Wild pedigrees: the way forward

Metrics derived from pedigrees are key to investigating several major issues in evolutionary biology, including the quantitative genetic architecture of traits, inbreeding depression, and the evolution of cooperation and inbreeding avoidance. There is merit in studying these issues in natural populations experiencing spatially and temporally variable environmental conditions, since these analyses may yield different results from laboratory studies and allow us to understand population responses to rapid environmental change. Partial pedigrees are now available for several natural populations which are the subject of long-term individual-based studies, and analyses using these pedigrees are leading to important insights. Accurate pedigree construction supported by molecular genetic data is now feasible across a wide range of taxa, and even where only imprecise pedigrees are available it is possible to estimate the consequences of imprecision for the questions of interest. In outbred diploid populations, the pedigree approach is superior to analyses based on marker-based pairwise estimators of coancestry.     

Green revolution: the way forward

The origin of agriculture led to the domestication of many plant species and to the exploitation of natural resources. It took almost 10,000 years for food grain production to reach 1 billion tons, in 1960, and only 40 years to reach 2 billion tons, in 2000. This unprecedented increase, which has been named the 'green revolution', resulted from the creation of genetically improved crop varieties, combined with the application of improved agronomic practices.     

Chemotaxis: signalling modules join hands at front and tail

Chemotaxis is the result of a refined interplay among various intracellular molecules that process spatial and temporal information. Here we present a modular scheme of the complex interactions between the front and the back of cells that allows them to navigate. First, at the front of the cell, activated Rho-type GTPases induce actin polymerization and pseudopod formation. Second, phosphatidylinositol-3,4,5-trisphosphate (PtdIns(3,4,5)P(3)) is produced in a patch at the leading edge, where it binds pleckstrin-homology-domain-containing proteins, which enhance actin polymerization and translocation of the pseudopod. Third, in Dictyostelium amoebae, a cyclic-GMP-signalling cascade has been identified that regulates myosin filament formation in the posterior of the cell, thereby inhibiting the formation of lateral pseudopodia that could misdirect the cell.     

Integrative biology--the way forward

Let me begin by thanking the editors for the opportunity tobe the guest editor of this themed issue on Integrative Biology.It is to their credit that they have recognised the importanceof these approaches and have been willing to set aside boththe December 2006 and this issue for what are closely related,emerging areas. Indeed, the distinction between IntegrativeBiology and Systems Biology (December's theme) is extremelysubtle. The latter concerns the development of computationaland mathematical models of the structure and behaviour of biologicalsystems with a view to reaching a quantitative understandingof them. The former has a greater emphasis on the process ofdeveloping such     

Lipids in exosomes: Current knowledge and the way forward

Lipids are essential components of exosomal membranes, and it is well-known that specific lipids are enriched in exosomes compared to their parent cells. In this review we discuss current knowledge about the lipid composition of exosomes. We compare published data for different lipid classes in exosomes, and what is known about their lipid species, i.e. lipid molecules with different fatty acyl groups. Moreover, we elaborate on the hypothesis about hand-shaking between the very-long-chain sphingolipids in the outer leaflet and PS 18:0/18:1 in the inner leaflet, and we propose this to be an important mechanism in membrane biology, not only for exosomes. The similarity between the lipid composition of exosomes, HIV particles, and detergent resistant membranes, used as lipid rafts models, is also discussed. Furthermore, we summarize knowledge about the role of specific lipids and lipid metabolizing enzymes on the formation and release of exosomes. Finally, the use of exosomal lipids as biomarkers and how the lipid composition of exosomes may be of importance for researchers aiming to use exosomes as drug delivery vehicles is discussed. In conclusion, we have summarized what is presently known about lipids in exosomes and identified issues that should be taken into consideration in future studies.     

Molluscan genomics: the road so far and the way forward

Hydrobiologia - Mollusca is the second most species-rich phylum within the metazoans, displaying critical economic, ecological and scientific importance. Yet, they are still largely...