Putative candidate genes for blood pressure control in the SHR.BN-RNO8 congenic substrains

The SHR-Lx congenic strain carrying a differential segment of chromosome 8 of BN and PD origin was recently shown to exhibit a significant decrease in blood pressure as compared to the SHR strain. There were two positional candidate genes for blood pressure control mapped to the differential segment: the rat kidney epithelial potassium channel gene (Kcnj1) and brain dopamine receptor 2 gene (Drd2). Bot these genes were separated into SHR.BN-RNO8 congenic substrains. In this communication, we are presenting the assignment of two further putative candidate genes, which might be involved in blood pressure control to the BN/PD differential segment of the SHR-Lx congenic strain. These are: the gene coding for smooth muscle cell specific protein 22 (Sm22) defined by the D8Mcw1 marker and neuronal nicotinic acetylcholine receptor gene cluster, defined by the D8Bord1 marker. Moreover, the glutamate receptor gene Grik4 which also maps to the differential segment of the SHR-Lx should be taken into account. The genetic separation of all these putative candidate genes of blood pressure control is being performed by recombinations and subsequent selection using (SHR×SHR-Lx) intercross population.     

Two closely linked tomato HKT coding genes are positional candidates for the major tomato QTL involved in Na+/K+ homeostasis

The location of major quantitative trait loci (QTL) contributing to stem and leaf [Na⁺] and [K⁺] was previously reported in chromosome 7 using two connected populations of recombinant inbred lines (RILs) of tomato. HKT1;1 and HKT1;2, two tomato Na⁺‐selective class I‐HKT transporters, were found to be closely linked, where the maximum logarithm of odds (LOD) score for these QTLs located. When a chromosome 7 linkage map based on 278 single‐nucleotide polymorphisms (SNPs) was used, the maximum LOD score position was only 35 kb from HKT1;1 and HKT1;2. Their expression patterns and phenotypic effects were further investigated in two near‐isogenic lines (NILs): 157‐14 (double homozygote for the cheesmaniae alleles) and 157‐17 (double homozygote for the lycopersicum alleles). The expression pattern for the HKT1;1 and HKT1;2 alleles was complex, possibly because of differences in their promoter sequences. High salinity had very little effect on root dry and fresh weight and consequently on the plant dry weight of NIL 157‐14 in comparison with 157‐17. A significant difference between NILs was also found for [K⁺] and the [Na⁺]/[K⁺] ratio in leaf and stem but not for [Na⁺] arising a disagreement with the corresponding RIL population. Their association with leaf [Na⁺] and salt tolerance in tomato is also discussed.     

Detection and validation of EST‐derived SNPs for poplar leaf rust Melampsora medusae f. sp. deltoidae

We report the discovery, characterization and validation of 118 single nucleotide polymorphisms (SNPs) for poplar leaf rust Melampsora medusae f. sp. deltoidae identified using a gene‐targeted approach in an expressed sequence tag (EST) library. We developed a genotyping assay using the iPLEX? primer extension method for two multiplex assays of 28 and 22 SNPs.     

淋病奈瑟菌肽基脯氨酰异构酶的原核表达及其作为候选疫苗的初步评价

【背景】淋病是我国主要的性传播疾病之一,感染淋病奈瑟菌可促进人类免疫缺陷病毒(human immunodeficiency virus, HIV)的传播和感染。目前我国淋病发病人数呈上升趋势,随着多重耐药菌株的出现,亟须研发保护性疫苗来防治淋病的传播和感染。【目的】分析淋病奈瑟菌(Neisseria gonorrhoeae, NG)肽基脯氨酰异构酶(peptidyl-prolyl isomerase, PPIase)蛋白的高级结构和表位,探讨其作为疫苗和分子诊断靶点的潜力。【方法】利用生物信息学软件分析PPIase蛋白的极性、亲水性、柔韧性、表面可及性、二级和三级结构,以及T、B细胞表位等;用pET32a(+)质粒构建PPIase蛋白的原核表达系统并纯化蛋白,用纯化的重组蛋白和超声波破碎的NG全菌抗原分别免疫BALB/c小鼠,收获免疫血清;制备NG全细胞抗原,分别以全细胞抗原酶联免疫吸附试验(enzyme linked immunosorbent assay, ELISA)和间接免疫荧光试验检测重组PPIase蛋白血清抗体与NG全细胞表面抗原的结合情况。【结果】生物信息学分析结果显示,...     

甘蓝型油菜种子硫代葡萄糖苷含量的QTL定位及候选基因鉴定

【目的】为了解析油菜种子硫代葡萄糖苷性状的重要遗传位点及候选基因,【方法】本研究利用KN DH群体在冬性环境2015-2018连续4年的种子硫苷含量表型和KN 高密度SNP遗传连锁图谱,通过Wincart 2.5软件的符合区间作图法对甘蓝型油菜种子硫代葡萄糖苷含量进行QTL定位和潜在候选基因鉴定。【结果】共鉴定到47个硫苷含量QTL,单个QTL解释表型变异最大是qGC.16YL19-4(19.44%),解释表型变异最小的是qGC.15YL12-5(1.82%)。利用元分析的方法将初步鉴定的47个QTL整合为38个consensus QTL,其中7个consensus QTL(cqGC.A9-5、cqGC.A9-7、cqGC.A9-9、cqGC.C2-9、cqGC.C2-10、cqGC.C9-5和cqGC.C9-6)为环境稳定表达QTL,包括3个硫苷含量主效QTL(cqGC.A9-5、cqGC.C2-10和cqGC.C9-5)。在主效QTLcqGC.A9-5和cqGC.C9-5鉴定到3个候选基因BnaA09g05480D,BnaC09g05620D和BnaC09g05810D,其功能主要涉及了油菜硫苷生物合成途径中吲哚-3-乙醛肟(IAOx)的合成和将2-烷基-苹果酸异构化形成3-烷基-苹果酸酯,以及硫苷的转运与分配。【结论】本研究获得了油菜种子硫苷含量3个主效QTL及3个候选基因,该结果为硫苷含量相关基因的功能机械和优质油菜品种培育提供理论依据。     

家蚕光泽小眼(varnished eye)突变基因的精细定位

家蚕(Bombyx mori)光泽小眼(varnished eye,ve)突变体是家蚕突变品种中少数关于家蚕复眼形态异常的自然隐性突变品种之一,表现为成虫复眼小,表面富有光泽,有瘤状突起;小眼数量少且不规则。经典遗传学连锁图谱将ve基因定位在第6连锁群32.2座位,但到目前为止,该突变性状的形成机理仍不清楚。文章以突变品种ve和对照品种Dz为亲本,杂交产生的F1代雄个体与轮回亲本ve雌个体回交产生的BC1代为材料进行ve基因的精细定位。通过对ve低密度连锁图谱分析发现,ve基因被定位在SNP3~SNP6之间,物理图谱距离大约为1.2 Mb。利用1563个BC1代个体构建ve高密度连锁图谱,最终将ve基因定位在SNP5~SNP61之间,物理图谱距离大约为221.8 kb。通过家蚕基因数据库对ve最终定位区域内进行预测基因检索,发现有6个预测基因。对6个预测基因进行生物信息学分析和测序,这些候选基因都有可能参与家蚕复眼形成,但在编码区没有发现ve特异的突变位点;对这些候选基因进行表达分析,发现编号为BGIBMGA013642的候选基因在ve复眼形成过程中的表达量明显比正常对照Dz低,推测该基因为最佳候选基因。     

北京大学与中南大学神经生物学硕士研究生课程设置分析

通过对北京大学与中南大学神经生物学研究生培养方案及课程设置进行分析,探寻两所高校之间的差别。结果显示两所高校神经生物学硕士研究生课程设置基本符合培养目标,北京大学课程设置较中南大学更加全面合理,尤其在学术道德、实验技能、学术交流等方面的课程设置优于中南大学,建议中南大学新设或加强部分课程。     

骨质疏松症易感基因BDNF的遗传学关联分析及功能研究

为探索脑源性神经营养因子BDNF基因与中国汉族人群骨密度(bone mineral density, BMD)的关系,解析该基因调节骨质疏松症的功能机制,进而为中国汉族人群的骨质疏松症的防治提供依据。本研究从我国陕西地区征集了1300例汉族样本,并测量髋部/脊椎骨密度。选取BDNF基因上的14个标签SNPs进行基因分型,与1300例样本BMD进行关联分析,发现8个SNPs与髋部/脊椎BMD显著关联(P < 0.05)。其中,SNP rs16917237同时与髋部和脊椎骨密度关联,经Bonferroni校正后仍表现出显著性(0.05/14 = 0.0036)。整合连锁不平衡和单体型分析、表观功能注释、表达数量基因座分析、代谢通路分析进一步探索BDNF基因调节骨质疏松症的机制。构建小鼠前成骨细胞系(MC3T3-E1)人骨形态形成蛋白(rhBMP-2)诱导分化模型,利用小干扰RNA(siRNA)敲除BDNF。结果显示：14个SNPs位于同一单体型内;rs16917237在成骨细胞中表现出较强的激活型组蛋白H3K4me1、H3K4me3、H3K27ac修饰信号以及P300结合信号,表明其在成骨细胞中可能具有调控活性;rs16917237在11个组织中均能显著影响BDNF基因表达;BDNF基因位于与成骨细胞增殖分化相关的MAPK通路中;BDNF敲低能够显著降低MAPK通路中与成骨分化相关的CREB 基因mRNA和蛋白表达水平,提示其可能通过调控CREB表达进而影响成骨分化。生物信息学分析和功能实验结果一致,表明BDNF基因可能是影响骨质疏松症的重要功能基因。     

Molecular signatures of lineage‐specific adaptive evolution in a unique sea basin: the example of an anadromous goby Leucopsarion petersii

Climate changes on various time scales often shape genetic novelty and adaptive variation in many biotas. We explored molecular signatures of directional selection in populations of the ice goby Leucopsarion petersii inhabiting a unique sea basin, the Sea of Japan, where a wide variety of environments existed in the Pleistocene in relation to shifts in sea level by repeated glaciations. This species consisted of two historically allopatric lineages, the Japan Sea (JS) and Pacific Ocean (PO) lineages, and these have lived under contrasting marine environments that are expected to have imposed different selection regimes caused by past climatic and current oceanographic factors. We applied a limited genome‐scan approach using seven candidate genes for phenotypic differences between two lineages in combination with 100 anonymous microsatellite loci. Neuropeptide Y (NPY) gene, which is an important regulator of food intake and potent orexigenic agent, and three anonymous microsatellites were identified as robust outliers, that is, candidate loci potentially under directional selection, by multiple divergence‐ and diversity‐based outlier tests in comparisons focused on multiple populations of the JS vs. PO lineages. For these outlier loci, populations of the JS lineage had putative signals of selective sweeps. Additionally, real‐time quantitative PCR analysis using fish reared in a common environment showed a higher expression level for NPY gene in the JS lineage. Thus, this study succeeded in identifying candidate genomic regions under selection across populations of the JS lineage and provided evidence for lineage‐specific adaptive evolution in this unique sea basin.