Evolutionary genetics: how flies get naked

Researchers studying evolution of 'naked' (hairless) larval cuticle in Drosophila sechellia have discovered surprising complexity in the pattern of cis-regulatory differences that differentiate this species from its 'hairy' ancestors.     

Assessing minimum viable population size: Demography meets population genetics

The discussion of a population's minimum viable size provides a focus for the study of ecological and genetic factors that influence the persistence of a threatened population. There are many causes of extinction and the fate of a specific population cannot generally be predicted. This uncertainty has been dealt with in two ways: through stochastic demographic models to determine how to minimize extinction probabilities; and through population genetic theory to determine how best to maintain genetic variation, in the belief that the ability to evolve helps buffer a population against the unknown. Recent work suggests that these two very different approaches lead to very similar conclusions, at least under panmictic conditions. However, defining the ideal spatial distribution for an endangered species remains an important challenge.     

When reverse genetics meets physiology: the use of site-specific recombinases in mice

The use of site-specific recombinases enables the precise introduction of defined genetic mutations into the mouse genome. In theory, any deletion, point mutation, inversion or translocation can be modeled in mice. Because gene targeting is controlled both spatially and temporally, the function of a given gene can be studied in the desired cell types and at a specific time point. This 'genetic dissection' allows to define gene function in development, physiology or behavior. In this review, we focus on the technical possibilities of Cre and other site-specific recombinases but also discuss their limitations.     

The mouse: genetics meets behaviour

Genetic studies in the mouse are important in the elucidation of molecular pathways that underlie behaviour. The advantages of the mouse for behavioural studies include an extensive array of genetic technologies and an elaborate behavioural repertoire that can be used to create models of human disease. This review discusses the relative advantages of forward and reverse genetic approaches to studying the genetic basis of behaviour in the mouse, and the complexities that behavioural studies need to address, such as phenotypic variability, genetic background effects and pleiotropy.     

Population genetics meets behavioral ecology

Populations are often composed of more than just randomly mating subpopulations - many organisms from social groups with distinct patterns of mating and dispersal. Such patterns have recieved much attention in behavioral ecology, yet theories of population genetics rarely take social structures into account. Consequently, population geneticists often report high levels of apparent in breeding and concomitantly low efective sizes, even for species that avoid mating between close kin. Recently, a view of gene dynamics has been introduced that takes dispersal and social structure into account. Accounting for social structure in population genetics leads to a different perspective on how genetic variation is partitoned and the rate at which genic diversity is lost in natural populations - a view that is more consistent with observed behaviors for the minimization of inbreeding.     

Plant transposable elements: where genetics meets genomics

Transposable elements are the single largest component of the genetic material of most eukaryotes. The recent availability of large quantities of genomic sequence has led to a shift from the genetic characterization of single elements to genome-wide analysis of enormous transposable-element populations. Nowhere is this shift more evident than in plants, in which transposable elements were first discovered and where they are still actively reshaping genomes.     

Nature meets nurture: molecular genetics of gastric cancer

The immensity of genes and molecules implicated in gastric carcinogenesis is overwhelming and the relevant importance of some of these molecules is too often unclear. This review serves to bring us up-to-date with the latest findings as well as to look at the larger picture in terms of how to tackle the problem of solving this multi-piece puzzle. In this review, the environmental nurturing of intestinal cancer is discussed, beginning with epidemiology (known causative factors for inducing molecular change), an update of H. pylori research, including the role of inflammation and stem cells in premalignant lesions. The role of E-cadherin in the nature (genotype) of diffuse gastric cancer is highlighted, and finally the ever growing discipline of SNP analysis (including IL1B) is discussed.     

Body-size regulation: combining genetics and physiology

New research has revealed that the activity of the insulin-signaling pathway in the prothoracic gland of Drosophila modulates ecdysone release and thereby influences both the duration and rate of larval growth.     

How geneticists can help reporters to get their story right

Many geneticists are disgruntled with the coverage of genetics in the mass media, yet geneticists themselves have a part to play in improving that coverage. This article aims to help geneticists to do so by explaining the forces that shape science news. It provides some specific options for reducing hype, countering genetic determinism and preventing the use of genetics to reinforce discriminatory messages, slants that many reporters are inclined to give to their articles.     

Parent-offspring conflict and co-adaptation: behavioural ecology meets quantitative genetics

The evolution of the complex and dynamic behavioural interactions between caring parents and their dependent offspring is a major area of research in behavioural ecology and quantitative genetics. While behavioural ecologists examine the evolution of interactions between parents and offspring in the light of parent-offspring conflict and its resolution, quantitative geneticists explore the evolution of such interactions in the light of parent-offspring co-adaptation due to combined effects of parental and offspring behaviours on fitness. To date, there is little interaction or integration between these two fields. Here, we first review the merits and limitations of each of these two approaches and show that they provide important complementary insights into the evolution of strategies for offspring begging and parental resource provisioning. We then outline how central ideas from behavioural ecology and quantitative genetics can be combined within a framework based on the concept of behavioural reaction norms, which provides a common basis for behavioural ecologists and quantitative geneticists to study the evolution of parent-offspring interactions. Finally, we discuss how the behavioural reaction norm approach can be used to advance our understanding of parent-offspring conflict by combining information about the genetic basis of traits from quantitative genetics with key insights regarding the adaptive function and dynamic nature of parental and offspring behaviours from behavioural ecology.     

Proteoglycans and pattern formation: sugar biochemistry meets developmental genetics

While it has been long appreciated that sugar-modified proteins coat the cell surface, their functions are poorly understood. Here, I describe recent genetic studies that demonstrate that one class of sugar-modified proteins, cell-surface proteoglycans, play crucial roles in morphogenesis, growth regulation and tumor suppression. Mutations that affect individual proteoglycans or the enzymes required for glycosaminoglycan synthesis regulate Wingless and Decapentaplegic signaling in Drosophila, and body size in mice and humans. Compromising proteoglycan function is also associated with the development of Wilm's tumors and hereditary multiple exostoses. In this review, these biological findings are placed in the context of proteoglycan biochemistry and molecular function.     

Sclerotome development and morphogenesis: when experimental embryology meets genetics

The vertebra develops from the ventral part of the somite, the sclerotome. Sclerotome progenitors are subject to multiple signaling molecules secreted by the adjacent tissues that control their fate. The aim of this article is to discuss the mechanisms of sclerotome induction, chondrogenesis and morphogenesis. By integrating the results from classical studies and recent molecular advances, this will illustrate how the powerful combination of experimental embryology and genetic approaches has recently illuminated the multiple steps of vertebra formation.     

Plant physiology meets phytopathology: plant primary metabolism and plant-pathogen interactions

Phytopathogen infection leads to changes in secondary metabolism based on the induction of defence programmes as well as to changes in primary metabolism which affect growth and development of the plant. Therefore, pathogen attack causes crop yield losses even in interactions which do not end up with disease or death of the plant. While the regulation of defence responses has been intensively studied for decades, less is known about the effects of pathogen infection on primary metabolism. Recently, interest in this research area has been growing, and aspects of photosynthesis, assimilate partitioning, and source-sink regulation in different types of plant-pathogen interactions have been investigated. Similarly, phytopathological studies take into consideration the physiological status of the infected tissues to elucidate the fine-tuned infection mechanisms. The aim of this review is to give a summary of recent advances in the mutual interrelation between primary metabolism and pathogen infection, as well as to indicate current developments in non-invasive techniques and important strategies of combining modern molecular and physiological techniques with phytopathology for future investigations.