大弹涂鱼白细胞介素-8基因分子进化及不同病原体刺激对其表达的影响

实验从大弹涂鱼皮肤组织转录组中筛选出大弹涂鱼IL-8基因,并分析了其序列特征,构建了系统发生树,评估了IL-8基因在健康个体不同组织中的表达差异,以及在不同病原体刺激下IL-8基因在机体主要免疫器官肝脏和脾脏中的表达情况。结果显示,该基因的开放阅读框由306个碱基组成,编码101个氨基酸残基,包含典型的由18个氨基酸残基组成的信号肽,和1个由62个氨基酸残基组成的SCY结构域,该结构域还包含了4个保守的半胱氨酸残基,分别为Cys-30、Cys-32、Cys-57和Cys-73。大弹涂鱼IL-8氨基酸序列中的受体结合位点基序ELR (Glu-Leu-Arg)被Asn-Ser-His (NSH)取代,系统进化分析表明,纯化选择影响了鱼类该基序的多样性,且IL-8基因在大弹涂鱼乃至硬骨鱼中不可取代。荧光定量实验结果显示,IL-8基因在大弹涂鱼的健康组织中广泛表达,在鳃和脑中表达量最高。细菌和poly(I∶C)注射实验表明,在受到感染后,肝、脾和脑组织中IL-8的表达量均上调,说明IL-8基因在大弹涂鱼肝、脾和脑组织的炎性反应和免疫应答中起到了重要作用,为大弹涂鱼免疫基因的后续研究提供了参考。     

水产动物分子标记辅助育种研究进展

本文介绍了水产动物分子标记辅助育种技术的发展。获得与经济性状连锁的标记是开展分子标记辅助育种的基础,因此,本文重点介绍了获得基因/标记技术的进步,探讨了基因/标记与性状间相互关系的复杂性,论述了准确鉴定性状紧密连锁的基因/标记的难度,指出难点主要源于基因组对性状的形成具有非常复杂的影响。近十年来,已有多个利用分子标记辅助育种技术培育的品种在产业上应用,表明这项新技术具有推动产业技术进步的作用;同时指出了分子标记辅助育种包括全基因组选择育种的不足之处,其根本原因在于鱼类性状的形成机制极其复杂、多变,从而决定了分子标记辅助育种技术具有发展阶段论的特征。     

甘肃白水江林区落叶松球蚜红杉亚种发生及防治

落叶松球蚜红杉亚种以成虫和若虫群集在落叶松嫩枝、梢、针叶上吸食汁液。温度和湿度对红松球蚜的发生影响较大;相对湿度在58％-70％时,危害严重;相对湿度在75％以上时,落叶松球蚜数量减少;5月为发生危害高峰期。施药区相对防治效果可达92．4％。     

Viscera of Labeo rohita: A Potential Source of Trypsin for Industrial Application

ABSTRACT

The serine protease trypsin was isolated and purified from the digestive system of carp Labeo rohita rohu by ammonium sulphate precipitation, ion exchange, and affinity chromatography. The purified enzyme showed high activity between pH 7.0 and 9.0. The activity was maximum at 40°C. Incubation of the purified enzyme with CaCl₂ (2 mM) stabilized the enzyme activity for 8 h. The enzyme showed stability at 30 and 40°C for 1 h, but above 40°C, enzyme activity was reduced. The kinetic constants were recorded as K_m (0.104 mM), k_cat (44.25 s^?1), and catalytic efficiency (427.54 s^?1 mM^?1). Monovalent, bivalent, and trivalent ions (Li⁺, K⁺, Hg²⁺, Al³⁺, Mg^2+, Cd^2+, Co^2+, Zn²⁺, and Al³⁺) influenced the enzyme activity. Phenylmethylsulfonylflouride, soybean trypsin inhibitor, and N-α-p-tosyl-_L-lysine chloromethyl ketone completely inhibited the enzyme activity, while ethylenediaminetetraacetate caused partial inhibition. Molecular mass of the purified enzyme was 22.46 kDa. The pH and temperature stability of enzyme may be useful for its industrial applications.     

九孔鲍选择群体F1的选择反应与现实遗传力估计

以中国九孔鲍（Haliotis diversicolor aquatili）养殖群体与日本野生群体杂交子二代为选育基础群体,采用群体选育方法进行九孔鲍的选择育种研究,以估计该养殖群体的选择反应与现实遗传力。截断选择壳长最大的10％个体作为选择组亲本（SS）,从基础群体中随机抽取相同数量的个体作为对照组亲本（sc）,选择强度为1．755,结果表明,选择组与对照组在卵径、受精率方面无显著的差别（P〉0．05）,但选择组在幼体附着率、幼体变态率、幼体成活率及稚贝早期生长方面与对照组相比表现出不同程度的生长优势（P〈0．05）,选择组50日龄的稚鲍成活率达到35．07％,显著大于对照组23．62％（P〈0．05）,40—270日龄的选择组壳长选择反应和现实遗传力变化范围分别为13．64％～81．88％和0．21～0．53,平均为31．63％和0．36,选择组平均壳长显著大于对照组（P〈0．01）。研究初步显示,养殖群体的选择反应极显著,群体选育是养殖九孔鲍遗传改良的有效途径。     

动物携带河豚毒素的分子机制与生态作用

河豚毒素在自然界中分布广泛,从微生物到植物、动物都有发现.除河豚外,河豚毒素还在节肢动物、棘皮动物、软体动物、蠕虫、蝾螈、青蛙等其他物种中都有不同含量的分布.不同动物产生、富集河豚毒素的机制可能存在很大差别,但是河豚毒素对其携带动物在自然选择进化中发挥着重大的作用.目前中国对河豚毒素的研究主要集中在河豚毒素的分离纯化、检测分析及抗体制备等方面,而对河豚毒素产生的分子机制及生态作用的研究还很少,文章通过综述国外对河豚毒素分子机制及生态作用的研究,进一步阐释动物携带河豚毒素的分子机制及河豚毒素对动物的重要生态作用.     

First approach to studying the genetics of the meagre (Argyrosomus regius; Asso, 1801) using three multigene families

The meagre (Argyrosomus regius) is a commercially important species for fisheries, and aquaculture production has been increasing in recent years. However, this growing importance has not been matched by increased genetic knowledge of the species. For this reason, an initial approach has been made to understanding the genetics of the meagre, using three particular multigene families (45S and 5S ribosomal DNA and U2 snRNA gene) as both molecular and cytogenetic markers. Only one type of 5S rDNA and only one ITS‐1 (from 45S rDNA) were obtained, and these therefore could provide the basis for the development of genetic markers for this species. However, the U2 snRNA gene produced a multi‐band electrophoretic pattern, and some of these bands were demonstrated to be linked with the U1 snRNA gene. This linkage could also provide a good species‐specific marker which could be useful for tracing the evolutionary history of the Sciaenidae family. In this study, we have described for the first time the karyotype of the meagre: this is composed of 48 acrocentric chromosomes. Each of the three gene families were localized on different chromosome pairs, although the U2 snRNA gene probe was also located scattered throughout the genome of the meagre, as expected by the amplification pattern.     

黄渤海夏季微藻调查

根据2011年夏季在黄渤海的采样调查分析了该海域网采浮游微藻的多样性,并从71个站位的采水样品与12个站位的拖网样品中分离了大量可培养的藻种。调查区拖网样品中共发现浮游微藻4门30属44种藻,以硅藻门(Bacillariophytas)为主,甲藻门(Dinophytas)次之。在实验室内利用毛细管法、平板法和稀释法分离纯化获得92株可培养微藻,经分子学鉴定为19种,包括9种硅藻、3种褐藻、3种不等鞭毛藻、2种绿藻、1种甲藻、1种定鞭藻。这些可培养微藻个体较小,多为微微型藻类和微型藻类,其中伪菱形藻(Pseudonitzschia sp.)和舟形藻(Navicula sp.)既能在固定样品中观察到,又能在实验室培养。圆筛藻(Coscinodiscus sp.)、梭角藻(Ceratium fusus)和夜光藻(Noctiluca scintillans)等小型藻类虽然在固定样品中所占比例较大,但是难以培养。此外,本次调查还首次在中国海域发现了Pseudobodo tremulans。黄渤海藻株的鉴定与培养不仅补充了中国微藻种质资源,还为促进微藻的研究和开发利用提供了重要材料。     

分子标记技术在棉花遗传育种中的应用

介绍了分子标记的类型及原理，综述了该技术在棉花的种质进化及亲缘关系、遗传结构和多样性、遗传图谱的构建与目标基因的定位、品种指纹图谱的构建与品种（杂种）纯度鉴定及分子标记辅助育种等研究中的应用情况．同时对其应用前景也进行了展望。     

Changes in incisor dentition of sheep influence biting force

The grazing behaviour by sheep, after the loss of the temporary incisors and before their replacement with the permanent incisors, was compared with that after the first pair of permanent incisors had completely developed in grazing experiments, conducted from June to September 2001, with three Suffolk castrated male sheep, born in late‐March 2000. A new method was developed to investigate bite mass and bite force, using hand‐constructed swards, which were composed of groups of four (4L), eight (8L), twelve (12L), sixteen (16L) and twenty (20L) leaves of cocksfoot (Dactylis glomerata) arranged 15 cm apart. Each group of leaves was attached to a separate three‐directional load cell. The period of time between loss of temporary incisors and the complete eruption of permanent incisors was c. 1 month. The number of bites per group of leaves increased with increasing leaf density. The number of bites per group of leaves was higher after the loss of temporary incisors than with the permanent incisors. The number of leaves per bite and dry‐matter (DM) intake per bite were almost twice as great with permanent incisors than after the loss of temporary incisors; DM intakes per bite force were 3·9–4·9 mg N^?1 and 1·7–2·6 mg N^?1 respectively. After the loss of temporary incisors, the proportion of forward‐direction forces accounted for 0·805 of the forces in the 4L treatment and 0·155–0·317 of the forces in the 8L–20L treatments. In contrast, the proportion of forward‐direction forces accounted for only 0·292 in the 4L treatment and 0·026–0·163 in the 8L–20L treatments with permanent incisors. The angles of bite forces were almost the same (54·7–56·3°) when sheep used a forward direction, and were 51·3–57·3° when sheep used a backward direction.