Comparative genome and proteome analysis of Anopheles gambiae and Drosophila melanogaster

Comparison of the genomes and proteomes of the two diptera Anopheles gambiae and Drosophila melanogaster, which diverged about 250 million years ago, reveals considerable similarities. However, numerous differences are also observed; some of these must reflect the selection and subsequent adaptation associated with different ecologies and life strategies. Almost half of the genes in both genomes are interpreted as orthologs and show an average sequence identity of about 56%, which is slightly lower than that observed between the orthologs of the pufferfish and human (diverged about 450 million years ago). This indicates that these two insects diverged considerably faster than vertebrates. Aligned sequences reveal that orthologous genes have retained only half of their intron/exon structure, indicating that intron gains or losses have occurred at a rate of about one per gene per 125 million years. Chromosomal arms exhibit significant remnants of homology between the two species, although only 34% of the genes colocalize in small "microsyntenic" clusters, and major interarm transfers as well as intra-arm shuffling of gene order are detected.     

Breeding and post-breeding responses of woodland birds to modification of habitat structure by deer

Birds in woodland can be affected by increasing deer populations through changes to vegetation structure and potential impacts on foraging resources; these effects need to be better understood. Effects of deer browsing are reported from a replicated split-plot exclusion experiment in English coppiced woodland. All stages of growth were examined up to eight years after felling. We used standardised mist-netting (totaling 1920 h) to sample birds in breeding and post-breeding periods. Deer browsing strongly altered vegetation structure by reducing canopy cover and shrub layer foliage density. However deer did not affect invertebrate density per unit of foliage, providing no evidence of an ungulate-mediated plant chemical response affecting forage quality for invertebrate herbivores. At avian guild level, significantly more ground and understorey foraging birds were captured where deer were excluded, and negative responses to browsing were more marked for pooled migrants than pooled residents. At the species level, especially pronounced negative effects were evident for dunnock (Prunella modularis) and garden warbler (Sylvia borin); approximately five times more dunnocks were captured in deer exclosures than in browsed vegetation. We also detected negative responses to browsing by nightingale (Luscinia megarhynchos) and long-tailed tit (Aegithalos caudatus). No significant positive responses to browsing were detected. For some species the use of young re-growth increased post breeding relative to the breeding period, including a marked shift by pooled residents that involved a disproportionate number of juveniles. Previous studies in North America have shown that, through vegetation modification, ungulate activity can alter woodland bird assemblages; as far as we are aware this is the first experimental demonstration of effects in Europe, and at low to moderate browsing intensity typical of the wider landscape scale.     

H3N2亚型犬流感病毒HA1基因的原核表达及抗原性分析

为原核表达H3N2亚型犬流感病毒(CIV)HA1蛋白,本研究利用特异性引物扩增CIV H3分离株的HA1基因,将其克隆到pMD18-T载体后进行序列测定。再将其亚克隆于pET-32a(+)中构建重组表达质粒pET-HA1。将该质粒转化于大肠杆菌BL21(DE3)中,经IPTG诱导,SDS-PAGE电泳分析,表达的重组蛋白约为58 ku。纯化的HA1蛋白经western blot和Dot-ELISA鉴定表明,表达的重组HA1蛋白可以与H3N2亚型CIV阳性血清发生特异性反应。     

Do summer temperatures trigger spring maturation in Pacific lamprey,Entosphenus tridentatus?

Abstract –  Pacific lamprey, Entosphenus tridentatus , return to streams and use somatic energy to fuel maturation. Body size decreases, the lamprey mature, spawn, and then die. We predicted that warm, summer temperatures (>20 °C) would accentuate shrinkage in body size, and expedite sexual maturation and subsequent death. We compared fish reared in the laboratory at diel fluctuating temperatures of 20–24 °C (mean = 21.8 °C) with fish reared at cooler temperatures (13.6 °C). The results confirmed our predictions. Lamprey from the warm water group showed significantly greater proportional decreases in body weight following the summer temperature treatments than fish from the cool water group. A greater proportion of warm water fish sexually matured (100%) and died (97%) the following spring than cool water fish (53% sexually mature, 61% died). Females tended to mature and die earlier than males, most obviously in the warm water group.     

Gross Morphometry of the Bovine Placentome during Gestation

Forty-seven pregnant uteri were collected from an abattoir at eight chronological stages of gestation. Assessments were made of placentome number, weight, length shape and ratio of foetal to maternal tissue by weight. The study showed that there was a great variation in number, size, weight and shape of placentomes. There was no significant change in the total number of placentomes during gestation. Both mean weight and length increased significantly during gestation, but there was a significant change in the relationship between the two as gestation progressed. There was no correlation between the number of placentomes and the mean weight or length of the placentomes. The development of the placenta in the non-pregnant horn was significantly different from that of the pregnant horn, with fewer, smaller, lighter placentomes. However, there was no evidence that placentome development in the non-pregnant horn was affected by placentome development in the pregnant horn. The proportion of the placentome that was maternal tissue increased during gestation, but there was no significant effect of placentome number, or individual placentome weight or length on this proportion. Two placentome shapes were identified, but no effect on foeto-maternal proportion or relationship between shape and total placentome number or weight was identified.     

An analysis of the effect of quality on prices of horticultural produce

This paper reports an analysis of price data for apples, tomatoes and bananas from three metropolitan markets in Australia. Weekly quantities, average prices and price differences for apples and tomatoes on the Brisbane market show large differences in prices at any particular time, irrespective of supplies and average price. Price data from the Sydney and Melbourne markets for Delicious apples and bananas, respectively are also examined for price level and variation for specific product lines.The attributes of quality in horticultural produce are described and classified as either sensory or objective. It is postulated that the reputation of a product line, and hence its average price, is influenced primarily by the composite of all attributes, particularly those sensory ones which are taste- and time-dependent. The price variation or bandwidth is controlled by a limited number of factors—appearance and colour, and, on the wholesale level, package weight. Objective quality attributes are of concern in the control of post-harvest deterioration and in nutritional matters.A framework for the analysis and price-quality relationships is proposed, based on the effects of supply and demand, reputation and price bandwidth of particular lines. This framework forms the basis for the prediction of prices of horticultural produce.