盖膜期间沙糖橘果实品质变化规律的研究

在果实成熟的1~3月,采样分析盖膜和不盖膜沙糖橘果实品质。结果表明:树冠盖膜后沙糖橘果皮色泽一直保持橘红色,而不盖膜的果皮色泽由前期的橘红色转为后期的橘黄色,且色泽暗淡;盖膜处理果实的酸含量在开始的20d内呈上升趋势,1月28日出现最高值0.31%,此后的10d内迅速下降至低于对照的水平,2月7日出现最低值,此后的20d内上升高于对照,之后又下降至3月15日的0.19%;对照果实的酸含量呈现明显的下降趋势,1月7日出现最高值为0.26%,3月15日出现最低值为0.08%,盖膜处理果实的酸含量在大多数时间内高于对照;盖膜处理果实的可溶性固形物含量从1月17日的12.33%提高到3月15日的13.40%,提高了1.07个百分点,总体呈上升趋势,而对照的从1月17日的10.70%下降至3月15日的9.90%,下降了0.80个百分点,总体呈下降趋势。     

Development of centrality indices of subcutaneous fat during growth

Changes of fat distribution were followed up in Czech and Slovak children from 1.5 to 15 years of age, using centrality indices, which relate the values of skinfolds on the trunk to the skinfolds on the extremities, head and neck. Up to 5 years of age, subcutaneous fat was deposited relatively more on the extremities, head and neck than on the trunk, which was expressed by lower values of the centrality indices. After the age of 5 years, the accumulation of subcutaneous fat was greater on the trunk, which was also expressed by higher values of the centrality indices. The comparison of the individual indices revealed in both genders a relatively higher amount of subcutaneous fat on the trunk in boys until 12 years of age. During puberty subcutaneous fat over triceps and on the forearm was reduced. In girls the deposition of the subcutaneous fat was relatively greater at different sites of the trunk than in boys, with the exception of the age of 14-15 years. The deposition of subcutaneous fat was greater on the trunk than on the head (cheek) and on the extremities in Czech compared to Slovak children, except for 12-year-old girls. During the period between the fifties and the seventies of the last century, in Czech children, especially in girls, the deposition of subcutaneous fat on the trunk was relatively smaller than on other parts of the body surface, which was expressed by the reduction of the centrality indices. Index 12 was therefore considered as the most valuable for the characterization of fat distribution on the body surface.     

Effect of growth conditions and storage on the specific activity of beta-lactamases of Bacteroides spp

The influences of growth conditions and cold storage on the specific activity of beta-lactamases of four strains of Bacteroides spp. was studied. Interbatch variation was observed in extracts prepared in an identical way on separate occasions but less variation was observed in extracts prepared from bacteria grown on Brain Heart Infusion agar supplemented with yeast extract, haemin and menadione, than in similar extracts of bacteria grown in broth or on other solid media. The loss of enzyme activity seen during the stationary phase of growth of some strains in broth was minimal during incubation for 48 h on agar. Storage of enzyme extracts at 4 degrees C was associated with loss of enzyme activity, but activity was retained during storage at -70 degrees C for up to 32 days. Freezing and thawing had little effect on enzyme activity.     

Pattern of growth of dominant follicles during the oestrous cycle of heifers

Ovarian follicular development was studied in 13 heifers by daily ultrasound examination during 2 complete and consecutive natural oestrous cycles. In 21 cycles (81%) 3 dominant follicles were identified, in 4 cycles (15%) 2 and in the remaining cycle 1 (4%). Consistently, the first dominant follicle was detected on average on Day 4, reached a maximum size on Day 6, went through a period of relative stability between Days 6 and 10, then began to decrease in size and was undetectable by Day 15. The second dominant follicle was detected by Day 12, reached maximum size on Day 16 (or 19 in the 4 cycles in which the 2nd dominant follicle was the ovulatory follicle) and was undetectable by Day 19. The 3rd (ovulatory) follicle was identified on average by Day 16 (range Days 10 to 19) and maximum size was reached on Day 21. The ovulatory follicles were larger (P less than 0.05) than the previous ones and the stage of the cycle at which maximum size was reached was significantly different for each dominant follicle (P less than 0.05). The analysis of the rates of growth and atresia suggest that the rate of growth is slowest during mid-cycle. The number of dominant follicles that developed in the ovary ipsilateral to the corpus luteum was greater (P less than 0.05) than in the contralateral ovary.     

Immunohistochemical localization of the transferrin receptor in the seminiferous epithelium of the rat

The transferrin receptor has been immunohistochemically localized in the seminiferous epithelium of the rat with a monoclonal antibody, MRC OX26, which recognizes the transferrin receptor glycoprotein. The receptor was detectable on mitotically and meiotically dividing germ cells and, less abundantly, on round spermatids. It was lost from germ cells during spermatid elongation and was undetectable on immature spermatozoa. The transferrin receptor was also present on Sertoli cells in the testes of immature animals and on Sertoli cells in the testes of aspermatogenic animals that had been irradiated in utero. It was not detectable on Sertoli cells in the testes of cryptorchid animals. These studies demonstrate that the transferrin receptor is abundant on dividing germ cells as well as dividing somatic cells.     

甘薯、胡萝卜发根单寄主培养体系繁殖马铃薯腐烂线虫的研究

利用发根农杆菌A4转化甘薯品种徐薯18和胡萝卜品种天红2号的发根,建立甘薯茎线虫病病原线虫(马铃薯腐烂线虫)的单寄主培养体系。通过该体系对马铃薯腐烂线虫的行为进行观察以及繁殖情况进行调查。结果表明:(1)马铃薯腐烂线虫在甘薯和胡萝卜发根上都能正常发育和繁殖,完成其生活周期;(2)培养4周和8周后,在甘薯发根上线虫繁殖倍数分别为2.6和50.6倍;在胡萝卜发根上线虫繁殖倍数分别为1.7和9.9倍;相同培养时间内,线虫在甘薯发根上的繁殖数极显著高于在胡萝卜发根上的繁殖数。(3)利用发根系统繁殖马铃薯腐烂线虫,便于研究其行为,在显微镜下可以直接观察到线虫在发根上活动情况,这对研究发根和线虫相互关系十分有利。基于上述结果,初步证实构建甘薯发根单寄主培养体系繁殖马铃薯腐烂线虫是可行的,且优于胡萝卜发根繁殖马铃薯腐烂线虫体系。     

Immunohistochemical analysis of the distribution of type VI collagen in the lingual mucosa of rats during the morphogenesis of filiform papillae

Iwasaki, S., Yoshizawa, H. and Aoyagi, H. 2012. Immunohistochemical analysis of the distribution of type VI collagen in the lingual mucosa of rats during the morphogenesis of filiform papillae. —Acta Zoologica (Stockholm) 93 : 80–87. We examined the distribution after immunostaining of immunofluorescence of type VI collagen, differential interference contrast (DIC) images, and images obtained using confocal laser‐scanning microscopy in transmission mode, after toluidine blue staining, during morphogenesis of the filiform papillae, keratinization of the lingual epithelium and myogenesis in the rat tongue on semi‐ultrathin sections of epoxy resin‐embedded samples. Immunoreactivity specific for type VI collagen was dispersed over a relatively wide range of connective tissue in the mesenchyme of fetuses on day 15 after conception (E15), at which time the lingual epithelium was composed of one or two layers of cuboidal cells and the lingual muscle was barely recognizable. Slight immunoreactivity specific for type VI collagen was scattered within the lamina propria in fetuses on E17 and on E19, and immunoreactivity was relatively distinct on the connective tissue around the lingual muscle during myogenesis. In fetuses on E19, the epithelium was already stratified squamous. At postnatal stages from P0 to P14, keratinization of the lingual epithelium advanced gradually as morphogenesis of the filiform papillae proceeded during postnatal development. In newborns on P0, myogenesis of the tongue was almost completed. The intensity of immunoreactivity specific for type VI collagen at postnatal stages was mainly restricted on the endomysium and perimysium around the lingual muscle, while scant immunoreactivity was evident in the connective tissue in the lamina propria. Immunoreactivity around the fully mature lingual muscle on P7 and P14 was weaker than that on E19 and P0. Thus, type VI collagen appeared in the connective tissue that surrounded the lingual muscles such as the endomysium and perimysium, in parallel with changes in extracellular components during myogenesis of the tongue.     

Effect of growth conditions and storage on the specific activity of β-lactamases of Bacteroides spp.

The influences of growth conditions and cold storage on the specific activity of β-lactamases of four strains of Bacteroides spp. was studied. Interbatch variation was observed in extracts prepared in an identical way on separate occasions but less variation was observed in extracts prepared from bacteria grown on Brain Heart Infusion agar supplemented with yeast extract, haemin and menadione, than in similar extracts of bacteria grown in broth or on other solid media. The loss of enzyme activity seen during the stationary phase of growth of some strains in broth was minimal during incubation for 48 h on agar. Storage of enzyme extracts at 4°C was associated with loss of enzyme activity, but activity was retained during storage at—70°C for up to 32 days. Freezing and thawing had little effect on enzyme activity.     

Localization of type II collagen in the lingual mucosa of rats during the morphogenesis of circumvallate papillae

Iwasaki, S., Aoyagi, H. and Yoshizawa, H. 2011. Localization of type II collagen in the lingual mucosa of rats during the morphogenesis of circumvallate papillae. —Acta Zoologica (Stockholm) 92 : 67–74. Immunoreactivity specific for type II collagen was recognized first in the mesenchymal connective tissue just beneath the circumvallate papilla placode in fetuses on E13. At this stage, most of the lingual epithelium was pseudostratified epithelium composed of one or two layers of cuboidal cells. However, the epithelium of the circumvallate papilla placode was composed of several layers of cuboidal cells. Immunoreactivity specific for type II collagen was detected mainly on the lamina propria just beneath the lingual epithelium of the rudiment of the circumvallate papilla in fetuses on E15 and on E17, and slight immunostaining was detected on the lamina propria around the rudiment. In fetuses on E19, immunoreactivity specific for type II collagen was widely and densely distributed on the connective tissue around the developing circumvallate papillae and on the connective tissue that surrounded the lingual muscle. Immunoreactivity specific for type II collagen was sparsely distributed on the lamina propria of central bulge. After birth, morphogenesis of the circumvallate papillae advanced gradually with the increase in size of the tongue. Immunoreactivity specific for type II collagen was distinctively distributed in the lamina propria around circumvallate papilla, in the central bulge, and in the connective tissue that surrounded the lingual muscle.     

Effects of exposure of pregnant rats to TRH on development of the pituitary-thyroid axis in their progeny

TRH (10 and 1000 micrograms/kg body weight (BW] was injected ip into pregnant rats daily from day 0 to 20 of pregnancy, and the pituitary-thyroid axis of their pups (Mat-TRH rats) was examined on days 0, 4, 10, 21 and 90 after birth. The pituitary TSH content of male Mat-TRH rats was significantly lower on day 4, and higher on day 10 than that of control rats. The serum TSH was significantly higher on day 10 (except female 10 micrograms/kg group). An exaggerated TSH response to exogenous TRH (10 micrograms/kg BW; ip) was observed on day 10 (males, 1000 micrograms/kg group). The serum T4 level of female Mat-TRH rats was low on day 4 (1000 micrograms/kg group), and higher on day 10. On days 21 and 90, the levels of pituitary TSH, serum TSH and T4 in Mat-TRH rats were similar to those in controls, but the TSH response to TRH was still exaggerated (1000 micrograms/kg group). No significant difference between control and TRH-treated mothers was seen on days 10 and 90 postpartum except for a decreased pituitary TSH content on day 10 in the 1000 micrograms/kg group. It is concluded that repeated administration of TRH to pregnant rats shows an effect on the pituitary-thyroid axis function of their progeny in later life.     

Autoradiographic study of the ontogeny of the imipramine receptors in the cerebral cortex of rats

Localization of 3H-imipramine binding sites in the cerebral cortex of rats was studied on the 19th day of prenatal development and on the 3d and 14th days of postnatal ontogenesis. Imipramine was injected into rats on days 17, 18 and 19 of gestation. The maximal imipramine receptor density was found in cortex layers IV-V. The therapeutic doses of imipramine provoked marked stimulation of the formation of imipramine receptors on the 3d day of postnatal development. However, on the 14th day the 3H-imipramine binding level was stabilized.     

Electron-cytochemical study of the localization of ATPase activity in the brain tissue of white rats]

A localization of ATPase activity in a rat's brain was studied by the lead method at the presence of Mg2+. The highest activity was noticed in the capillar basal layer, in nucleoli and nuclear chromatin. Less intensive sedimentation of precipitate was observed on the external nuclear membrane, granular cytoplasmic reticulum, ribosomes and in lipofuscin granules. Besides, the reaction product was observed on the cytomembrane of neurons, in synaptic slits and on the vesicles of some terminals. No ATPase activity was seen in mitochondria in the experimental conditions. Equal distribution of reaction product was seen in the cortex and hypothalamus.     

Transient increase of tryptophan fluorescence of enzyme caused by photoexcitation of ligand in luciferase-luciferin complex

An experiment was proposed and accomplished that was based on the hypothesis of the dissociation of the luciferase-luciferin complex in photoexcitation. A pump-probe experiment was performed with the use of picosecond laser pulses and was based on the effect of quenching of enzyme tryptophan fluorescence caused by luciferin binding. A photoinduced increase of the tryptophan fluorescence intensity was detected. Experimental results were interpreted on the basis of the assumptions on photoinduced dissociation of the luciferin-luciferase complex and Forster energy transfer from tryptophan to luciferin. Under the assumption on the photoinduced dissociation and stationary quenching of tryptophan fluorescence the rate of propagation of the conformational changes in the protein caused by the complex dissociation was estimated to be >20 m/s.     

藏红花瓣状体的诱导与花柱-柱头状物的定向分化

藏红花 (ＣｒｏｃｕｓｓａｔｉｖｕｓＬ .)又名番红花、西红花 ;藏药中称为苟日苟木。它是鸢尾科草本植物 ,原产于欧洲、地中海地区。我国长期以来把它作为珍贵的中藏药。其药用部位是柱头 ,有效成分主要是藏红花素、藏红花酸、藏红花醛和藏红花苦素。丁葆祖等于 1979年首次从藏红花的球茎获得完整的植株[1 ] 。Ｓａｎｏ等人 1987年在离体条件下 ,诱导花柱 柱头状物再生获得成功[2 ] ,此后国内外不断有相关报道[3～ 7] 。但试验大多集中在由外植体直接或由愈伤组织间接诱导柱头状物 ,且花柱 柱头状物的频率低和数量少。我们试图先由藏红花…     

寄主及寄主食物对雅脊金小蜂子代性比、体型和翅型的影响

通过三级营养关系的传递,研究不同寄主食物和寄主对雅脊金小蜂Theocolax elegans(Westwood)子代性比、体型和翅型的影响。结果表明:雅脊金小蜂寄生小麦粒中的玉米象Sitophilus zeamais(Motschulsky)或米象Sitophilus oryzae(L.)的子代蜂量均显著高于寄生玉米粒中的玉米象或米象的子代蜂量;寄生小麦粒中的米象与玉米象的蜂量之间差异不显著,雌雄性比之间也差异不显著。子代雌蜂个体的体长均显著长于雄蜂的体长;但在寄生玉米粒中的米象时,其子代雌蜂和雄蜂的个体大小是最小的。长翅型雅脊金小蜂在寄生小麦粒中的米象或玉米象时,其子代长翅型的个体数量显著多于寄生于玉米粒中的米象或玉米象的子代长翅型个体数量。因此,用小麦粒中的米象或玉米象来繁殖雅脊金小蜂较之用玉米粒中的玉米象或米象的繁殖效率更高。     

The spreading of monolayers of myosin

The spreading of the muscle proteins myosin and actomyosin depends both on the salt solution in which the proteins are dissolved and on the solution on which they are spread. The spreading is more complete the lower the concentration of the salt solution in which the proteins are dissolved and the higher the salt concentration of the solutions on which the proteins are spread. This effect seems to be due partially to the difference in density allowing the spread droplets a longer life on the surface, and partially to the effect of salt on the charge of the protein. A change in the pH of the substrate has a smaller effect than a change in the salt concentration. Heavy metals like Cu⁺⁺ or Zn⁺⁺, inhibit spreading almost completely. The dependence of spreading on these salts and on time was investigated in detail.The effect of the different salts was also compared with the effect of different phosphate compounds. It was noted that the above substances, including the different salts, phosphate compounds, and heavy metals, affect the mechanism of spreading but not films already spread. The viscosity of these fibrillar proteins was compared with other proteins in the monomolecular film state and in myosin an unusually high viscosity was found.     

饲养密度对黄粉虫幼虫生长发育的影响

黄粉虫原是一种仓库害虫 ,由于其幼虫、蛹、成虫都含有丰富的蛋白质和多种氨基酸 ,已被作为饲用资源昆虫来开发利用。作为一种群集性的昆虫 ,黄粉虫幼虫的生长受密度影响可分为 2个阶段 ,一是幼虫孵化后 1个月这段时间内 ,高密度处理的幼虫平均体重大于低密度处理的幼虫平均体重 ;二是孵化 1个月后直到化蛹 ,这段时间低密度的幼虫生长要比高密度的幼虫快得多。密度越大 ,历期越长。但密度对化蛹率没有影响。在幼虫生长过程中 ,各处理组中只有 3 2 0头虫密度处理组的幼虫在生长 1个月后显出拥挤效应。     

Predominant role of hydrocarbon solubilization in the microbial uptake of hydrocarbons

Using EDTA and proteolytic enzymes to suppress hydrocarbon solubilization, direct evidence is presented in support of the mechanism of liquid hydrocarbon uptake by microbial cells predominantly from the solubilized or accommodated substrate. EDTA (2-5mM) strongly inhibited growth of three yeast species and one bacterial species on n-hexadecane and the inhibition was removed by surfactant-emulsified and surfactant-solubilized alkane and also by excess addition of Ca(2+). EDTA had no inhibitory effect on the growth of the organisms on soluble substrates such as sodium acetate and nutrient broth or on n-pentane, a volatile alkane which was primarily transported by diffusion from gas phase. EDTA was shown to have no significant effect on the adsorption of cells on alkane drops. EDTA inhibition of growth was considered to be due to suppression of alkane solubilization, brought about by the solubilizing factor(s) produced by cells. It was shown that this chelating agent did not inhibit the growth of yeast on solubilized alkane but strongly inhibited its growth on alkane drops. It was demonstrated that adherent capacity of microbial cell to oil phase was closely related to the state of hydrocarbon emulsification and had no relationship to the ability of organisms to grow on hydrocarbon. Certain proteolytic enzymes inhibited the growth of yeast on alkane, presumably by digesting the alkane solubilizing protein, but not on glucose, and the inhibition was removed by a supply of surfactant-emulsified and surfactant-solubilized alkane. Specific solubilization of various hydrocarbon types during growth of the prokaryotic bacterial strain was demonstrated. The specific solubilization of hydrocarbon was strongly inhibited strain was demonstrated. The specific solubilization of hydrocarbon was strongly inhibited by EDTA, and the inhibition was removed by excess Ca(2+). It was concluded that specific solubilization of hydrocarbons is an important mechanism in the microbial uptake of hydrocarbons.     

Effect of culture density on the polyteny degree of giant chromosomes in inbred lines and hybrids of Drosophila melanogaster

The influence of culture density and genotype on the polyteny degree of giant chromosomes (PDC) in Drosophila melanogaster was investigated. The reliable depression of the polytene chromosomes endoreduplication function under increased culture density was revealed. The essential dependence of the PDC on the genotype was shown. Correlation between the PDC and the number of adaptive features was established. The certain parallelism between the increased heterosis effect on the number of quantitative characters and the superiority of the hybrids above the inbred lines on the PDC in conditions of high culture density was found out. The sex-dependent distinctions and maternal effect at the inheritance of the PDC in drosophila were shown.     

Effect of host-plant manipulation by a gall-inducing insect on abundance of herbivores on chestnut trees

We investigated plant-mediated effects of the stem gall wasp, Dryocosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae), on other herbivores on the chestnut tree Castanea crenata. In the early season, leaves emerged earlier and in greater numbers on galled shoots than on ungalled shoots. On galled shoots the leaf to shoot biomass ratio was lower and the leaves were physically different. In May and June the concentration of nitrogen in leaves was higher on galled shoots than on ungalled shoots. In July, the water content of leaves was lower on galled shoots. In May and June, the number of aphids, Myzocallis kuricola Matsumura (Homoptera: Aphidoidea), on leaves was higher on galled shoots than on ungalled shoots, but the opposite was true at the end of July. Laboratory experiments showed that aphid fecundity and body weight decrease were higher in May and June when aphids fed on leaves on a galled shoot than when they fed on those on ungalled shoots. In contrast, aphid performance in July was greater on ungalled leaves than on galled leaves. Our findings suggest that gall initiation in a chestnut tree affected aphid performance by affecting host plant quality.