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Frontiers in Physiology 2022Diapause is a physiological adaptation to conditions that are unfavorable for growth or reproduction. During diapause, animals become long-lived, stress-resistant,... (Review)
Review
Diapause is a physiological adaptation to conditions that are unfavorable for growth or reproduction. During diapause, animals become long-lived, stress-resistant, developmentally static, and non-reproductive, in the case of diapausing adults. Diapause has been observed at all developmental stages in both vertebrates and invertebrates. In adults, diapause traits weaken into adaptations such as hibernation, estivation, dormancy, or torpor, which represent evolutionarily diverse versions of the traditional diapause traits. These traits are regulated through modifications of the endocrine program guiding development. In insects, this typically includes changes in molting hormones, as well as metabolic signals that limit growth while skewing the organism's energetic demands toward conservation. While much work has been done to characterize these modifications, the interactions between hormones and their downstream consequences are incompletely understood. The current state of diapause endocrinology is reviewed here to highlight the relevance of diapause beyond its use as a model to study seasonality and development. Specifically, insect diapause is an emerging model to study mechanisms that determine lifespan. The induction of diapause represents a dramatic change in the normal progression of age. Hormones such as juvenile hormone, 20-hydroxyecdysone, and prothoracicotropic hormone are well-known to modulate this plasticity. The induction of diapause-and by extension, the cessation of normal aging-is coordinated by interactions between these pathways. However, research directly connecting diapause endocrinology to the biology of aging is lacking. This review explores connections between diapause and aging through the perspective of endocrine signaling. The current state of research in both fields suggests appreciable overlap that will greatly contribute to our understanding of diapause and lifespan determination.
PubMed: 35242054
DOI: 10.3389/fphys.2022.825057 -
Zebrafish Feb 2020Zebrafish () are highly social animals that engage in a diverse variety of nonreproductive social behaviors that emerge as early as 14 days postfertilization (dpf)....
Zebrafish () are highly social animals that engage in a diverse variety of nonreproductive social behaviors that emerge as early as 14 days postfertilization (dpf). However, we observe considerable behavioral variability at this stage, and comparisons across studies are potentially complicated both by chronological gaps in measurements and inconsistencies in developmental staging. To address these issues, we adapted our assay for social orienting and cueing in the adult zebrafish and used it to probe behavior in a critical window of larval development. In addition, we performed measurements of body length and tested a cohort of larvae with impaired growth to understand if this morphological feature is predictive of individual sociality. We report that zebrafish exhibit increasingly complex social behaviors between 10 and 16 dpf, including place preference, orienting, and social cueing. Furthermore, social behavior is related to standard length on an individual basis beginning at 14 dpf, such that developmentally stunted 14 dpf zebrafish raised on dry feed do not exhibit social behaviors, suggesting some morphological features are more predictive than chronological age. This highly variable and early stage in development provides an opportunity to further understand how genetic and environmental factors affect the assembly of neural circuits underlying complex behaviors.
Topics: Animals; Body Size; Cues; Orientation, Spatial; Social Behavior; Zebrafish
PubMed: 31930951
DOI: 10.1089/zeb.2019.1815 -
Nature Methods Dec 2023During animal development, embryos undergo complex morphological changes over time. Differences in developmental tempo between species are emerging as principal drivers...
During animal development, embryos undergo complex morphological changes over time. Differences in developmental tempo between species are emerging as principal drivers of evolutionary novelty, but accurate description of these processes is very challenging. To address this challenge, we present here an automated and unbiased deep learning approach to analyze the similarity between embryos of different timepoints. Calculation of similarities across stages resulted in complex phenotypic fingerprints, which carry characteristic information about developmental time and tempo. Using this approach, we were able to accurately stage embryos, quantitatively determine temperature-dependent developmental tempo, detect naturally occurring and induced changes in the developmental progression of individual embryos, and derive staging atlases for several species de novo in an unsupervised manner. Our approach allows us to quantify developmental time and tempo objectively and provides a standardized way to analyze early embryogenesis.
Topics: Animals; Deep Learning; Embryonic Development; Biological Evolution; Temperature
PubMed: 37996754
DOI: 10.1038/s41592-023-02083-8 -
Fly Dec 2023Valosin-containing protein (VCP) is a versatile and ubiquitously expressed AAA+ ATPase that regulates multiple stages of spermatogenesis. While VCP has documented roles...
Valosin-containing protein (VCP) is a versatile and ubiquitously expressed AAA+ ATPase that regulates multiple stages of spermatogenesis. While VCP has documented roles in mitotic spermatogonia and meiotic spermatocytes, it is also highly expressed in post-meiotic spermatids, suggesting potential late-stage developmental functions as well. However, tools to assess late-stage activities of pleiotropic spermatogenesis genes such as are lacking. Available germline-specific Gal4 drivers activate in stem cells or spermatogonia; consequently, knocking down using one of these drivers disrupts or blocks early germ-cell development, precluding analysis of VCP in later stages. A Gal4 driver that activates later in development, such as at the meiotic spermatocyte stage, may permit functional analyses of VCP and other factors in post-meiotic stages. Here, we describe a germline-specific Gal4 driver, Rbp4-Gal4, which drives transgene expression beginning in the early spermatocyte stage. We find that Rbp4-Gal4-driven knockdown of causes defects in spermatid chromatin condensation and individualization without affecting earlier developmental stages. Interestingly, the defect in chromatin condensation appears linked to errors in the histone-to-protamine transition, a key event in spermatid development. Overall, our study reveals roles for VCP in spermatid development and establishes a powerful tool to dissect the functions of pleiotropic spermatogenesis genes.
Topics: Male; Animals; Spermatids; Valosin Containing Protein; Spermatogenesis; Meiosis; Drosophila; Chromatin
PubMed: 37436409
DOI: 10.1080/19336934.2023.2234795 -
Bioinformatics (Oxford, England) Jan 2022The hourglass model is a popular evo-devo model depicting that the developmental constraints in the middle of a developmental process are higher, and hence the...
MOTIVATION
The hourglass model is a popular evo-devo model depicting that the developmental constraints in the middle of a developmental process are higher, and hence the phenotypes are evolutionarily more conserved, than those that occur in early and late ontogeny stages. Although this model has been supported by studies analyzing developmental gene expression data, the evolutionary explanation and molecular mechanism behind this phenomenon are not fully understood yet. To approach this problem, Raff proposed a hypothesis and claimed that higher interconnectivity among elements in an organism during organogenesis resulted in the larger constraints at the mid-developmental stage. By employing stochastic network analysis and gene-set pathway analysis, we aim to demonstrate such changes of interconnectivity claimed in Raff's hypothesis.
RESULTS
We first compared the changes of network randomness among developmental processes in different species by measuring the stochasticity within the biological network in each developmental stage. By tracking the network entropy along each developmental process, we found that the network stochasticity follows an anti-hourglass trajectory, and such a pattern supports Raff's hypothesis in dynamic changes of interconnections among biological modules during development. To understand which biological functions change during the transition of network stochasticity, we sketched out the pathway dynamics along the developmental stages and found that species may activate similar groups of biological processes across different stages. Moreover, higher interspecies correlations are found at the mid-developmental stages.
SUPPLEMENTARY INFORMATION
Supplementary data are available at Bioinformatics online.
Topics: Embryonic Development; Biological Evolution
PubMed: 34677580
DOI: 10.1093/bioinformatics/btab735 -
PloS One 2022One challenge in avian embryology is establishing a standard developmental timetable, primarily because eggs incubated for identical durations can vary in developmental...
One challenge in avian embryology is establishing a standard developmental timetable, primarily because eggs incubated for identical durations can vary in developmental progress, even within the same species. For remedy, avian development is classified into distinct stages based on the formation of key morphological structures. Developmental stages exist for a few galliform species, but the literature is lacking a description of normal stages for California valley quail (Callipepla californica). Thus, the objective of this study was to stage and document the morphological and structural development of California valley quail. Over two laying seasons, 390 eggs were incubated at 37.8֯ C in 60% RH for ≤23 days. Eggs were opened every ≤6 hours to document embryonic development, including, blastoderm diameter, anterior angle of nostril to beak tip, and lengths of wing, tarsus, third toe, total beak, total foot, and embryo. California valley quail embryos were staged and compared to domestic chicken (Gallus gallus domesticus), the staging standard for galliformes, as well as Japanese quail (Coturnix japonica), blue-breasted quail (Synoicus chinensis) and northern bobwhite quail (Colinus virginianus). This study produced the first description of the 43 normal stages of development for California valley quail. Compared with other galliformes, the California valley quail has a different number of stages and displays developmental heterochrony in stages 1-24, and morphological and developmental differences in stages 25-hatch. The observed differences emphasize the importance of staging individual avian species instead of relying on poultry animal models or close relatives for developmental reference. This is extremely important in species-specific embryological studies that evaluate critical windows of development or evaluate the impacts of environmental change on avian development. This study also suggests that staging frequencies of ≤6 hours and egg transport protocols should be standardized for future staging studies.
Topics: Animals; Blastoderm; California; Chickens; Colinus; Coturnix; Galliformes; Quail
PubMed: 35580090
DOI: 10.1371/journal.pone.0268524 -
Developmental Neurobiology Jul 2022Compared with that of even the closest primates, the human cortex displays a high degree of specialization and expansion that largely emerges developmentally. Although... (Review)
Review
Compared with that of even the closest primates, the human cortex displays a high degree of specialization and expansion that largely emerges developmentally. Although decades of research in the mouse and other model systems has revealed core tenets of cortical development that are well preserved across mammalian species, small deviations in transcription factor expression, novel cell types in primates and/or humans, and unique cortical architecture distinguish the human cortex. Importantly, many of the genes and signaling pathways thought to drive human-specific cortical expansion also leave the brain vulnerable to disease, as the misregulation of these factors is highly correlated with neurodevelopmental and neuropsychiatric disorders. However, creating a comprehensive understanding of human-specific cognition and disease remains challenging. Here, we review key stages of cortical development and highlight known or possible differences between model systems and the developing human brain. By identifying the developmental trajectories that may facilitate uniquely human traits, we highlight open questions in need of approaches to examine these processes in a human context and reveal translatable insights into human developmental disorders.
Topics: Animals; Brain; Cerebral Cortex; Humans; Mammals; Mice; Neurogenesis
PubMed: 35644985
DOI: 10.1002/dneu.22879 -
Glia Mar 2022Kallikrein related peptidase 6 (Klk6) is a secreted serine protease highly expressed in oligodendrocytes and implicated in demyelinating conditions. To gain insights...
Kallikrein related peptidase 6 (Klk6) is a secreted serine protease highly expressed in oligodendrocytes and implicated in demyelinating conditions. To gain insights into the significance of Klk6 to oligodendrocyte biology, we investigated the impact of global Klk6 gene knockout on CNS developmental myelination using the spinal cord of male and female mice as a model. Results demonstrate that constitutive loss of Klk6 expression accelerates oligodendrocyte differentiation developmentally, including increases in the expression of myelin proteins such as MBP, PLP and CNPase, in the number of CC-1+ mature oligodendrocytes, and myelin thickness by the end of the first postnatal week. Co-ordinate elevations in the pro-myelinating signaling pathways ERK and AKT, expression of fatty acid 2-hydroxylase, and myelin regulatory transcription factor were also observed in the spinal cord of 7d Klk6 knockouts. LC/MS/MS quantification of spinal cord lipids showed sphingosine and sphingomyelins to be elevated in Klk6 knockouts at the peak of myelination. Oligodendrocyte progenitor cells (OPCs)-derived from Klk6 knockouts, or wild type OPCs-treated with a Klk6 inhibitor (DFKZ-251), also showed increased MBP and PLP. Moreover, inhibition of Klk6 in OPC cultures enhanced brain derived neurotrophic factor-driven differentiation. Altogether, these findings suggest that oligodendrocyte-derived Klk6 may operate as an autocrine or paracrine rheostat, or brake, on pro-myelinating signaling serving to regulate myelin homeostasis developmentally and in the adult. These findings document for the first time that inhibition of Klk6 globally, or specifically in oligodendrocyte progenitors, is a strategy to increase early stages of oligodendrocyte differentiation and myelin production in the CNS.
Topics: Animals; Cell Differentiation; Female; Kallikreins; Male; Mice; Mice, Inbred C57BL; Myelin Sheath; Oligodendroglia; Tandem Mass Spectrometry
PubMed: 34626143
DOI: 10.1002/glia.24100 -
Infant Behavior & Development Feb 2022Stage models have been influential in characterizing infant vocalizations in the first year of life. These models are basically descriptive and do not explain why... (Review)
Review
Stage models have been influential in characterizing infant vocalizations in the first year of life. These models are basically descriptive and do not explain why certain types of vocal behaviors occur within a particular stage or why successive patterns of vocalization occur. This review paper summarizes and elaborates a theory of Developmental Functional Modules (DFMs) and discusses how maturational gradients in the DFMs explain age typical vocalizations as well as the transitions between successive stages or other static forms. Maturational gradients are based on biological processes that effect the reconfiguration and remodeling of the respiratory, laryngeal, and craniofacial systems during infancy. From a dynamic systems perspective, DFMs are part of a complex system with multiple degrees of freedom that can achieve stable performance with relatively few control variables by relying on principles such as synergies, self-organization, nonlinear performance, and movement variability.
Topics: Biological Phenomena; Humans; Infant; Movement; Voice
PubMed: 34920296
DOI: 10.1016/j.infbeh.2021.101682 -
Environmental Science and Pollution... Dec 2023The pattern of arsenic (As) uptake at different developmental stages in plants and its consequent influence on the growth of plants was investigated in bean and lettuce....
The pattern of arsenic (As) uptake at different developmental stages in plants and its consequent influence on the growth of plants was investigated in bean and lettuce. Further, the human health risk from the consumption of these As-laced vegetables was determined. The irrigation water was contaminated with As at concentrations of 0.1, 0.25, and 0.5 mg/L. The As concentration in the plant parts (root, stem, leaves, and flower/fruit) was determined in bean at the young, flowering, and fruiting stages and lettuce at the young and mature stages. At the different growth stages, As had an impact on the biomass of bean and lettuce plant parts, but none of the biomass changes were significant (p>0.05). The increase in As concentration of the irrigation water elevated the As concentration of plant parts of both plants at all growth stages, with the exception of the bean fruit. The As concentration in the developmental stages was in the order: lettuce (young>mature) and bean (fruiting>young>flowering). In lettuce, the transfer factor was higher at the young stage (0.09-0.19, in the control and 0.1 mg/L As treatment), while in bean, it was highest at the flowering stage (0.09-0.41, in all treatments). In the edible part, lettuce possessed substantially elevated As concentrations (0.30, 0.61, and 1.21 mg/kg DW) compared to bean (0.008, 0.005, and 0.022 mg/kg DW) at As treatments of 0.1, 0.25, and 0.5 mg/L, respectively, and posed significant health risks at all applied As concentrations.
Topics: Humans; Lactuca; Arsenic; Vegetables; Plant Leaves; Water
PubMed: 37917265
DOI: 10.1007/s11356-023-30593-7