Independent evolution of song structure and note structure in American wood warblers

This study addresses the issue of how evolutionary convergence within shared environments shapes some features of bird song while leaving others unaffected, using as an example the songs of 51 North American wood warblers (Parulinae). I combined published information on breeding habitats and evolutionary relationships to show that the structure of warbler songs is correlated with habitat, whereas the structure of the notes that comprise the songs is relatively unaffected by habitat and more closely related to phylogenetic history. The results confirm known relationships between bird song and habitat, including correlations between song frequency and the type and density of canopy foliage, and between the number and arrangement of notes in the song and foliage density and moisture. More importantly, the results suggest that individual notes and whole songs are to some extent functionally independent, because the configuration of notes shows more evidence of evolutionary constraint than does the way notes are assembled into songs.     

转基因鱼构建模式的研究II.构建转基因鱼的几个影响因素(英文)

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Maternal effects on early juvenile traits inIris pumila (Iridaceae)

The variation in the maternal effects on a number of the earlyIris pumila seedling traits expressed under high and low light levels in a growthroom was studied. A reciprocal crossing design was used for the establishment of 20 full-sib families. Each family consisted of two maternal groups differing only in genotype used as a seed parent. Maternal variation was estimated from the variance between maternal groups within sibships. Two parameters for maternal variation were computed: the maternal effects coefficient m² and the coefficient of maternal variation CV_M. Maternal effects significantly accounted for the phenotypic variation in seed mass and most of the early seedling traits. Light conditions prevailing during the seedling development markedly influenced overall structure of maternal correlations. Implications of maternal correlations on the integration of juvenile phenotype have also been discussed.     

Benefits of a predtor-induced morphology in crucian carp

Crucian carp (Carassius carassius) develop a deeper body in response to chemical cues from piscivores. This change in body morphology has been suggested to be a predator-induced defence. Here we investigate the possible benefits of the induced body morphology in laboratory experiments. Pike foraging behaviour when feeding on crucian carp of different body depths was recorded using video. Further, in a preference experiment pike were allowed to choose between shallow-bodied and deep-bodied crucian carp of similar lengths. Crucian carp body morphology did not affect predatory behaviours (activity, searching, following, observing, capture success) in northern pike, but an increase in crucian carp body depth led to an increase in handling time in pike. In the preference experiment, pike preferred shallow-bodied crucian carp over deep-bodied. Thus, a change in body morphology, induced by the presence of piscivores, benefits crucian carp by increasing piscivore handling times and an avoidance of the deep-bodied phenotype.     

Internet-Based Integrated Environmental Assessment Using Ontologies to Share Computational Models

New advances in Internet technologies and computer modeling provide opportunities for collaborative systems to support research and development in the field of industrial ecology. In particular, new information technologies such as semantic search engines based on ontologies could help researchers to link fragments of knowledge generated at research centers from around the world. Using a storyline of four imaginary researchers who hope to find collaborators in order to develop their research findings, we illustrate two levels of a four-level architecture for an Internet-based knowledge integration and collaboration environment for integrated environmental assessment. The foundation of the proposed architecture is a belief that computational models are an effective medium for conveying expert knowledge of various phenomena. Drawing from this premise, the first level of the architecture stands on a base of computational models that in some way represent the expert knowledge of the model builder. At the second level, we provide markup and interface definition tools to describe the type of knowledge contained in each model, together with the types of information services that can be provided.
The results of research at these two levels of an Internet-based knowledge integration environment for integrated environmental assessment in industrial ecology are presented in this article. Our work on the third level of model searching and matching and the fourth level of parametric model integration and solving will be presented in subsequent articles.     

Applications of an optimized monocot expression vector in studying transient gene expression and stable transformation of barley

Protoplasts of a barley ( Hordeum vulgare L. cv. Golden Promise) suspension cell line were used for PEG-mediated gene transfer. Transient gene expression in barley protoplasts was studied using a chimeric CaMV 35S cat construct, which was only poorly expressed in barley cells. However, insertion of exon 1 and intron 1 of the maize Shrunken-1 (Sh1) gene in the 5'-untranslated leader of the construct strongly stimulated gene expression. By using the optimized chimeric cat construction the amount of CAT protein that was reached 19 hours after DNA uptake was 0.5% of total protein, which was calculated from western blot data.
As an alternative marker gene for expression studies, we also tested the firefly luciferase gene in barley protoplasts. Low level expression of chimeric CaMV 35S luciferase genes could be highly stimulated when Sh1 exon1 and intron1 were inserted in the 5'-untranslated leader of the constructs. Enhanced luciferase gene expression by Shrunken-1 intronic sequences enabled us to monitor gene integration events early after DNA uptake using a promoterless luciferase marker gene, which could only be expressed after integration behind an endogenous promoter.     

Kinetics of Efficient Recombinant Adeno-Associated Virus Transduction in Retinal Pigment Epithelial Cells

The aim of this study was to investigate the premise that retinal pigment epithelial (RPE) cells are more permissive to recombinant adeno-associated virus (rAAV) transduction than other cells. We investigated the kinetics and mechanisms of rAAV transduction in RPE cells and found that the transduction efficiencies of cultured RPE cells HRPE51 and ARPE19 were significantly higher than those of 293 (P < 0.008) and HeLa (P < 0.025) cells. In addition, RPE cells reached maximum transduction efficiency at a much lower m.o.i. (m.o.i. 10) than 293 cells (m.o.i. 25). Competition experiments using 1 microg/ml heparin inhibited the high level of transduction in RPE cells by 30%, but additional heparin failed to reduce rAAV transduction further. Southern hybridization of low-molecular-weight DNA from transduced RPE cells indicated that 42% of single-stranded rAAV DNA was translocated into the nucleus by 2 h postinfection. By 6 h postinfection, double-stranded rAAV DNA was observed, which coincided with the onset of transgene expression. Southern and fluorescence in situ hybridization of total genomic DNA indicated that long-term transgene expression in RPE cells was maintained by the integration of rAAV into the cellular chromosome. Together, these results suggest that the high permissiveness of RPE cells is not related to the presence of heparan sulfate receptors or nuclear trafficking but may be due to an enhanced rate of second-strand synthesis and that integration in RPE cells is responsible for long-term transgene expression.     

A plant transformation vector with a minimal T-DNA II. Irregular integration patterns of the T-DNA in the plant genome

A minimal T-DNA binary vector was used for Agrobacterium-mediated transfer of a chimeric T4 lysozyme gene located next to the left border, and transgenic potato plants which expressed T4 lysozyme protein were identified and further analysed. Frequent rearrangements of T4 lysozyme transgenes were detected. A vector derivative containing two matrix associated regions (MARs) flanking its multiple cloning site was constructed. In transgenic potato plants, reduced variability in gene expression due to position effects was detected. When either the donor vector contained MAR sequences, or when vector pPCV701 which contains a pBR322 fragment next to the left border were used, only relatively few rearrangements were observed. However, when the T4 lysozyme gene was driven by a CaMV 35S promoter modified by multiplied enhancer region carrying either 2 or 4 elements, frequent rearrangements were again obtained.     

Environmental,parental and adaptive variation in egg size of Tengmalm's owls under fluctuating food conditions

We studied egg size variation of Tengmalm's owls in western Finland during 1981–1990. The owls fed on voles whose population fluctuated in a predictable manner: low (1981, 1984, 1987, 1990), increase (1982, 1985, 1988) and peak (1983, 1986, 1986) phases of the cycle occurred every third year. Eggs were largest in the increase phase of the vole cycle, even though that voles were more abundant and egg-laying started earlier in the peak phase than in the increase phase. This suggests that owls invest mostly in egg size when vole abundance increases along with survival chances of offspring. Territory quality and female age had no effects on egg size, but egg size decreased with laying data in the increase phase of the vole cycle. Egg size was significantly positively related to the male age in the increase phase, but the opposite relationship was significant in the peak phase of the vole cycle. The partners of adult males also decreased their egg volume from the increase to the peak phase, whereas the partners of yearling males produced their largest eggs in the peak phase of the vole cycle. This suggests the importance of experience in prevailing food fluctuations. Possibly male Tengmalm's owls can adjust the intensity of courtship feeding not only in relation to the food abundance on their territories at the time of egg laying, but also to the survival prospects of their offspring. Phenotypic plasticity seems to play a substantial role, as the egg size repeatabilities of individual females and partners of individual males were low. Obviously, under cyclic food conditions, predictability and inter-generational trade-offs are important to life history traits.     

用聚合酶链反应检测T细胞白血病／淋巴瘤中HTLV－I前病毒DNA

用聚合酶链反应检测Ｔ细胞白血病／淋巴瘤中ＨＴＬＶ－Ｉ前病毒ＤＮＡ陈国敏,何士勤,王柠,张永利,曾毅（中国预防医学科学院病毒学研究所北京１０００５２）关键词聚合酶链反应（ＰＣＲ）,人Ｔ淋巴细胞病毒Ｉ型（ＨＴＬＶ－Ｉ）,前病毒,基因整合目前,国内对人Ｔ淋...