Genetic identification and separation of innate and experience-dependent courtship behaviors in Drosophila.

Wild-type D. melanogaster males innately possess the ability to perform a multistep courtship ritual to conspecific females. The potential for this behavior is specified by the male-specific products of the fruitless (fru(M)) gene; males without fru(M) do not court females when held in isolation. We show that such fru(M) null males acquire the potential for courtship when grouped with other flies; they apparently learn to court flies with which they were grouped, irrespective of sex or species and retain this behavior for at least a week. The male-specific product of the doublesex gene (dsx(M)) is necessary and sufficient for the acquisition of the potential for such experience-dependent courtship. These results reveal a process that builds, via dsx(M) and social experience, the potential for a more flexible sexual behavior, which could be evolutionarily conserved as dsx-related genes that function in sexual development are found throughout the animal kingdom.

Genetic and neural mechanisms that inhibit Drosophila from mating with other species.

Genetically hard-wired neural mechanisms must enforce behavioral reproductive isolation because interspecies courtship is rare even in sexually naïve animals of most species. We find that the chemoreceptor Gr32a inhibits male D. melanogaster from courting diverse fruit fly species. Gr32a recognizes nonvolatile aversive cues present on these reproductively dead-end targets, and activity of Gr32a neurons is necessary and sufficient to inhibit interspecies courtship. Male-specific Fruitless (Fru(M)), a master regulator of courtship, also inhibits interspecies courtship. Gr32a and Fru(M) are not coexpressed, but Fru(M) neurons contact Gr32a neurons, suggesting that these genes influence a shared neural circuit that inhibits interspecies courtship. Gr32a and Fru(M) also suppress within-species intermale courtship, but we show that distinct mechanisms preclude sexual displays toward conspecific males and other species. Although this chemosensory pathway does not inhibit interspecies mating in D. melanogaster females, similar mechanisms appear to inhibit this behavior in many other male drosophilids.

Gene x responsive parenting interactions in social development: Characterizing heterogeneity in autism spectrum disorder.

Emerging research suggests that caregiving environments and genetic variants independently contribute to social functioning in children with typical development or autism spectrum disorder (ASD). However, biologically plausible interactive models and complimentary assessment of mechanisms are needed to: (a) explain considerable social heterogeneity, (b) resolve inconsistencies in the literature, and (c) develop and select optimal treatments based on individual differences. This study examined the role of child genotypes and responsive parenting in the social development of 104 children with ASD (ages 4-7 years). We utilized a longitudinal, multi-informant design and structural equation models to evaluate: (a) the additive and interactive effects of biologically plausible candidate genes (5-HTTLPR, OXTR, DRD4) and responsive parenting in predicting prospective social development in ASD across three time points spanning 1.5 years, and (b) whether child emotion regulation mediated observed gene x environment interactions (GxEs). Responsive parenting positively predicted prospective change in child social skills; these associations were moderated by 5-HTTLPR and DRD4 in teacher-report models, and DRD4 in parent-report models. No GxE effects were found for OXTR. Emotion regulation did not significantly mediate the GxEs involving 5-HTTLPR and DRD4. Acknowledging the complexities of GxE research, implications for future research, and targeted intervention efforts are discussed.

Sex-specific regulation of Lgr3 in Drosophila neurons.

The development of sexually dimorphic morphology and the potential for sexually dimorphic behavior in Drosophila are regulated by the Fruitless (Fru) and Doublesex (Dsx) transcription factors. Several direct targets of Dsx have been identified, but direct Fru targets have not been definitively identified. We show that Drosophila leucine-rich repeat G protein-coupled receptor 3 (Lgr3) is regulated by Fru and Dsx in separate populations of neurons. Lgr3 is a member of the relaxin-receptor family and a receptor for Dilp8, necessary for control of organ growth. Lgr3 expression in the anterior central brain of males is inhibited by the B isoform of Fru, whose DNA binding domain interacts with a short region of an Lgr3 intron. Fru A and C isoform mutants had no observed effect on Lgr3 expression. The female form of Dsx (Dsx(F)) separately up- and down-regulates Lgr3 expression in distinct neurons in the abdominal ganglion through female- and male-specific Lgr3 enhancers. Excitation of neural activity in the Dsx(F)-up-regulated abdominal ganglion neurons inhibits female receptivity, indicating the importance of these neurons for sexual behavior. Coordinated regulation of Lgr3 by Fru and Dsx marks a point of convergence of the two branches of the sex-determination hierarchy.

Patterns of Sensitivity to Parenting and Peer Environments: Early Temperament and Adolescent Externalizing Behavior.

Although parenting behavior and friendship quality predict adolescent externalizing behaviors (EBs), individual differences in temperament may differentially affect susceptibility to these factors over time. In a multi-method and multi-informant study of 141 children followed prospectively from toddlerhood to adolescence, we tested the independent and interactive associations of age 3 reactive temperament (e.g., negative emotionality) and age 13 observed parenting (i.e., positive and negative behavior) and friendship (i.e., conflict and warmth), with multi-informant ratings of age 15 aggression and rule-breaking behavior. Negative parenting predicted growth in parent-rated EB, but only for adolescents with early reactive temperament. Temperament did not affect sensitivity to positive parenting or friendship. Results are discussed in the context of differential susceptibility theory and intervention implications for adolescents.

Developmental Patterns of Child Emotion Dysregulation as Predicted by Serotonin Transporter Genotype and Parenting.

Individual differences in emotion regulation are central to social, academic, occupational, and psychological development, and emotion dysregulation (ED) in childhood is a risk factor for numerous developmental outcomes. The present study aimed to (a) describe the developmental trajectory of ED across early childhood (3-6 years) and (b) examine its sensitivity to youth serotonin transporter genotype, positive and negative parenting behaviors, and their interaction. Participants were 99 families in the Collaborative Family Study, a longitudinal study of children with or without developmental delays. Child ED and early parenting were coded from parent-child interactions. To examine serotonin transporter genotype as a moderator between parenting and child emotion dysregulation (ED), children with the homozygous short (SS) genotype were compared to children with the homozygous long (LL) or heterozygous (SL) genotype. We used latent growth curve modeling (LGCM) to model yearly change in ED from child age 3 to 6 years. LGCM revealed that ED decreased overall across early childhood. In addition, we observed separate Genotype × Positive and Genotype × Negative parenting behavior interactions in predictions of ED growth curves. Children with the SL/LL genotype had ED trajectories that were minimally related to positive and negative parenting behavior, whereas ED decreased more precipitously among children with the SS genotype when exposed to low negative parenting or high positive parenting. These findings provide evidence for Gene × Environment interactions (G×Es) in the development of ED in a manner that is conceptually consistent with vantage sensitivity, and they improve inferences afforded by prospective designs.

Constraints on the evolution of a doublesex target gene arising from doublesex's pleiotropic deployment.

"Regulatory evolution," that is, changes in a gene's expression pattern through changes at its regulatory sequence, rather than changes at the coding sequence of the gene or changes of the upstream transcription factors, has been increasingly recognized as a pervasive evolution mechanism. Many somatic sexually dimorphic features of Drosophila melanogaster are the results of gene expression regulated by the doublesex (dsx) gene, which encodes sex-specific transcription factors (DSX(F) in females and DSX(M) in males). Rapid changes in such sexually dimorphic features are likely a result of changes at the regulatory sequence of the target genes. We focused on the Flavin-containing monooxygenase-2 (Fmo-2) gene, a likely direct dsx target, to elucidate how sexually dimorphic expression and its evolution are brought about. We found that dsx is deployed to regulate the Fmo-2 transcription both in the midgut and in fat body cells of the spermatheca (a female-specific tissue), through a canonical DSX-binding site in the Fmo-2 regulatory sequence. In the melanogaster group, Fmo-2 transcription in the midgut has evolved rapidly, in contrast to the conserved spermathecal transcription. We identified two cis-regulatory modules (CRM-p and CRM-d) that direct sexually monomorphic or dimorphic Fmo-2 transcription, respectively, in the midguts of these species. Changes of Fmo-2 transcription in the midgut from sexually dimorphic to sexually monomorphic in some species are caused by the loss of CRM-d function, but not the loss of the canonical DSX-binding site. Thus, conferring transcriptional regulation on a CRM level allows the regulation to evolve rapidly in one tissue while evading evolutionary constraints posed by other tissues.

Intellectual Disability and Developmental Risk: Promoting Intervention to Improve Child and Family Well-Being.

Initial intervention processes for children with intellectual disabilities (IDs) largely focused on direct efforts to impact core cognitive and academic deficits associated with the diagnosis. Recent research on risk processes in families of children with ID, however, has influenced new developmental system approaches to early intervention. Recent risk and resilience processes are reviewed that connect stress, family process, and the high rates of behavioral problems in children with ID that have substantial influence on child and family outcomes. These models are linked to emerging evidence-based intervention processes that focus on strategic parent skill training and mindfulness interventions that reduce parental stress and create indirect benefits for children's behavioral competencies. A family-focused developmental systems approach (M. J. Guralnick, 2011) is emphasized.

Symptoms and development of anxiety in children with or without intellectual disability.

The purpose of this study was to examine group differences in presentation and trajectory of anxiety symptoms and disorders in children with moderate to borderline intellectual disability (ID) and children with typical cognitive development (TD). Examined anxiety disorders and symptoms in children with ID (n=74) or TD (n=116) annually from ages 5 through 9 using a parent structured interview and questionnaire. Logistic regression was used to examine odds of meeting anxiety criteria and hierarchical linear modeling was used to examine anxiety trajectory. Children with ID had significantly higher rates of clinical levels of anxiety on the Child Behavior Checklist at ages 8 and 9 and higher rates of separation anxiety disorder at age 5 compared to those with TD. Children with ID were also more likely to have externalizing problems co-occurring with anxiety. The rate of increase of anxiety symptoms over time was positive and similar in the two groups, and neither group showed sex differences in anxiety rates. Results suggest that children with ID have both higher rates of anxiety across time and are delayed in showing typical decreases in separation anxiety in early childhood. Implications for intervention are discussed in terms of the importance of screening for and treating anxiety in children with ID.

Joint control of Drosophila male courtship behavior by motion cues and activation of male-specific P1 neurons.

Sexual behaviors in animals are governed by inputs from multiple external sensory modalities. However, how these inputs are integrated to jointly control animal behavior is still poorly understood. Whereas visual information alone is not sufficient to induce courtship behavior in Drosophila melanogaster males, when a subset of male-specific fruitless (fru)- and doublesex (dsx)-expressing neurons that respond to chemosensory cues (P1 neurons) were artificially activated via a temperature-sensitive cation channel (dTRPA1), males followed and extended their wing toward moving objects (even a moving piece of rubber band) intensively. When stationary, these objects were not courted. Our results indicate that motion input and activation of P1 neurons are individually necessary, and under our assay conditions, jointly sufficient to elicit early courtship behaviors, and provide insights into how courtship decisions are made via sensory integration.

Direct targets of the D. melanogaster DSXF protein and the evolution of sexual development.

Uncovering the direct regulatory targets of doublesex (dsx) and fruitless (fru) is crucial for an understanding of how they regulate sexual development, morphogenesis, differentiation and adult functions (including behavior) in Drosophila melanogaster. Using a modified DamID approach, we identified 650 DSX-binding regions in the genome from which we then extracted an optimal palindromic 13 bp DSX-binding sequence. This sequence is functional in vivo, and the base identity at each position is important for DSX binding in vitro. In addition, this sequence is enriched in the genomes of D. melanogaster (58 copies versus approximately the three expected from random) and in the 11 other sequenced Drosophila species, as well as in some other Dipterans. Twenty-three genes are associated with both an in vivo peak in DSX binding and an optimal DSX-binding sequence, and thus are almost certainly direct DSX targets. The association of these 23 genes with optimum DSX binding sites was used to examine the evolutionary changes occurring in DSX and its targets in insects.

Predictors of treatment engagement in ethnically diverse, urban children receiving treatment for trauma exposure.

Keeping traditionally underrepresented children and their families engaged in treatment until completion is a major challenge for many community-based mental health clinics. The current study used data collected as part of the National Child Traumatic Stress Network Core Data Set to examine whether racial/ethnic disparities exist in treatment duration and completion in children seeking treatment for trauma exposure. We then explored whether disparities persist after accounting for other variables associated with children's social contexts and the treatment setting. The sample included 562 ethnically diverse children receiving services from a child abuse prevention and treatment agency in Southern California. The results indicated that African American children had significantly shorter trauma-informed treatment duration and higher rates of premature termination than Spanish-speaking Latino children. These disparities persisted even with other variables associated with treatment duration and completion (e.g., child's age, level of functional impairment, and receipt of group and field services) in the model. Implications and future directions for research and practice are discussed.

Male-specific Fruitless isoforms have different regulatory roles conferred by distinct zinc finger DNA binding domains.

BACKGROUND: Drosophila melanogaster adult males perform an elaborate courtship ritual to entice females to mate. fruitless (fru), a gene that is one of the key regulators of male courtship behavior, encodes multiple male-specific isoforms (Fru(M)). These isoforms vary in their carboxy-terminal zinc finger domains, which are predicted to facilitate DNA binding. RESULTS: By over-expressing individual Fru(M) isoforms in fru-expressing neurons in either males or females and assaying the global transcriptional response by RNA-sequencing, we show that three Fru(M) isoforms have different regulatory activities that depend on the sex of the fly. We identified several sets of genes regulated downstream of Fru(M) isoforms, including many annotated with neuronal functions. By determining the binding sites of individual Fru(M) isoforms using SELEX we demonstrate that the distinct zinc finger domain of each Fru(M) isoforms confers different DNA binding specificities. A genome-wide search for these binding site sequences finds that the gene sets identified as induced by over-expression of Fru(M) isoforms in males are enriched for genes that contain the binding sites. An analysis of the chromosomal distribution of genes downstream of Fru(M) shows that those that are induced and repressed in males are highly enriched and depleted on the X chromosome, respectively. CONCLUSIONS: This study elucidates the different regulatory and DNA binding activities of three Fru(M) isoforms on a genome-wide scale and identifies genes regulated by these isoforms. These results add to our understanding of sex chromosome biology and further support the hypothesis that in some cell-types genes with male-biased expression are enriched on the X chromosome.

Midline crossing by gustatory receptor neuron axons is regulated by fruitless, doublesex and the Roundabout receptors.

Although nervous system sexual dimorphisms are known in many species, relatively little is understood about the molecular mechanisms generating these dimorphisms. Recent findings in Drosophila provide the tools for dissecting how neurogenesis and neuronal differentiation are modulated by the Drosophila sex-determination regulatory genes to produce nervous system sexual dimorphisms. Here we report studies aimed at illuminating the basis of the sexual dimorphic axonal projection patterns of foreleg gustatory receptor neurons (GRNs): only in males do GRN axons project across the midline of the ventral nerve cord. We show that the sex determination genes fruitless (fru) and doublesex (dsx) both contribute to establishing this sexual dimorphism. Male-specific Fru (Fru(M)) acts in foreleg GRNs to promote midline crossing by their axons, whereas midline crossing is repressed in females by female-specific Dsx (Dsx(F)). In addition, midline crossing by these neurons might be promoted in males by male-specific Dsx (Dsx(M)). Finally, we (1) demonstrate that the roundabout (robo) paralogs also regulate midline crossing by these neurons, and (2) provide evidence that Fru(M) exerts its effect on midline crossing by directly or indirectly regulating Robo signaling.

Sex and the single cell. II. There is a time and place for sex.

The Drosophila melanogaster sex hierarchy controls sexual differentiation of somatic cells via the activities of the terminal genes in the hierarchy, doublesex (dsx) and fruitless (fru). We have targeted an insertion of GAL4 into the dsx gene, allowing us to visualize dsx-expressing cells in both sexes. Developmentally and as adults, we find that both XX and XY individuals are fine mosaics of cells and tissues that express dsx and/or fruitless (fru(M)), and hence have the potential to sexually differentiate, and those that don't. Evolutionary considerations suggest such a mosaic expression of sexuality is likely to be a property of other animal species having two sexes. These results have also led to a major revision of our view of how sex-specific functions are regulated by the sex hierarchy in flies. Rather than there being a single regulatory event that governs the activities of all downstream sex determination regulatory genes-turning on Sex lethal (Sxl) RNA splicing activity in females while leaving it turned off in males-there are, in addition, elaborate temporal and spatial transcriptional controls on the expression of the terminal regulatory genes, dsx and fru. Thus tissue-specific aspects of sexual development are jointly specified by post-transcriptional control by Sxl and by the transcriptional controls of dsx and fru expression.

Associations of grassland bird communities with black-tailed prairie dogs in the North American Great Plains.

Colonial burrowing herbivores can modify vegetation structure, create belowground refugia, and generate landscape heterogeneity, thereby affecting the distribution and abundance of associated species. Black-tailed prairie dogs (Cynomys ludovicianus) are such a species, and they may strongly affect the abundance and composition of grassland bird communities. We examined how prairie dog colonies in the North American Great Plains affect bird species and community composition. Areas occupied by prairie dogs, characterized by low percent cover of grass, high percent cover of bare soil, and low vegetation height and density, supported a breeding bird community that differed substantially from surrounding areas that lacked prairie dogs. Bird communities on colony sites had significantly greater densities of large-bodied carnivores (Burrowing Owls [Athene cunicularia], Mountain Plovers, [Charadrius montanus], and Killdeer [Charadrius vociferus]) and omnivores consisting of Horned Larks (Eremophila alpestris) and McCown's Longspurs (Rhynchophanes mccownii) than bird communities off colony sites. Bird communities off colony sites were dominated by small-bodied insectivorous sparrows (Ammodramus spp.) and omnivorous Lark Buntings (Calamospiza melanocorys), Vesper Sparrows (Pooecetes gramineus), and Lark Sparrows (Chondestes grammacus). Densities of 3 species of conservation concern and 1 game species were significantly higher on colony sites than off colony sites, and the strength of prairie dog effects was consistent across the northern Great Plains. Vegetation modification by prairie dogs sustains a diverse suite of bird species in these grasslands. Collectively, our findings and those from previous studies show that areas in the North American Great Plains with prairie dog colonies support higher densities of at least 9 vertebrate species than sites without colonies. Prairie dogs affect habitat for these species through multiple pathways, including creation of belowground refugia, supply of prey for specialized predators, modification of vegetation structure within colonies, and increased landscape heterogeneity.

Male-specific fruitless specifies the neural substrates of Drosophila courtship behaviour.

Robust innate behaviours are attractive systems for genetically dissecting how environmental cues are perceived and integrated to generate complex behaviours. During courtship, Drosophila males engage in a series of innate, stereotyped behaviours that are coordinated by specific sensory cues. However, little is known about the specific neural substrates mediating this complex behavioural programme. Genetic, developmental and behavioural studies have shown that the fruitless (fru) gene encodes a set of male-specific transcription factors (FruM) that act to establish the potential for courtship in Drosophila. FruM proteins are expressed in approximately 2% of central nervous system neurons, at least one subset of which coordinates the component behaviours of courtship. Here we have inserted the yeast GAL4 gene into the fru locus by homologous recombination and show that (1) FruM is expressed in subsets of all peripheral sensory systems previously implicated in courtship, (2) inhibition of FruM function in olfactory system components reduces olfactory-dependent changes in courtship behaviour, (3) transient inactivation of all FruM-expressing neurons abolishes courtship behaviour, with no other gross changes in general behaviour, and (4) 'masculinization' of FruM-expressing neurons in females is largely sufficient to confer male courtship behaviour. Together, these data demonstrate that FruM proteins specify the neural substrates of male courtship.

Emotion discourse, social cognition, and social skills in children with and without developmental delays.

This study examined parent-child emotion discourse, children's independent social information processing, and social skills outcomes in 146 families of 8-year-olds with and without developmental delays. Children's emergent social-cognitive understanding (internal state understanding, perspective taking, and causal reasoning and problem solving) was coded in the context of parent-child conversations about emotion, and children were interviewed separately to assess social problem solving. Mothers, fathers, and teachers reported on children's social skills. The proposed strengths-based model partially accounted for social skills differences between typically developing children and children with delays. A multigroup analysis of the model linking emotion discourse to social skills through children's prosocial problem solving suggested that processes operated similarly for the two groups. Implications for ecologically focused prevention and intervention are discussed.

The Etiology of Oppositional Defiant Disorder for Children with and without Intellectual Disabilities: A Preliminary Analysis.

BACKGROUND: Oppositional Defiant Disorder (ODD) appears more prevalent among children with intellectual disabilities (ID) as compared to children with typical development (Christensen et al., 2013). However, it remains unclear what drives this difference. METHODS: Data from 70 youth with typical development (TD) and 20 youth with ID were drawn from The Collaborative Family Study. The relationships between child temperament and parent psychopathology (age 3), parenting behavior and child behavior problems (age 5), and ODD diagnosis (age 13) were explored via structural equation modeling. The predicted model was examined in the total sample, among children with and without ID separately, and with status (TD vs. ID) as a predictor. CONCLUSION: Many of the predicted relationships hold true for youth with and without ID. However, we found an unexpected relationship between negative-controlling parenting and child externalizing behavior problems for children with ID. The positive role of parental intrusiveness for children with ID is discussed, although limitations are noted due to the small sample size and preliminary nature of this study.

Daily living skills in adolescents with autism spectrum disorder: Implications for intervention and independence.

BACKGROUND: Challenges in adaptive behaviors are present in individuals with autism spectrum disorder (ASD), while variation in IQ, social skills, and comorbidities are possible influences on adaptive behaviors. However, adaptive behaviors do not consistently map onto cognitive abilities in ASD, as high IQ is not protective against challenges in adaptive behaviors. Additionally, individuals with both ASD and elevated levels of externalizing problem behaviors experience even worse adaptive behaviors. Identifying factors that contribute to the variance in adaptive behaviors, particularly daily living skills (DLS), may inform strategies to improve adaptive behaviors necessary for independence in adulthood. METHOD: Adolescents with typical cognitive development (TD, n=84), intellectual disability (ID, n=30), or ASD (n=45) were included in this study to examine group differences in adaptive behaviors, identify relations between IQ and DLS, and determine factors that contribute to variance in DLS at youth age 13. The Vineland Adaptive Behavior Scales, 2nd Edition (VABS-II) was used to measure adaptive behaviors. RESULTS: All domains of adaptive behavior were significantly higher in TD groups compared to ASD and ID youth. Significant positive correlations were observed between IQ and DLS in the ASD and ID groups. In the ASD youth group, higher externalizing behavior problems explained the most variance in DLS. CONCLUSIONS: DLS are below age-expected levels in young adolescents with ASD, in part because of the higher externalizing behavior problems in this group. Incorporating adaptive skills training and behavior management strategies into current interventions may serve to prepare adolescents and families for the transition to adulthood.