The Fate of [3H]Ecdysone in Three Species of Annelids

Summary

The metabolism of [³H]ecdysone was examined in 3 species of annelids: the bloodworm, Tubifex vulgaris (a freshwater oligochaete), the earthworm, Lumbricus terrestris (a terrestrial oligochaete) and the ragworm, Nereis divtrsicolor (a marine polychaete). One of these species, N. diversicolor, metabolised injected [³H]ecdysone into compounds which co-chromatographed on both reversed-phase and adsorption HPLC with authentic 20-hydroxyecdysone, 26-hydroxyecdysone and 20,26-dihydroxyecdysone, thus demonstrating the occurrence of 20-hydroxylation and 26-hydroxylation capability in the Annelida. Furthermore, [³H]ecdysonoic acid was also formed and excreted by N. diversicolor, suggesting that 26-oic acid formation is involved in ecdysteroid inactivation in this species. Other, as yet unidentified, radioactive metabolites were also excreted by N. diversicolor. Several metabolites of [³H]ecdysone were also detected in the other 2 species examined, T. vulgaris and L. terrestris.     

Locomotion and habitat utilization in free-rangingTarsius bancanus: A preliminary report

Four adultTarsius bancanus were followed for a total of over 120 hrs in Sepilok Forest Reserve, Sabah, using radiotracking techniques. Seven hundred and twenty-two records of locomotor and postural behaviour were gathered.Tarsius bancanus travels a mean of 1,800 m per night, over large (4.5 to 11.25 ha) ranges. They move at a mean height of 0.89 m, utilizing primarily vertical sapling trunks of diametre 2 to 4 cm. Lateral movement is carried out largely by leaping.Tarsius were found on the ground in 5.3% of cases, but movement on the ground is very largely restricted to short investigative movements by walking. Climbing is mostly related to foraging behaviour and characteristically occurs on relatively small supports.Tarsius bancanus' locomotion is similar to, but more specialized than that ofT. spectrum, Galago alleni, andGalago senegalensis, all of which have rather similar patterns of habitat utilization. We suggest that the energetic constraints of small body size together with the need to patrol large home ranges may have lead both toTarsius bancanus extreme degree of locomotor specialization and to its exclusive animalivory.     

Antarctic ecosystems in transition – life between stresses and opportunities

Important findings from the second decade of the 21st century on the impact of environmental change on biological processes in the Antarctic were synthesised by 26 international experts. Ten key messages emerged that have stakeholder-relevance and/or a high impact for the scientific community. They address (i) altered biogeochemical cycles, (ii) ocean acidification, (iii) climate change hotspots, (iv) unexpected dynamism in seabed-dwelling populations, (v) spatial range shifts, (vi) adaptation and thermal resilience, (vii) sea ice related biological fluctuations, (viii) pollution, (ix) endangered terrestrial endemism and (x) the discovery of unknown habitats. Most Antarctic biotas are exposed to multiple stresses and considered vulnerable to environmental change due to narrow tolerance ranges, rapid change, projected circumpolar impacts, low potential for timely genetic adaptation, and migration barriers. Important ecosystem functions, such as primary production and energy transfer between trophic levels, have already changed, and biodiversity patterns have shifted. A confidence assessment of the degree of ‘scientific understanding’ revealed an intermediate level for most of the more detailed sub-messages, indicating that process-oriented research has been successful in the past decade. Additional efforts are necessary, however, to achieve the level of robustness in scientific knowledge that is required to inform protection measures of the unique Antarctic terrestrial and marine ecosystems, and their contributions to global biodiversity and ecosystem services.     

Evolutionary Robotic Approaches in Primate Gait Analysis

Understanding how primates move is particularly challenging because many of the experimentation techniques that would normally be available are unsuitable for ethical and conservation reasons. We therefore need to develop techniques that can maximize the data available from minimally intrusive experimentation. One approach for achieving this is to use evolutionary robotic techniques to build a musculoskeletal simulation and generate movement patterns that optimize some global parameter such as economy or performance, or to match existing kinematic data. If the simulation has a sufficiently high biofidelity and can match experimentally measured performance criteria then we can use it to predict aspects of locomotor mechanics that would otherwise be impossible to measure. This approach is particularly valuable when studying fossil primates because it can be based entirely on morphology and can generate movements spontaneously. A major question in human evolution is the origin of bipedal running and the role of elastic energy storage. By using an evolutionary robotics model of humanoid running we can show that elastic storage is required for efficient, high-performance running. Elasticity allows both energy recovery to minimize total energy cost and also power amplification to allow high performance. The most important elastic energy store on the human hind limb is the Achilles tendon: a feature that is at best weakly expressed among the African great apes. By running simulations both with and without this structure we can demonstrate its importance, and we suggest that identification of the presence or otherwise of this tendon—perhaps by calcaneal morphology or Sharpey’s fibers—is essential for identifying when and where in the fossil record human style running originated.     

Future-proofing regulation for rapidly changing biotechnologies

Our understanding of DNA structure and how it interacts with the environment to give form and function at the organism level is growing at an unprecedented pace which shows no sign of slowing. These developments have already led to many new products and will continue to underpin as yet unpredicted future developments in biotechnology. However, this potential will not be realised unless the mechanisms for risk assessment, regulatory approval, product claims and labelling etc. are fit for purpose, have the confidence of all stakeholders and are sufficiently agile to support this rapidly changing field. The sectors that are making particular advances in biotechnological processes include agriculture, pharmaceuticals, food, chemical and human diagnostics and therapeutics. In many of these areas the research, investment and innovation pipeline is operating well as evidenced by the many marketed products. However, developments in plant breeding methods have posed particular challenges for regulators which in turn is stifling R&D and innovation, particularly in the EU. In rapidly moving areas of research and development, it is imperative that regulatory frameworks are future-proofed by design.

     

Interference with function of plasmatocytes of Heliothis virescens in vivo by calyx fluid of the parasitoid Campoletis sonorensis

Summary Immature stages of the ichneumonid parasitoid, Campoletis sonorensis, develop within the haemocoel of its noctuid host, Heliothis virescens. The host cannot encapsulate the parasitoid egg owing to the suppressive effect of the polydnavirus-laden calyx fluid injected by the female parasitoid during oviposition. We have examined the effects of injection of calyx fluid on the following haemocytic manifestations of the immune system of 5th-instar larvae of H. virescens: encapsulation, nodulation, phagocytosis, erythrocyte rosetting and coagulation. Of these phenomena, only those requiring the formation of a multicellular sheath of plasmatocytes were affected. In general, encapsulation was fully suppressed; all of the C. sonorensis eggs and most of the glass rods implanted as targets were devoid of attached haemocytes 3 days after implantation although a few of the latter were coated by a sparsely distributed layer of granulocytes. Plasmatocytes also appeared to be present in thicker depositions of haemocytes. In nodulation, only the second, encapsulation-like phase was inhibited. The resistant first stage, involving the entrapment of particles by haemocytes, only resulted in the formation of amorphous, disorganized nodules. Granulocyte-dependent aspects of the immune system (phagocytosis, rosetting and possibly coagulation and the first stage of encapsulation and nodulation) occurred normally. The data suggest that in 5th-instar hosts injection of calyx fluid acts specifically on plasmatocyte function.     

A transfer function approach to measuring cell inheritance

Background  

The inheritance of cellular material between parent and daughter cells during mitosis is highly influential in defining the properties of the cell and therefore the population lineage. This is of particular relevance when studying cell population evolution to assess the impact of a disease or the perturbation due to a drug treatment. The usual technique to investigate inheritance is to use time-lapse microscopy with an appropriate biological marker, however, this is time consuming and the number of inheritance events captured are too low to be statistically meaningful.     

Mediterranean v. continental small mammal communities and the environmental degradation of the Dinaric Alps

In order to test for the existence of distinct, regionally-based small mammal faunas, distributional patterns were examined in thirty one species of small mammals (insectivores and rodents) inhabiting the Dinaric Alps (western Balkans). The small mammal fauna was found to consist of three groups: a group of ‘generalist’ species that occurred throughout the study area, plus distinct coastal and continental small mammal assemblages. The continental small mammal assemblage is considerably more species-rich, whilst that of the coastal zone is largely restricted to generalists and species with geophilic or fossorial life-styles (many of which are also commensal with humans). The two assemblages appear to be associated with different vegetation types, and the transition between them lies on the coastal slopes of the Dinaric Alps at c. 700–900 m of altitude. We discuss possible determinants of assemblage composition and species richness, and particularly the possible role of prehistoric environmental degradation in the context of the reduced species-richness of the coastal zone.