Pattern Of Developmental Changes Research Articles

Cellular basis of morphological variation and temperature-related plasticity in Drosophila melanogaster strains with divergent wing shapes.

Organ shape evolves through cross-generational changes in developmental patterns at cellular and/or tissue levels that ultimately alter tissue dimensions and final adult proportions. Here, we investigated the cellular basis of an artificially selected divergence in the outline shape of Drosophila melanogaster wings, by comparing flies with elongated or rounded wing shapes but with remarkably similar wing sizes. We also tested whether cellular plasticity in response to developmental temperature was altered by such selection. Results show that variation in cellular traits is associated with wing shape differences, and that cell number may play an important role in wing shape response to selection. Regarding the effects of developmental temperature, a size-related plastic response was observed, in that flies reared at 16°C developed larger wings with larger and more numerous cells across all intervein regions relative to flies reared at 25°C. Nevertheless, no conclusive indication of altered phenotypic plasticity was found between selection strains for any wing or cellular trait. We also described how cell area is distributed across different intervein regions. It follows that cell area tends to decrease along the anterior wing compartment and increase along the posterior one. Remarkably, such pattern was observed not only in the selected strains but also in the natural baseline population, suggesting that it might be canalized during development and was not altered by the intense program of artificial selection for divergent wing shapes.

Interplay of normative beliefs and behavior in developmental patterns of physical and relational aggression in adolescence: a four-wave longitudinal study.

In a longitudinal study with N = 1,854 adolescents from Germany, we investigated patterns of change and gender differences in physical and relational aggression in relation to normative beliefs about these two forms of aggression. Participants, whose mean age was 13 years at T1, completed self-report measures of physically and relationally aggressive behavior and indicated their normative approval of both forms of aggression at four data waves separated by 12-month intervals. Boys scored higher than did girls on both forms of aggression, but the gender difference was more pronounced for physical aggression. Physical aggression decreased and relational aggression increased over the four data waves in both gender groups. The normative acceptance of both forms of aggression decreased over time, with a greater decrease for the approval of physical aggression. In both gender groups, normative approval of relational aggression prospectively predicted relational aggression across all data waves, and the normative approval of physical aggression predicted physically aggressive behavior at the second and third data waves. A reciprocal reinforcement of aggressive norms and behavior was found for both forms of aggression. The findings are discussed as supporting a social information processing perspective on developmental patterns of change in physical and relational aggression in adolescence.

Heterogeneous impact of motion on fundamental patterns of developmental changes in functional connectivity during youth

Several independent studies have demonstrated that small amounts of in-scanner motion systematically bias estimates of resting-state functional connectivity. This confound is of particular importance for studies of neurodevelopment in youth because motion is strongly related to subject age during this period. Critically, the effects of motion on connectivity mimic major findings in neurodevelopmental research, specifically an age-related strengthening of distant connections and weakening of short-range connections. Here, in a sample of 780 subjects ages 8–22, we re-evaluate patterns of change in functional connectivity during adolescent development after rigorously controlling for the confounding influences of motion at both the subject and group levels. We find that motion artifact inflates both overall estimates of age-related change as well as specific distance-related changes in connectivity. When motion is more fully accounted for, the prevalence of age-related change as well as the strength of distance-related effects is substantially reduced. However, age-related changes remain highly significant. In contrast, motion artifact tends to obscure age-related changes in connectivity associated with segregation of functional brain modules; improved preprocessing techniques allow greater sensitivity to detect increased within-module connectivity occurring with development. Finally, we show that subject’s age can still be accurately estimated from the multivariate pattern of functional connectivity even while controlling for motion. Taken together, these results indicate that while motion artifact has a marked and heterogeneous impact on estimates of connectivity change during adolescence, functional connectivity remains a valuable phenotype for the study of neurodevelopment.

Developmental changes in patterns of brain activity associated with moment-to-moment adjustments in control

The current study investigated age-related changes in patterns of brain activity associated with moment-to-moment adjustments in control through the use of fMRI. Fifty-eight participants ranging continuously in age from 9 to 32 years were scanned as they performed a task in which the need for rapid adjustments in control was greater in one condition than another. Despite comparable behavioral performance across ages, moment-to-moment adjustments were associated with stronger engagement of anterior cingulate, anterior insula, lateral prefrontal cortex and the intraparietal sulcus in older than in younger participants. The findings confirm the importance of cingulo-insular and fronto-parietal cortices for moment-to-moment adjustments in control, and suggest continuous increases in the utilization of these networks over development.

Infant Attention to Dynamic Audiovisual Stimuli: Look Duration From 3 to 9 Months of Age

The goal of this study was to examine developmental change in visual attention to dynamic visual and audiovisual stimuli in 3‐, 6‐, and 9‐month‐old infants. Infant look duration was measured during exposure to dynamic geometric patterns and Sesame Street video clips under three different stimulus modality conditions: unimodal visual, synchronous audiovisual, and asynchronous audiovisual. Infants looked longer toward Sesame Street stimuli than geometric patterns, and infants also looked longer during multimodal audiovisual (synchronous and asynchronous) presentations than during unimodal visual presentations. There was a three‐way interaction of age, stimulus type, and stimulus modality. Significant differences were found within and between age groups related to stimulus modality (visual or audiovisual) while viewing Sesame Street clips. No significant interaction was found between age and stimulus type while infants viewed dynamic geometric patterns. These findings indicate that patterns of developmental change in infant attention vary based on stimulus complexity and modality of presentation.

Parent-reported Attention Deficit/Hyperactivity symptomatology in preschool-aged children: factor structure, developmental change, and early risk factors.

Although Attention Deficit/Hyperactivity Disorder (ADHD) has increasingly been studied in preschool-aged children, relatively few studies have provided a comprehensive evaluation of the factor structure and patterns of developmental changes in parent-reported ADHD symptomatology across the early childhood period. This study used confirmatory factor analyses to test for longitudinal measurement invariance of ADHD symptoms and semi-parametric finite mixture models to identify prototypic patterns of developmental changes in ADHD symptomatology from 3 to 5 years of age. Participants were 1155 children and their parents who participated in a prospective longitudinal study involving a representative sample of children who resided in six non-metropolitan counties in the United States. Results indicated that (1) ADHD symptomatology was best represented by a single latent factor that exhibited partial measurement invariance from 3 to 5 years of age, (2) 8.5 % of children exhibited sustained high levels of ADHD symptoms from age 3-5 years, and (3) a variety of risk factors differentiated children with sustained high from those with sustained low levels of ADHD, relatively few (most notably caregiver education) were able to differentiate children with sustained high levels of ADHD symptoms from all other groups. Children who exhibit persistent ADHD symptomatology across the early childhood period may define a clinically important group for etiologic research and/or early intervention efforts.

Parenting styles and body mass index trajectories from adolescence to adulthood.

Parenting styles such as authoritarian, disengaged, or permissive are thought to be associated with greater adolescent obesity risk than an authoritative style. This study assessed the relationship between parenting styles and changes in body mass index (BMI) from adolescence to young adulthood. The study included self-reported data from adolescents in the National Longitudinal Study of Adolescent Health. Factor mixture modeling, a data-driven approach, was used to classify participants into parenting style groups based on measures of acceptance and control. Latent growth modeling (LGM) identified patterns of developmental changes in BMI. After a number of potential confounders were controlled for, parenting style variables were entered as predictors of BMI trajectories. Analyses were also conducted for male and female individuals of 3 racial-ethnic groups (Hispanic, black, white) to assess whether parenting styles were differentially associated with BMI trajectories in these 6 groups. Parenting styles were classified into 4 groups: authoritarian, disengaged, permissive, and balanced. Compared with the balanced parenting style, authoritarian and disengaged parenting styles were associated with a less steep average BMI increase (linear slope) over time, but also less leveling off (quadratic) of BMI over time. Differences in BMI trajectories were observed for various genders and races, but the differences did not reach statistical significance. Adolescents who reported having parents with authoritarian or disengaged parenting styles had greater increases in BMI as they transitioned to young adulthood despite having a lower BMI trajectory through adolescence.

Patterns of developmental change in infants' nighttime sleep awakenings from 6 through 36 months of age.

Nighttime sleep awakenings and infant and family characteristics were measured longitudinally in more than 1,200 infants when the infants were 6, 15, 24, and 36 months old. By 6 months of age, the majority of children slept through the night, awakening their mothers only about once or twice per week. However, not all children followed this predominant developmental pattern. Using growth mixture modeling, we identified 2 distinct developmental patterns. One group, labeled Sleepers, included 66% of the children. These children showed a flat trajectory of sleep awakenings from 6 through 36 months, with mothers reporting their infant awakening from sleep about 1 night per week. The second group, labeled Transitional Sleepers, included 34% of the infants. These children had 7 reported nights of awakenings per week at 6 months, dropping to 2 nights per week at 15 months and to 1 night per week by 24 months. Compared with Sleepers, Transitional Sleepers were more likely to be boys, score higher on the 6-month difficult temperament assessment, be breastfed at 6 and 15 months old, and have more depressed mothers at 6 months old. Using 2-group structural equation modeling, we examined individual differences at different points on the individual infants' sleep trajectories. For infants in both groups, reported sleep awakenings were associated with difficult temperament measured at 6 months, breastfeeding, infant illness, maternal depression, and greater maternal sensitivity. Infant-mother attachment measures were not related to these sleep awakenings.

Patterns of change in ocular motor development

This study examined development of pro- and anti-saccadic eye movements in a cross-sequential research design. A hundred and seventeen subjects aged 6-18years at initial testing were retested 18.9±1.2months later. Pro- and anti-saccades were elicited under the gap and overlap conditions. We found strong longitudinal developmental effects on all parameters analysed, in particular those derived from the anti-saccade task. These longitudinal changes structurally resembled the cross-sectional age effects observed for the same data. However, the principal component analyses of longitudinal "true" and raw difference scores revealed a stable three-factor solution that was robust to age effects and included (a) an express saccade factor, (b) a variability factor and (c) a factor consisting of direction errors with regular latencies and pro-saccadic RT. Cross-sectional factor analysis, by contrast, merged these two last-mentioned factors. We thus conclude that longitudinal data can provide unique information regarding individual differences in the patterns of developmental change.

Developmental Trajectories of Impulsivity and Their Association With Alcohol Use and Related Outcomes During Emerging and Young Adulthood I

Research has documented normative patterns of personality change during emerging and young adulthood that reflect decreases in traits associated with substance use, such as impulsivity. However, evidence suggests variability in these developmental changes. This study examined trajectories of impulsivity and their association with substance use and related problems from ages 18 to 35. Analyses were based on data collected from a cohort of college students (N = 489), at high and low risk for AUDs, first assessed as freshmen at a large, public university. Mixture modeling identified five trajectory groups that differed in baseline levels of impulsivity and developmental patterns of change. Notably, the trajectory group that exhibited the sharpest declines in impulsivity tended to display accelerated decreases in alcohol involvement from ages 18 to 25 compared to the other impulsivity groups. Findings highlight the developmental nature of impulsivity across emerging and young adulthood and provide an empirical framework to identify key covariates of individual changes of impulsivity.

Photosynthetic performance and stomatal characteristics during ex vitro acclimatisation of true service tree (Sorbus domestica L.)

SummaryMortality rates of micropropagated plantlets after transfer to an ex vitro environment are often high. The temporal pattern of developmental changes was examined in a slow-growing true service tree (Sorbus domestica L.) in relation to its photosynthetic and stomatal characteristics. The rates of net photosynthesis (Pn), transpiration (E), and stomatal conductance (gs), the maximum photochemical efficiency of photosystem II (Fv/Fm), potential electron capacity (‘area’), maximum-to-initial fluorescence ratio (Fm/F0), as well as stomatal densities and sizes, were determined over the course of a 63-day acclimatisation period. In vitro-rooted plantlets were photosynthetically competent. A sudden decrease in Pn was observed 7 d after transfer. The recovery of Pn took place within the next 28 d, and the rate remained steady until the end of acclimatisation.The most prominent changes in the Fv/Fm and Fm/F0 ratios were found between days-7 and -35. Full acclimatisation was achieved 63 d after transfer. This stage was associated with the lowest values of E, gs, and stomatal density, as well as the highest values of Fv/Fm, ‘area’, Fm/F0, and stomatal size.

Wood formation during ex vitro acclimatisation in micropropagated true service tree (Sorbus domestica L.)

Micropropagated plantlets derived from a superior 90+-year-old slow-growing true service tree (Sorbus domestica L.) have been successfully acclimatised to the ex vitro environment. The temporal pattern of developmental changes was examined in relation to secondary xylem growth during ex vitro acclimatisation. In vitro rooted plantlets already initiated lignification of secondary xylem cells. During early days after transfer to ex vitro conditions, the growth of woody tissue was slow. The most prominent increase in woody tissue development occurred between days 7 and 35. From days 35 to 63, sizes of vessel lumen areas significantly increased. In developing woody tissue, a characteristic diffuse-porous pattern of roughly even vessel area distribution throughout the growing season, typical for mature wood, was not followed. The proportion of woody area occupied by vessels was significantly higher in stems of fully acclimatised plantlets than in stems sampled 35 days after transfer. On day 63 after transfer, a proportion of woody tissue area in fully acclimatised plantlets represented up to 14.8% of the stem area. Early formation of wood during ex vitro acclimatisation provides brittle plantlets with a mechanical support to cope better with deformations and mechanical injuries during handling at the subsequent transplantations.

Distribution of intracellular and secreted surfactant during postnatal rat lung development

Pulmonary surfactant prevents alveolar collapse via reduction of surface tension. In contrast to human neonates, rats are born with saccular lungs. Therefore, rat lungs serve as a model for investigation of the surfactant system during postnatal alveolar formation. We hypothesized that this process is associated with characteristic structural and biochemical surfactant alterations. We aimed to discriminate changes related to alveolarization from those being either invariable or follow continuous patterns of postnatal changes. Secreted active (mainly tubular myelin (tm)) and inactive (unilamellar vesicles (ulv)) surfactant subtypes as well as intracellular surfactant (lamellar bodies (lb)) in type II pneumocytes (PNII) were quantified before (day (d) 1), during (d 7), at the end of alveolarization (d 14), and after completion of lung maturation (d 42) using electron microscopic methods supplemented by biochemical analyses (phospholipid quantification, immunoblotting for SP-A). Immunoelectron microscopy determined the localization of surfactant protein A (SP-A). (1) At d 1 secreted surfactant was increased relative to d 7-42 and then decreased significantly. (2) Air spaces of neonatal lungs comprised lower fractions of tm and increased ulv, which correlated with low SP-A concentrations in lung lavage fluid (LLF) and increased respiratory rates, respectively. (3) Alveolarization (d 7-14) was associated with decreasing PNII size although volume and sizes of Lb continuously increased. (4) The volume fractions of Lb correlated well with the pool sizes of phospholipids in lavaged lungs. Our study emphasizes differential patterns of developmental changes of the surfactant system relative to postnatal alveolarization.

A Brain-Based Account of the Development of Rule Use in Childhood

The ability to follow explicit rules improves dramatically during the course of childhood, but relatively little is known about the changes in brain structure and function that underlie this behavioral improvement. Drawing from neuroscientific studies in human adults and other animals, as well as from an emerging literature in developmental cognitive neuroscience, we propose a brain-based account of the development of rule use in childhood. This account focuses on four types of rules represented in different parts of the prefrontal cortex: simple rules for reversing stimulus–reward associations, pairs of conditional stimulus–response rules (both univalent and bivalent), and higher-order stimulus–response rules for selecting among task sets. It is hypothesized that the pattern of developmental changes in rule use reflects the different rates of development of specific regions within the prefrontal cortex.

Age Differences in Narcissistic Tendency in Adolescence

The purpose of the present study was to investigate age differences in narcissistic tendency during adolescence. Narcissistic tendency of 489 participants, junior and senior high school students and college undergraduates, was measured with Narcissistic Personality Inventory, Short Version (NPI-S). Results showed an increase in the tendency along with the age, but no significant difference was found between boys and girls. However, detailed examination revealed different patterns of developmental changes over time in subscales of NPI-S, and therefore further examination of age differences in them appeared to be necessary.

What have we learned about cognitive development from neuroimaging?

Changes in many domains of cognition occur with development. In this paper, we discuss neuroimaging approaches to understanding these changes at a neural level. We highlight how modern imaging methods such as functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) are being used to examine how cognitive development is supported by the maturation of the brain. Some reports suggest developmental changes in patterns of brain activity appear to involve a shift from diffuse to more focal activation, likely representing a fine-tuning of relevant neural systems with experience. One of the challenges in investigating the interplay between cognitive development and maturation of the brain is to separate the contributions of neural changes specific to development and learning. Examples are given from the developmental neuroimaging literature. The focus is on the development of cognitive control, as the protracted developmental course of this ability into adolescence raises key issues. Finally, the relevance of normative studies for understanding neural and cognitive changes in developmental disorders is discussed.

The nonmycorrhizal root – a strategy for survival in nutrient‐impoverished soils

The nonmycorrhizal root – a strategy for survival in nutrient‐impoverished soils

Hox code in embryos of Chinese soft-shelled turtlePelodiscus sinensis correlates with the evolutionary innovation in the turtle

Turtles have the most unusual body plan of the amniotes, with a dorsal shell consisting of modified ribs. Because this morphological change in the ribs can be described as an axial-level specific alteration, the evolution of the turtle carapace should depend on changes in the Hox code. To identify turtle-specific changes in developmental patterns, we cloned several Hox genes from the Chinese soft-shelled turtle, Pelodiscus sinensis, examined their expression patterns during embryogenesis, and compared them with those of chicken and mouse embryos. We detected possibly turtle-specific derived traits in Hoxc-6 expression, which is restricted to the paraxial part of the embryo; in the expression of Hoxa-5 and Hoxb-5, the transcripts of which were detected only at the cervical level; and in Hoxc-8 and Hoxa-7 expression, which is shifted anteriorly relative to that of the other two amniote groups. From the known functions of the Hox orthologs in model animals, these P. sinensis-specific changes apparently correlate with specializations in the turtle-specific body plan.

The Aspergillus nidulans npkA gene encodes a Cdc2-related kinase that genetically interacts with the UvsBATR kinase.

The DNA damage response is a protective mechanism that ensures the maintenance of genomic integrity. We have used Aspergillus nidulans as a model system to characterize the DNA damage response caused by the antitopoisomerase I drug, camptothecin. We report the molecular characterization of a p34Cdc2-related gene, npkA, from A. nidulans. The npkA gene is transcriptionally induced by camptothecin and other DNA-damaging agents, and its induction in the presence of camptothecin is dependent on the uvsBATR gene. There were no growth defects, changes in developmental patterns, increased sensitivity to DNA-damaging agents, or effects on septation or growth rate in the A. nidulans npkA deletion strain. However, the DeltanpkA mutation can partially suppress HU sensitivity caused by the DeltauvsBATR and uvsD153ATRIP checkpoint mutations. We demonstrated that the A. nidulans uvsBATR gene is involved in DNA replication and the intra-S-phase checkpoints and that the DeltanpkA mutation can suppress its intra-S-phase checkpoint deficiency. There is a defect in both the intra-S-phase and DNA replication checkpoints due to the npkA inactivation when DNA replication is slowed at 6 mm HU. Our results suggest that the npkA gene plays a role in cell cycle progression during S-phase as well as in a DNA damage signal transduction pathway in A. nidulans.

Putative protease inhibitor gene discovery and transcript profiling during fruit development and leaf damage in grapefruit (Citrus paradisi Macf.).

Seven putative protease inhibitor (PPI) cDNAs, representing four protein families, were isolated from a grapefruit (Citrus paradisi Macf. Cv. Marsh) immature fruit flavedo cDNA library. Cloned open reading frames encoded proteins with similarity to, and protein signatures for: legume Kuntiz inhibitors (lkiL-1, lkiL-2, lkiL-3), potato trypsin inhibitor I (ptiIL-1), serpins (serpL-1), cystatins (cystL-1), and gamma thionins (gthL-1). Response of transcript abundance to fruit development and leaf wounding was determined for all but lkiL-1 using real-time RT-PCR. Immature leaves had the highest transcript levels for all PPIs. The gthL-1 transcript in immature leaves was the most abundant transcript but was absent from healthy mature leaves. In fruit flavedo, transcripts for all PPIs were most abundant in youngest fruit (<15 mm dia. fruit), and declined during development, but displayed different patterns of developmental change. Mechanical or Diaprepes root weevil (DRW) feeding damage to leaves caused a <10-fold reduction or had no effect on transcript level with the exception of gthL-1 which, as a result of damage, increased >50-fold in mature leaves and decreased >1400-fold in immature leaves. This developmental control of transcript response to wounding in a woody perennial is opposite of what has been observed for defensive proteinase inhibitors (PIs) in other plants (typically herbaceous and/or annual plants), where younger leaves typically invoke a higher defensive proteinase inhibitor transcript accumulation than older tissues. Except for gthL-1, the PPI transcripts were minimally responsive or unresponsive to wounding. Changes in PPI transcript levels suggest diverse roles for the products of these genes in citrus, with only gthL-1 responding in a defense-like manner.