羊狂蝇化蛹、羽化的生物学研究

本文揭示羊狂蝇羽化与环境因素的相关性,幼虫在土壤栖息定位,蛹态,蛹与幼虫大小的相关性,成蝇活动行为和寿命,雌雄蝇比率等生物学特性,为羊狂蝇应用研究提供具有指导意义的基础资料。     

大豆子叶内酸性磷酸酶活性的超微结构定位

开花后３５～５０ ｄ 期间和萌发早期（播种后４～８ ｄ）的大豆（Ｇｌｙｃｉｎｅｍ ａｘ Ｌ．）种子中,酸性磷酸酶主要分布在子叶细胞中的蛋白体内;在内质网内也检测到酸性磷酸酶活性。此外,在萌发早期的部分子叶细胞的质膜外侧及其细胞壁基质中可见密集的酸性磷酸酶活性;而且在近质膜的胞质中常见到一些富含磷酸铅沉淀的胞质小泡,似与质膜融合     

菠菜BADH单抗细胞株及其应用初探

用菠菜甜菜碱醛脱氢酶 ( BADH)免疫巴比西 ( BALB/c)小鼠 ,将其脾细胞与骨髓瘤细胞 SP2 /O-Ag1 4融合 ,在 1 92孔中 ,有约 1 4 %孔生长的杂交瘤细胞 ,用间接酶联免疫方法 ( ELISA)检测表现为阳性。选择其中 2 G3和 2 D10 细胞系 ,用有限稀释法进行克隆化培养 ,约 2 0 %克隆化细胞为强阳性。选择其中 2 G3- H3细胞株注射到 BALB/c小鼠腹腔中诱导腹水 ,腹水的单抗效价为 1∶ 1 0 3。应用 BADH单抗检查了大麦、水稻、高粱、小麦幼苗的叶片和根的粗提物 ,均呈阳性反应 ,表明 BADH除在光合组织中存在外 ,在非光合组织中也可能存在。讨论了非光合组织 BADH的意义     

Membrane receptors for estrogen,progesterone, and testosterone in the rat brain: Fantasy or reality

Summary 1. There are numerous circumstantial evidence supporting the concept that steroid hormones control cellular function by means other than the nuclear receptor steroid binding mechanism. It is the intent of this report to present evidence indicating that steroids bind to specific sites in neuronal membranes.2. Some of the criteria to define steroid membrane receptors using steroid-BSA conjugates that can be radioiodinated to desired specific activity have been fulfilled for each of the three sex steroids using crude synaptosomal membrane preparations (P2 fractions) from the CNS of female and male rats. Ligand binding for each of the three steroids indicate high-affinity and high-capacity sites with distinct brain selectivity and stereospecificity. For example, 17-E-6-[¹²⁵I]BSA binds hypothalamic P2 fractions (HYP-P2) with an estimatedK _d of about 3±0.7 nM (X ± SE;n=3), whereas the cerebellum P2 (CB-P2) fractions bind the ligand with aK _d of 34±7 nM and, aB _max of 3 and 42 pmol/mg protein, respectively. Estrogen and testosterone binding fit best a one-single site, while progesterone binding sites can be best represented by a two-binding site, one high-affinity (K _d=1–2 nM) and one low affinity (K _d=62 nM), in CB-P2 fractions from intact adult female rat brain. Kinetics studies for T-3-[¹²⁵I]BSA indicate that the estimatedK _d of 30±2 nM for the olfactory bulb P2 fractions (OB-P2) from male rats is in good agreement withK _d values computed from Scatchard-derived data using the LIGAND algorithm.3. 17-E-6-[¹²⁵I]BSA binding sites are stereospecific and appears to be present as early as 5 days of age in both the OB- and the CB-P2 fractions without changes during development. In contrast, P-6-[¹²⁵I]BSA binding sites are practically absent during days 5 and 12 and appear by day 22.4. Finally, membrane receptor molecules for estrogen and progesterone have been isolated and purified by affinity chromatography and characterized by PAGE and Western blot. Microsequencing of one of the membrane estrogen binding proteins indicates that the high-affinity site corresponds to the OSCP subunit of the proton ATP synthase.5. It remains to be determined if P and T also bind to this complex enzyme or if they bind to other subunits of the family of proton ATPases. Overall the data indicate that steroid hormones conjugated to BSA are important tools to study the reality of membrane steroid receptors.     

Trace elements in scalp hair of professional drivers and university teachers in Hong Kong

Hair samples of 23 male professional drivers and 20 male university teachers in Hong Kong were collected, and the concentrations of Al, Sb, As, Ca, Cu, Fe, Pb, Mg, Mn, Hg, K, Sr, S, V, and Zn were measured. Both of the target groups fell within the same age group of 35–45. The washing method of using detergent and powder was found to be comparable to that of using ether. Difference in the mean concentration of each detected element in the two groups was tested by the Student'st-test and the Wilcoxon rank-sums test. Hair concentrations of Al, Sb, Pb, Mg, Mn, and K in the «Driver Group» were significantly (p<0.05) higher than those in the “Teacher Group.” On the other hand, As and Hg were found to have a higher concentration in hair of teachers. Interpretation of the findings in terms of the environmental factor and the metabolic rate was attempted.     

Structure and analysis of phospholipase D gene from Ricinus communis L

Phospholipase D (PLD; EC 3.1.4.4) has been proposed to play a pivotal role in various cellular processes, but molecular understanding of this enzyme is rather limited. This report describes the nucleotide sequence, structure, and genomic organization of a PLD gene from castor bean (Ricinus communis L. cv. Hale). The PLD gene was isolated from a castor bean genomic library using the PLD cDNA as a hybridization probe. Sequence comparison with the PLD cDNA revealed that the PLD gene consisted of four exons and three introns, one of which interrupts the 5-untranslated region. Southern blot analysis indicated that the cloned PLD gene was present as a single-copy gene, and yet there were other PLD or PLD-related sequences in the castor bean genome.     

人胎盘滋养层细胞培养与体外hCG释放的研究

本研究的目的是了解细胞滋养层细胞和合胞体滋养层细胞体外分化和生物学特性。方法:采用酶消化和Percoll密度梯度离心法,对人足月胎盘细胞滋养层细胞进行分离、纯化和体外培养。采用放射免疫法(RIA)检测细胞培养上清液hCG含量的变化。结果:经分离和纯化的细胞滋养层细胞在体外培养中生长良好,通过细胞分裂和融合形成合胞体滋养层细胞,随着合胞体滋养层细胞的生长,细胞培养上清液中hCG含量显著升高。我们认为从胎盘中分离和纯化的细胞滋养层细胞在体外培养中可分化和融合形成合胞体滋养层细胞,体外hCG含量的增加与合胞体滋养层细胞生长有关。     

RFLP mapping of QTLs for yield and related characters in rice (Oryza sativa L.)

Quantitative triat loci (QTLs) for yield and related traits in rice were mapped based on RFLP maps from two indica/indica F₂ populations, Tesanai 2/CB and Waiyin 2/CB. In Tesanai 2/CB, 14 intervals carrying QTLs for eight traits were detected, including 3 for grain weight per plant (GWT), 2 for number of panicles per plant (NP), 2 for number of grains per panicle (NG), 1 for total number of spikelets per panicle (TNS), 1 for spikelet fertility (SF), 3 for 1000-grain weight (TGWT), 1 for spikelet density (SD), and 1 for number of first branches per main panicle. The 3 QTLs for GWT were located on chromosomes 1, 2, and 4, with 1 in each chromosome. The additive effect of the single locus ranged from 2.0 g to 9.1 g. A major gene (np4) for NP was detected on chromosome 4 within the interval of RG143–RG214, about 4cM for RG143, and this locus explained 26.1% of the observed phenotypic variance for NP. The paternal allele of this locus was responsible for reduced panicles per plant (3 panicles per plant). In another population, Waiyin 2/CB, 12 intervals containing QTLs for six of the above-mentioned traits were detected, including 3 for GWT, 2 for each of NP, TNS, TGWT and SD, 1 for SF. Three QTLs for GWT were located on chromosome 1, 4, and 5, respectively. The additive effect of the single locus for GWT ranged from 6.7 g to 8.8 g, while the dominance effect was 1.7–11.5 g. QTL mapping in two populations with a common male parent is compared and discussed.     

The LIM domain-containing Dbm1 GTPase-activating protein is required for normal cellular morphogenesis in Saccharomyces cerevisiae.

Normal cell growth in the yeast Saccharomyces cerevisiae involves the selection of genetically determined bud sites where most growth is localized. Previous studies have shown that BEM2, which encodes a GTPase-activating protein (GAP) that is specific for the Rho-type GTPase Rho1p in vitro, is required for proper bud site selection and bud emergence. We show here that DBM1, which encodes another putative Rho-type GAP with two tandemly arranged cysteine-rich LIM domains, also is needed for proper bud site selection, as haploid cells lacking Dbm1p bud predominantly in a bipolar, rather than the normal axial, manner. Furthermore, yeast cells lacking both Bem2p and Dbm1p are inviable. The nonaxial budding defect of dbm1 mutants can be rescued partially by overproduction of Bem3p and is exacerbated by its absence. Since Bem3p has previously been shown to function as a GAP for Cdc42p, and also less efficiently for Rho1p, our results suggest that Dbm1p, like Bem2p and Bem3p, may function in vivo as a GAP for Cdc42p and/or Rho1p. Both LIM domains of Dbm1p are essential for its normal function. Point mutations that alter single conserved cysteine residues within either LIM domain result in mutant forms of Dbm1p that can no longer function in bud site selection but instead are capable of rescuing the inviability of bem2 mutants at 35 degrees C.     

Characterization of universal small-subunit rRNA hybridization probes for quantitative molecular microbial ecology studies.

Universal oligonucleotide hybridization probes targeting the small-subunit rRNA are commonly used to quantify total microbial representation in environmental samples. Universal probes also serve to normalize results obtained with probes targeting specific phylogenetic groups of microorganisms. In this study, six universal probes were evaluated for stability of probe-target duplexes by using rRNA from nine organisms representing the three domains of Bacteria, Archaea, and Eucarya. Domain-specific variations in dissociation temperatures were observed for all probes. This could lead to a significant bias when these probes are used to quantify microbial populations in environmental samples. We suggest lowering the posthybridization wash stringency for two of the universal probes (S-*-Univ-1390-a-A-18 and S-*-Univ-1392-a-A-15) examined. These two probes were evaluated with traditional and modified hybridization conditions to characterize defined mixtures of rRNAs extracted from pure cultures and rRNA samples obtained from anaerobic digester samples. Probe S-*-Univ-1390-a-A-18 provided excellent estimations of domain-level community composition of these samples and is recommended for future use in microbial ecology studies.