of the main clusters consisted of characteristics including incisor shoveling,double shoveling and mesial ridge;and(iii)all the characteristics in this cluster were significantly correlated with the genetic variant EDARV370A.The extracted composite phenotypic factor was also significantly associated with EDARV370A,which explained 18%of the total phenotypic variance.This indicated a pleiotropic effect,i.e.,the same genetic factor affects a number of dental characteristics at the same time.Our results confirmed that EDARV370A,a genetic variant that first originated in East Asia about 30000 years ago,played an important role in incisor shoveling in East Asia.This finding suggested that incisor shoveling in modern humans in East Asia is likely to have appeared after the late Pleistocene.     

BALB/C鼠冷诱导RNA结合蛋白的原核表达、纯化及其单克隆抗体的制备

为了获得冷诱导RNA结合蛋白（CIRP）的单克隆抗体,本通过RT-PCR 方法从冷处理BALB/C小鼠睾丸的总RNA中扩增获得CIRP基因序列,克隆至pGEM-T载体,获得重组质粒pGEM-CIRP,并进行序列测定。将测序正确的CIRP序列插入质粒pQE-30-Xa,构建表达载体pQE-30-CIRP并转化E.coli M15,IPTG 诱导后SDS-PAGE分析表明CIRP基因在大肠杆菌中获得高效表达, 可溶性分析表明CIRP融合蛋白以包涵体形式表达。采用Ni-NTA亲和层析、电洗脱纯化融合蛋白CIRP,将纯化的蛋白免疫BALB/C小鼠,三次免疫后,间接ELISA测定小鼠效价,效价为1:105,采用杂交瘤技术融合,用间接ELISA法、有限稀释法筛选阳性杂交瘤细胞,通过Western blot对McAb特异性进行鉴定,利用间接ELISA方法对McAb的Ig亚类(型)、杂交瘤细胞上清、腹水效价进行测定。结果获得了1A6、2D3、3C5及4C4 4株稳定分泌CIRP McAb的杂交瘤细胞株,1A6、3C5、4C4产生的单克隆抗体亚类均为IgG2b,2D3产生的单抗亚类为IgG3,轻链均属κ链。4株单克隆细胞上清效价均在1:103以上,腹水效价均达1:107以上。Western-blot分析4株单抗均能与重组蛋白CIRP特异性结合,与空载体对照没有反应。以3C5细胞株的腹水为一抗,检测冷应激小鼠多种组织中天然CIRP蛋白表达,结果显示3C5细胞腹水能识别心、肝、脾、肺、肾、脑、睾丸等多种组织中天然CIRP,并与能之与结合。这证明该抗体具有良好特异性和结合活性,制备的单克隆抗体可以用于深入开展CIRP的功能性和应用性研究。