城市池塘水质时间变化特性--以扬州大学江阳路南校区池塘为例

城市中的池塘是城市水体的重要组成部分,为揭示城市化背景下池塘水体水质的时间变化特性,选取扬州大学江阳路南校区池塘为研究区,对该池塘2018年7月至2019年6月的水质参数蓝绿藻浓度(Phyco)、水温(WT)、溶解氧(DO)、pH与电导率(EC)进行观测,采用变异系数法、单因子水质标识指数法以及多元线性回归法对各参数的变化特性进行评价。结果显示:池塘WT呈季节性变化;观测期间pH变化范围为7.74~9.98,水体呈碱性;DO变化的随机性较强,未表现出明显变化规律;各水质参数变异性及权重从大到小依次为WT>DO>EC>pH;以DO为指标的单因子水质标识指数结果表明:池塘DO达到Ⅲ类水要求的时段占总观测时段的84%;多元线性回归分析结果表明:DO与WT、pH呈正相关,与Phyco呈负相关,Phyco及pH的变化对DO浓度的影响相对于WT大。     

鱼类组蛋白核苷酸的多态性及其在杀鱼爱德华氏菌感染中的作用

组蛋白是染色体核小体的重要组分,在调控染色质结构、基因转录、个体发育等不同生物学过程中起着重要作用。为了研究鱼类组蛋白基因是否存在核苷酸的多态性以及组蛋白核苷酸多态性是否会影响鱼类的抗病力,本实验以斑马鱼和草鱼为研究对象,通过PCR扩增克隆了组蛋白H2A的全长开放阅读框;利用过表达技术、菌落平板计数、感染存活分析以及荧光定量PCR技术,研究了斑马鱼和草鱼组蛋白H2A核苷酸多态性不同变异体在杀鱼爱德华氏菌感染中的作用。在本研究中,实验发现鱼类组蛋白H2A存在着丰富的核苷酸多态性。序列分析结果显示斑马鱼和草鱼组蛋白H2A核苷酸多态性的变异体核苷酸序列相似性为90%～100%;而两两H2A核苷酸多态性变异体氨基酸序列之间最多只有3个位点存在差异。通过体内和体外抗菌实验可知,斑马鱼和草鱼组蛋白H2A核苷酸的多态性显著影响H2A的抗菌活性。此外,筛选出的抗菌组蛋白H2A核苷酸多态性的变异体在斑马鱼体内的过表达,不仅具有免疫增强的作用,还能显著增强斑马鱼对杀鱼爱德华氏菌感染的抗病力。本研究为筛选具有抗病作用的组蛋白H2A免疫保护原奠定了重要基础。     

施用有机肥替代化肥、化肥减量对结球生菜生长的影响

本研究通过施用黑老虎、时科两种微生物有机肥,对化肥进行减量,与常规施肥进行对比,发现：施用微生物有机肥,化肥减量10%、减量20%,结球生菜的死亡率明显低于常规施肥；在结球生菜生长中期,施用生物有机肥结球生菜的展开幅度明显好于常规施肥；在结球生菜采收期,施用生物有机肥,化肥减量10%,时科微生物有机肥和黑老虎微生物有机肥的结球生菜单果重分别为0.54g和0.80g,相比与常规施肥,提高了31.7%和95.1%。施用微生物有机肥,化肥减量20%,时科微生物有机肥和黑老虎微生物有机肥的结球生菜单果重分别为0.49g和0.61g,相比与常规施肥,提高了19.5%和48.7%。     

Identification of SNPs and expression patterns of FZD3 gene and its effect on wool traits in Chinese Merino sheep(Xinjiang Type)

As a member of the Frizzled family, Frizzled3(FZD3) is a receptor of the canonical Wnt signaling pathway and plays a vital role in mammalian hair follicle developmental processes. However, its effects on wool traits are not clear. The objectives of this study were to identify the single nucleotide polymorphisms(SNPs) and the expression patterns of FZD3 gene, and then to determine whether it affected wool traits of Chinese Merino sheep(Xinjiang Type) or not. PCR-single stranded conformational polymorphism(PCR-SSCP) and sequencing were used to identify mutation loci, and general linear model(GLM) with SAS 9.1 was used for the association analysis between wool traits and SNPs. Quantitative real-time PCR(q RTPCR) was used to investigate FZD3 gene expression levels. The results showed that six exons of FZD3 gene were amplified and two mutation loci were identified in exon 1(NC_019459.2: g.101771685 TC(SNP1)) and exon 3(NC_019459.2: g.101810848, AC(SNP2)), respectively. Association analysis showed that SNP1 was significantly associated with mean fiber diameter(MFD)(P=0.04) and live weight(LW)(P=0.0004), SNP2 was significantly associated with greasy fleece weight(GFW)(P=0.04). The expression level of FZD3 gene in skin tissues of the superfine wool(SF) group was significantly lower(P0.05) than that of the fine wool(F) group. Moreover, it had a higher expression level(P0.01) in skin tissues than in other tissues of Chinese Merino ewes. While, its expression level had a fluctuant expression in skin tissues at different developmental stages of embryos and born lambs, with the highest expression levels(P0.01) at the 65 th day of embryos. Our study revealed the genetic relationship between FZD3 variants and wool traits and two identified SNPs might serve as potential and valuable genetic markers for sheep breeding and lay a molecular genetic foundation for sheep markerassisted selection(MAS).     

基于转录组测序开发糜子SSR标记

【目的】 以6份不同地理来源的糜子资源为试验材料,基于前期转录组测序获得的1 000对SSR引物,选出200对进行多态性检测,以期构建一批可以准确评估糜子种质遗传差异的分子标记。【方法】 用Primer Premier 5.0软件设计引物,改良CTAB法提取DNA,PCR扩增DNA和聚丙烯酰胺凝胶电泳筛选引物多态性;用PowerMarker 3.25和PopGen 1.32计算遗传多样性参数。【结果】 200对引物中97对呈单态性,80对呈多态性。单碱基序列重复引物有20对,10对具多态性,其重复基元是A（50%）和T（50%）。二碱基序列重复引物有36对,15对具多态性,其碱基重复类型有7种（AG最多,TC、GC和GA次之,CA、TA和AC最少）。三碱基序列重复引物有144对,55对具多态性,其碱基重复类型有24种（GGC、GCG和GCC最多,GAA、GCT和CGC等次之,ACC、AGG、CAG、CGT、AAG、AAC、TCG、CGA、ATT、CAA和CCA最少）。就引物分辨率(Rp)值而言,1—3碱基序列重复引物分别为0.67—4.67（平均2.07）、1.33—4.33（平均2.73）和0.67—4.00（平均1.83）。基于Rp值分析SSR分布频次,发现80个标记分布在5个区间：0—1、1—2、2—3、3—4和4—5,分别包含17（21.25%）、36（45.00%）、11（13.75%）、14（17.50%）和2个（2.50%）。就$\overline{\text{Rp}}$值而言,1—3碱基序列重复引物分别为0.33—0.67（平均0.51）、0.40—0.78（平均0.59）和0.33—0.83（平均0.59）。单碱基序列重复标记共检测到22个等位变异,每个位点为2—3个（平均2.2000）,其中8个和2个位点分别具2和3个变异;二碱基序列重复标记共检测到38个等位变异,每个位点为2—3个（平均2.5333）,其中7个和8个位点分别具2和3个变异;三碱基重复标记共检测到136个等位变异,每个位点为2—3个（平均2.4727）,其中29个和26个位点分别具2和3个变异。就多态性信息含量而言,1—3碱基序列重复引物分别为0.3750—0.5355（平均0.4293）、0.2392—0.7438（平均0.4293）和0.2392—0.7438（平均0.3989）。就多样性指数而言,1—3碱基序列重复分别为0.6365—1.0776（平均0.7497）、0.5623—1.0986（平均0.8339）和0.5623—1.0889（平均0.8312）。【结论】 基于转录组测序结果,检测200对SSR引物的多态性,发现177对（88.5%）可以扩增出完整条带,其中80对具多态性,多态率为40%。     

Morphological differences among Raphanus raphanistrum populations and their relationship to related crops

Wild radish (Raphanus raphanistrum) has developed introgressed populations after hybridization with its cultivated counterpart (R. sativus) in California. Hybridization with various Brassica and Sinapis species is also possible. To determine if hybridization is responsible of the genetic diversity of European populations, six wild radish populations with distinct morphological traits were sampled from geographically distant regions in Europe. Plants were cultivated in an oilseed rape field and in insect‐proof cages. Silique and flower morphology, growth, and reproductive traits were measured. The wild radish populations could be discriminated by the morphological traits, but not related to geographic regions. In particular, populations of one region showed wide variability in terms of silique shape and growth behaviour, and small‐sized flowers. Although the origin of morphological diversity in wild radish is unclear, i.e. native or due to gene flow from the cultivated radish or other Brassicaceae, significant morphological divergence was found that could have relevant effects on plant ecology and adaptation.     

Three SNPs within exons of INHA and ACVR2B genes are significantly associated with litter size in Dazu black goats

The aim of this study was to analyse the association between single-nucleotide polymorphisms within INHA and ACVR2B and litter size in Dazu black goats. In total, twenty-two SNPs were genotyped in 190 individuals by SNaPshot and resequencing. The results showed that three SNPs (SNP_1, SNP_12 and SNP_13 in this study) were detected to have significant additive genetic effect on the recorded goat litter size (p < .05). The SNP_1 (NC_030809.1), a non-synonymous substitution of G for T at chr2-g. 28314990 in the exon 2 of INHA gene (NM_001285606.1), resulted in homozygote 2 (HOM2) contributed 0.25 and heterozygote (HET) contributed 0.12 larger litter than homozygote 1 (HOM1). Meanwhile, SNP_12 (Chr22-g. 11721225 A > T) and SNP_13 (Chr22-g. 11721227 A > C) (NC_030829.1) simultaneously mutated at the first and third position of a triplet AAA (lysine, K) in the exon 4 of ACVR2B gene (XM_018066623.1) had estimated genetic effects of HOM1 (0.00) and HOM2 (0.03) larger than HET (−0.12). In conclusion, one SNPs (chr2-g. 28314990 T > G) within the exon 2 of INHA and two SNPs (Chr22-g. 11721225 A > T and Chr22-g. 11721227 A > C) i n the exon 4 of ACVR2B gene were highly recommended as candidate markers of litter size in Dazu black goats. A large-scale association study to assess the impact of these variants on litter size is still necessary.     

红富士苹果芽变系DNA甲基化研究

以35份富士苹果(Malus×domestica Borkh.‘Fuji’)芽变材料为试材,利用甲基化敏感扩增多态性(Methylation Sensitive Amplified Polymorphism,MSAP)分析和UPGMA聚类方法,对其基因组甲基化修饰水平、变异模式以及表观遗传变异关系进行研究。结果表明:(1)不同富士系得到不同的MSAP扩增,总DNA甲基化水平27.90%～36.16%,平均32.87%,双链全甲基化为主要甲基化方式;(2)富士芽变材料绝大多数位点保持了原有甲基化模式;(3)绝大多数芽变(68.57%)检测到全部的甲基化变异模式(12种),去甲基化频率极显著高于甲基化频率(P 0.01),且CG去甲基化极显著高于CHG;(4)36份种质遗传相似系数平均值0.89(0.79～0.92),在聚类图上,富士原种分布在芽变系集中区外,新近发生的芽变系更倾向于聚在一起,着色系片红型和条红型芽变呈分散排布状态。总的来看,富士芽变的甲基化变异模式丰富,超甲基化和去甲基化相伴发生,但以去甲基化为主;‘富士’着色芽变与其最原始品种富士,以及芽变之间发生了较大表观遗传变异;片红和条红型芽变聚类未表现明显偏好性。本研究将为进一步开展富士着色系芽变机理研究提供指导,可以CG去甲基化为切入点展开深入研究。     

动物DGAT基因的研究进展

DGAT基因包括二酰基甘油酰基转移酶1（DGAT1）基因和二酰基甘油酰基转移酶2（DGAT2）基因，前者属于酰基辅酶A胆固醇酰基转移酶（ACAT）基因家族，后者属于单酰甘油酰基转移酶（MGAT）基因家族，分别编码微粒体酶DGAT1和DGAT2，这两种酶控制着甘油三酯的合成，均是定位于内质网的跨膜蛋白，其膜拓扑结构具有与其他蛋白质和细胞器相互作用的能力，影响脂肪代谢及脂类在组织中的沉积，参与调节动物机体的能量合成和分解代谢，影响心脏和肝脏中甘油三酯的代谢；同时DGAT基因的多态性影响着牛乳中脂肪的含量及泌乳量。因此，了解DGAT基因的结构和生物学功能对畜禽生长发育和生产等相关研究具有重要的意义。文章简述了DGAT基因的基本结构和生物学功能及相关的作用机制，分析了其在畜牧生产中的基础应用，如参与哺乳动物生产调控的脂肪沉积、乳脂含量等方面的研究进展。     

11种鲈形目鱼类ITS2特征及系统应用

ITS2 (Internal transcribed spacer 2)是位于核糖体5.8S和28S基因之间的非编码序列。为了探讨该片段的多样性特征以及进化模式,本研究选取了鲈形目(Perciformes) 5科11种鱼类为研究对象,共获得了444条ITS2克隆序列,其长度范围为332～515 bp。比较种内不同序列的长度发现,金带细鲹(Selaroides leptolepis)在种内存在24 bp的差异,剑鱼(Xiphias gladius)在种内存在32 bp的差异,这2种鱼类的差异较为明显;其余9种鱼类的长度相对比较保守,长度差异小于14 bp。依据11种鱼类的保守位点数、变异位点数、简约信息位点数、单倍型数、保守位点比例、单倍型多样性指数、核苷酸多样性等特征分析发现,种内存在着不同程度差异,特别是金带细鲹的ITS2序列存在着Type A、Type B和Type C 3种类型,各类型间差异较大。根据序列的多样性特征推断,金带细鲹和剑鱼的进化方式为非协同进化;蓝圆鲹(Decapterus maruadsi)、大甲鲹(Megalaspis cordyla)、吉打副叶鲹(Alepes djedaba)和日本竹筴鱼(Trachurus japonicas)的长度和变异位点均存在着一定程度的差异,但差异并不明显,视为不严格的协同进化;泰拉鰆鲹(Scomberoides tala)、布氏鲳鲹(Trachinotus blochii)、尖吻鲈(Lates calcarifer)、射水鱼(Toxotes chatareus)和军曹鱼(Rachycentron canadum) 5种鱼类为协同进化;另外,协同和非协同进化状态与分类系统没有相关性。序列比对发现,大甲鲹种内存在着由协同进化方式演变为非严格的协同进化方式的过度序列;在金带细鲹的3个不同个体中,序列间存在着从协同进化、非严格的协同进化演变为非协同进化的3种进化方式。基于ITS2序列构建的11种鱼类的邻接系统树显示,每种鱼类的克隆都分别按种单独聚为一支,鲹科7属鱼类各属也是单独聚支,表明ITS2不仅可以用在种类的分子鉴定,同时也可以作为分子标记应用于鲹科和属级水平的系统关系研究。