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Journal of Child & Adolescent Trauma Jun 2023The death of a loved one represents one of the most distressing and potentially traumatic life events in childhood and adolescence. Grief reactions in youth are...
The death of a loved one represents one of the most distressing and potentially traumatic life events in childhood and adolescence. Grief reactions in youth are influenced by ongoing developmental processes and manifest differently depending on the child's age and developmental stage. These grief-related processes unfold within youths' caregiving context, as children and adolescents rely heavily on the adults in their environment to navigate and cope with the death of a loved one. Despite the field's increasing recognition of the potential for maladaptive grief reactions to impede functioning over time, few longitudinal research studies on childhood grief currently exist. In this article, we will (a) provide a brief overview of the childhood bereavement literature; (b) review the new DSM-5 and ICD-11 Prolonged Grief Disorder diagnostic criteria through a developmentally-informed lens; (c) describe how grief reactions manifest in children and adolescents of different ages through the lenses of multidimensional grief theory and relational developmental systems theory; (d) highlight key moderating factors that may influence grief in youth, and (e) discuss a primary moderating factor, the caregiving environment, and the potential mechanisms through which caregivers influence children's grief.
PubMed: 35106114
DOI: 10.1007/s40653-021-00435-0 -
Insect Biochemistry and Molecular... Jun 2022The heterochronic microRNA let-7, which was first identified in Caenorhabditis elegans, controls the timing of developmental programs, and let-7 triggers the onset of...
The heterochronic microRNA let-7, which was first identified in Caenorhabditis elegans, controls the timing of developmental programs, and let-7 triggers the onset of the juvenile-adult transition in bilaterians. The expression of let-7 is strongly induced during the last larval stage of C. elegans and is highly expressed in the late last instar larvae/nymphs of the fly Drosophila melanogaster and the cockroach Blattella germanica. In the silkworm Bombyx mori, the expression of let-7 remarkably increases in the corpus cardiacum-corpus allatum complex (CC-CA) at the beginning of the last larval instar and is maintained at high levels during this instar. To determine the biological function of let-7 in B. mori, we generated a let-7 knockout line and a transgenic UAS-let-7 line. The let-7 knockout larvae were developmentally arrested in the prepupal stage and became pupal-adult intermediates after apolysis. When let-7 was ubiquitously overexpressed under the transcriptional control of an Actin3-GAL4 driver, developmental timing and growth of larvae were severely impaired in the penultimate (L4) instar, and these larvae underwent precocious metamorphosis from L4. Furthermore, our results showed that reception and signaling of ecdysteroids and juvenile hormones (JHs) normally occurred in the absence of let-7, whereas the biosynthesis of ecdysone and JHs were affected by disruption and overexpression of let-7. Together, the present study demonstrates that let-7 is required for the coordination of the biosynthesis of ecdysone and JH to ensure the developmental transition during the metamorphosis of B. mori.
Topics: Animals; Bombyx; Caenorhabditis elegans; Drosophila melanogaster; Ecdysone; Gene Expression Regulation, Developmental; Juvenile Hormones; Larva; Metamorphosis, Biological; MicroRNAs
PubMed: 35533806
DOI: 10.1016/j.ibmb.2022.103784 -
Developmental Dynamics : An Official... Feb 2022Divergent morphology and placentation of Poeciliids make them suitable model for investigating how evolutionary selection has altered and conserved the developmental...
BACKGROUND
Divergent morphology and placentation of Poeciliids make them suitable model for investigating how evolutionary selection has altered and conserved the developmental mechanisms. However, there is limited description of their embryonic staging, despite representing a key evolutionary node that shares developmental strategy with placental vertebrates. Here, we describe the embryonic developmental stages of Gambusia holbrooki from zygote to parturition using freshly harvested embryos.
RESULTS
We defined 40 embryonic stages using a numbered (stages 0-39; zygote to parturition, respectively) and named (grouped into seven periods, ie, zygote, cleavage, blastula, gastrula, segmentation, pharyngula, and parturition) staging system. Two sets of quantitative (ie, egg diameter, embryonic total length, otic vesicle closure index, heart rates, the number of caudal fin rays and elements) and qualitative (ie, three-dimensional analysis of images and key morphological criteria) data were acquired and used in combination to describe each stage. All 40 stages are separated by well-defined morphological traits, revealing developmental novelties that are influenced by narrow perivitelline space, placentation, internal gestation, and sex differentiation.
CONCLUSIONS
The principal diagnostic features described are quick, reliable, and easy to apply. This system will benefit researchers investigating molecular ontogeny, particularly sexual differentiation mechanisms in G. holbrooki.
Topics: Animals; Blastula; Cyprinodontiformes; Embryonic Development; Female; Placenta; Pregnancy; Zygote
PubMed: 34139034
DOI: 10.1002/dvdy.388 -
Developmental Biology Sep 2024Regeneration, regrowing lost and injured body parts, is an ability that generally declines with age or developmental transitions (i.e. metamorphosis, sexual maturation)....
Regeneration, regrowing lost and injured body parts, is an ability that generally declines with age or developmental transitions (i.e. metamorphosis, sexual maturation). Regeneration is also an energetically costly process, and trade-offs occur between regeneration and other costly processes such as growth, or sexual reproduction. Here we investigate the interplay of regeneration, reproduction, and developmental stage in the segmented worm Platynereis dumerilii. P. dumerilii can regenerate its whole posterior body axis, along with its reproductive cells, thereby having to carry out the two costly processes (somatic and germ cell regeneration) after injury. We specifically examine how developmental stage affects the success of germ cell regeneration and sexual maturation in developmentally young versus developmentally old organisms. We hypothesized that developmentally younger individuals (i.e. with gametes in early mitotic stages) will have higher regeneration success than the individuals at developmentally older stages (i.e. with gametes undergoing meiosis and maturation). Surprisingly, older amputated worms grew faster and matured earlier than younger amputees. To analyze germ cell regeneration during and after posterior regeneration, we used Hybridization Chain Reaction for the germline marker vasa. We found that regenerated worms start repopulating new segments with germ cell clusters as early as 14 days post amputation. In addition, vasa expression is observed in a wide region of newly-regenerated segments, which appears different from expression patterns during normal growth or regeneration in worms before gonial cluster expansion.
Topics: Animals; Germ Cells; Regeneration; Sexual Maturation; Polychaeta
PubMed: 38797257
DOI: 10.1016/j.ydbio.2024.05.013 -
Developmental Biology Oct 2017Oocyte differentiation is a highly dynamic and intricate developmental process whose mechanistic understanding advances female reproduction, fertility, and ovarian...
Oocyte differentiation is a highly dynamic and intricate developmental process whose mechanistic understanding advances female reproduction, fertility, and ovarian cancer biology. Despite the many attributes of the zebrafish model, it has yet to be fully exploited for the investigation of early oocyte differentiation and ovarian development. This is partly because the properties of the adult zebrafish ovary make it technically challenging to access early stage oocytes. As a result, characterization of these stages has been lacking and tools for their analysis have been insufficient. To overcome these technical hurdles, we took advantage of the juvenile zebrafish ovary, where early stage oocytes can readily be found in high numbers and progress in a predictable manner. We characterized the earliest stages of oocyte differentiation and ovarian development and defined accurate staging criteria. We further developed protocols for quantitative microscopy, live time-lapse imaging, ovarian culture, and isolation of stage-specific oocytes for biochemical analysis. These methods have recently provided us with an unprecedented view of early oogenesis, allowing us to study formation of the Balbiani body, a universal oocyte granule that is associated with oocyte survival in mice and required for oocyte and egg polarity in fish and frogs. Despite its tremendous developmental significance, the Bb has been little investigated and how it forms was unknown in any species for over two centuries. We were able to trace Balbiani body formation and oocyte symmetry breaking to the onset of meiosis. Through this investigation we revealed novel cytoskeletal structures in oocytes and the contribution of specialized cellular organization to differentiation. Overall, the juvenile zebrafish ovary arises as an exciting model for studies of cell and developmental biology. We review these and other recent advances in vertebrate oogenesis in an accompanying manuscript in this issue of Developmental Biology. Here, we describe the protocols for ovarian investigation that we developed in the zebrafish, including all experimental steps that will easily allow others to reproduce such analysis. This juvenile ovary toolbox also contributes to establishing the zebrafish as a model for post-larval developmental stages.
Topics: Animals; Cells, Cultured; Cytoskeleton; DNA; Female; Genes, Reporter; In Situ Hybridization, Fluorescence; Luminescent Proteins; Meiosis; Microscopy, Confocal; Oocytes; Oogenesis; Organelles; Ovary; Ovum; RNA, Messenger; Sex Determination Processes; Specimen Handling; Staining and Labeling; Time-Lapse Imaging; Zebrafish
PubMed: 27988227
DOI: 10.1016/j.ydbio.2016.12.014 -
Toxicology Letters Sep 2023Acetaminophen is a common analgesic and fever reduction medicine for pregnant women. Epidemiological studies suggest that prenatal acetaminophen exposure (PAcE) affects...
Acetaminophen is a common analgesic and fever reduction medicine for pregnant women. Epidemiological studies suggest that prenatal acetaminophen exposure (PAcE) affects offspring health and development. However, the effects of PAcE on fetal long bone development and its potential mechanisms have not been elucidated. Based on clinical dosing characteristics, fetal mouse femurs were obtained for detection after oral gavage of acetaminophen at different doses (0, 100 or 400 mg/kg d), courses (single or multiple times) or stages (mid- or late pregnancy) during pregnancy in Kunming mice. The results showed that compared with the control group, PAcE reduced the length of total femur and the primary ossification center (POC), delayed the mineralization of POC and the ossification of epiphyseal region, and down-regulated the mRNA expression of osteogenic function markers (such as Runx2, Bsp, Ocn , Col1a1) in fetal femur, particularly in the high dose, multiple courses, and mid-pregnancy group. Meanwhile, the osteoclast and angiogenic function were also inhibited by PAcE at high dose, multiple courses, and mid-pregnancy, but the inhibition level was less than osteogenic function. Moreover, the alteration of canonical Wnt signalling pathway in PAcE fetal bone were consistent with its osteogenesis function changes. In conclusion, PAcE caused development toxicity and multi-cellular function inhibition in fetal long bone, particularly in the high dose, multiple treatments and mid-pregnancy group, and the alteration of canonical Wnt signalling pathway may be its potential mechanism.
Topics: Humans; Mice; Pregnancy; Female; Animals; Acetaminophen; Fetal Development; Osteogenesis; Bone and Bones; Prenatal Exposure Delayed Effects
PubMed: 37741353
DOI: 10.1016/j.toxlet.2023.09.007 -
DNA and Cell Biology Apr 2021The fall armyworm () is one of the most significant agricultural pests in the world and invaded China in early 2019. We sampled and sequenced RNA-seq data from 15...
The fall armyworm () is one of the most significant agricultural pests in the world and invaded China in early 2019. We sampled and sequenced RNA-seq data from 15 individuals across different developmental stages. Developmental stages were the larval stage (5th instar larvae and 6th instar larvae), chrysalis stage, and adult stage (female adult and male adult). Individual samples were mainly clustered by developmental stages and we then identified variation between developmental stages of differentially expressed transcripts (DETs). There were 2136 upregulated DETs and 1391 downregulated DETs in the larval stage when comparing larval and chrysalis stages. In the comparison between the chrysalis and adult stages, there were 2033 upregulated DETs and 1391 downregulated DETs in the chrysalis stage. In total, 19,195 abundantly expressed transcripts were obtained and 10% of them were DETs. We then obtained stage-specific DETs to investigate the potential function of the fall armyworm during different developmental stages. We also constructed our annotation background set for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. This indicated that the fall armyworm may undergo active metabolism during its lifespan, even in the chrysalis stage. And it also may experience detoxifying and xenobiotic metabolism throughout its life, especially in the larval stage, which partially explains the difficulty to eradicate using chemical control. Our study is the first insight into the developmental patterns of the fall armyworm and we also provide the fundamental information about enhanced drug resistance at the level of transcriptome. These results are beneficial for a future investigation related to the eradication and/or control stage.
Topics: Animals; China; Gene Expression; Gene Expression Regulation, Developmental; Gene Ontology; Larva; RNA-Seq; Spodoptera; Transcriptome
PubMed: 33761271
DOI: 10.1089/dna.2020.6191 -
Cell Reports Feb 2023During pre-implantation stages of mammalian development, maternally stored material promotes both the erasure of the sperm and oocyte epigenetic profiles and is...
During pre-implantation stages of mammalian development, maternally stored material promotes both the erasure of the sperm and oocyte epigenetic profiles and is responsible for concomitant genome activation. Here, we have utilized single-cell methylome and transcriptome sequencing (scM&T-seq) to quantify both mRNA expression and DNA methylation in oocytes and a developmental series of human embryos at single-cell resolution. We fully characterize embryonic genome activation and maternal transcript degradation and map key epigenetic reprogramming events in developmentally high-quality embryos. By comparing these signatures with early embryos that have undergone spontaneous cleavage-stage arrest, as determined by time-lapse imaging, we identify embryos that fail to appropriately activate their genomes or undergo epigenetic reprogramming. Our results indicate that a failure to successfully accomplish these essential milestones impedes the developmental potential of pre-implantation embryos and is likely to have important implications, similar to aneuploidy, for the success of assisted reproductive cycles.
Topics: Animals; Humans; Male; Multiomics; Semen; Embryonic Development; Embryo, Mammalian; Oocytes; Epigenesis, Genetic; Blastocyst; Mammals
PubMed: 36763500
DOI: 10.1016/j.celrep.2023.112100 -
American Journal of Botany Apr 2020The size and shape (physiognomy) of woody, dicotyledonous angiosperm leaves are correlated with climate. These relationships are the basis for multiple paleoclimate...
PREMISE
The size and shape (physiognomy) of woody, dicotyledonous angiosperm leaves are correlated with climate. These relationships are the basis for multiple paleoclimate proxies. Here we test whether Vitis exhibits phenotypic plasticity and whether physiognomy varies along the vine.
METHODS
We used Digital Leaf Physiognomy (DiLP) to measure leaf characters of four Vitis species from the USDA Germplasm Repository (Geneva, New York) from the 2012-2013 and 2014-2015 leaf-growing seasons, which had different environmental conditions.
RESULTS
Leaf shape changed allometrically through developmental stages; early stages were more linear than later stages. There were significant differences in physiognomy in the same developmental stage between the growing seasons, and species had significant differences in mean physiognomy between growing seasons. Phenotypic plasticity was defined as changes between growing seasons after controlling for developmental stage or after averaging all developmental stages. Vitis amurensis and V. riparia had the greatest phenotypic plasticity. North American species exhibited significant differences in tooth area:blade area. Intermediate developmental stages were most likely to exhibit phenotypic plasticity, and only V. amurensis exhibited phenotypic plasticity in later developmental stages.
CONCLUSIONS
Leaves have variable phenotypic plasticity along the vine. Environmental signal was strongest in intermediate developmental stages. This is significant for leaf physiognomic-paleoclimate proxies because these leaves are likely the most common in leaf litter and reflect leaves primarily included in paleoclimate reconstructions. Early season and early developmental stages have the potential to be confounding factors but are unlikely to exert significant influence because of differential preservation potential.
Topics: Climate; Environment; New York; Plant Leaves; Vitis
PubMed: 32270876
DOI: 10.1002/ajb2.1460 -
Journal of Experimental Botany Dec 2021Determining the grain yield potential contributed by grain number is a step towards advancing the yield of cereal crops. To achieve this aim, it is pivotal to recognize...
Determining the grain yield potential contributed by grain number is a step towards advancing the yield of cereal crops. To achieve this aim, it is pivotal to recognize the maximum yield potential (MYP) of the crop. In barley (Hordeum vulgare L.), the MYP is defined as the maximum spikelet primordia number of a spike. Many barley studies assumed the awn primordium (AP) stage to be the MYP stage regardless of genotypes and growth conditions. From our spikelet-tracking experiments using the two-rowed cultivar Bowman, we found that the MYP stage can be different from the AP stage. Importantly, we find that the occurrence of inflorescence meristem deformation and its loss of activity coincided with the MYP stage, indicating the end of further spikelet initiation. Thus, we recommend validating the barley MYP stage with the shape of the inflorescence meristem and propose this approach (named 'spikelet stop') for MYP staging. To clarify the relevance of AP and MYP stages, we compared the MYP stage and the MYP in 27 barley accessions (two- and six-rowed accessions) grown in the greenhouse and in the field. Our results reveal that the MYP stage can be reached at various developmental stages, which greatly depend on the genotype and growth conditions. Furthermore, we propose that the MYP stage and the time to reach the MYP stage can be used to determine yield potential in barley. Based on our findings, we suggest key steps for the identification of the MYP stage in barley that may also be applied in a related crop such as wheat.
Topics: Edible Grain; Hordeum; Inflorescence; Meristem; Triticum
PubMed: 34291795
DOI: 10.1093/jxb/erab342