Developmental Pathways (developmental + pathway)

Distribution by Scientific Domains
Distribution within Life Sciences


Selected Abstracts


METAMODELS AND PHYLOGENETIC REPLICATION: A SYSTEMATIC APPROACH TO THE EVOLUTION OF DEVELOPMENTAL PATHWAYS

EVOLUTION, Issue 11 2009
Artyom Kopp
Molecular genetic analysis of phenotypic variation has revealed many examples of evolutionary change in the developmental pathways that control plant and animal morphology. A major challenge is to integrate the information from diverse organisms and traits to understand the general patterns of developmental evolution. This integration can be facilitated by evolutionary metamodels,traits that have undergone multiple independent changes in different species and whose development is controlled by well-studied regulatory pathways. The metamodel approach provides the comparative equivalent of experimental replication, allowing us to test whether the evolution of each developmental pathway follows a consistent pattern, and whether different pathways are predisposed to different modes of evolution by their intrinsic organization. A review of several metamodels suggests that the structure of developmental pathways may bias the genetic basis of phenotypic evolution, and highlights phylogenetic replication as a value-added approach that produces deeper insights into the mechanisms of evolution than single-species analyses. [source]


The Transition to High School: A Prodigal Analysis of Developmental Pathways

NEW DIRECTIONS FOR CHILD & ADOLESCENT DEVELOPMENT, Issue 101 2003
Tom W. Cadwallader
This chapter explores the relationship between childhood aggressive behavior and later adjustment, with a focus on the transition to high school. Pattern-oriented prodigal analysis is used to identify four homogeneous groups, based on stability or change in risk and nonrisk status over time. [source]


Developmental Pathways in Close Relationships

CHILD DEVELOPMENT, Issue 5 2000
Alan Fogel
Multiple case study developmental pathway research is needed to substantiate the theoretical propositions of the target article. [source]


Developmental pathways of eating problems in adolescents

INTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 8 2008
Annie Aimé PhD
Abstract Objective: To examine the developmental eating trajectories of adolescents and identify psychological correlates and risk factors associated with those trajectories. Method: Seven hundred thirty-nine adolescents completed self-reported measures of eating problems, internalizing and externalizing behaviors, alcohol and drug use, peer victimization, and depression. Results: Five eating trajectories were obtained. The proportions of males and females were the same in the increasing eating problems trajectory. For both genders, internalizing and externalizing problems were identified as associated risk factors of an eating pathology and reporting at least some eating problems was associated with an increased likelihood of psychological problems. Other risk factors found only in boys were frequency of drug use, victimization, and depressive symptoms. Conclusion: Externalizing problems in girls and internalizing behaviors in boys with disordered eating should not be overlooked. Atypical eating behaviors in boys are of particular concern since it increases their risk of cooccurring psychopathology. © 2008 by Wiley Periodicals, Inc. Int J Eat Disord 2008 [source]


Developmental pathways in food allergy: a new theoretical framework

ALLERGY, Issue 4 2009
A. DunnGalvin
Background:, To date, there is no model of psychosocial development based on empirical food allergy (FA) research. This limits the ability of clinicians, researchers and policy-makers to predict and evaluate the real impact of FA on the child, with implications for prevention, treatment, intervention and health policy. Objectives:, To provide an integrated conceptual framework to explain the onset, development and maintenance of FA-related cognitions, emotions and behaviour, with particular attention to transition points. Method:, Fifteen focus groups meetings were held with 62 children (6,15 years). Developmentally appropriate techniques were designed to stimulate discussion, maintain interest and minimize threat to children's self-esteem. Data were analysed using grounded theory. Results:, FA impacts directly on children's normal trajectory of psychological development in both an age- and disease-specific manner. Six key themes emerged from the analysis: ,meanings of food'; ,autonomy, control and self-efficacy'; ,peer relationships'; ,risk and safety'; ,self/identity'; and ,coping strategies'. Conclusions:, Coping with FA is more than simply a strategy, it is a cumulative history of interactive processes (age, gender and disease specific) that are embedded in a child's developmental organization. Clinical Implications:, The early recognition and incorporation of an FA-specific developmental framework into a treatment plan is essential and sets the stage for an effective medical care and the eventual transition from paediatric to adult care. Capsule Summary:, This study represents a first attempt to provide an integrated developmental framework to explain the onset, development and maintenance of FA-related cognitions, emotions and behaviour. [source]


Developmental pathways to conduct disorder: Implications for serving youth who show severe aggressive and antisocial behavior

PSYCHOLOGY IN THE SCHOOLS, Issue 8 2004
Paul J. Frick
Research has uncovered a large number of risk factors that can place a child at risk for showing severe antisocial and aggressive behavior and to be diagnosed with conduct disorder. In this paper, recent research is outlined that has organized these risk factors into distinct pathways, each involving somewhat distinct causal processes, through which children develop this disorder. This body of research has been important for advancing our understanding of the causes of conduct disorder. In addition, it has some important implications for service delivery. The comprehensive and individualized approach to intervention that seems most indicated based on this research is consistent with the way most educators are trained to view service delivery. As a result, this body of research could be very helpful in guiding school personnel in the development of individualized educational plans that meet the needs of children with conduct disorder. © 2004 Wiley Periodicals, Inc. Psychol Schs 41: 823,834, 2004. [source]


Development of the neuromuscular system during asexual propagation in an invertebrate chordate

DEVELOPMENTAL DYNAMICS, Issue 8 2009
Stefano Tiozzo
Abstract Botryllus schlosseri is a colonial ascidian, and the closest relative to vertebrates that can completely regenerate its entire body, including all somatic and germline tissues, using an asexual developmental pathway called blastogenesis. This regenerative potential exhibited by Botryllus and other colonial ascidians does not exist in any other chordate and makes B. schlosseri a promising model to investigate the cellular and molecular basis of regeneration. In this report, we describe postembryonic myogenesis and characterized the development of the neural system during blastogenic development. ,-Tubulin immunoreactivity revealed a high correlation with previous studies on the motor nervous system. The pattern of the serotoninergic system in the adult reflects that observed in solitary ascidians, but in early blastogenesis suggests a morphogenic role of this monoamine. In summary, this study provides the morphological framework to dissect the mechanisms underlying the ability to regenerate entire organ systems as an adult in a chordate model. Developmental Dynamics 238:2081,2094, 2009. © 2009 Wiley-Liss, Inc. [source]


IL-23 and the Th17 pathway promote inflammation and impair antifungal immune resistance

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2007
Teresa Zelante
Abstract Although inflammation is an essential component of the protective response to fungi, its dysregulation may significantly worsen fungal diseases. We found here that the IL-23/IL-17 developmental pathway acted as a negative regulator of the Th1-mediated immune resistance to fungi and played an inflammatory role previously attributed to uncontrolled Th1 cell responses. Both inflammation and infection were exacerbated by a heightened Th17 response against Candida albicans and Aspergillus fumigatus, two major human fungal pathogens. IL-23 acted as a molecular connection between uncontrolled fungal growth and inflammation, being produced by dendritic cells in response to a high fungal burden and counter-regulating IL-12p70 production. Both IL-23 and IL-17 subverted the inflammatory program of neutrophils, which resulted in severe tissue inflammatory pathology associated with infection. Our data are the first demonstrating that the IL-23/IL-17 pathway promotes inflammation and susceptibility in an infectious disease model. As IL-23-driven inflammation promotes infection and impairs antifungal resistance, modulation of the inflammatory response represents a potential strategy to stimulate protective immune responses to fungi. See accompanying commentary: http://dx.doi.org/10.1002/eji.200737804 [source]


METAMODELS AND PHYLOGENETIC REPLICATION: A SYSTEMATIC APPROACH TO THE EVOLUTION OF DEVELOPMENTAL PATHWAYS

EVOLUTION, Issue 11 2009
Artyom Kopp
Molecular genetic analysis of phenotypic variation has revealed many examples of evolutionary change in the developmental pathways that control plant and animal morphology. A major challenge is to integrate the information from diverse organisms and traits to understand the general patterns of developmental evolution. This integration can be facilitated by evolutionary metamodels,traits that have undergone multiple independent changes in different species and whose development is controlled by well-studied regulatory pathways. The metamodel approach provides the comparative equivalent of experimental replication, allowing us to test whether the evolution of each developmental pathway follows a consistent pattern, and whether different pathways are predisposed to different modes of evolution by their intrinsic organization. A review of several metamodels suggests that the structure of developmental pathways may bias the genetic basis of phenotypic evolution, and highlights phylogenetic replication as a value-added approach that produces deeper insights into the mechanisms of evolution than single-species analyses. [source]


Towards a molecular definition of worker sterility: differential gene expression and reproductive plasticity in honey bees

INSECT MOLECULAR BIOLOGY, Issue 5 2006
G. J. Thompson
Abstract We show that differences in the reproductive development of honey bee workers are associated with locus-specific changes to abundance of messenger RNA. Using a cross-fostering field experiment to control for differences related to age and environment, we compared the gene expression profiles of functionally sterile workers (wild-type) and those from a mutant strain in which workers are reproductively active (anarchist). Among the set of three genes that are significantly differentially expressed are two major royal jelly proteins that are up-regulated in wild-type heads. This discovery is consistent with sterile workers synthesizing royal jelly as food for developing brood. Likewise, the relative underexpression of these two royal jellies in anarchist workers is consistent with these workers' characteristic avoidance of alloparental behaviour, in favour of selfish egg-laying. Overall, there is a trend for the most differentially expressed genes to be up-regulated in wild-type workers. This pattern suggests that functional sterility in honey bee workers may generally involve the expression of a suite of genes that effectively ,switch' ovaries off, and that selfish reproduction in honey bee workers, though rare, is the default developmental pathway that results when ovary activation is not suppressed. [source]


Dieting history in obese youngsters with and without disordered eating

INTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 8 2006
Line Claus MA
Abstract Objective: This article examines the relationship between the emergence of disordered eating and the history of weight and dieting in obese youngsters. Method: Both child and parent reports were obtained from 40 obese disordered eaters (objective bulimic episodes, n = 20; objective overeating episodes, n = 20) and 40 obese matched controls aged 10,16 years. Results: No significant differences between subsamples with regard to weight and dieting history were found. In dieters, it was shown that overweight onset preceded dieting onset, which in turn preceded dietary restraint onset. Despite some discordance regarding precise onset ages of different behaviors, parent and child re ports revealed the same temporal sequences. Conclusion: A developmental pathway from weight problems through dieting to binge eating is plausible for a subgroup of obese children. Convergence between parent and child reports supports the assumption that children's reports are a viable means of monitoring dieting and weight behaviors. © 2006 by Wiley Periodicals, Inc. Int J Eat Disord 2006; 39:721,728 [source]


Erythropoiesis and Molecular Mechanisms for Sexual Determination in Malaria Parasites

IUBMB LIFE, Issue 4 2000
R. E. L. Paul
Abstract Malaria parasites proliferate asexually within the vertebrate host but must undergo sexual reproduction for transmission to mosquitoes and hence infection of new hosts. The developmental pathways controlling gametocytogenesis are not known, but several protein kinases and other putative signal transduction elements possibly involved in this phenomenon have been found in Plasmodium. Recently, another developmental pathway, that of Plasmodium sex determination (male or female), has been shown to be triggered by erythropoiesis in the host. Rapid progress is being made in our understanding of the molecular basis of mammalian erythropoiesis, revealing kinase pathways that are essential to cellular responses triggered by the hormone erythropoietin. Although the molecular mechanisms whereby this hormone modulates the sex ratio of malaria parasites remain to be elucidated, it probably activates, within the parasite, transduction pathways similar to those found in other eukaryotes. Indeed, enzymes belonging to protein kinase families known to be involved in the response of mammalian cells to erythropoietin (such as the mitogen-activated protein kinases) have been identified in P. falciparum gametocytes. Some of these enzymes differ markedly from their mammalian homologs; therefore, identification of the transduction pathways of the parasite that are responsible for its developmental response to erythropoietin opens the way to the development of transmission-blocking drugs based on kinase inhibitors. [source]


Barx1 and evolutionary changes in feeding

JOURNAL OF ANATOMY, Issue 5 2005
Isabelle Miletich
Abstract During mouse embryonic development, the Barx1 homeobox gene is expressed in the mesenchymal cells of molar teeth and stomach. During early stages of molar development, Barx1 has an instructive role, directing the as yet undetermined ectomesenchymal cells in the proximal region of the jaws to follow a multicuspid tooth developmental pathway. We review here recent results showing an absence of stomach tissue in Barx1 mutant mice. The data strongly suggest that in the presumptive stomach mesenchyme Barx1 acts to attenuate Wnt signalling allowing digestive tract endoderm to differentiate into a highly specialized stomach epithelium. In the light of these new data, we discuss the possibility that evolutionary changes in the Barx1 gene could have simultaneously altered the dentition and the digestive system, therefore positioning Barx1 as a key gene in the evolution of mammals. [source]


Getting domestication straight: ramosa1 in maize

MOLECULAR ECOLOGY, Issue 7 2010
HANNES DEMPEWOLF
Knowledge of the identities and characteristics of genes that govern the dramatic phenotypic differences between cultivated plants and their wild ancestors has greatly enhanced our understanding of the domestication process. In this issue of Molecular Ecology, Sigmon & Vollbrecht report the discovery of a new maize domestication gene, ramosa1, which encodes a putative transcription factor in the ramosa developmental pathway. Ramosa1 appears to be instrumental in determining the straightness of kernel rows on the maize cob. The key domestication alleles at ramosa1 are prevalent in landraces of maize. These results reinforce findings from previous studies of crop evolution by highlighting the importance of standing genetic variation and changes in transcriptional regulators in domestication. The evolutionary genetics of domestication also provides a framework for predicting the evolutionary response of organisms to strong human-induced selection pressures over limited time intervals. [source]


Temporal separation of distinct differentiation pathways by a dual specificity Rap-Phr system in Bacillus subtilis

MOLECULAR MICROBIOLOGY, Issue 1 2007
Wiep Klaas Smits
Summary In bacterial differentiation, mechanisms have evolved to limit cells to a single developmental pathway. The establishment of genetic competence in Bacillus subtilis is controlled by a complex regulatory circuit that is highly interconnected with the developmental pathway for spore formation, and the two pathways appear to be mutually exclusive. Here we show by in vitro and in vivo analyses that a member of the Rap family of proteins, RapH, is activated directly by the late competence transcription factor ComK, and is capable of inhibiting both competence and sporulation. Importantly, RapH is the first member of the Rap family that demonstrates dual specificity, by dephosphorylating the Spo0F,P response regulator and inhibiting the DNA-binding activity of ComA. The protein thus acts at the stage where competence is well initiated, and prevents initiation of sporulation in competent cells as well as contributing to the escape from the competent state. A deletion of rapH induces both differentiation pathways and interferes with their temporal separation. Together, these results indicate that RapH is an integral part of a multifactorial regulatory circuit affecting the cell's decision between distinct developmental pathways. [source]


Seed after-ripening is a discrete developmental pathway associated with specific gene networks in Arabidopsis

THE PLANT JOURNAL, Issue 2 2008
Esther Carrera
Summary After-ripening (AR) is a time and environment regulated process occurring in the dry seed, which determines the germination potential of seeds. Both metabolism and perception of the phytohormone abscisic acid (ABA) are important in the initiation and maintenance of dormancy. However, molecular mechanisms that regulate the capacity for dormancy or germination through AR are unknown. To understand the relationship between ABA and AR, we analysed genome expression in Arabidopsis thaliana mutants defective in seed ABA synthesis (aba1-1) or perception (abi1-1). Even though imbibed mutant seeds showed no dormancy, they exhibited changes in global gene expression resulting from dry AR that were comparable with changes occurring in wild-type (WT) seeds. Core gene sets were identified that were positively or negatively regulated by dry seed storage. Each set included a gene encoding repression or activation of ABA function (LPP2 and ABA1, respectively), thereby suggesting a mechanism through which dry AR may modulate subsequent germination potential in WT seeds. Application of exogenous ABA to after-ripened WT seeds did not reimpose characteristics of freshly harvested seeds on imbibed seed gene expression patterns. It was shown that secondary dormancy states reinstate AR status-specific gene expression patterns. A model is presented that separates the action of ABA in seed dormancy from AR and dry storage regulated gene expression. These results have major implications for the study of genetic mechanisms altered in seeds as a result of crop domestication into agriculture, and for seed behaviour during dormancy cycling in natural ecosystems. [source]


Origin, diffusion and reproduction of the giant reed (Arundo donax L.): a promising weedy energy crop

ANNALS OF APPLIED BIOLOGY, Issue 2 2010
C. Mariani
Giant reed (Arundo donax) is a promising energy crop of the Mediterranean areas. It has long been associated with humans and has been cultivated in Asia, southern Europe, North Africa and the Middle East for thousands of years. It is a perennial herbaceous plant (Poaceae) found in grasslands and wetlands throughout a wide range of climatic zones. Amplified fragment length polymorphism (AFLP) analysis was used to assess genetic inter and intrarelationships between A. donax and other Arundo species. Furthermore, the development of the sexual apparatus was analysed to understand the basis of sterility in the accession examined. The dendrograms obtained by phenetic and cladistic analysis support the monophyletic origin of giant reed and suggest that it originated in Asia and began to spread into the Mediterranean without traces of hybridisation with the other Arundo species. In particular, samples from Mediterranean areas are characterisd by a lower gene diversity and incidence of rare AFLP fragments indicating that these populations are recent in origin. Moreover, results indicate the occurrence of post-meiotic alterations in the ovule and pollen developmental pathway. Thus, the success of giant reed can be attributed mainly to its rapid clonal spread by rhizome extension, flood dispersal of rhizome and culm fragments. [source]


Delayed memory B cell recovery in peripheral blood and lymphoid tissue in systemic lupus erythematosus after B cell depletion therapy

ARTHRITIS & RHEUMATISM, Issue 9 2007
Jennifer H. Anolik
Objective Recent data suggest that the reconstituting peripheral B cell compartment after B cell depletion therapy may be functionally immature, with a preponderance of transitional B cells and a paucity of memory B cells. This study was undertaken to determine the magnitude, duration, and cause of these defects in rituximab-treated systemic lupus erythematosus (SLE) patients. Methods Fifteen patients with SLE previously treated with rituximab as part of a phase I/II dose-escalation study were evaluated during a long-term followup (mean followup period 41 months). B cells from peripheral blood and tonsils were assessed using multicolor flow cytometry, and their developmental pathway was classified based on the expression of defined surface markers. Results Reconstitution of peripheral blood CD27+ memory B cells was delayed for several years after B cell depletion therapy in a subset of patients with prolonged clinical responses and autoantibody normalization. This delay correlated with the degree of expansion of B cells of a transitional phenotype during the B cell reconstitution phase (P = 0.005) and the absence of baseline autoantibodies directed against extractable nuclear antigens (RNP, Sm, Ro antigen, La antigen). Despite the paucity of peripheral blood memory cells and the prolonged expansion of functionally immature transitional B cells, tonsil biopsy tissues revealed active germinal center (GC) reactions, but with decreased Fc receptor homolog 4,positive memory B cells. Conclusion These results suggest heterogeneity in the B cell depletion and reconstitution process that impacts clinical and immunologic outcomes in SLE. The presence of GC reactions, but with altered memory B cell subpopulations in tonsils, suggests that peripheral blood memory cell reconstitution lags behind a slow secondary lymphoid tissue recovery, with important implications for immunologic competence and tolerance. [source]


Sexual devolution in plants: apomixis uncloaked?

BIOESSAYS, Issue 9 2008
Richard D. Noyes
There are a growing number of examples where naturally occurring mutations disrupt an established physiological or developmental pathway to yield a new condition that is evolutionary favored. Asexual reproduction by seed in plants, or apomixis, occurs in a diversity of taxa and has evolved from sexual ancestors. One form of apomixis, diplospory, is a multi-step development process that is initiated when meiosis is altered to produce an unreduced rather than a reduced egg cell. Subsequent parthenogenetic development of the unreduced egg yields genetically maternal progeny. While it has long been apparent from cytological data that meiosis in apomicts was malfunctional or completely bypassed, the genetic basis of the phenomenon has been a long-standing mystery. New data from genetic analysis of Arabidopsis mutants1 in combination with more sophisticated molecular understanding of meiosis in plants indicate that a weak mutation of the gene SWI, called DYAD, interferes with sister chromatid cohesion in meiosis I, causes synapsis to fail in female meiosis and yields two unreduced cells. The new work shows that a low percentage of DYAD ovules produce functional unreduced egg cells (2n) that can be fertilized by haploid pollen (1n) to give rise to triploid (3n) progeny. While the DYAD mutants differ in some aspects from naturally occurring apomicts, the work establishes that mutation to a single gene can effectively initiate apomictic development and, furthermore, focuses efforts to isolate apomixis genes on a narrowed set of developmental events. Profitable manipulation of meiosis and recombination in agronomically important crops may be on the horizon. BioEssays 30:798,801, 2008. © 2008 Wiley Periodicals, Inc. [source]


Linking animal models to human congenital diaphragmatic hernia

BIRTH DEFECTS RESEARCH, Issue 8 2007
Niels Beurskens
Abstract BACKGROUND:Congenital diaphragmatic hernia (CDH) is a major life-threatening malformation, occurring in approximately 1 in 3,000 live births. Over the years, different animal models have been used to gain insight into the etiology of this complex congenital anomaly and to develop treatment strategies. However, to date the pathogenic mechanism is still not understood, and treatment remains difficult because of the associated pulmonary hypoplasia and pulmonary hypertension. METHODS: In this review, data available from several animal models will be discussed. The retinoic acid signaling pathway (RA pathway, retinoid pathway) will be addressed as a developmental pathway that is potentially disrupted in the pathogenesis of CDH. Furthermore, genetic factors involved in diaphragm and lung development will be discussed. CONCLUSIONS: With this review article, we aim to provide a concise overview of the current most important experimental genetic data available in the field of CDH. Birth Defects Research (Part A), 2007. © 2007 Wiley-Liss, Inc. [source]


Cytokeratin 20 expression identifies a subtype of pancreatic adenocarcinoma with decreased overall survival

CANCER, Issue 3 2006
Evan Matros M.D.
Abstract BACKGROUND Cytokeratins are markers of epithelial cell differentiation useful in determining histogenesis for malignancies with an unknown primary. Application of this principle to a single malignancy may identify cancer subtypes with altered developmental programs. Herein, we investigate the relevance of two widely used cytokeratins (CKs), 7 and 20, to subtype pancreas cancer and identify associations with clinical features. METHODS A tissue microarray was constructed using tumor specimens from 103 patients who underwent resection for pancreatic adenocarcinoma with curative intent. A subset of resection specimens was evaluated for pancreatic intraepithelial neoplasia (PanIN) lesions. Tissues were immunostained by using specific anticytokeratin 7 and 20 monoclonal antibodies. RESULTS CK 7 and 20 expression was present in 96% and 63% cases of pancreatic adenocarcinoma, respectively. Ubiquitous CK 7 expression precluded further analysis. Tumoral CK 20 expression was not associated with any histopathologic parameter but correlated with worse prognosis when considered as either a dichotomous (P = 0.0098) or continuous (P = 0.007) variable. In a multivariate model, tumoral CK 20 expression remained a significant independent prognosticator. CK 20 expression was absent in all PanIN lesions from eight resection specimens in which the tumor component was negative for CK 20. In contrast, presence of tumoral CK 20 was highly concordant with its expression in corresponding PanINs. CONCLUSIONS CK 20 expression defines a subtype of pancreas cancer with important biologic properties. When present, CK 20 expression is an early event in pancreatic carcinogenesis identifiable in precursor lesions. Further studies to identify the underlying genetic changes associated with this altered developmental pathway are warranted. Cancer 2006. © 2005 American Cancer Society. [source]


Developmental perspectives on copy number abnormalities of the 22q11.2 region

CLINICAL GENETICS, Issue 3 2010
TY Tan
Tan TY, Gordon CT, Amor DJ, Farlie PG. Developmental perspectives on copy number abnormalities of the 22q11.2 region. The 22q11.2 chromosomal landscape predisposes to genomic rearrangements that are associated with a variety of clinical phenotypes. The most well known of these include the 22q11.2 deletion and Cat-eye syndromes (CES), but more recently other copy number abnormalities have been recognised, especially with increased use of microarrays in the investigation of patients with congenital malformations or cognitive impairment. In addition, mutations in the TBX1 gene have been found in patients with phenotypes reminiscent of 22q11.2 syndromes. Recent advances in our understanding of 22q11.2 genes and their interactions provide insight into the mechanisms underlying the phenotypic variability of the 22q11.2 syndromes, and suggest a possible common developmental pathway perturbed by copy number abnormalities of this locus. [source]


Early predictors of antisocial developmental pathways among boys and girls

ACTA PSYCHIATRICA SCANDINAVICA, Issue 1 2010
M. Pitzer
Objective:, We investigated in a high-risk sample the differential impact of biological and psychosocial risk factors on antisocial behaviour pathways. Method:, One hundred and thirty-eight boys and 155 girls born at differing degrees of obstetric and psychosocial risk were examined from birth until adolescence. Childhood temperament was assessed by a highly-structured parent-interview and standardized behavioural observations, adolescent temperament was measured by self-report. Neurodevelopmental variables were assessed by age-specific developmental tests. Emotional and behaviour problems were measured at the ages of 8 and 15 by the Achenbach scales. Results:, In both genders, psychosocial adversity and early self-control temperament were strongly associated with early-onset persistent (EOP) antisocial behaviour. Psychosocial adversity and more severe externalizing problems differentiated the EOP from childhood-limited (CL) pathway. In girls, adolescent-onset (AO) antisocial behaviour was strongly associated with novelty seeking at 15 years. Conclusion:, Our findings emphasize the need for early support and intervention in psychosocially disadvantaged families. [source]


Baseline cortisol measures and developmental pathways of anxiety in early adolescence

ACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2009
K. Greaves-Lord
Objective:, This study investigated whether baseline cortisol measures predicted future anxiety, and compared cortisol values of groups with different developmental pathways of anxiety. Method:, Cortisol levels were assessed in 1768 individuals (10,12 years). Anxiety levels were assessed at the same age and 2 years later. Results:, Cortisol measures did not predict future anxiety levels. Individuals with persistent anxiety problems did not show higher morning cortisol levels than those with persistently low, decreasing, or increasing anxiety levels. Instead, individuals with persistently high anxiety levels showed significantly lower evening cortisol levels than all other individuals. Further, participants with increasing anxiety levels showed higher morning cortisol levels (area under the curve; AUC) than individuals with persistently low anxiety levels. Conclusion:, The extent to which the HPA-axis , by itself , plays a role in the aetiology of anxiety is questionable. Interactions of the HPA-axis with other biological or environmental factors may be more important. [source]


Busulfan-induced central polydactyly, syndactyly and cleft hand or foot: A common mechanism of disruption leads to divergent phenotypes

DEVELOPMENT GROWTH & DIFFERENTIATION, Issue 6 2007
Takuji Naruse
The prevalence of clinical phenotypes that exhibit combinations of central polydactyly, syndactyly, or cleft hand or foot is higher than would be expected for random independent mutations. We have previously demonstrated that maternal ingestion of a chemotherapeutic agent, busulfan, at embryonic day 11 (E11) induces these defects in various combinations in rat embryo limbs. In an effort to determine the mechanism by which busulfan disrupts digital development, we examined cell death by Nile Blue staining and TdT-mediated dUTP nick end labeling (TUNEL) assays; we also carried out whole mount in situ hybridization for fibroblast growth factor-8 (Fgf8), bone morphogenetic protein-4 (Bmp4), and sonic hedgehog (Shh) to examine developmental pathways linked to these defects. In busulfan-treated embryos, diffuse cell death was evident in both ectoderm and mesoderm, peaking at E13. The increased cell death leads to regression of Fgf8 in the apical ectodermal ridge (AER) and Bmp4 and Shh in the underlying mesoderm. The subsequent pattern of interdigital apoptosis and cartilage condensation was variably disrupted. These results suggest that busulfan manifests its teratogenic effects by inducing cell death of both ectoderm and mesoderm, with an associated reduction in tissue and a disruption in the generation of patterning molecules during critical periods of digit specification. [source]


Groucho corepressor proteins regulate otic vesicle outgrowth

DEVELOPMENTAL DYNAMICS, Issue 3 2005
Baubak Bajoghli
Abstract The Groucho/Tle family of corepressor proteins is known to regulate multiple developmental pathways. Applying the dominant-negative effect of the short member Aes, we demonstrate here a critical role of this gene family also for ear development. Misexpression of Aes in medaka embryos resulted in reduced size or loss of otic vesicles, whereas overexpression of the full-length Groucho protein Tle4 gave the opposite phenotype. These results are in close agreement with phenotypes observed for eye formation, suggesting a similar role for Groucho/Tle proteins in the developmental pathways of both sensory organs. Furthermore, by using the heat-inducible HSE promoter, we observed reversible branching of the embryonic axis upon Aes misexpression, indicating a transient duplication of the organizer. Groucho proteins, therefore, are critical for organizer maintenance. Developmental Dynamics 233:760,771, 2005 © 2005 Wiley-Liss, Inc. [source]


Growth curve analyses are best suited to examine the relation between developmental pathways and selective breeding: Comment on Hofer, Shair, Masmela, & Brunelli, "Developmental effects of selective breeding for an infantile trait: The rat pup ultrasonic isolation call"

DEVELOPMENTAL PSYCHOBIOLOGY, Issue 4 2001
George F. Michel
Abstract Hofer, Brunelli, Shair, & Masmela (2001) provide valuable information about the effects of selective breeding on rat-pup behaviors and physiology. Although the design and statistical analytic techniques employed are typical of those used to evaluate behavioral development in animals, I offer several suggestions about how to evaluate the influence of selective breeding on developmental pathways using modern statistical techniques. As Hofer et al. demonstrate, the development of rat behavior and physiology can be an excellent model for examining the relation between selection and development. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 247,250, 2001 [source]


How do plants know when other plants are flowering?

ECOLOGY LETTERS, Issue 11 2009
Resource depletion, mast-seeding in a perennial wildflower, pollen limitation
Abstract Mast-seeding is the synchronous and periodic reproduction by plant populations. This phenomenon has been widely studied from a community-level perspective, but we know extremely little about how plants are able to synchronize reproduction. Here, we present the first experimental test of proximate mechanisms of mast-seeding, by preventing reproduction in an iteroparous, mast-seeding wildflower. Through a series of experiments, we show that mobile carbohydrate stores (NSC) control alternate-year flowering by individual plants; seed set depletes NSC which prevents flowering the following year. Plants are synchronized by density-dependent pollen limitation; when plants flower asynchronously, they set fewer seeds, which prevents NSC depletion. Therefore, these individual plants flower in subsequent years and become synchronized. Because mast-seeding is a consequence of physiological controls of reproduction, differences in plant resource acquisition and allocation could dramatically change patterns of seed production, and changes in plant consumers and pollinators could change selection on physiological and developmental pathways. [source]


The personality-identity interplay in emerging adult women: convergent findings from complementary analyses

EUROPEAN JOURNAL OF PERSONALITY, Issue 3 2006
Koen Luyckx
Abstract The present study examined whether identity development occurs in tandem with personality development in emerging adulthood. Three-wave longitudinal data on a sample of 351 female college students were used to answer questions about stability and change, direction of effects, and interrelated developmental trajectories. Four identity dimensions (i.e. commitment making, exploration in breadth, identification with commitment, and exploration in depth) and the Big Five were assessed. Identity and personality were found to be meaningfully related at the level of both the time-specific adjacent measures and the underlying developmental trajectories with various degrees of convergence. Cross-lagged analyses substantiated reciprocal influences and Latent Growth Curve Modelling substantiated common developmental pathways that partially mirrored the concurrent relations. Implications and suggestions for future research are discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source]


METAMODELS AND PHYLOGENETIC REPLICATION: A SYSTEMATIC APPROACH TO THE EVOLUTION OF DEVELOPMENTAL PATHWAYS

EVOLUTION, Issue 11 2009
Artyom Kopp
Molecular genetic analysis of phenotypic variation has revealed many examples of evolutionary change in the developmental pathways that control plant and animal morphology. A major challenge is to integrate the information from diverse organisms and traits to understand the general patterns of developmental evolution. This integration can be facilitated by evolutionary metamodels,traits that have undergone multiple independent changes in different species and whose development is controlled by well-studied regulatory pathways. The metamodel approach provides the comparative equivalent of experimental replication, allowing us to test whether the evolution of each developmental pathway follows a consistent pattern, and whether different pathways are predisposed to different modes of evolution by their intrinsic organization. A review of several metamodels suggests that the structure of developmental pathways may bias the genetic basis of phenotypic evolution, and highlights phylogenetic replication as a value-added approach that produces deeper insights into the mechanisms of evolution than single-species analyses. [source]