Effect of genetic background on growth of mice hemizygous for wild-type or dwarf mutated bovine growth hormone transgenes

The effects of a high-growth genetic background on the growth of mice hemizygous for one of two growth hormone transgenes were examined. Male mice hemizygous for wild-type (W) and dwarf mutant (M) bovine growth hormone (bGH) transgenes were crossed with females of a high-growth selected (S) and control (C) line as follows: W x S, W x C, M x S and M x C. Body weights of progeny were recorded weekly from 2 to 10 weeks of age. F₁ progeny were classified as carriers (P) or non-carriers (N) of the transgene by assaying tail DNA for bGH using the polymerase chain reaction and agarose gel electrophoresis. A deficiency in the number of f₁ progeny carrying the W (P<0.05) and M (P<0.01) bGH transgene was most likely due to differential prenatal and early postnatal mortality. Bodyweight means of wild-type transgenic mice were larger (P < 0.05) than those of non-transgenic littermates by 3 weeks of age in a C background in contrast to 5 weeks in S. The wild-type bGH transgene increased adult body weights more in the C (155%) than in the S (136%) background, indicating transgene expression by selection background interaction (P < 0.05). However, the growth response to the wild-type transgene in the S background was still large. The dwarf mutant transgene had a greater effect on growth reduction in the S (70%) than in the C (84%) background, thus causing transgene expression by selection background interaction (P < 0.05). Gender by wild-type transgene effect interactions (P < 0.001) for adult body weight were caused by the transgene reducing the gender difference for body weight in C and eliminating it in S. The dwarf mutant caused a larger negative effect on growth in males than in females, resulting in a gender by dwarf mutant transgene interaction (P < 0.001) for adult body weights. Results indicate that the effect of a GH transgene on growth can be affected both by a high-growth genetic background and the gender of progeny.     

Measures of food quality as demographic predictors in freshwater copepods

This study examines the ability of a number of short-term measuresof algal food quality to predict longer term demographic parametersfor two species of freshwater calanoid copepods, Diaptomus minuiusand Epischura lacustris. Food quality of two species of algaethat are usually considered highly edible (Cryptomonas erosavar. reflexa and Chlamydomonas reinhardtii) are compared withrespect to: (i) the biochemical constituents of the algae (totalN, total C and protein); (ii) short-term foraging responsesby D.minutus to either algal species (e.g. clearance, ingestionand assimilation rates); (iii) longer term demographic responses(e.g. survivorship and reproduction) by both D.minutus and E.lacustrisfed a diet of either algal species. Demographic responses ofthe two copepod species indicate that C.erosa is a higher qualityfood. In fact, survival and reproduction of both copepod speciesfed C.reinhardtii were not different from starved treatments.Cryptomonas erosa treatments also had greater C, N and protein.However, D.minutus ingested five times more C.reinhardtii thanC.erosa, indicative of ‘compensatory feeding’ inthe presence of poor-quality food. Based upon these higher ingestionrates, individuals fed C.reinhardai actually ingested greateramounts of C, N and protein. Hence, ingestion rates taken aloneor coupled with biochemical parameters are not reliable predictorsof consumer demographic response. Assimilation rate, which waspositive for C.erosa and zero for C.reinhardtii, was the singlebest short-term predictor of food quality.     

Nucleotide sequence and style-specific expression of a novel proline-rich protein gene from Nicotiana alata

cDNA clones encoding a novel proline-rich protein (NaPRP4) have been isolated from a Nicotiana alata stylar cDNA library. The N-terminal part of the derived protein is highly rich in proline (32.2%) and contains several repeats such as Lys-Pro-Pro (7 times) and Pro-Thr-Lys-Pro-Pro-Thr-Tyr-Ser-Pro-Ser-Lys-Pro-Pro (twice); the C-terminal part, on the other hand, has a lower proline content (9.9%) and contains two potential N-glycosylation sites and all the six cysteine residues. Northern blot and in situ hybridisation analyses indicate that expression of the NaPRP4 gene is restricted to cells of the transmitting tract of the style.     

Fertile plants regenerated from suspension culture-derived protoplasts of an indica type rice (Oryza sativa L.)

Calluses were induced from immature embryos of an indica type rice and finely dispersed cell suspension cultures were initiated from the callus using modified AA medium (S₁ medium). The suspension cultures were maintained alternatively (1–2 passages in each medium) in S₁ medium and S₂ medium, the latter containing KNO₃, NH₄NO₃, proline and glutamine as nitrogen source. Protoplasts of high quality were isolated form suspension cells cultured in S₂ medium supplemented with ABA. Embedding the protoplasts in agarose blocks containing NH₄NO₃-free modified KM8P(PM₁) medium and immersing the blocks in NH₄NO₃-containing modified KM8P(PM₃) medium were most effective for obtaining protoplast division and callus formation. The protoplast-derived calluses were precultured in potato extract-aand/or ABA-containing N₆(D₁, D₂ or D₃) media and many embryo-like structures were formed. These structures developed into plantlets after being transferred to N₆ differentiation (D₄) medium. The regenerated plantlets grew into mature plants and beard seeds normally.Abbreviations AA medium amino acids based medium - ABA abscisic acid - BA benzyladenine - 2,4-D 2,4-dichlorophenoxyacetic acid - DF division frequency - IAA indoleacetic acid - KIN kinetin - NAA naphthaleneacetic acid - PE planting efficiency     

α-Domain of human metallothionein IA can bind to metals in transgenic tobacco plants

We have introduced a genetically marked Dissociation transposable element (Ds ^HPT ) into tomato (Lycopersicon esculentum) by Agrobacterium tumefaciens-mediated transformation. Probes for the flanking regions of the T-DNA and transposed Ds ^HPT elements were obtained with the inverse polymerase chain reaction (IPCR) technique and used in RFLP linkage analyses. The RFLP map location of 11 T-DNAs carrying Ds ^HPT was determined. The T-DNAs are distributed on 7 of the 12 tomato chromosomes. To explore the feasibility of gene tagging strategies in tomato using Ds ^HPT , we examined the genomic distribution of Ds ^HPT receptor sites relative to the location of two different, but very closely linked, T-DNA insertion sites. After crosses with plants expressing Ac transposase, the hygromycin phosphotransferase (HPT) marker on the Ds element and the excision markers β-glucuronidase (GUS) and Basta resistance (BAR) facilitated the identification of plants bearing germinally transposed Ds ^HPT elements. RFLP mapping of 21 transposed Ds ^HPT elements originating from the two different T-DNA insertions revealed distinct patterns of reintegration sites.     

微小根毛霉感染机理研究

本文在首次报告二例肺结核、糖尿病患者合并感染肺微小根毛霉的基础上,进一步探讨免疫功能受损与微小根毛霉感染关系。本文采用不同剂量~(60)Co-γ全身辐照小鼠,然后以不同途径注射同剂量的微小根毛霉的孢囊孢子,观察动物的感染情况和感染后的真菌检出率,结果发现各种辐射剂量均在辐射后7-14日感染菌的检出率最高;各种脏器感染菌的检出率以脾脏最高(66.7—81.8％);淋巴结最低(0.0—25.0％);其他脏器的感染菌检出率也有不同程度的差异。     

十字花科上的链格孢属真菌同工酶凝胶电泳分析

本文报道对从国内外收集到的生于十字花科植物上的3种链格孢属真菌21个菌株进行的10种同工酶的聚丙烯酰胺凝胶电泳分析结果。这10种酶分别是:酯酶(EST)、碱性磷酸酶(AKP)、酸性磷酸酶(ACP)、多酚氧化酶(PPO)、过氧化氢酶(CAT)、谷氨酸脱氢酶(GDH)、甘露醇脱氢酶(MADH)、乙醇脱氢酶(ADH)、黄嘌呤脱氢酶(XDH)、过氧化物岐化酶(SOD)。对同工酶酶谱资料的聚类分析,在较高的相似性水平上将21个菌株归为3大类群,每一类群所包括的菌株与形态学的鉴定结果完全一致,各菌株的归类关系与其寄主植物、地理来源无关。表明同工酶凝胶电泳在Alternaria种级分类中是一个有用的工具,可以明确地将不同菌株鉴定到种级水平。     

TWO NEW SPECIES OF STICK INSECTS FROM XIZANG AUTONOMOUS REGION (PHASMATODEA: PHASMATIDAE, HETEKONEMIIDAE)

Abstract  This paper deals with two new species of Phasmatodea from the Xizang Aut. Reg. belonging to Phasmatidae and Heteronemiidae. Their comparisons with close species and figures of characteristics are given.     

波形蛋白、核纤层蛋白与排核关系的研究

以网织红细胞与K_(582)细胞融合形成的胞质体杂种细胞K-RRneo为研究对象,对Vimentin、Lamin蛋白与K-RRneo细胞分化排核的关系进行了研究。结果表明:随着K-RRneo细胞的分化,Vimentin mRNA、Lamin蛋白表达明显降低,与我们整装电镜观察及Western印迹分析所得到的结论相一致,证实了薛社普提出的Vimentin、Lamin蛋白在红系细胞分化排核中所起的作用,为最终阐明红系细胞分化排核机制提供了新线索。     

籼,粳稻及其杂种粗线期的核型分析

研究了典型籼,粳稻及其杂种粗线期的核型,结果表明：（１）籼稻品种南特号具有两对随体染色体,分别为第十和第十二染色体,粳稻品种巴利拉具１对随体染色体,为第十染色体,杂种南特号／巴利拉的随体染色体与南特号相同;（２）在粗线期,两品种均可见单核仁和双核仁的细胞存在,说明细胞贩核仁数目与随体数目并不对应;（３）两品种的对应染色体之间,在染色体相对长度,臂比及染色粒分布上均无明显差异。