Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.

We report a high-quality draft of the genome sequence of the grey, short-tailed opossum (Monodelphis domestica). As the first metatherian ('marsupial') species to be sequenced, the opossum provides a unique perspective on the organization and evolution of mammalian genomes. Distinctive features of the opossum chromosomes provide support for recent theories about genome evolution and function, including a strong influence of biased gene conversion on nucleotide sequence composition, and a relationship between chromosomal characteristics and X chromosome inactivation. Comparison of opossum and eutherian genomes also reveals a sharp difference in evolutionary innovation between protein-coding and non-coding functional elements. True innovation in protein-coding genes seems to be relatively rare, with lineage-specific differences being largely due to diversification and rapid turnover in gene families involved in environmental interactions. In contrast, about 20% of eutherian conserved non-coding elements (CNEs) are recent inventions that postdate the divergence of Eutheria and Metatheria. A substantial proportion of these eutherian-specific CNEs arose from sequence inserted by transposable elements, pointing to transposons as a major creative force in the evolution of mammalian gene regulation.

Background Contextual variation in child disruptive behavior is well documented but remains poorly understood. We first examine how variation in observed disruptive behavior across interactional contexts is associated with maternal reports of contextual variation in oppositional-defiant behavior and functional impairment. Second, we test whether child inhibitory control explains the magnitude of contextual variation in observed disruptive behavior. Methods Participants are 497 young children (mean age = 4 years, 11 months) from a subsample of the MAPS, a sociodemographically diverse pediatric sample, enriched for risk of disruptive behavior. Observed anger modulation and behavioral regulation problems were coded on the Disruptive Behavior Diagnostic Observation Schedule (DB-DOS) during interactions with parent and examiner. Oppositional-defiant behavior, and impairment in relationships, with parents and nonparental adults, were measured with the Preschool Age Psychiatric Assessment (PAPA) interview with the mother. Functional impairment in the home and out-and-about was assessed with the Family Life Impairment Scale (FLIS), and expulsion from child care/school was measured with the baseline survey and FLIS. Results Observed disruptive behavior on the DB-DOS Parent Context was associated with oppositional-defiant behavior with parents, and with impairment at home and out-and-about. Observed disruptive behavior with the Examiner was associated with oppositional-defiant behavior with both parents and nonparental adults, impairment in relationships with nonparental adults, and child care/school expulsion. Differences in observed disruptive behavior in the Parent versus Examiner Contexts was related to the differences in maternal reports of oppositional-defiant behavior with parents versus nonparental adults. Children with larger decreases in disruptive behavior from Parent to Examiner Context had better inhibitory control and fewer attention-deficit/hyperactivity disorder symptoms. Conclusions The DB-DOS showed clinical utility in a community sample for identifying contextual variation that maps onto reported oppositional-defiant behavior and functioning across contexts. Elucidating the implications of contextual variation for early identification and targeted prevention is an important area for future research.

No abstract

this is clearly below the clinical cut-off. Is a child with such a clinical profile not meaningfully different from a child exhibiting six or more symptoms in all settings? It has long been recognized that this is the case [22]. We argue that this vaguely defined criterion reflects a broader neglected issue of variability in number and contextual (in)stability of symptoms that is so typical in ADHD affected populations. We believe that variation in number and contextual expression of symptoms is a key factor to improve diagnostic and treatment procedures. Below we provide a new perspective on this issue and how to embrace and not erase it in clinical practice and research [9]. We further believe that observational assessment that allows for standardized assessment of cross-contextual variation in child behavior of the child may aid in a more precise measurement of contextual variability of ADHD symptoms in a manner that is clinically feasible and ecologically valid [7]. Observational assessment should be part of the assessment of ADHD for clinical and research purposes in a similar manner as is currently the gold standard for autism spectrum disorder (ASD).In comparison to the DSM-IV, the DSM-5 has slightly toned down the contextual variability of symptoms. In the DSM-IV, the contextual variability of symptoms was clearly emphasized: it is very unusual for an individual to display the same level of dysfunction in all settings or within the same setting at all times (p. 81). In contrast, in the DSM-5 this contextual variability is formulated as 'typically, symptoms vary depending on context within a given setting' (p. 61). However, in both DSM versions, several situations are specifically described that suppress ADHD symptoms in individuals with ADHD, namely: when (1) frequent rewards are given for appropriate behavior (DSM-IV and DSM-5); (2) the person is under very strict control (DSM-IV) or under close supervision (DSM-5); (3) the person is engaged in especially interesting activities 'Several inattentive or hyperactive-impulsive symptoms are present in two or more settings (e.g., at home, school or work; with friends or relatives; in other activities). ' (p. 60,. It is remarkable that the DSM-5 stresses symptoms rather than impairment in relation to different contexts in the diagnostic criteria for Attention-Deficit/Hyperactivity Disorder (ADHD). One would expect that pervasiveness (criterion C) means the presence of impairment of functioning, due to ADHD symptoms, in two or more settings. According to the DSM-5, a diagnosis of ADHD is warranted-when all other criteria are met-if only two out of the minimal six symptoms occur at school, even though