不同碳源条件下草菇内切型纤维素酶基因（eg1）转录表达的分析

利用Northernblot方法分析了不同碳源条件下草菇切型纤维素酶基因(eg1)的表达.结果发现,在含有纤维素的液体培养基中生长10d,eg1在草菇菌丝中有高效表达;纤维二糖、α-乳糖、β-乳糖,也能诱导eg1的表达,但和纤维素相比,eg1的表达量相对较低,并且它们的诱导效应在加入这类糖12h后迅速减弱;槐糖和龙胆二糖的诱导作用非常弱.在天然稻草为基质的固体栽培料生长时,草菇eg1的表达和草菇菌丝生长与出菇相对应,在菌丝生长期(d8)可见eg1的表达,d12时菌丝已长满,表达减弱,在出菇及菇体的分化及增大期,eg1的表达量逐渐增强,在成熟期达到最高水平;表明在草菇菇体发育中需要更多碳源及能源的补充,eg1在这方面起着非常重要的作用.图4参14     

Disaster in the South Paciic: Impact of tropical cyclone "Nomu" on the Solomon Islands, May 1986

Tropical Cyclone "Namu" struck the Pacific nation of the Solomon Islands during 18-20th May 1986. It was sthe most serious natural disaster in the Solomons in lining memory. Nearly a third of the total population of 267,000 were diriven from their homes and 150 people were killed, with damage estimates beginning in AUD 25 million. It has been estimated by the Solomon Islands Ministry of Economic Planning that it will take seven years for the economy to recover. This paper discusses the major events of the disaster episode by employing the Powell and Rayner model of "disaster-time." Factors relating to current disaster Planning and management within the Solomon Islands are outlined. The paper also highlights assistance provided by Australla during the Post-impact sequence and illustrates the type of general disaster preparatory support which Australia provides to South pacific.     

Books Received

Publications Received

Books Received     

Adaptive superparasitism and patch time allocation in solitary parasitoids : the influence of pre-patch experience

Summary Dynamic optimal diet models predict that host selection decisions and patch time allocation are influenced by the resource value of the habitat. We tested these predictions using the solitary' parasitoid Leptopilina heterotoma. Assuming that travel times between patches, the quality of previously visited patches and parasitoid density affect the parasitoids' estimation of the resource value of the habitat, different treatments were given before introducing parasitoids singly to a patch containing 5 unparasitized and 15 parasitized hosts. The decision to superparasitize is only slightly influenced by the rate of patch encounter. The quality of the previously visited patch has a strong influence. When a poor patch has been visited on the previous day, more superparasitism is observed in the partly depleted patch than when a rich patch has been searched. More superparasitism is also observed when the parasitoids are kept with conspecifics before the experiment than when they are kept alone. Increasing patch residence times are observed as the quality of the previously presented patch decreases. Host selection decisions and patch time allocation are thus clearly influenced by the pre-patch experience of the parasitoid, as predicted by dynamic optimal diet models. This can also explain why females that have never oviposited in unparasitized hosts will superparasitize readily. Correspondence to: M.E. Visser     

Effects of temperature,nutritional factors and salinity on the uptake of L-methionine by the Sydney rock oyster Saccostrea commercialis

The effects of physiological and nutritional factors and of temperature on the uptake of L-methionine by Saccostrea commercialis were investigated on cultured rock oysters from Port Stephens, New South Wales, Australia, in 1983. Optimum conditions for L-methionine accumulation were 30°C, 18 h exposure and concentrations of other amino acids less than that of L-methionine. The uptake of L-glycine was inhibited by L-methionine in a reciprocal manner. There was no effect of salinity on the accumulation of L-methionine by acclimated oysters. During the latter investigations the range of osmoconformity was found to be 15 to 45 S. Oysters take 2 d to conform to new media osmolarities after salinity changes of 15. Amino acid supplements in oyster diets should be kept within the same order of magnitude to reduce inhibition of uptake.     

The use of the oyster Saccostrea glomerata as a biomonitor of trace metal contamination: intra-sample, local scale and temporal variability and its implications for biomonitoring

Cu, Cd, Zn, Pb and Se concentrations were measured in the bivalve mollusc Saccostrea glomerata(Iredale and Roughly) from two uncontaminated locations, Clyde River Estuary, Batemans Bay and Moona Moona Creek, Jervis Bay, to determine natural variability of metals associated with mass, gender, age, tissue type and site within location. Trace metals were also measured in the Clyde River Estuary over an 11 year period and in five other NSW estuaries (Hastings River, Hunter River, Georges River, Tillgerry Creek and Lake Pambula) over a 13-month period to determine temporal variability and if diploid and triploid oysters accumulate trace metals differently. There were few significant relationships between trace metal concentrations and mass and no significant differences in trace metal concentrations between female and male oysters. Younger oysters (1.3 years) had significantly higher copper concentrations and higher trace metal variability than mature oysters (3 years). Different tissues have different trace metal concentrations with muscle tissues having lower concentrations. Considerable inherent variability occurs in oyster cohorts. Analysing specific tissues did not reduce variability of trace metal concentrations. Comparison of trace metal concentrations at two sites within the Clyde Estuary showed a significant difference in zinc concentrations. Cu, Cd, Zn and Se concentrations were generally higher and less variable in triploids than diploids. Pb had a variable pattern of accumulation with no consistent elevation in diploids or triploids. Inter annual variability of trace metal concentrations was considerable and trace metal concentrations also fluctuated throughout an annual cycle with no clear seasonal trends. Measurement of trace metals at known contaminated locations showed that Saccostrea glomerata accumulates metals in response to contamination. Saccostrea glomerata meet most of the requirements to be a biomonitor of trace metal contamination as they are abundant, sessile/sedentary, easy to identify, provide sufficient tissue for analysis, and accumulate trace metals in response to contamination. However, as trace metal concentrations can vary with mass, age, estuary position, ploidy type and temporally, care must be taken to collect individual organisms of similar mass, age and ploidy type to minimise variability, and from similar consistent positions and times to allow for seasonal changes in environmental conditions. Trace metal concentration variability is higher in young animals, thus to reduce variability, older mature animals could be selected. However, with immature oysters there are no complications because of the effects of spawning i.e. sudden loss of trace metals or body mass.     

不同碳源条件下草菇内切型纤维素酶基因(egl)转录表达的分析

利用Northern blot方法分析了不同碳源条件下草菇內切型纤维素酶基因(eg1)的表达.结果发现,在含有纤维素的液体培养基中生长10 d,eg1在草菇菌丝中有高效表达;纤维二糖、α-乳糖、β-乳糖,也能诱导eg1的表达,但和纤维素相比,eg1的表达量相对较低,并且它们的诱导效应在加入这类糖12 h后迅速减弱;槐糖和龙胆二糖的诱导作用非常弱.在天然稻草为基质的固体栽培料生长时,草菇eg1的表达和草菇菌丝生长与出菇相对应,在菌丝生长期(d 8)可见eg1的表达,d 12时菌丝已长满,表达减弱,在出菇及菇体的分化及增大期,eg1的表达量逐渐增强,在成熟期达到最高水平;表明在草菇菇体发育中需要更多碳源及能源的补充,eg1在这方面起着非常重要的作用. 图4 参14