Stabile production of a thrombin resistant pro-urokinase derivative (PRO-UKS1) by Namalwa KJM-1 cells adapted to serum-free medium

Pro-UKS1 was designed as a thrombin-resistant derivative of pro-urokinase (pro-UK) by introducing a glycosylation site using site-directed mutagenesis. An expression plasmid for pro-UKS1, pMo1UKS1SEd1-5, was constructed and introduced into Namalwa KJM-1 cells (Hosoiet al., 1988), and cells resistant to G418 and Methotrexate (MTX) were obtained. Amongst them, the highest pro-UKS1 producer (resistant to 500 nM of MTX), clone 41-8, was selected and further characterized. Clone 41-8 was cultured in serum-free ITPSGF medium (Hosoiet al., 1988). Under the conventional conditions, the concentration of pro-UKS1 reached 26 g ml^–1. Addition of glucose and tri-iodothyronine (T₃) improved productivity, and the maximal productivity of pro-UKS1 was 67 g ml^–1 day^–1. In this conditioned medium, content of pro-UKS1 was above 80% of total proteins.Abbreviations BSA bovine serum albumin - dhfr dihydrofolate reductase - HEPES 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid - kb kilobase pairs - kDa kilodaltons - MTX Methotrexate - PBS phosphate buffered saline - pro-UK pro-urokinase - SDS-PAGE sodium dodecyl sulfate-polyacrylamide gel electrophoresis - T₃ tri-iodothyronine - Tween-PBS phosphate buffered saline containing 0.05% Tween 80     

陕南地区油橄榄生长发育与生态条件关系的研究

根据定位观测和实地调查资料研究了油橄榄在陕南地区的生长发育和环境条件的关系,油橄榄树的枝条日高生长量为昼夜生长类型。夜间生长高于昼间的１２１％－１６０％;６、７、８、９月的生长量占全年生长量的７６％。油橄榄树的年生长量和产量状况与土壤含水量和土壤质地性质有密切关系;油橄榄树为阳性树种,在增加光照的环境条件下生长和结实良好,反之较差。     

Parthenogenetic development of bovine oocytes treated with ethanol and cytochalasin B after in vitro maturation.

The present study was conducted to investigate the effects of different culture durations (24-36 hr) on bovine oocyte maturation in vitro and the effect of the presence or absence of cumulus cells at the time of treatment to induce parthenogenetic activation (exposure to ethanol and cytochalasin B; CB) (experiment I). The effects of dosage (2.5 or 5.0 micrograms/ml) and incubation time (2.5, 5, or 10 hr) in CB (experiment II) on the subsequent development to the blastocyst stage in vitro was also investigated. In experiment I, cleavage and development to the blastocyst stage were not affected by the presence or absence of cumulus cells at the time of parthenogenetic activation. However, the 24-hr culture duration for in vitro maturation had a significantly lower rate of development to the blastocyst stage than the longer culture durations (27-36 hr). In experiment II, treatment with 5 micrograms/ml CB for 5 hr showed the highest percentage of development to blastocyst in the oocytes matured for both 27 and 30 hr. To determine the viability of the parthenogenetic embryos (morulae and blastocysts), four recipient heifers received two embryos each, and one heifer was found to be pregnant on day 35 following transfer. Although fetal heartbeat was not observed, the subsequent estrus was prolonged in all heifers. The present results demonstrate development of in vitro-matured, parthenogenetically activated bovine embryos up to the preimplantation stage.     

Ecological release in feeding behaviour: the case of bluegills in Japan

The stomach contents were analyzed monthly for each year-class to elucidate the foraging pattern of bluegills in a small vegetated lake by the frequency occurrence and the points methods. Seasonal dietary changes of the year-classes were considered comparing the monthly fluctuations in abundance of major prey organisms. Though these bluegills are dietary generalists and opportunists like those in North America, their foraging pattern was characterized by a relatively clearer dietary shift during ontogeny and a wider food niche including piscivorous than those of bluegills with congeners in their home land. Therefore this finding provides evidence of the ecological release caused by the absence of congeners.     

Root biomass fraction as a function of growth degree days in wheat

Root, underground and above-ground biomass were measured on various wheat cultivars from 1986 to 1988 in the south-east of France. The results are expressed as root: total (f _r) or underground: total (f _u) biomass fractions. Observed f _r and f _u values are in good agreement with previous results. f _r and f _u decrease steadily from emergence to maturity, with an exponential tendency. When using cumulative growth degree days since emergence relative to cumulative growth degree days until ear emergence () as time scale, f _r and f _u can be expressed as simple functions of % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGceaqabeaacaWGMb% addaWgaaqaaiaadkhaaeqaamaabmaabaGccqaH4oqCdaahaaWcbeqa% aiaacQcaaaaamiaawIcacaGLPaaakiabg2da9iaaicdacaGGUaGaaG% imaiaaiwdacqGHRaWkcaaIWaGaaiOlaiaaiwdacaaI4aGaamyzamaa% CaaaleqabaGaeyOeI0IaaGymaiaac6cacaaI0aGaaGioaiabeI7aXn% aaCaaameqabaGaaiOkaaaaaaaakeaacaWGMbaddaWgaaqaaiaadwha% aeqaamaabmaabaGccqaH4oqCdaahaaWcbeqaaiaacQcaaaaamiaawI% cacaGLPaaakiabg2da9iaaicdacaGGUaGaaGymaiaaikdacqGHRaWk% caaIWaGaaiOlaiaaiIdacaaI4aGaamyzamaaCaaaleqabaGaeyOeI0% IaaGOmaiaac6cacaaIYaGaaGioaiabeI7aXnaaCaaameqabaGaaiOk% aaaaaaaaaaa!610D!\[\begin{gathered} f_r \left( {\theta ^* } \right) = 0.05 + 0.58e^{ - 1.48\theta ^* } \hfill \\ f_u \left( {\theta ^* } \right) = 0.12 + 0.88e^{ - 2.28\theta ^* } \hfill \\ \end{gathered} \]The incremental root biomass partitioning coefficient, % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqySde2aaS% baaSqaaiaadkhaaeqaaOGaeyypa0JaaiikaiaadsgacaWGxbWaaSba% aSqaaiaadkhaaeqaaOGaai4laiaadsgacaWG0bGaaiykaiaac+caca% GGOaGaamizaiaadEfadaWgaaWcbaGaamiDaaqabaGccaGGVaGaamiz% aiaadshacaGGPaaaaa!4834!\[\alpha _r = (dW_r /dt)/(dW_t /dt)\], which describes the net increase in root biomass dW _r over time dt relative to the increase in total biomass (dW _r) over the same time period, has been derived from f and the relative growth rate. Its time course is accurately represented by% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqySdegdda% WgaaqaaiaadkhaaeqaamaabmaabaGccqaH4oqCdaahaaWcbeqaaiaa% cQcaaaaamiaawIcacaGLPaaakiabg2da9iabgkHiTiaaicdacaGGUa% GaaGymaiaaiwdacqGHRaWkcaaIWaGaaiOlaiaaiAdacaaIZaGaamyz% amaaCaaaleqabaGaeyOeI0IaaGimaiaac6cacaaI5aGaaGioaiabeI% 7aXnaaCaaameqabaGaaiOkaaaaaaaaaa!4D15!\[\alpha _r \left( {\theta ^* } \right) = - 0.15 + 0.63e^{ - 0.98\theta ^* } \]Under our experimental conditions, with no severe water stresses or nutrient deficiencies, and for our sampling frequency, around 2 weeks, the development scale , is the main factor governing the time courses of f _r, f _u and _r.     

A study of factors affecting anther culture of cauliflower (Brassica oleracea var. botrytis)

Experiments on three autumn-heading cauliflower genotypes (2 hybrids and a genotype selected from a population) were conducted to study different factors affecting anther culture. Culture conditions of the donor plants proved to be important: the best results were obtained during spring in a greenhouse where the temperature was maintained between 10 and 20°C. Overall winter and spring seemed more suitable than summer and early autumn for culture establishment. The optimal bud development stage depended on the genotype: for the hybrid 702, the greatest number of embryos for 100 plated anthers was obtained at the uninucleate pollen stage of the microspores; for V23.2 and 703, the optimal stage of the buds corresponded to the first mitotic division. Sucrose proved to be the best carbon supply for embryogenesis with an optimal concentration of 140 g l^-1. The addition of a cytokinin (BAP) in the medium led to lower embryo production, and this negative effect increased when the hormone concentration in the medium increased. The use of liquid medium and a dark incubation period immediately after the high temperature treatment were favourable for embryogenesis.     

Pathogenic fungal dynamics in a fall population of the blackmargined aphid (Monellia caryella)

A fall population of the blackmargined aphid, Monellia caryella (Fitch) (Homoptera: Aphididae), was monitored daily for mortality caused by fungi and parasitoids. Three species of Entomophthorales fungi were found. Fungal-induced mortality was found to be correlated with minimum temperature. During the period when the minimum temperature was consistently above 8°C, fungal-induced mortality was positively correlated with the sum of hours of leaf-wetness on days 5, 6, and 7 before sampling. Parasitoid wasps killed fewer hosts than fungi and were not affected by environmental factors.

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Résumé La mortalité quotidienne provoquée par des parasitoïdes et des champignons sur une population automnale de M. caryella Fitch (Homopt. Aphididae) a été suivie à Byron (Géorgie, USA), avec enregistrement de la température, de la pluie et de l'humidité des feuilles. 3 espèces de champignons entomophthorales ont été trouvées: Neozygites sp., Entomophthora planchoniana et Erynia sp. 54% des pucerons morts étaient contaminés par Neozygites et 46% par E. planchoniana. Seuls 2 pucerons avaient été tués par Erynia sp. Les taux de mortalité quotidienne par champignons s'élevaient après les périodes pluvieuses et d'humidité des feuilles. La mortalité due au parasitisme était inférieure à la mortalité due aux champignons et ne semblait pas liée aux conditions écologiques. La discussion porte sur l'importance de la mortalité provoquée par les champignons sur la dynamique de la population de pucerons.

     

Tissue specific variation of C-glycosylflavone patterns in oat leaves as influenced by the environment

A comparison is made between the flavone patterns accumulating in epidermal tissues and in the mesophyll of oat primary leaves grown in a phytotron and under field conditions. In developing leaves cultivated under standard conditions, varying patterns of two vitexin-derived O-rhamnosides and of one isovitexin O-arabinoside are produced in the basal region as the result of basal meristem activity. These patterns are tissue specific and differ quantitatively in the epidermis and the mesophyll. During the course of subsequent growth and differentiation, this pattern is constant as the compounds are moved upwards due to basipetal leaf growth. In comparison, the flavone patterns generated in the basal section of leaves grown in the field do not vary significantly. There is the additional accumulation of isoorientin O-arabinoside. Again flavone patterns are tissue specific, but in contrast to standard growth they are modified characteristically in those leaf tissues which are already morphologically differentiated. It is possible that the isovitexin moiety of the O-arabinoside is oxidized to the corresponding isoorientin derivative in the mesophyll. Moreover, field-grown leaves show a two-fold increase in flavone content in each leaf epidermis and a six-fold increase in the mesophyll when compared to the corresponding tissues of phytotron-grown leaves.     

Population ecology of a Stratiotes aloides l. stand in a riverside lagoon in N. Sweden

A stand of Stratiotes aloides L. in a riverside lagoon, Abborravan on the Vindelälven river in N Sweden, was studied for 3 years (1975–1977). The stand was vegetative, at all times submerged and therefore never flowering. On average each plant produced 3 adventitious roots and 40 leaves. One or two turions were also produced each year, together with stolons and associated offsets. At the beginning of June 1977 the population density was 42 plants/m² and the biomass was 290 kg/ha (dry wt. basis). At the end of September that year the respective values were 90/m² and 756 kg/ha. The dry wt./fresh wt. ratio of the biomass changed little during that period, from 6.4 to 6.5%. These and other results are compared with the respective data for Stratiotes stands in Central European lakes. In Abborravan Stratiotes seems well-adapted to survive the prevailing, hard, winter conditions. Freezing in situ is quite normal and is only lethal if the overwintering basal rosettes become frozen solid. The turions are quite frost-hardy.     

Can soil Chytridiomycota survive and grow in different osmotic potentials?

Twenty isolates from soil in the orders Spizellomycetales, Blastocladiales and Chytridiales (Chytridiomycota) grew on complex solid media supplemented with 10 g l⁻¹ sodium chloride. In a synthetic liquid medium, 4.4 g l⁻¹ sodium chloride strongly inhibited growth in three of the five isolates, possibly because of the effect of the ions or osmolarity of the solution. The maximum concentration for growth in synthetic liquid medium with different osmotic potentials using polyethylene glycol (PEG) varied considerably amongst the isolates. Three patterns of growth with increasing concentrations of PEG were evident among isolates within the genus Rhizophydium. Up to the concentration where growth ceased, the dry weight of each isolate either decreased, remained constant, or in one case, increased. Most of the fungi survived when incubated at room temperature for 7 d in complex liquid media supplemented with 35 g l⁻¹ sodium chloride or 300 g l⁻¹ PEG. These data indicate that soil Chytridiomycota can survive various osmotic potentials that may occur during the wetting and drying phases in soils.