家蚕微粒子虫(Nosema bombycis)感染家蚕的病理学研究

Nosema bombycis感染家蚕后 ,家蚕中肠海藻糖酶活性显著下降 ,大量裂殖体的形成是其下降的重要原因 .血淋巴总糖和海藻糖等与能量代谢密切相关物质的含量也明显下降 .感染后血淋巴海藻糖酶活性略有上升 ,但对血糖总量无明显影响 .血淋巴蛋白质含量的下降要滞后于与能量代谢有关的物质 ,其中贮存蛋白量的下降明显高于 30 K蛋白     

家蚕血液过氧化氢酶遗传性及其与经济性状相关性研究

家蚕血液过氧化氢酶活性在品种间差异极显著,广义遗传力很高。ＣＡＴ活性与５龄历期,同宫率无关,与全龄期,死笼率,普茧率呈一定的负相关,与全茧量,茧层量,茧层率呈不显著的正相关,与万蚕产茧量,万蚕茧层量接近显著正相关,与虫蛹率,幼虫生命率有显著正相关。     

家蚕人工饲养配方研究

比较四种成分不同的人工饲料配方,其饲料成本、疏毛率、蚕体生长发育及防腐性能均有明显 的差异。用豆腐渣、乙醇处理豆饼粉、甲醇处理豆饼粉及未处理豆粉配制成人工饲料饲养小蚕,收蚁后 ４８ ｈ的疏毛率分别为６８．２％,８４．７％,９５．４％和８０．９％,结果表明以乙醇和甲醇浸提处理后的豆饼粉配 制人工饲料,蚕的疏毛率和生长发育速度均有显著改善,其中以甲醇处理为最好。     

高原蚕区家蚕茧层率遗传分析

旨在验证并丰富家蚕茧层率性状的遗传规律,为培育高茧层率的家蚕纯种提供理论依据。以高丝量品种‘菁松’、‘皓月’和中丝量品种‘芙蓉’、‘湘晖’为亲本,构建5世代遗传群体,运用多世代联合分析方法分析茧层率的遗传规律。结果表明：家蚕茧质性状具有明显的性别效应,雄性茧层率大于雌性;亲本的茧层率性状与茧层量呈显著正相关;F₁代的茧层率介于两亲本之间,反交组合茧层率高于正交组合;回交群体的频数呈双峰或偏态的单峰分布;茧层率的杂种优势率在-3.82%~5.63%之间,几乎没有杂种优势。研究得出结论为茧层率高值对低值为显性,呈偏母本遗传,遗传体系中存在主基因,可能存在于性染色体上。     

Identification and Characterization of Aldehyde Oxidase 5 in the Pheromone Gland of the Silkworm (Lepidoptera: Bombycidae)

Aldehyde oxidases (AOXs) are a subfamily of cytosolic molybdo-flavoenzymes that play critical roles in the detoxification and degradation of chemicals. Active AOXs, such as AOX1 and AOX2, have been identified and functionally analyzed in insect antennae but are rarely reported in other tissues. This is the first study to isolate and characterize the cDNA that encodes aldehyde oxidase 5 (BmAOX5) in the pheromone gland (PG) of the silkworm, Bombyx mori. The size of BmAOX5 cDNA is 3,741 nucleotides and includes an open reading frame, which encodes a protein of 1,246 amino acid residues. The theoretical molecular weight and isoelectric point of BmAOX5 are approximately 138 kDa and 5.58, respectively. BmAOX5 shares a similar primary structure with BmAOX1 and BmAOX2, containing two [2Fe-2S] redox centers, a FAD-binding domain, and a molybdenum cofactor (MoCo)-binding domain. RT–PCR revealed BmAOX5 to be particularly highly expressed in the PG (including ovipositor) of the female silkworm moth, and the expression was further confirmed by in situ hybridization, AOX activity staining, and anti-BmAOX5 western blotting. Further, BmAOX5 was shown to metabolize aromatic aldehydes, such as benzaldehyde, salicylaldehyde, and vanillic aldehyde, and fatty aldehydes, such as heptaldehyde and propionaldehyde. The maximum reaction rate (V_max) of benzaldehyde as substrate was 21 mU and K_m was 1.745 mmol/liter. These results suggested that BmAOX5 in the PG could metabolize aldehydes in the cytoplasm for detoxification or participate in the degradation of aldehyde pheromone substances and odorant compounds to identify mating partners and locate suitable spawning sites.     

环境激素壬基酚对体外培养家蚕造血器官的影响

目的:为探讨环境激素对鳞翅目昆虫组织的影响及其利用途径,研究了壬基酚(NP)对家蚕造血器官和翅原基的影响。方法: TC-100培养基中添加对壬基酚(NP),悬滴培养方法体外培养家蚕5～3d幼虫造血器官和翅原基。结果:0．016mmol/L的NP,造血器官和翅原基的发育变慢,造血器官分泌血球数量减少、分泌时间延迟;NP达0．032mmol/L,培养144h内部分组织发黑死亡、无血球分泌;0．128mmol/L的NP,96h后大部分组织萎缩死亡,培养144h无血球分泌。结论:家蚕幼虫造血器官接触NP后,首先影响血球分泌功能,进一步导致造血器官萎缩死亡,对翅原基的不良影响也导致器官萎缩死亡。NP对造血器官和翅原基的影响都有明显的浓度效应。     

Bacillus thuringiensis Cry1Ab, but not Cry1Aa or Cry1Ac, disrupts liposomes

We evaluated the ability of Cry1Aa9, Cry1Ab4, and Cry1Ac1 insecticidal toxins from Bacillus thuringiensis to destroy liposomes. Cry1A toxins are thought to form pores in midgut apical cell membranes (BBMV), thereby disrupting midgut cells. Liposomes containing fluorescent calcein were prepared using phosphatidylcholine (PC) and phosphatidylserine (PS) (PC/PS-Liposomes) or PC alone (PC-Liposomes). Cry1Ab (1.4 μM), but not Cry1Aa or Cry1Ac, disrupted PC/PS-Liposomes and PC-Liposomes. PC/PS-Liposomes containing cholesterol and oligosaccharylceramide from Plutella xylostella midgut were damaged even more extensively by Cry1Ab, but the inclusion of either lipid alone had no effect. The initial velocity of Cry1Ab-mediated liposome disruption increased 17-fold when liposomes were prepared with Triton X-100-soluble proteins from Bombyx mori BBMV and PC (PC/Proteo-Liposomes), and Cry1Aa and Cry1Ac also caused slight disruption. These data suggest that Cry1Ab achieves higher penetration into PC/PS-Liposomes, PC-Liposomes, and PC/Proteo-Liposomes compared with Cry1Aa or Cry1Ac and that Cry1Ab may interact with membrane proteins.     

家蚕广食性系统C01对不含桑叶粉人工饲料摄食性的遗传

C01是用不含桑叶粉的人工饲料作检测物,从家蚕种质资源中国系统中筛选得到的摄食性优良的品种。用对不含桑叶粉的人工饲料无摄食性的中国系统1015与C01杂交,对F1、F2和BC1世代蚁蚕用不含桑叶粉的人工饲料检测,分析C01对不含桑叶粉的人工饲料摄食性的遗传规律。结果表明:C01对不含桑叶粉的人工饲料摄食性为隐性遗传,并且由常染色体基因支配。卡平方(X2,chi-square)测定结果显示,广食性品种C01对不含桑叶粉人工饲料摄食性遗传除了受1个隐性主基因控制外,同时还有修饰基因的作用。     

家蚕iap基因在原核表达系统中的表达

为研究IAP蛋白抑制细胞凋亡的作用,用PCR法扩增出家蚕iap基因的cDNA,然后插入pET28a载体,得到阳性质粒pET28a-iap,并转化感受态细胞BL21,使用异丙基硫代-β-D-半乳糖苷(IPTG)诱导IAP蛋白的表达,应用SDS-PAGE和Western Blotting法分析目的蛋白,得到一条分子量约为38.8 kDa的特异表达条带,与表达产物的理论值相符。为进一步研究BmIAP蛋白的功能奠定了基础。