Risk factors and genetic bases: the case of attention deficit hyperactivity disorder.

Attention deficit hyperactivity disorder (ADHD) is considered to be the most frequent mental disorder in childhood. Although its diagnosis in the most utilized handbook of psychiatry in the world today - the Diagnostic and statistical handbook of mental disorders (DSM-5) - is based on behaviors of inattention, hyperactivity and impulsivity, numerous attempts to describe the biological bases of the disorder can be found, to be used for and also as risk markers. In this paper, we will critically analyze the validity of studies associated with the search for genetic markers of ADHD.

Contrasting levels of genotype by environment interaction for life history and morphological traits in invasive populations of Zaprionus indianus (Diptera: Drosophilidae).

It has been demonstrated that phenotypic plasticity and genotype by environment interaction are important for coping with new and heterogeneous environments during invasions. Zaprionus indianus Gupta (Diptera: Drosophilidae) is an Afrotropical invasive fly species introduced to the South American continent in 1999. This species is generalist and polyphagous, since it develops and feeds in several different fruit species.

Positive selection in nucleoporins challenges constraints on early expressed genes in Drosophila development.

Developmental conservation among related species is a common generalization known as von Baer's third law and implies that early stages of development are the most refractory to change. The "hourglass model" is an alternative view that proposes that middle stages are the most constrained during development. To investigate this issue, we undertook a genomic approach and provide insights into how natural selection operates on genes expressed during the first 24 h of Drosophila ontogeny in the six species of the melanogaster group for which whole genome sequences are available.

Evolutionary Genomics of Genes Involved in Olfactory Behavior in the Drosophila melanogaster Species Group.

Previous comparative genomic studies of genes involved in olfactory behavior in Drosophila focused only on particular gene families such as odorant receptor and/or odorant binding proteins. However, olfactory behavior has a complex genetic architecture that is orchestrated by many interacting genes. In this paper, we present a comparative genomic study of olfactory behavior in Drosophila including an extended set of genes known to affect olfactory behavior.

Stage-specific effects of candidate heterochronic genes on variation in developmental time along an altitudinal cline of Drosophila melanogaster.

Background: Previously, we have shown there is clinal variation for egg-to-adult developmental time along geographic gradients in Drosophila melanogaster. Further, we also have identified mutations in genes involved in metabolic and neurogenic pathways that affect development time (heterochronic genes). However, we do not know whether these loci affect variation in developmental time in natural populations.

Identifying candidate genes affecting developmental time in Drosophila melanogaster: pervasive pleiotropy and gene-by-environment interaction.

Background: Understanding the genetic architecture of ecologically relevant adaptive traits requires the contribution of developmental and evolutionary biology. The time to reach the age of reproduction is a complex life history trait commonly known as developmental time. In particular, in holometabolous insects that occupy ephemeral habitats, like fruit flies, the impact of developmental time on fitness is further exaggerated.