Environmental conditions experienced early in the life of an animal can result in gene expression changes later in its life history. We have previously shown that animals that experienced the developmentally arrested and stress resistant dauer stage (postdauers) retain a cellular memory of early-life stress that manifests during adulthood as genome-wide changes in gene expression, chromatin states, and altered life history traits. One consequence of developmental reprogramming in postdauer adults is the downregulation of TRPV channel gene expression in the ADL chemosensory neurons resulting in reduced avoidance to a pheromone component, ascr#3.
View Article and Find Full Text PDFWhile reports on the generational inheritance of a parental response to stress have been widely reported in animals, the molecular mechanisms behind this phenomenon have only recently emerged. The booming interest in epigenetic inheritance has been facilitated in part by the discovery that small non-coding RNAs are one of its principal conduits. Discovered 30 years ago in the nematode, these small molecules have since cemented their critical roles in regulating virtually all aspects of eukaryotic development.
View Article and Find Full Text PDFBuilding a brain is complicated but maintaining one may be an even greater challenge. Epigenetic mechanisms, including DNA methylation, histone and chromatin modifications, and the actions of non-coding RNAs, play an indispensable role in both. They orchestrate long-term changes in gene expression that underpin establishment of cellular identity as well as the distinct functionality of each cell type, while providing the needed plasticity for the brain to respond to a changing environment.
View Article and Find Full Text PDFIn animals, early-life stress can result in programmed changes in gene expression that can affect their adult phenotype. In nematodes, starvation during the first larval stage promotes entry into a stress-resistant dauer stage until environmental conditions improve. Adults that have experienced dauer (postdauers) retain a memory of early-life starvation that results in gene expression changes and reduced fecundity.
View Article and Find Full Text PDFNeurochem Int
September 2021
Since their discovery, small non-coding RNAs have emerged as powerhouses in the regulation of numerous cellular processes. In addition to guarding the integrity of the reproductive system, small non-coding RNAs play critical roles in the maintenance of the soma. Accumulating evidence indicates that small non-coding RNAs perform vital functions in the animal nervous system such as restricting the activity of deleterious transposable elements, regulating nerve regeneration, and mediating learning and memory.
View Article and Find Full Text PDFObjective: To investigate whether emotional intelligence (EI) skills measured via the Perceiving, Understanding, and Managing Emotions branches of the Mayer-Salovey-Caruso Emotional Intelligence Test V2.0 are associated with community integration (CI) and return to work (RTW) after moderate-to-severe acquired brain injury (ABI), after accounting for other established predictors.
Design: Retrospective cohort study.
Environmental stress during early development in animals can have profound effects on adult phenotypes via programmed changes in gene expression. Using the nematode C. elegans, we demonstrated previously that adults retain a cellular memory of their developmental experience that is manifested by differences in gene expression and life history traits; however, the sophistication of this system in response to different environmental stresses, and how it dictates phenotypic plasticity in adults that contribute to increased fitness in response to distinct environmental challenges, was unknown.
View Article and Find Full Text PDFExperiences during early development can influence neuronal functions and modulate adult behaviors [1, 2]. However, the molecular mechanisms underlying the long-term behavioral effects of these early experiences are not fully understood. The C.
View Article and Find Full Text PDFThe developmental accumulation of proliferative germ cells in the hermaphrodite is sensitive to the organismal environment. Previously, we found that the TGFβ signaling pathway links the environment and proliferative germ cell accumulation. Neuronal DAF-7/TGFβ causes a DAF-1/TGFβR signaling cascade in the gonadal distal tip cell (DTC), the germline stem cell niche, where it negatively regulates a DAF-3 SMAD and DAF-5 Sno-Ski.
View Article and Find Full Text PDFSocial and emotional problems are commonly reported after moderate to severe acquired brain injury (ABI) and pose a significant barrier to rehabilitation. However, progress in assessment of emotional skills has been limited by a lack of validated measurement approaches. This study represents the first formal psychometric evaluation of the use of the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) V2.
View Article and Find Full Text PDFAnimals can adapt to unfavorable environments through changes in physiology or behavior. In the nematode, , environmental conditions perceived early in development determine whether the animal enters either the reproductive cycle, or enters into an alternative diapause stage named dauer. Here, we show that endogenous RNAi pathways play a role in dauer formation in crowding (high pheromone), starvation, and high temperature conditions.
View Article and Find Full Text PDFLittle is known about the role of state versus trait characteristics on our enjoyment of music. The aim of this study was to investigate the influence of state and trait absorption upon preference for music, particularly preference for music that evokes negative emotions. The sample consisted of 128 participants who were asked to listen to two pieces of self-selected music and rate the music on variables including preference and felt and expressed emotions.
View Article and Find Full Text PDFThe C. elegans dauer is an attractive model with which to investigate fundamental biological questions, such as how environmental cues are sensed and are translated into developmental decisions through a series of signaling cascades that ultimately result in a transformed animal. Here we describe a simple method of using egg white plates to obtain highly synchronized purified dauers that can be used in downstream applications requiring large quantities of dauers or postdauer animals.
View Article and Find Full Text PDFIn recent years, distinct classes of small RNAs ranging in size from ~21 to 26 nucleotides have been discovered and shown to play important roles in a wide array of cellular functions. Because of the abundance of these small RNAs, library preparation from an RNA sample followed by deep sequencing provides the identity and quantity of a particular class of small RNAs. In this chapter we describe a detailed protocol for preparing small RNA libraries for deep sequencing on the Illumina platform from the nematode C.
View Article and Find Full Text PDFThe present study investigated effects of signaled reinforcer magnitude in a delayed identity matching-to-sample procedure. Four individuals with intellectual disabilities were trained on conditional discrimination with three geometric stimuli as sample and comparison stimuli. Retention intervals ranged from 0.
View Article and Find Full Text PDFEarly environmental experiences profoundly influence adult phenotypes through complex mechanisms that are poorly understood. We previously showed that adult Caenorhabditis elegans that transiently passed through the stress-induced dauer larval stage (post-dauer adults) exhibit significant changes in gene expression profiles, chromatin states, and life history traits when compared with adults that bypassed the dauer stage (control adults). These wild-type, isogenic animals of equivalent developmental stages exhibit different signatures of molecular marks that reflect their distinct developmental trajectories.
View Article and Find Full Text PDFComplement Ther Clin Pract
August 2012
Autism spectrum disorders (ASD) have rapidly become one of the more frequent reasons for seeking diagnosis and treatment. Depending on health care services available, the standard treatment options are often limited; many parents turn to complementary and alternative medicine (CAM) approaches. CAM treatments and some of the factors that may contribute to parents' decisions to use CAM treatments were examined using a web-based survey.
View Article and Find Full Text PDFMechanisms of attention are required to prioritise goal-relevant sensory events under conditions of stimulus competition. According to the perceptual load model of attention, the extent to which task-irrelevant inputs are processed is determined by the relative demands of discriminating the target: the more perceptually demanding the target task, the less unattended stimuli will be processed. Although much evidence supports the perceptual load model for competing stimuli within a single sensory modality, the effects of perceptual load in one modality on distractor processing in another is less clear.
View Article and Find Full Text PDFBeing able to wait is an essential part of self-regulation. In the present study, the authors examined the developmental course of changes in the latency to and duration of target-waiting behaviors by following 65 boys and 55 girls from rural and semirural economically strained homes from ages 18 months to 48 months. Age-related changes in latency to and duration of children's anger expressions and attention focus (e.
View Article and Find Full Text PDFEarly life experiences have a major impact on adult phenotypes [1-3]. However, the mechanisms by which animals retain a cellular memory of early experience are not well understood. Here we show that adult wild-type Caenorhabditis elegans that transiently pass through the stress-resistant dauer larval stage exhibit distinct gene expression profiles and life history traits, as compared to adult animals that bypassed this stage.
View Article and Find Full Text PDFHigher eukaryotic centromeres contain thousands of satellite repeats organized into tandem arrays. As species diverge, new satellite variants are homogenized within and between chromosomes, yet the processes by which particular sequences are dispersed are poorly understood. Here, we isolated and analyzed centromere satellites in plants separated from Arabidopsis thaliana by 5-20 million years, uncovering more rapid satellite divergence compared to primate alpha-satellite repeats.
View Article and Find Full Text PDFThe condensed centromeric regions of higher eukaryotic chromosomes contain satellite sequences, transposons and retroelements, as well as transcribed genes that perform a variety of functions. These chromosomal domains nucleate kinetochores, mediate sister chromatid cohesion and inhibit recombination, yet their characterization has often lagged behind that of chromosome arms. Here, we describe a whole-genome fractionation technique that rapidly identifies bacterial artificial chromosome (BAC) clones derived from plant centromeric regions.
View Article and Find Full Text PDFMeiotic and mitotic chromosome segregation are highly conserved in eukaryotic organisms, yet centromeres--the chromosomal sites that mediate segregation--evolve extremely rapidly. Plant centromeres have DNA elements that are shared across species, yet they diverge rapidly through large- and small-scale changes. Over evolutionary time-scales, centromeres migrate to non-centromeric regions and, in plants, heterochromatic knobs can acquire centromere activity.
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