牛蛙蝌蚪的生长特性研究

试验对牛蛙(Rana catesbeiana Shaw)蝌蚪在不同生长发育变态时期的主要性状进行了测定,并对其比值间的差异进行了比较分析。结果表明,牛蛙蝌蚪在后肢长出前、后肢长出后到前肢长出前、前肢长出后这3个阶段,尾长/体长、消化道长/体长比值的差异显著,说明此为蝌蚪形态的剧变时期。牛蛙蝌蚪体长生长方程Lt=3.738[1-e-0.0948(t+1.2529)];体重生长方程Wt=123.65[1-e-0.9852(t+1.4058)]2.1819;体长与体重关系式W=0.074 2 L3.067。温度对牛蛙蝌蚪的生长发育有显著的影响,当温度在22℃以上时,蝌蚪才能完成变态发育,并以在30℃时的变态率最高。     

鲍幼虫变态分子机制的研究进展

综述了鲍幼虫变态及其分子机制的研究进展.鲍因其幼虫营卵黄营养,且同昆虫和蛙类相比,鲍幼虫变态速度快、存在提早发育（‘anticipatory’developmental program）现象,是研究贝类乃至海洋无脊椎动物变态现象的理想模式.早期研究采用药理学和电生理学方法发现了GABA等能够诱导鲍变态的物质,并且提出了变态过程信号通路,但调节幼虫变态的分子机制仍然所知甚少.研究人员采用差异显示PCR和基因芯片等手段获得了一些变态前后差异表达的基因.但是变态是由众多的基因和信号分子共同决定和影响的.传统获得差异基因的方法效率低、获得基因数量少、受公布的EST（表达序列标签）限制大,所以调控变态的分子网络和机制还尚未建立,缺乏对调控这一细胞过程的整体认识.转录组学分析获得大量变态差异基因,并且有助于建立差异基因相互作用网络,是研究变态分子机制的新方向.此外,变态差异基因的功能验证和注释是鲍变态分子机制研究的另一问题,基因干扰可能是解决方向之一.     

Silent hemoglobin alpha genes in apes: potential source of thalassemia

Small quantities of unusual hemoglobins were found in 1 of 37 chimpanzees and 2 of 6 gorillas. In each genus these hemoglobins contain unique alpha chains that differ from the ordinary by eight to nine scattered amino acid changes. The unusual chains arise from a hitherto undetected hemoglobin (3)alpha locus. No (3)alpha products are found in most apes; accordingly, (3)alpha is considered synthetically inactive in all but a few reversion mutants. Indirect evidence that the inactive (3)alpha locus is juxtaposed to an active alpha locus together with the supposition that (3)alpha exists in man provides a setting wherein thalassemia might be produced by nonhomologous recombination between two loci.     

Tadpole Antibodies against Frog Hemoglobin and Their Effect on Development

Rana catesbeiana tadpoles immunized with the main hemoglobin component of the adult frog of the same species produced precipitating and agglutinating antibodies against the immunogen. After natural metamorphosis, the immunized froglets have as their only major hemoglobin a protein immunologically and electrophoretically different from the major hemoglobin of control froglets.     

林蛙输卵管糖蛋白的纯化方法研究

林蛙输卵管糖蛋白是由输卵管上皮细胞分泌的一类高分子量的特异性蛋白质,对配子的成熟和运输、受精以及早期胚胎发育具有重要影响。长白山林蛙输卵管糖蛋白具有特殊药用价值和广泛的应用前景,目前对其提取和纯化工艺的研究也比较深入。简述输卵管糖蛋白的性质及生物学功能,着重论述分离纯化方法。     

Hemoglobin adaptation for fast and slow water habitats in sympatric catostomid fishes

The oxygen equilibria of Catostomus insignis hemoglobins are pH dependent. Catostomus clarkii hemoglobins have some components (20 percent) whose oxygen equilibria are independent of pH because the alpha chains have NH(2)-termini that are blocked and the beta chains lack the "usual" COOH-terminal histidine. Since the Bohr effect is normally a beneficial phenomenon, the maintenance of some hemoglobins without a Bohr effect must provide a physiological advantage that is habitat specific. The intrastream ecological preferences of these sympatric catostomids suggest that the hemoglobins without the Bohr effect confer an ecological advantage in a swift water habitat.     

林蛙皮多肽制备及其理化性质

从林蛙皮肤中提取的小分子多肽具有诸多生物活性。以鲜活林蛙为试验材料,剥离皮肤,采用酶解法提取小分子活性多肽,并研究其理化性质。结果表明:制备的林蛙皮多肽的紫外特征吸收峰位于220 nm处,280 nm附近吸收峰较小;分子量主要分布在190~1 000 u,并且在250~540 u的分布最多,占37.47%;该混合多肽具有多种生物活性因子,尤其是抗菌肽和凋亡调控蛋白;在不同p H值缓冲溶液中都具有良好的溶解性;抑菌试验表明其对大肠杆菌和金黄色葡萄球菌有不同程度的抑菌活性。证明制备的小分子混合多肽有望成为新的制剂原料。     

吉林省不同地区中国林蛙种质资源评定

采用方差分析及聚类分析法对吉林省16个县市的林蛙种质资源进行了评价.结果表明：16个县市的中国林蛙体质量、产油量和产油率存在极显著差异.体质量最大的是龙井,最小的是舒兰;产油量最多的是桦甸,最少的是靖宇;产油率最高的是吉林,最低的是靖宇.聚类分析结果显示：16个县市的林蛙种质资源可聚为4类,吉林、磐石、桦甸和集安聚为一类,和龙、珲春、图们、柳河、延吉、长白、舒兰、敦化、抚松、蛟河为一类,靖宇、龙井各成一类.     

Hemoglobin interaction: modification of solid phase composition in the sickling phenomenon

Direct analyses of solid phase formed by deoxygenating solutions of sickle-cell hemoglobin (Hb S) in the presence of certain other hemoglobin species show that hemoglobins A and C can participate in the filamentous fine structure characteristic of the sickling phenomenon. In contrast, fetal hemoglobin (Hb F) is nearly completely excluded.     

不同发育期的牛蛙蝌蚪消化道组织学观察

取不同发育期牛蛙蝌蚪通过解剖和切片观察可以看出，牛蛙蝌蚪消化道组织由不发达慢慢发育完全，表现为浆膜层逐渐明显，肌肉层由不成层平滑肌细胞逐渐发育成层、增厚；粘膜层、食道粘膜上皮由单层柱状上皮向复层扁平上皮演变，固有层在后期出现食道腺，胃肠道粘膜上皮为单层柱状上皮，各级消化道结构在变态时变化最大。     

Localized control of ligand binding in hemoglobin: effect of tertiary structure on picosecond geminate recombination

The picosecond geminate rebinding of molecular oxygen was monitored in a variety of different human, reptilian, and fish hemoglobins. The fast (100 to 200 picoseconds) component of the rebinding is highly sensitive to protein structure. Both proximal and distal perturbations of the heme affect this rebinding process. The rebinding yield for the fast process correlates with the frequency of the stretching motion of the iron-proximal histidine mode (VFe-His) observed in the transient Raman spectra of photodissociated ligated hemoglobins. The high-affinity R-state species exhibit the highest values for VFe-His and the highest yields for fast rebinding, whereas low affinity R-state species and T-state species exhibit lower values of VFe-His and correspondingly reduced yields for this geminate process. These findings link protein control of ligand binding with events at the heme.     

Ethylene Oxide for Sterilizing Diets

The filter paper strips used in V. L. Johnson and J. S. Dunlap "Electrophoretic separation of hemoglobins from the chicken" [Science 122, 1186 (1955)] should be listed as follows: S. and S. No. 2043 B.     

Histological Study on Reproductive Organ of Rana Temporaria Chensinesis David

The experiment was designed to study the histology of reproductive organ of Rana temporaria chensinesis David in reproductive season and dereproductive season, The results displayed that the sexual gland weight and oviduct weight of the Rana temporaria chensinesis David were significantly different between reproductive season and dereproductive season.     

ggr-Aminobutyric Acid, a Neurotransmitter, Induces Planktonic Abalone Larvae to Settle and Begin Metamorphosis

gamma-Aminobutyric acid (a simple amino acid and potent neurotransmitter in human brain and other tissues of higher animals) and certain of its congeners rapidly and synchronously induce planktonic larvae of the red abalone, Haliotis rufescens, to settle and commence behavioral and developmental metamorphosis. These naturally occurring inducers of algal origin apparently are responsible, in part, for the substrate-specific recruitment, induction of settling, and the onset of metamorphosis of abalone and other planktonic larvae upon specific algae which provide naturally favorable habitats for the young of these species in coastal waters. These observations provide a convenient experimental model for further analysis of the basic molecular mechanisms by which environmental and endogenous factors control the recruitment and development of planktonic larvae. Halogenated organic pesticides significantly interfere with larval settling, as quantified in a new bioassay based upon these findings.     

Hemoglobins S and C interfere with actin remodeling in Plasmodium falciparum-infected erythrocytes

The hemoglobins S and C protect carriers from severe Plasmodium falciparum malaria. Here, we found that these hemoglobinopathies affected the trafficking system that directs parasite-encoded proteins to the surface of infected erythrocytes. Cryoelectron tomography revealed that the parasite generated a host-derived actin cytoskeleton within the cytoplasm of wild-type red blood cells that connected the Maurer's clefts with the host cell membrane and to which transport vesicles were attached. The actin cytoskeleton and the Maurer's clefts were aberrant in erythrocytes containing hemoglobin S or C. Hemoglobin oxidation products, enriched in hemoglobin S and C erythrocytes, inhibited actin polymerization in vitro and may account for the protective role in malaria.     

林蛙嗜水气单胞菌气溶素基因的克隆及原核表达

以长白山林蛙中分离的嗜水气单胞菌为材料,对嗜水气单胞菌气溶素基因进行克隆、序列分析及基因表达等研究,为嗜水气单胞菌的分子生物学研究提供依据。通过实验成功克隆了气溶素基因,大小为1163bp,对其进行同源性检测,与基因库中DQ186611基因序列的同源性高达99%;构建原核表达重组质粒pGEX-Aer,在大肠杆菌BL21中获得表达,蛋白分子量约为69ku,以包涵体形式存在。     

Structure, antigenic determinants of some clinically important insect allergens: chironomid hemoglobins

Determination of the molecular structure and properties of allergens that elicit severe immediate-type hypersensitivity diseases in humans and a knowledge of the structure of their antibody-binding sites should provide new insight into the pathogenetic mechanisms of allergic diseases. Monomeric and homodimeric hemoglobins (CTT I to X) have been identified as potent allergenic components of Chironomidae, a family of Diptera. Immunologic investigations of peptides of three of these hemoglobins (CTT IV, CTT VI, and CTT VIII) showed that human antibodies of the E and G classes recognize at least two different sites within each molecule. Individual hemoglobin peptides were aligned with homologous regions of chironomid hemoglobin CTT III, whose tertiary structure has been determined by x-ray analysis at a resolution of 1.4 angstroms. The antigenic site CTT IV(91 to 101) showed the following characteristics: (i) seven polar or hydroxylated amino acids, from a total of eleven, occupying predominantly superficial regions; (ii) the property of linkage to other molecules by hydrogen bonds or solvent clusters; and (iii) high thermal mobility factors. In contrast, peptide CTT IV(102 to 108), which does not bind human antibodies, contained no polar amino acids and had low thermal mobility factors. These results support the idea that the antigenicity of clinically relevant proteins is related to regions with a predominance of polar amino acids and with low energy barriers between different conformations, which allow high flexibility, including site-specific adaptation in antibody binding.     

贵州黔东南3种野生棘蛙肌肉的氨基酸组成与含量

为了解贵州黔东南棘蛙的肌肉营养价值,采用常规氨基酸分析方法测定黔东南棘胸蛙、棘侧蛙和棘腹蛙3种野生棘蛙肌肉的氨基酸组成与含量,并以鸡蛋蛋白质为标准蛋白,以WHO/FAO氨基酸参考模式为标准对其进行氨基酸营养评价。结果表明:黔东南3种野生棘蛙肌肉的氨基酸组成一致,其中含有苏氨酸、缬氨酸、蛋氨酸、异亮氨酸、亮氨酸、苯丙氨酸和赖氨酸7种人体必需氨基酸,非必需氨基酸5种,天冬氨酸、谷氨酸、甘氨酸和丙氨酸4种鲜味氨基酸。棘胸蛙、棘腹蛙和棘侧蛙肌肉中氨基酸总量分别为84.19%、87.43%和86.12%。必需氨基酸含量占总氨基酸含量的比值分别为39.79%、40.07%和39.06%,在蛙科动物中均属于较高水平。3种棘蛙肌肉中,均以谷氨酸的含量最高,天冬氨酸的含量次之,蛋氨酸含量最低。氨基酸评分(AAS)和化学评分(CS)表明,棘蛙肌肉中第一限制性氨基酸为蛋氨酸,第二限制性氨基酸为缬氨酸。必需氨基酸指数(EAAI)显示,棘胸蛙为86.72、棘腹蛙为89.79、棘侧蛙为86.22。综合各项指标分析,贵州黔东南3种野生棘蛙具有较高的经济价值。     

Structural transitions upon ligand binding in a cooperative dimeric hemoglobin

Comparison of the 2.4 angstrom resolution crystal structures of dimeric clam hemoglobin in the deoxygenated and carbon-monoxide liganded states shows how radically different the structural basis for cooperative oxygen binding is from that operative in mammalian hemoglobins. Heme groups are in direct communication across a novel subunit interface formed by the E and F helices. The conformational changes at this interface that accompany ligand binding are more dramatic at a tertiary level but more subtle at a quaternary level than those in mammalian hemoglobins. These findings suggest a cooperative mechanism that links ligation at one subunit with potentiation of affinity at the second subunit.     

稳定小分子量RNA指纹图谱技术在根瘤菌分类研究中的发展和应用

综述了稳定小分子量RNA指纹图谱技术的原理和发展历程,并对该技术在根瘤菌分类研究中的应用现状和前景进行了阐述。稳定小分子量RNA指纹图谱包括5S rRNA和tRNA,该技术在微生物分类鉴定方面具有很大的潜力。