基于18S rRNA和线粒体16S rRNA基因序列的柳蚕进化分析

为探讨柳蚕Actias selene Hübner与鳞翅目昆虫的系统发育关系,本研究利用PCR扩增获得了柳蚕核糖体18S rRNA和线粒体16S rRNA基因的部分序列,长度分别为391bp和428bp。并采用邻近距离法(NJ)、最大简约法(MP)、类平均聚类法(UPGMA)构建系统进化树。结果表明,柳蚕线粒体16SrRNA基因序列与大蚕蛾科昆虫的16SrRNA基因序列均表现出偏好于碱基AT的倾向。柳蚕与所研究的其它蚕类的遗传距离介于0.016至0.140之间,其中与温带柞蚕Antheraea roylii的遗传距离最小,与野桑蚕Bombyx mandarina的遗传距离最大。而基于鳞翅目昆虫18S rRNA基因部分序列的进化分析显示,柳蚕与柞蚕Antheraea pernyi之间的遗传距离最小(0.010),与蓖麻蚕Samia ricini的遗传距离最大(0.017)。     

褶纹冠蚌()和三角帆蚌(■)人工杂交试验

1.要求通过杂交种能培育大型珍珠。目前较好的育珠河蚌是三角帆蚌(Hyriopsis cumingii)和褶纹冠蚌(Cristaria plicata),但它们的育珠性状还不理想。三角帆蚌所产珍珠,质量虽佳,但插核植片部位的壳间距离小,不能育成大珠;褶纹冠蚌体型大,插核植片部位的壳间距离也大,外套膜厚实,能插大核植大片育成大型     

樗蚕与柳蚕

由于蓖蔴蚕与柞蚕推广饲养,要适应当地的气候与饲料的条件,才能成功,如果能找到和它们相近的种类进行杂交试验,以提高其生活力,便有着重要的意义。樗蚕与蓖蔴蚕杂交,已经中国科学院试验成功;柳蚕经华东工学院试验,其蚕茧可供纺织用,但柳蚕比柞蚕丝量少,品质差,如能把柞蚕与其相近的柳蚕杂交,来提高柞蚕的生活力,却是很有价值的。     

柳蚕S3a基因的鉴定及原核表达分析

采用RT-PCR法克隆了柳蚕S3a基因序列,并通过构建重组质粒,对其进行了原核表达及蛋白纯化。柳蚕S3a基因ORF长度为795bp,编码264个氨基酸,预测蛋白的等电点和分子量大小分别为9．74和30kD。序列比对及进化关系表明,柳蚕S3a蛋白与其他物种S3a蛋白相似度介于71％和97％之间,其中与鳞翅目昆虫的同源性最高。SDS—PAGE和Western blotting结果显示柳蚕S3a在大肠杆菌中获得了高效表达,分离获得的重组蛋白的纯度较高。     

搞好小蚕共育 促进蚕业协调发展

"养好小蚕八成收",这充分说明养好小蚕的重要性,小蚕饲养是整个养蚕过程中的基础环节,也是最关键的环节。小蚕的集中共育为大蚕安全顺利的饲养提供了保障,以达到高产、稳产的目的,所以必须充分做好小蚕的饲养工作。     

鱼鰾体积改变的观察

用一个带孔的塞子塞住玻璃瓶,然后插上一根玻璃管。在瓶中放上水和一条小魚(注意:瓶子不要漏气,玻璃管要插在水中)。当魚沉在瓶底和上升时,就会发現玻璃管的水面,也会随着下降和上升。由此可以根据小魚所     

梨小食心虫性信息素在四种载体中释放速率及田间迷向率研究

【目的】研究4种常用缓释载体对梨小食心虫Grapholithamolesta性信息素的释放速率及田间迷向效果,为制作梨小食心虫迷向剂筛选合适的缓释材料。【方法】采用气相色谱法测定野外条件下梨小食心虫性信息素在PE管、PE瓶、PE袋和PVC管4种载体中的释放速率,并通过田间试验研究4种缓释载体处理下桃园梨小食心虫的迷向率和持效期。【结果】在测试期内,PE管和PE瓶中梨小食心虫性信息素释放速率范围分别为0.32-1.62mg/d和0.59-2.73mg/d,两种载体持效期均达到5个月;PVC管的释放速率在0.71-6.86 mg/d之间,田间持效期3个月;PE袋释放速率1.14-19.27 mg/d,持效期仅1个月。4种缓释载体中梨小食心虫性信息素释放过程均符合一级动力学方程,4种载体的半衰期由高到低顺序为：PE管>PE瓶>PVC管>PE袋。在持效期内,4种缓释材料的迷向效果均达到90%以上。【结论】野外条件下PE管和PE瓶中梨小食心虫性信息素释放速率较稳定,持效期长,迷向率高,适合作为制作梨小食心虫的迷向剂的缓释材料。     

证明光合作用需要CO_2的简易实验装置

取两个广口罐头瓶,甲瓶内盛NaOH水溶液,再将盛有清水、插有带叶的植物枝条的小瓶放入瓶中(注意勿使NaOH溶液进入小瓶),然后用另一个广口瓶倒扣在甲瓶瓶口上,瓶口接头处用多层胶布封严。乙瓶的装置与甲瓶同,只是将瓶内的     

柞蚕和柳蚕雌蛾粘液腺及内容物的研究对比分析

本实验测定了柳蚕卵表面的胶着物质的含量以及粘液腺的形状、大小,并对粘液腺的内容物进行了SDS一聚丙烯酰胺凝胶电泳分析。结果表明：柳蚕卵表面的胶着物质的含量为1．11mg／卵,与柞蚕（1．01mg／卵）相当。柞蚕、柳蚕雌蛾的粘液腺整体呈较细长的管状结构且几乎无枝状部分枝,柳蚕粘液腺的干状部长约为2．0cm,柞蚕为1．8cm,二者相近。柳蚕粘液腺的内容物经SDS-聚丙烯酰胺凝胶电泳分析出现了7条蛋白质谱带,分子量分别为114kD,92kD,78kD,53kD,50kD,23kD,12kD,与柞蚕存在差别。     

多胺对月季切花衰老过程中生理生化和瓶插寿命的影响

精胺处理可保持月季切花瓶插前期花瓣还原糖和蛋白质的较高水平、减缓花瓣和叶片细胞膜稼性的增加,减少共 积累以及降低乙烯释放速率,这与精胺处理后月季切花瓶插寿命提高相一致;但亚精胺处理对季切花瓶插寿命和改善观赏品质无明显影响。     

The complete mitochondrial genome of the wild silkworm moth, Actias selene

The complete mitochondrial genome (mitogenome) of Actias selene (Lepidoptera: Saturniidae) was determined to be 15,236 bp, including 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and a control region. The arrangement of 13 PCGs was similar to that of other sequenced lepidopterans. The AT skew of the mitogenome of A. selene was slightly negative, indicating a higher number of T compared to A nucleotides. The nucleotide composition of the mitogenome of A. selene was also biased toward A+T nucleotides (78.91%). All PCGs were initiated by ATN codons, except for the gene encoding cytochrome c oxidase subunit 1 (cox1), which may be initiated by the TTAG, as observed in other lepidopterans. Three genes, including cox1, cox2, and nad5, had incomplete stop codons consisting of just a T. With an exception for trnS1(AGN), all the other tRNA genes displayed a typical clover-leaf structure of mitochondrial tRNA. The A+T-rich region of the mitogenome of A. selene was 339 bp in length, and contains several features common to the Lepidopteras, including non-repetitive sequences, a conserved structure combining the motif ATAGA and an 18-bp poly-T stretch and a poly-A element upstream of trnM gene. Phylogenetic analysis showed that A. selene was close to Saturniidae.     

Antioxidative responses in females and males of the spider Xerolycosa nemoralis (Lycosidae) exposed to natural and anthropogenic stressors

The aim of this study was to assess the intensity of enzymatic antioxidative parameters [i.e., superoxide dismutase (SOD), catalase (CAT), and the glutathione peroxidases each selene dependent, GPOX or selene independent, including GSTPx, glutathione S-transferase, and GST] and non-enzymatic antioxidative parameters [i.e., glutathione total (GSH-t), the heat shock proteins of Hsp70, and metallothioneins (Mt)] in the midgut glands of female and male wolf spiders Xerolycosa nemoralis (Lycosidae) exposed to natural stressors (i.e., heat shock and starvation) and anthropogenic stressors (i.e., the organophosphorous pesticide dimethoate) under laboratory conditions. The spiders were collected from two differentially polluted sites both localized in southern Poland: Olkusz, which is heavily polluted with metals, and Pilica, the reference site. In response to the stressing factors, increases in Hsp70 levels, in the concentrations of total glutathione and in the activity levels of glutathione-dependent enzymes (GPOX, GSTPx, and GST) were found in the midgut glands of males. In the females, high levels of activity of CAT and SOD were revealed, as well as an increased percentage of Mt-positive cells. Preexposed females, in comparison to the individuals from the reference site, responded with increased SOD activity, irrespective of the stressing factor. In contrast, the changes in the antioxidative parameters in the midgut glands of male X. nemoralis seem to reflect a short-term reaction to the applied stressors and do not confirm the effects of long-term selection in a polluted environment.     

Biosynthesis of phorcabiline, blue-green biliary pigment of Actias selene (Lepidoptera, Attacidae)]

The blue-green bile pigments of Actias selene (Attacidae) have been investigated at different stages of its development. Coproporphyrinogen-14-C, protoporphyrin-IX3-H, and pterobilin-14-C, injected to larvae are metabolised into phorcabilin I, the main neopterobilin in this animal. It is concluded that phorcabilin I is a bile pigment of the IX gamma series and that pterobilin is its direct precursor. A method for the preparation of labelled protoporphyrin from quail egg-shell is reported.     

Comparing the rheology of mulberry and "wild" silkworm spinning dopes

Lepidoperan silks provide a superb opportunity for comparative studies of spinning and fiber characteristics. Comparing the four species, Bombyx mori (China), Actias selene (India), Antheraea yamamai (Japan), Gonometa postica (Africa), allows us to examine differences on the family, species, and race levels. Measured rheological properties were consistent with phylogenetic relationships and in the context of resource allocation and gland morphology. We propose that the thorough domestication of the mulberry silkworm B. mori for high silk yield has resulted in a compensatory optimization for spinning efficiency. This is in stark contrast to the wild silkworms, where Saturnids appear to minimize their energetic input toward silk output and G. postica seems to balance both. We conclude that comparative studies provide valuable baseline information for future biomimetic applications and modeling, as well as illuminating biologically important details of silk processing.     

β-sheet topology prediction with high precision and recall for β and mixed α/β proteins

The prediction of the correct β-sheet topology for pure β and mixed α/β proteins is a critical intermediate step toward the three dimensional protein structure prediction. The predicted beta sheet topology provides distance constraints between sequentially separated residues, which reduces the three dimensional search space for a protein structure prediction algorithm. Here, we present a novel mixed integer linear optimization based framework for the prediction of β-sheet topology in β and mixed α/β proteins. The objective is to maximize the total strand-to-strand contact potential of the protein. A large number of physical constraints are applied to provide biologically meaningful topology results. The formulation permits the creation of a rank-ordered list of preferred β-sheet arrangements. Finally, the generated topologies are re-ranked using a fully atomistic approach involving torsion angle dynamics and clustering. For a large, non-redundant data set of 2102 β and mixed α/β proteins with at least 3 strands taken from the PDB, the proposed approach provides the top 5 solutions with average precision and recall greater than 78%. Consistent results are obtained in the β-sheet topology prediction for blind targets provided during the CASP8 and CASP9 experiments, as well as for actual and predicted secondary structures. The β-sheet topology prediction algorithm, BeST, is available to the scientific community at http://selene.princeton.edu/BeST/.     

Factors influencing parasitism of Trichogramma dendrolimi on eggs of the Asian corn borer, Ostrinia furnacalis

Laboratory studies were made to determine the capacity of Trichogramma dendrolimi to parasitize eggs of Ostrinia furnacalis, as affected by the rearing host species, substrate of host eggs, host age, original locality of host populations, and cold storage of host eggs. Wasps reared from eggs of Antheraea pernyi showed parasitic capacity on eggs of O. furnacalis on average twice as high as that of the wasps reared from eggs of Corcyra cephalonica. When the age of O. furnacalis eggs at 26 °C increased from 0–6 h to 18–24 h, the proportion of wasps that successfully parasitized host eggs, the number of host eggs parasitized, and the rate of parasitization all decreased by >50%. The number of O. furnacalis eggs parasitized per female T. dendrolimi increased with the number of host eggs available, and reached 22.9 in a 24 h period. However, the parasitic capacity of female T. dendrolimi on eggs of O. furnacalis laid on plant leaves was similar to that of O. furnacalis eggs laid on wax paper. Levels of parasitism of O. furnacalis eggs from two widely separated localities, i.e. Changchun (43.50° N, 125.20° E) and Hangzhou (30.18° N, 120.07° E), were similar. Cold storage of O. furnacalis eggs at 4 °C for 5 days did not affect parasitization. Results obtained in this study indicate that although O. furnacalis is a less preferred and less suitable host than many other hosts, such as Dendrolimus punctatus, Actias selene ningpoane, Philosamia cynthia, A. pernyi, C. cephalonica, within the host-species range of T. dendrolimi, the parasitoid has the potential to achieve 50–60% or even higher rates of parasitization of O. furnacalis eggs in corn fields under suitable conditions, and could be used in the biological control of the pest.     

生物技术发展趋势与预测

预测了未来10～20年内生物技术在人类医学领域、农业生物技术领域、工业生物技术领域、生物计算学领域、材料学领域、生物工程领域和环境生物工程领域的主要发展趋势,对生物技术的发展进程也作了预测,并对生物技术在人类疾病治疗方面、农业领域、工业领域、数学领域、材料学科、生物工程方面和环境生物工程领域作出了实际预测。