Embryonic Stages Research Articles

The Hypothetic Nutrient Constraint to Continuously Maintain as Gradient from Gastrula to Postnatal Development: An Important Mechanism for Recapitulation

It was suggested by Cai a theory that the nutrient gradient differentiate the cellular living states to form the three germ layers of animal embryonic gastrula differential developing to three different subsequent fates, with the endoderm manifesting cellular living states in nutritious condition and forming the epithelium of digestive and respiratory system; the ectoderm manifesting cellular living states of nutrient dependence and environmental effects, and giving rise to the nervous and epithelial tissues; the mesoderm lying between them and forming the muscle and adipose. In parallel, it was also complied with the regulation of nutrients on various cultured stem cells. In this article, to account for these phenomena, it is extended this theory and suggested that there be a constraint maintaining such nutrient gradient from gastrula to postnatal development continuously, due to the animals necessarily to deal with the nutritional transport and environmental effects being the same across all developmental stages after gastrula, for most animals before the appearance of rigid eggshell in evolution. It is the nutrient constraint forming gradient at gastrula that coordinates the development of all animals into fixed nutrient gradient as the most primitive animal of gastrula, recapitulating the developmental program at gastrula. In contrast, it is unnecessary for all animals universally to deal with nutritional transport before gastrula, generating evolutionary diversity in early embryonic stages before gastrula, as well as violations to Haeckel’s recapitulation.

Lrig1 regulates cell fate specification of glutamatergic neurons via FGF-driven Jak2/Stat3 signaling in cortical progenitors.

The cell-intrinsic mechanisms underlying the decision of a stem/progenitor cell to either proliferate or differentiate remain incompletely understood. Here, we identify the transmembrane protein Lrig1 as a physiological homeostatic regulator of FGF2-driven proliferation and self-renewal of neural progenitors at early-to-mid embryonic stages of cortical development. We show that Lrig1 is expressed in cortical progenitors (CPs), and its ablation caused expansion and increased proliferation of radial/apical progenitors and of neurogenic transit-amplifying Tbr2+ intermediate progenitors. Notably, our findings identify a previously unreported EGF-independent mechanism through which Lrig1 negatively regulates neural progenitor proliferation by modulating the FGF2-induced IL6/Jak2/Stat3 pathway, a molecular cascade that plays a pivotal role in the generation and maintenance of CPs. Consistently, Lrig1 knockout mice showed a significant increase in the density of pyramidal glutamatergic neurons placed in superficial layers 2 and 3 of the postnatal neocortex. Together, these results support a model in which Lrig1 regulates cortical neurogenesis by influencing the cycling activity of a set of progenitors that are temporally specified to produce upper layer glutamatergic neurons.

Embryonic and Fetal Mortality in Dairy Cows: Incidence, Relevance, and Diagnosis Approach in Field Conditions

Pregnancy loss (PL) in dairy cattle results in animal health and welfare disruption and has a great economic impact on farms, with decreases in fertility and increased culling. It can occur at any stage of embryonic or fetal development. Abortion occurring from the second half of pregnancy has a more negative impact on dairy farms. There are several infectious and non-infectious factors that can lead to PL and vary according embryonic or fetal stages. As this is a multifactorial or multi-etiological occurrence, it is important to identify the risk factors and the best diagnostic tools to approach these reproductive losses that can occur sporadically or by outbreaks. Reaching a final diagnosis can be challenging, especially when it occurs at a very early stage of pregnancy, where losses may not be detected and neonatal deaths may be related to alterations in the fetus in utero. Also, laboratorial results from animal samples should be interpreted according to the full clinical approach. This review aimed to highlight all these essential aspects, identifying the main infectious and non-infectious causes leading to PL, as well as the best veterinary practices for diagnosing it, mainly through transrectal palpation, ultrasound, and laboratory methods, in bovine dairy farms.

Embryotoxicity and biochemical changes of clioquinol (CQ) and their impact on zebrafish (Danio rerio): An environmental safety concern

Antibiotic residues and their conversion into toxic products have the potential to place human health at risk and ecosystem, which is precisely the continued accumulation of antibiotics in the environment has greatly alarmed humans and aquatic animals. This work sought to assess the possible impacts of clioquinol (CQ) on hepatotoxicity, teratogenicity, and biochemical alterations in zebrafish adults and embryos. The study examined the acute toxicity of CQ treatment to zebrafish embryos, adults, and 96-hour post fertilisation (hpf), in addition to the teratogenicity of CQ to embryonic and sac-fry stages. The lethal toxicity indicates that the 96 h LC50 values of CQ treated with 48, 72, and 96- hpf larvae; adult fish were 4.78, 3.75, 2.69; 10.86, 8.75, and 6.55 mg/L. This finding implies that zebrafish were more susceptible to CQ in their early life stages than in their adult stages, which is in accordance with in silico analyses using ECOSAR and T.E.S.T. At doses of 5 mg/L or higher, CQ would suppress zebrafish embryonic motility, heart rate, hatching rate, and body length of surviving larvae. Furthermore, to pericardial oedema, CQ also resulted in morphological abnormalities, including tail, spine, and yolk sac oedema. Histopathological alterations were noted in the kidney, intestines, gills, liver, and brain. Glutathione-S-transferase, catalase, and superoxide dismutase levels in the adult zebrafish decreased in a dose-dependent manner following 96 h of treatment. In addition, the adult zebrafish exposed to CQ had significantly downregulated levels of SOD, growth hormone 1, and TNF-α in the liver and blood. The findings provided the foundation for further research into the mechanism behind CQ toxicity in zebrafish, as they demonstrated that CQ had notable detrimental effects on zebrafish at different life stages.

Changes in monocyte subsets in volunteers who received an oral wild-type Salmonella Typhi challenge and reached typhoid diagnosis criteria.

An oral Controlled Human Infection Model (CHIM) with wild-type S. Typhi was re-established allowing us to explore the development of immunity. In this model, ~55% of volunteers who received the challenge reached typhoid diagnosis criteria (TD), while ~45% did not (NoTD). Intestinal macrophages are one of the first lines of defense against enteric pathogens. Most organs have self-renewing macrophages derived from tissue-resident progenitor cells seeded during the embryonic stage; however, the gut lacks these progenitors, and all intestinal macrophages are derived from circulating monocytes. After infecting gut-associated lymphoid tissues underlying microfold (M) cells, S. Typhi causes a primary bacteremia seeding organs of the reticuloendothelial system. Following days of incubation, a second bacteremia and clinical disease ensue. S. Typhi likely interacts with circulating monocytes or their progenitors in the bone marrow. We assessed changes in circulating monocytes after CHIM. The timepoints studied included 0 hours (pre-challenge) and days 1, 2, 4, 7, 9, 14, 21 and 28 after challenge. TD participants provided extra samples at the time of typhoid diagnosis, and 48-96 hours later (referred as ToD). We report changes in Classical Monocytes -CM-, Intermediate Monocytes -IM- and Non-classical Monocytes -NCM-. Changes in monocyte activation markers were identified only in TD participants and during ToD. CM and IM upregulated molecules related to interaction with bacterial antigens (TLR4, TLR5, CD36 and CD206). Of importance, CM and IM showed enhanced binding of S. Typhi. Upregulation of inflammatory molecules like TNF-α were detected, but mechanisms involved in limiting inflammation were also activated (CD163 and CD354 downregulation). CM upregulated molecules to interact/modulate cells of the adaptive immunity, including T cells (HLA-DR, CD274 and CD86) and B cells (CD257). Both CM and IM showed potential to migrate to the gut as integrin α4β7 was upregulated. Unsupervised analysis revealed 7 dynamic cell clusters. Five of these belonged to CM showing that this is the main population activated during ToD. Overall, we provide new insights into the changes that diverse circulating monocyte subsets undergo after typhoid diagnosis, which might be important to control this disease since these cells will ultimately become intestinal macrophages once they reach the gut.

Bacterial dynamics and biotic sources in the developing swimming crab embryos

The microbial community associated with aquatic animals begins to assemble from the embryonic stage and plays a vital role in their growth and survival. However, the microbial community of the swimming crab Portunus trituberculatus during its embryonic period has not yet been studied. In this study, we investigated the embryonic bacterial community (EBC) of this species across the developmental cycle to elucidate its longitudinal dynamics and biotic sources. The results showed that the diversity of the EBC decreased with host development. The composition of the EBC varied across embryonic development, with a high percent of persistent bacteria and the gradual replacement of γ-Proteobacteria (mainly Oceanospirillaceae and Colwelliaceae) by α-Proteobacteria (Rhodobacteraceae and Flavobacteriaceae) as the major signatures of the succession patterns. Moreover, the unique amplicon sequence variants (ASVs) exhibited the highest functional potentials at the cleavage stage, whereas the shared ASVs did so at the later stages. Furthermore, maternal tissue, mainly the ovary and abdominal setae, contributed the most to the EBC, while rearing water contributed minimally. Overall, our results reveal succession patterns and biotic sources of EBC during the developmental cycle, highlighting that the dominance of embryonic bacteria starts from the early stage of embryo and bacterial vertical transmission is of significance during embryonic development. We also suggest the necessity of microbial management from maternal crabs.

Temporal Transcriptomic Profiling of the Developing Xenopus laevis Eye.

Retinal progenitor cells (RPCs) are a multipotent and highly proliferative population that give rise to all retinal cell types during organogenesis. Defining their molecular signature is a key step towards identifying suitable approaches to treat visual impairments. Here, we performed RNA sequencing of whole eyes from Xenopus at three embryonic stages and used differential expression analysis to define the transcriptomic profiles of optic tissues containing proliferating and differentiating RPCs during retinogenesis. Gene Ontology and KEGG pathway analyses showed that genes associated with developmental pathways (including Wnt and Hedgehog signaling) were upregulated during the period of active RPC proliferation in early retinal development (Nieuwkoop Faber st. 24 and 27). Developing eyes had dynamic expression profiles and shifted to enrichment for metabolic processes and phototransduction during RPC progeny specification and differentiation (st. 35). Furthermore, conserved adult eye regeneration genes were also expressed during early retinal development, including sox2, pax6, nrl, and Notch signaling components. The eye transcriptomic profiles presented here span RPC proliferation to retinogenesis and include regrowth-competent stages. Thus, our dataset provides a rich resource to uncover molecular regulators of RPC activity and will allow future studies to address regulators of RPC proliferation during eye repair and regrowth.

A Potential Neurotoxic Mechanism: Bisphenol S-Induced Inhibition of Glucose Transporter 1 Leads to ATP Excitotoxicity in the Zebrafish Brain.

Many environmental pollutants have neurotoxic effects, but the initial molecular events involved in these effects are unclear. Here, zebrafish were exposed to the neurotoxicant bisphenol S (BPS, 1, 10, or 100 μg/L) from the embryonic stage to the larval stage to explore the ability of BPS to interfere with energy metabolism in the brain. BPS, which is similar to a glucose transporter 1 (GLUT1) inhibitor, inhibited GLUT1 function but increased mitochondrial activity in the brains of larval zebrafish. Interestingly, GLUT1 inhibitor treatment and BPS exposure did not reduce energy production in the brain; instead, they increased ATP production by inducing the preferential use of ketone bodies. Moreover, BPS promoted the protein expression of the purinergic 2X receptor but inhibited the purinergic 2Y-mediated phosphatidylinositol signaling pathway, indicating that excess ATP acts as a neurotransmitter to activate the purinergic 2X receptor under the BPS-induced restriction of GLUT1 function. BPS-induced inhibition of GLUT1 increased the number of neurons but promoted apoptosis by activating ATP-purinergic 2X receptors in the brain, causing ATP excitatory neurotoxicity. Our data reveal a potential neurotoxic mechanism induced by BPS that may represent a new adverse outcome pathway.

The subsistence strategy transformation of the Yangshao culture (6900-4800BP) in the Guanzhong Area and Western Henan based on new faunal materials from the Miaodigou site

While the significance of the Yangshao culture in early China is widely recognized, systematic and detailed analysis and discussion of its subsistence strategy are lacking, especially for faunal materials. This paper examines the new and crucial faunal remains that include 3,400 identified specimens from the Miaodigou site unearthed in 2002. At that site, pig husbandry was predominant and wild animals were occasionally hunted as supplemental resources. In combination with published research including zooarchaeology, paleoethnobotany, and carbon and nitrogen stable isotope studies of 29 other sites mainly from the Guanzhong area and western Henan, we argue that subsistence strategy underwent a comprehensive and profound transformation during the middle period of Yangshao culture, namely Miaodigou period, as crop production and pig husbandry flourished in a wide range of areas. Domestic pigs accounted for over 80% of mammals, reaching an unprecedented proportion in the Neolithic age and manifesting a high level of consistency in feeding and slaughtering, and foxtail millet replaced broomcorn to become the most important crop at all sites, both of which demonstrate the breadth and depth of this transformation. The tension between the deterioration of climate, the decrease of surrounding wildlife resources due to excessive development and the continuous growth of the population may have contributed to this transformation. This study enriches our understanding of human-environment interactions in the embryonic stage of Chinese civilization and triggers further thoughts on how culture, society, the environment and subsistence were entangled in the development of civilization.

Survival of Calliphora vicina (Diptera: Calliphoridae) embryos under cold temperature conditions: forensic implications.

Most blow flies (Diptera: Calliphoridae) species are sarcosaprophagous during the larval stage, primarily feeding on the soft tissues of carcasses during the early stages of decomposition, making them valuable forensic indicators for minimum post-mortem interval (minPMI) estimations. Like other insects, their developmental rates are strongly influenced by the environmental temperature. Although several studies have examined the influence of temperature on the development of different blow fly species, the impact of cold temperatures remains largely unstudied, despite its potential forensic implications. The present study investigates the effect of three cold temperatures (0, -2.5 and -5°C) on the survival of Calliphora vicina embryos of five different ages (0%, 20%, 40%, 60% and 80% of the total embryonic development) and two exposure times (6 and 24 h). Our results revealed significant differences in egg survival at the earliest embryonic stages (0% and 20% of the total embryonic development), resulting in high mortality rates. While at 20% of the total embryonic development high mortality was only observed under -5°C, at 0% of the total embryonic development high mortality rates were observed at all the temperatures tested. Although C. vicina embryos demonstrate tolerance to cold temperatures once they have completed the first 20% of the total embryonic development, potentially mitigating the impact of cold weather events, the possibility of minPMI underestimations due to the death of the first egg batches should not be disregarded. Additionally, considering that the embryonic development stages may last for several days under low temperatures, caution should be taken in the analysis of entomological evidence if a cadaver is discovered following cold weather episodes.

The maternal lifestyle in pregnancy: Implications for foetal skeletal muscle development.

The world is facing a global nutrition crisis, as evidenced by the rising incidence of metabolic disorders such as obesity, insulin resistance and chronic inflammation. Skeletal muscle is the largest tissue in humans and plays an important role in movement and host metabolism. Muscle fibre formation occurs mainly during the embryonic stage. Therefore, maternal lifestyle, especially nutrition and exercise during pregnancy, has a critical influence on foetal skeletal muscle development and the subsequent metabolic health of the offspring. In this review, the influence of maternal obesity, malnutrition and micronutrient intake on foetal skeletal muscle development is systematically summarized. We also aim to describe how maternal exercise shapes foetal muscle development and metabolic health in the offspring. The role of maternal gut microbiota and its metabolites on foetal muscle development is further discussed, although this field is still in its 'infancy'. This review will provide new insights to reduce the global crisis of metabolic disorders and highlight current gaps to promote further research.

Incubation time, embryonic development and the vomeronasal organ of the Laysan albatross (Phoebastria immutabilis).

The effect of lengthened incubation periods on embryonic development, especially vestigial structures, is poorly understood. An example of which is the avesuchian vomeronasal organ (VNO), a nasal chemosensory organ found in many tetrapods but absent in adult avesuchians (crocodilians and birds) in whom it is presumed to be a transitory fetal structure. The Laysan Albatross (Phoebastria immutabilis) has an incubation period of their eggs of about 65 days. This incubation period is twice that of domestic fowl, wherein a putative VNO has been documented as an epithelial thickening. The purpose of this study is to document the development of a putative VNO in the albatross. Serial histological sections of nine albatross embryonic heads, across 6 stages (representing days 19 to 32: stages 31-39), were examined. A paired putative VNO was present as a short, tubular structure in the anterodorsal aspect on either side of the nasal septum from stage 32 onwards, getting steadily longer in later specimens. At the earliest stages, the epithelial walls of the tube resemble a neuroepithelium, but then becomes thinner and simpler in morphology. Based on our available age range, it is unclear whether it persists as a rudimentary structure (like that of the human) or if it is a transitory structure (like in chickens) in these mid embryonic stages. Though future studies must determine the fate of the Laysan albatross VNO (e.g., is it retained postnatally?), the role of incubation period length on embryonic development is a bigger question to be explored.

Integrating ATAC-Seq and RNA-Seq Reveals the Signal Regulation Involved in the Artemia Embryonic Reactivation Process.

Embryonic diapause is a common evolutionary adaptation observed across a wide range of organisms. Artemia is one of the classic animal models for diapause research. The current studies of Artemia diapause mainly focus on the induction and maintenance of the embryonic diapause, with little research on the molecular regulatory mechanism of Artemia embryonic reactivation. The first 5 h after embryonic diapause breaking has been proved to be most important for embryonic reactivation in Artemia. In this work, two high-throughput sequencing methods, ATAC-seq and RNA-seq, were integrated to study the signal regulation process in embryonic reactivation of Artemia at 5 h after diapause breaking. Through the GO and KEGG enrichment analysis of the high-throughput datasets, it was showed that after 5 h of diapause breaking, the metabolism and regulation of Artemia cyst were quite active. Several signal transduction pathways were identified in the embryonic reactivation process, such as G-protein-coupled receptor (GPCR) signaling pathway, cell surface receptor signaling pathway, hormone-mediated signaling pathway, Wnt, Notch, mTOR signaling pathways, etc. It indicates that embryonic reactivation is a complex process regulated by multiple signaling pathways. With the further protein structure analysis and RT-qPCR verification, 11 GPCR genes were identified, in which 5 genes function in the embryonic reactivation stage and the other 6 genes contribute to the diapause stage. The results of this work reveal the signal transduction pathways and GPCRs involved in the embryonic reactivation process of Artemia cysts. These findings offer significant clues for in-depth research on the signal regulatory mechanisms of the embryonic reactivation process and valuable insights into the mechanism of animal embryonic diapause.

Molecular Identification and Functional Characterization of LC-PUFA Biosynthesis Elongase (elovl2) Gene in Chinese Sturgeon (Acipenser sinensis).

Elongases of very-long-chain fatty acids (Elovls) are critical rate-limiting enzymes that are involved in LC-PUFA biosynthesis through catalyzing the two-carbon elongation of a pre-existing fatty acyl chain. Thus far, several Elovls have been extensively studied in teleost. However, the functional and physiological roles of Elovls in chondrichthyans have rarely been reported. In this study, we identified and characterized elovl2 from the endangered Chinese sturgeon (Acipenser sinensis) by whole genome scanning. The results show that the coding sequence of elovl2 was 894 bp in length, for a putative protein of 297 amnio acids. Comparative genomic analyses indicated that Chinese sturgeon elovl2 was evolutionarily conserved. Functional characterization in yeast demonstrated that the Chinese sturgeon Elovl2 could efficiently elongate C20 (ARA and EPA) and C22 (22:4n-6 and 22:5n-3) substrates, confirming its critical roles in LC-PUFA biosynthesis. Spatial and temporal expression analyses showed high elovl2 mRNA levels were detected in the liver and brain and showed an increase trend both in embryonic and post-hatching stages. Interestingly, diets with vegetable oils as lipid sources could significantly induce the high expression of elovl2 in Chinese sturgeon, implying that the endogenous LC-PUFA biosynthesis pathway was stimulated by lack of LC-PUFA in their diets. Our findings will enhance our understanding about the evolutionary and functional roles of elovl2 and provide novel insights into the LC-PUFA biosynthesis mechanism in vertebrates.

Geomorphological features and formation mechanism of the Taixinan canyon‐channel system in the north‐eastern South China Sea

During the formation and evolution of the South China Sea, a series of multiscale submarine geomorphologies have been produced in the continental margin. The obvious submarine canyons and channels are widely distributed in the continental shelf and slope of the South China Sea. In the Taixinan Basin, several submarine canyons and channels termed as the Taixinan canyon‐channel system (TCCS) are distributed between the active and passive continental margins. Based on acquired ship‐borne multi‐beam bathymetry data in this study and the global GEBCO 2023 bathymetric dataset, we identify and define nine submarine canyons and seven submarine channels in the Taixinan Basin. The TCCS consists of the Dongsha, Taiwan, Jiulong, West Penghu, Penghu, Kaoping, Shoushan, Kaohsiung and the Fangliao canyons and submarine channels. The detailed geomorphological features of different submarine canyons and channels within the TCCS are analysed and summarized using multi‐beam bathymetry data and seismic reflection profiles across canyons. Based on the slope variations of the continental margin and the effects of turbidity currents and bottom currents on canyon, we propose a three‐stage evolutionary model of the TCCS. In the initial formation stage of canyon, the initial erosional grooves were created by tectonic activity on the continental slope and it represents the foundation of submarine canyons. During the growth and development stage, the submarine canyons are further evolved and the canyons began to deepen and widen from the continental slope to the deep‐water areas. It shows the weak erosion and sediment infilling within the canyons in this stage. On the northern continental slope of the South China Sea, continuous transportation and erosion of sediments led to the initial formation of grooves and it becomes the embryonic stage of submarine channels. The present stage of the TCCS was formed when the initial grooves on the continental slope have further developed and rebuilt under the erosion by the turbidity current and the scouring by the bottom current. In the last stage, the intense erosion by the turbidity current is supported by sediment waves around the submarine canyons and the migration of canyons is suggested by the cyclic steps formed within some canyons.

Evolution stage identification and spatial pattern analysis of Nitraria tangutorum nebkhas based on Gaofen-2 satellite data

The quantitative extraction and evolution stage identification of the Nitraria tangutorum nebkhas are the basis for the restoration of regional plants and the reconstruction of degraded ecosystems. In this paper, the Nitraria tangutorum nebkha in Dengkou County of China was taken as the research object. Through the spectral and texture information of Gaofen-2 satellite image, the quantitative extraction of Nitraria tangutorum nebkha area and coverage information was completed using methods of gray threshold method, mathematical morphology, FCLSU mixed pixel decomposition, kernel density spatial analysis; the current evolution stage of the Nitraria tangutorum nebkha was identified, and their spatial distribution characteristics were analyzed. The results showed that: (1) The user accuracy and mapping accuracy of Nitraria tangutorum nebkha extracted from Random Forest combined with object-oriented classification method were up to 90.32%. (2) The method proposed can achieve an accuracy of 93.76% in extracting the spatial position of Nitraria tangutorum nebkhas. (3) The evolution of Nitraria tangutorum nebkhas can be divided into three stages: embryonic or developmental stage, stable stage, and declining stage, with a proportion of 60.70%, 20.97%, and 18.33%, respectively; The Nitraria tangutorum nebkhas in the study area is mainly in their embryonic or developmental stage, and the proportion of Nitraria tangutorum nebkhas in the declining stage is also large. It can provide technical and theoretical support for the precise extraction of nebkhas in arid and semi-arid desert areas, the identification of their current evolutionary stages, and the study of their spatial distribution patterns.

Voltage-gated ion channel’s gene expression in the myocardium of embryo and adult chickens

The functioning of the cardiovascular system is critical for embryo survival. Cardiac contractions depend on the sequential activation of different classes of voltage-gated ion channels. Understanding the fundamental features of these interactions is important for identifying the mechanisms of pathologies development in the myocardium. However, at present there is no consensus on which ion channels are involved in the formation of automaticity in the early embryonic stages. The aim of this study was to elucidate the expression of genes encoding various types of ion channels that are involved in the generation of electrical activity chicken heart at different stages of ontogenesis. We analyzed the expression of 14 genes from different families of ion channels. It was revealed that the expression profiles of ion channel genes change depending on the stages of ontogenesis. The HCN4, CACNA1D, SCN1A, SCN5A, KCNA1 genes have maximum expression at the tubular heart stage. In adult, a switch occurs to the higher expression of CACNA1C, KCNH6, RYR and SLC8A1 genes. This data correlated with the results obtained by the microelectrode method. It can be assumed that the automaticity of the tubular heart is mainly due to the mechanism of the «membrane–clock» (hyperpolarization-activated current (If), Ca2+–current L–type (ICaL), Na+–current (INa) and the slow component of the delayed rectifier K+–current (IKs)). Whereas in adult birds, the mechanism for generating electrical impulses is determined by both « membrane– clock» and «Ca2+–clock».

Deletion of endocannabinoid synthesizing enzyme DAGLα from cerebellar Purkinje cells decreases social preference and elevates anxiety.

ABSTRACTThe endocannabinoid (eCB) signaling system is robustly expressed in the cerebellum starting from the embryonic developmental stages to adulthood. There it plays a key role in regulating cerebellar synaptic plasticity and excitability, suggesting that impaired eCB signaling will lead to deficits in cerebellar adjustments of ongoing behaviors and cerebellar learning. Indeed, human mutations inDAGLαare associated with neurodevelopmental disorders. In this study, we show that selective deletion of the eCB synthesizing enzyme diacylglycerol lipase alpha (Daglα) from mouse cerebellar Purkinje cells (PCs) alters motor and social behaviors, disrupts short-term synaptic plasticity in both excitatory and inhibitory synapses, and reduces Purkinje cell activity during social exploration. Our results provide the first evidence for cerebellar-specific eCB regulation of social behaviors and implicate eCB regulation of synaptic plasticity and PC activity as the neural substrates contributing to these deficits.Abstract FigureGraphical abstract.Cerebellar anatomy, morphology of Purkinje cells, localization, density, and spontaneous activity of excitatory and inhibitory synapses are normal in cerebellar-Purkinje-cell-specific Daglα KOs. However, endocannabinoid-dependent short-term synaptic plasticity (DSE and DSI) and activity of Purkinje cells in lobe VI during social exploration are dramatically reduced, and the KO mice exhibit alterations in sensorimotor coordination, deceased social preference, and increased anxiety.

The ATP-binding cassette transporter subfamily G member 4 mediates cuticular hydrocarbon transport to regulate drought tolerance in Acyrthosiphon pisum

ABC transporters are a highly conserved membrane protein class that promote the transport of substances across membranes. Under drought conditions, insects primarily regulate the content of cuticular hydrocarbon (CHC) to retain water and prevent evaporative loss. Involvement of ABC transporter protein G (ABCG) subfamily genes in insect CHC transport has been relatively understudied. In this study, we demonstrated that ABCG4 gene in Acyrthosiphon pisum (ApABCG4) is involved in CHC transport and affects drought tolerance by regulating CHC accumulation. ApABCG4 is strongly expressed in the abdominal cuticle and embryonic stages of A. pisum. Effective silencing of ApABCG4 was achieved using RNAi, and the silencing duration was analyzed. ApABCG4 silencing resulted in a significant decrease in the total and component contents of the CHC and cuticular waxy coatings of A. pisum. Nevertheless, the internal hydrocarbon content remained unchanged. The lack of cuticular hydrocarbons significantly reduced the drought tolerance of A. pisum, shortening its survival time under drought stress. Drought stress caused significant upregulation of ApABCG4. Molecular docking showed that ApABCG4 has a high binding affinity for nine n-alkanes of CHC through electrostatic interactions. These results indicate that ApABCG4 is a novel RNAi target with key applications in aphid biological control.

Tcf21 as a Founder Transcription Factor in Specifying Foxd1 Cells to the Juxtaglomerular Cell Lineage.

This manuscript provides novel insights into the role of Tcf21 in the differentiation of Foxd1+ cells into JG cells. Utilizing integrated scRNA-seq and scATAC-seq, the study reveals that Tcf21 expression is crucial during early embryonic stages, with its peak at embryonic day 12. The findings demonstrate that inactivation of Tcf21 leads to fewer renin-positive areas and altered renal arterial morphology, underscoring the importance of Tcf21 in the specification of renin-expressing JG cells and kidney development.