家蚕性连锁平衡致死系性别控制基因的导入方法

本发明公开了一种家蚕性连锁平衡致死系性别控制基因的导入方法，采用通过平衡致死系与现行品种的杂交把平衡致死系的性别控制基因分散在3个子系统中；接着对每个子系统中现行品种连续回交，使3个子系统基本上全为现行品种血缘；最后通过3次不同型式的交配，把性别控制基因组合到一个新的品种，形成新的平衡致死系品种。由于家蚕性连锁平衡致死系是用特殊基因来控制原种和杂交种的性别，使其自交能繁殖继代，与其他品种杂交保证下一代只有雄蚕孵化。本发明能育成经济性状优良，雄蚕率在98％以上的新型雄蚕品种。     

桑蚕的性别控制与专养雄蚕的研究

雄蚕较雌蚕有较高的生命力和叶丝转化率。近半个世纪来各国学者对蚕的性别控制进行了广泛的研究,建立了许多产生桑蚕单一性别后代的方法。作者对这些方法进行了综合评价后,认为俄罗斯科学斯特隆尼柯夫育成的桑蚕性连锁平衡致死系,能产生理想的雄蚕杂交后代,可实现专养雄蚕的目标。     

利用平衡致死系S8,S4选配雄蚕杂交组合的研究

以常规品种雌为母本，平衡致死系Ｓ８，Ｓ１４雄为欠本，按中×日的形式选配蚕杂交组合，通过对部共２８个雄蚕组合的雄蚕率及主要茧丝质性状的配合力测定，选拔出２对优良雄蚕杂交组合夏５×Ｓ１４，夏Ｓ４×Ｓ８，它们的雄蚕率达到９９％以上，目前已有少量进入农村中试。     

春秋兼用雄蚕品种夏·华×平8的选育

以俄罗斯引进的性连锁平衡致死系S14和春用多丝量家蚕品种春日为材料 ,采用杂交、回交并结合测交和标记基因选择的方法 ,育成性连锁平衡致死系平 8,与常规蚕品种夏·华选配雄蚕杂交组合夏·华×平 8,其雄蚕率达到 99%以上。农村试养表现发育齐一、强健好养、产量高等特点。     

春用多丝量雄蚕品种“鲁菁×华阳”的育成

以家蚕平衡致死系平76为受体亲本,以丝质优良的普通蚕品种皓月为基因供体材料,采用杂交、自交和回交三步改良家蚕性连锁平衡致死系的方法,育成了经济性状优良的性连锁平衡致死系华阳;以限性皮斑蚕品种857为母本,以茧丝质优良、茧层率高、配合力优的蚕品种菁松为父本,转育成限性皮斑蚕品种鲁菁。两者组配成雄蚕杂交组合鲁菁×华阳,其雄蚕率达到98%以上,茧层率、万蚕茧层量和鲜茧出丝率分别比对照品种菁松×皓月高3.42%、0.46 kg和3.52个百分点,是一对经济性状优良的春用多丝量雄蚕品种。     

几个家蚕性连锁平衡致死系与限性斑纹母本的配合力测定

以限性斑纹品系Y7、JS、MC为母本,性连锁平衡致死系sd2、px2、YH4、8、12和YH18为父本,采用不完全双列杂交法测试分析家蚕性连锁平衡致死系的配合力。结果表明,不同家蚕性连锁平衡致死系的配合力不同,同一家蚕性连锁平衡致死系不同性状间的配合力也存在一定的差异。其中:性连锁平衡致死系18的万蚕产茧量和万蚕茧层量的一般配合力效应值最高,分别为2.83和3.07;雄蚕杂交组合Y7×YH18的万蚕产茧量的特殊配合力效应值最高(为4.32),Y7×YH8的万蚕茧层量的特殊配合力效应值最大(为5.08);而MC×sd2在万蚕产茧量和万蚕茧层量方面的配合力总效应值均为最高(分别为9.92和8.96)。以配合力效应值为选择依据,筛选出产茧量和茧层量预期较高的雄蚕杂交组合MC×sd2,实验室饲养结果表明,该组合的综合性状优良,茧丝生产性能较好。     

春用多丝量雄蚕品种“鲁菁×华阳”的育成

以家蚕平衡致死系平76为受体亲本,以丝质优良的普通蚕品种皓月为基因供体材料,采用杂交、自交和回交三步改良家蚕性连锁平衡致死系的方法,育成了经济性状优良的性连锁平衡致死系华阳;以限性皮斑蚕品种857为母本,以茧丝质优良、茧层率高、配合力优的蚕品种菁松为父本,转育成限性皮斑蚕品种鲁菁。两者组配成雄蚕杂交组合鲁菁×华阳,其雄蚕率达到98%以上,茧层率、万蚕茧层量和鲜茧出丝率分别比对照品种菁松×皓月高3.42%、0.46 kg和3.52个百分点,是一对经济性状优良的春用多丝量雄蚕品种。     

家蚕性连锁平衡致死系的杂交改良方法

家蚕性连锁平衡致死系是专养雄蚕品种的关键亲本材料,为了全面改良其实用经济性状,初步建立了一种杂交改良家蚕性连锁平衡致死系的方法。该方法先将常规品种的雄性与平衡致死系的雌性连续回交,育成一个在性染色体W上带有易位的+l1基因的中间材料,然后再用此材料的雌性与平衡致死系雄性杂交,并连续自交,同时结合致死基因表型差异进行选择,育成新的平衡致死系品种。采用该方法改良育成的平衡致死系品种平60和普通品种华菁的一代杂交种,雄蚕率达99%以上,茧丝质量和生命力性状均达到了现行普通品种的雄蚕群体水平。     

蚕业科技的发展动向

1 .分子生物学基础理论研究丝蛋白分子结构与丝蛋白基因表达调控机制的进一步阐明 ,将为增产蚕丝、改进丝质提供分子生物学理论基础。2 .分子连锁图与家蚕基因工程研究高密度的分子连锁图可使数量性状基因座 (ＱＴＬ)精确定位 ,分子标记可提高桑蚕常规育种的选择效率 ,反向遗传学的发展将会促进基因工程技术应用于桑蚕品种改良。3.性别控制与专养雄蚕性连锁平衡致死基因的应用已有很大进展 ,专养雄蚕将成为 2 1世纪提高桑蚕产丝能力和改善丝工艺性状的重大突破口。4.发育生理与昆虫激素在蚕业上的应用蜕皮激素、保幼激素以及保幼激素类似物…     

雄蚕蚕种繁育技术研究

利用家蚕性连锁平衡致死系基因控制家蚕性别达到专养雄蚕的目的,有着十分诱人的前景.几十年来业内人士进行了广泛的研究,并取得了卓有成效的业绩,其中以俄罗斯斯特隆尼科夫研究最为成功.     

Immunohistochemical localization of S-100 protein in the pig pituitary gland

Immunohistochemical localization of S-100 protein was studied in anterior, intermediate and posterior lobe of the pig pituitary gland. Two immunopositive cells for S-100 protein were identified: the folliculo-stellate cells (FSc) in the glandular lobes and the pituicytes in the neural lobe. In the anterior lobe, immunoreactive folliculo-stellate cells were scattered among secretory cells. In the area where the secretory cells form strands and follicle-like groups the positive cells were concentrated in groups. In the intermediate lobe, S-100 protein-positive cells were located sparsely among secretory cells and next to secretory follicles and the pituitary cleft. These FSc were more voluminous and displayed fewer cytoplasmic processes. In the neurohypophysis, positive reaction for S-100 protein was seen in the pituicytes. These cells were distributed singly or concentrated in groups. The distribution, and morphologic characteristics of the FSc in the glandular lobes and the pituicytes in the neural lobe in the pig indicate different origin of both S-100 protein-positive cells.     

Cerebrospinal fluid S-100B concentrations in normal and diseased cattle

We measured the concentrations of S-100B, a marker protein used in humans to detect brain damage, in the cerebrospinal fluid (CSF) of clinically normal cattle (n=15, mean age +/- SD: 31.8 +/- 37.5 months) and of cattle with various inflammatory disorders (n=43, 70.6 +/- 31.9 months). The mean +/- SD CSF S-100B level was 2.9 +/- 1.6 ng/ml in the normal group and 7.0 +/- 7.4 ng/ml in the diseased group. Thirteen diseased cattle that had developed no obvious neurological signs showed abnormally high S-100B concentrations (> 8.0 ng/ml), whereas the two cattle with neurological disorders did not. No particular disease could be related to the S-100B rise. Therefore, it remains inconclusive whether measurement of CSF S-100B concentration is useful in veterinary neurological diagnosis.     

烯效唑对水稻秧苗抵御不同类型低温胁迫能力的影响

为明确烯效唑对水稻秧苗抵御不同类型低温胁迫能力的影响,本试验以D优527和Ⅱ优162为材料,采用不同浓度的烯效唑浸种,研究了不同类型低温胁迫对秧苗受害率及部分抗寒生理指标的影响.结果表明,低温胁迫使秧苗受害率和电解质外渗率、可溶性糖、游离脯氨酸和丙二醛含量增加,叶片叶绿素相对含量即SPAD(soil andplant arialyzer development)值、根活力及呼吸速率下降.以秧苗萌发后第15天受连续4 d的低温胁迫的影响较大,其次为第20天受连续6 d和第7天受连续2 d的低温胁迫.烯效唑能提高秧苗抗寒性,最佳浸种浓度为40mg/L.低温胁迫下与不浸种比较,烯效唑浸种降低了丙二醛、电解质外渗率的增加幅度和叶片SPAD值、根活力及呼吸速率的下降幅度;同时提高了可溶性糖及游离脯氨酸增加幅度,从而增强了秧苗抗寒性.不同品种的抗寒能力不同,Ⅱ优162的抗寒性明显优于D优527.     

Examination of the 16S-23S rRNA intergenic spacer sequences of 'Candidatus Mycoplasma haemobos' and Mycoplasma haemofelis

The intergenic spacer region between the 16S and 23S rRNA genes of mycoplasmas has been used for a genetic marker for identification of the species. Here we show the intergenic spacer regions of two hemotropic mycoplasmas, Mycoplasma haemofelis and 'Candidatus Mycoplasma haemobos (synonym: 'C. M. haemobovis')' are also useful for classification of this particular group of mycoplasms. The spacer region of M. haemofelis and `C. M. haemobos' consisted of 209 and 210 base pairs, respectively, and both lacked the spacer tRNA genes. Phylogenetic analysis suggested a monophyletic relationship among hemoplasmas and M. fastidiosum. A hypothetical secondary structure predicted in the spacer regions tentatively assigned the boxA and boxB motifs peculiar to the members of the genus Mycoplasma. M. haemofelis and 'C. M. haemobos' possessed a stem-loop structure in common, despite the presence of a palindromic nucleotide substitution in the stem region.     

Identification and differentiation of canine Mycoplasma isolates by 16S-23S rDNA PCR-RFLP

Conventional serological methods for the identification of canine mycoplasma isolates depend on the availability of a panel of species-specific diagnostic antisera and are not always reliable in terms of specificity. To enable simultaneous identification of field isolates, PCR-RFLP analysis of the 16S-23S rRNA intergenic spacer region was used to characterize the type strains of the 12 currently described canine mycoplasmas of the Genus Mycoplasma which represent the "classic" non-hemotropic species. The use of 16S-23S rDNA PCR in the first step of this analysis revealed specific size differences of amplicons which allowed to classify these 12 canine Mycoplasma species into three groups. Depending on the length of the amplicon, subsequent RFLP analysis of PCR products using two restriction endonucleases in a single digest (ApoI/DdeI or TaqI/VspI) generated unique banding patterns. For further evaluation of the 16S-23S rDNA PCR-RFLP assay system as identification and differentiation tool, a total of 262 field isolates collected from the canine genital tract were tested. PCR-RFLP results for 251 field isolates correlated with traditional serological test results. The remaining 11 isolates had an RFLP pattern distinct from the type strains included in this study and were identified by 16S rDNA sequencing as closely related to M. sp. HRC689. The PCR-RFLP assay established in this study enabled a rapid, accurate and easily performed identification and differentiation of all 12 currently described non-hemotropic canine Mycoplasma species.     

Differential localization of immunoreactive alpha- and beta-subunits of S-100 protein in feline testis

This study investigates the differential localization of the alpha-subunit (S100-alpha) and the beta-subunit (S100-beta) of the S-100 protein in the feline testis, using immunohistochemistry with polyclonal antibodies to bovine S-100 protein (S-100) and monoclonal antibodies to bovine S100-alpha and S100-beta. Appreciable differences were observed in the cellular localization of the immunoreactivity of each subunit. S-100 was observed in the Sertoli cells, the epithelial cells of the transitional segment of the seminiferous tubules, Leydig cells and the peritubular cells of the seminiferous tubules, but was not observed in the epithelial cells of straight tubules and the rete testis or in the endothelial cells of blood and lymph vessels. S100-alpha immunoreactivity was localized in Sertoli cells, peritubular cells and the epithelial cells of the terminal segment of the tubules, whereas S100-beta immunoreactivity was localized in Leydig cells. The differential localization of the alpha- and beta-subunits of the S-100 protein in the feline testis suggests that this protein is multifunctional and be useful as an investigative tool in studying feline testis function.     

A comparative study on S-100 protein-immunoreactive cells in lymph nodes

S-100 protein-immunoreactive cells of the lymph node were examined in the duck and 9 mammalian species, such as guinea pigs, dogs, cats, horses, pigs, goats, cows, Japanese serows and crab-eating monkeys. S-100 protein was detected in follicular dendritic cells (FDC) and tangible-body macrophages (TBM), sinus and parenchymal macrophage (MP), sinus endothelial cells (SEC) and interdigitating reticulum-like cells (IRC) in the node of mammalian species, but not in the duck except nervous elements. S-100-positive FDC and TBM were detected in germinal centers of the nodes in all mammalian species, but immunoreactivity of the other 3 cell types varied according to animal species and individuals of the same species. S-100 alpha subunit was detected in FDC, with the exception of those of the duck and guinea pig. The subunit was also detected in SEC of the dog, cow and Japanese serow. In the guinea pig, a unique S-100 alpha-positive giant dendritic cell (GDC) was found in the subsinusal cortical area. In addition, S-100 immunoreactive lymphocytes were observed in the paracortex-equivalent area of pig nodes. Arterial endothelial cells of the pig and cow were immunoreactive to S-100 beta subunit.