Expression Domains Research Articles

Understanding supervisory practice and development in the pre-HDR space: an ethogenic approach

ABSTRACT This article addresses the lack of support for new supervisors in the pre-Higher Degree Research space, including undergraduate honours and postgraduate capstone projects. The research provides an inter-faculty perspective on the needs of pre-HDR students and supervisors, informing an online professional learning resource to address the problem. Concepts from ethogenic social psychology were used to theorise supervision as a complex practice involving two analytically distinct domains of human behaviour: the expressive and practical domains. Semi-structured focus group interviews with alumni and supervisors from Education, Arts-Humanities, and Health Sciences provided data for a needs analysis and to stimulate deliberation amongst the research team, which included course coordinators and supervisors across the different faculties and a representative from the university’s teaching and learning centre. The findings illustrate expressive and practical aspects of supervision and elaborate salient themes for the development of pre-HDR supervisory practice through inquiry. The article advances theory by supporting a view of supervision as a process of supervisor, student, and supervisory practice co-development. The results will be of interest to supervisors, honours and masters course coordinators and providers of professional development for academics.

Reproductive development in Trithuria submersa (Hydatellaceae: Nymphaeales): the involvement of AGAMOUS-like genes

Main conclusionIn the early diverging angiosperm Trithuria submersaTsAG1 and TsAG2 are expressed in different flower organs, including bracts, while TsAG3 is more ovule-specific, probably functioning as a D-type gene.Species of Trithuria, the only genus of the family Hydatellaceae, represent ideal candidates to explore the biology and flower evolution of early diverging angiosperms. The life cycle of T. submersa is generally known, and the “reproductive units” are morphologically well described, but the availability of genetic and developmental data of T. submersa is still scarce. To fill this gap, a transcriptome analysis of the reproductive structures was performed and presented in this work. This analysis provided sequences of MADS-box transcription factors, a gene family known to be involved in flower and fruit development. In situ hybridization experiments on floral buds were performed to describe the spatiotemporal expression patterns of the AGAMOUS genes, revealing the existence of three AG genes with different expression domains in flower organs and in developing ovules. Trithuria may offer important clues to the evolution of reproductive function among early angiosperms and Nymphaeales in particular, and this study aims to broaden relevant knowledge regarding key genes of reproductive development in non-model angiosperms, shaping first flower appearance and evolution.

Histological and gene-expression analyses of pyloric sphincter formation during stomach metamorphosis in Xenopus laevis

During anuran metamorphosis from herbivorous tadpoles to carnivorous frogs, the gastrointestinal (GI) tract undergoes drastic remodeling, such as the formation of the stomach-intestine boundary and the development of the pyloric sphincter at the posterior end of the stomach. However, the morphogenetic process and molecular mechanisms of how the pyloric sphincter is formed during metamorphosis, instead of during embryogenesis as in amniotes, are largely uninvestigated. Using the African clawed frog Xenopus laevis, we histologically examined the development of the pylorus region from embryonic to froglet stages and performed spatiotemporal gene expression analyses. We found that the pyloric sphincter is formed at a flexure within the pyloric region during metamorphic climax, and that the pyloric and duodenal epithelia, which are morphologically indistinguishable before sphincter formation, become clearly demarcated by the sphincter at the end of metamorphosis. Consistent with these morphological changes, expression domains of a stomach marker barx1 and an intestine marker cdx2 overlapped until late metamorphic climax, but became separated after metamorphosis. Despite the absence of the sphincter before metamorphosis, various genes crucial for sphincter formation in amniotes were already expressed in the pylorus region of Xenopus embryos. RNA-sequencing analysis at pre-metamorphic and metamorphic-climax stages suggest unappreciated roles of genes, such as those for retinoic acid signaling and various transcription factors, in suppressing or promoting sphincter formation. These data provide histological and molecular insights into the heterochrony of the pyloric sphincter formation in amniotes and anurans.

Molecular mechanisms and behavioral relevance underlying neural correlates of childhood neglect

BackgroundChildhood neglect is associated with brain changes, yet the molecular mechanisms and behavioral relevance underlying such associations remain elusive. MethodsWe calculated fractional amplitude of low-frequency fluctuations (fALFF) using resting-state functional MRI and tested their correlation with childhood neglect across a large sample of 510 healthy young adults. Then, we investigated the spatial relationships of the identified neural correlates of childhood neglect with gene expression, neurotransmitter, and behavioral domain atlases. ResultsWe found that more severe childhood neglect was correlated with higher fALFF in the bilateral anterior cingulate cortex. Remarkably, the identified neural correlates of childhood neglect were spatially correlated with expression of gene categories primarily involving neuron, synapse, ion channel, cognitive and perceptual processes, and physiological response and regulation. Concurrently, there were significant associations between the neural correlates and specific neurotransmitter systems including serotonin and GABA. Finally, neural correlates of childhood neglect were associated with diverse behavioral domains implicating mental disorders, emotion, cognition, and sensory perception. LimitationsThe cross-sectional study design cannot unequivocally establish causality. ConclusionsOur findings may not only add to the current knowledge regarding the relationship between childhood neglect and mental health, but also have clinical implications for developing preventive strategies for individuals exposed to childhood neglect who are at risk for mental disorders.

Genetic requirement of dact1/2 to regulate noncanonical Wnt signaling and calpain 8 during embryonic convergent extension and craniofacial morphogenesis.

Wnt signaling plays crucial roles in embryonic patterning including the regulation of convergent extension during gastrulation, the establishment of the dorsal axis, and later, craniofacial morphogenesis. Further, Wnt signaling is a crucial regulator of craniofacial morphogenesis. The adapter proteins Dact1 and Dact2 modulate the Wnt signaling pathway through binding to Disheveled. However, the distinct relative functions of Dact1 and Dact2 during embryogenesis remain unclear. We found that dact1 and dact2 genes have dynamic spatiotemporal expression domains that are reciprocal to one another suggesting distinct functions during zebrafish embryogenesis. Both dact1 and dact2 contribute to axis extension, with compound mutants exhibiting a similar convergent extension defect and craniofacial phenotype to the wnt11f2 mutant. Utilizing single-cell RNAseq and an established noncanonical Wnt pathway mutant with a shortened axis ( gpc4 ), we identified dact1/2 specific roles during early development. Comparative whole transcriptome analysis between wildtype and gpc4 and wildtype and dact1/2 compound mutants revealed a novel role for dact1/2 in regulating the mRNA expression of the classical calpain capn8 . Over-expression of capn8 phenocopies dact1/2 craniofacial dysmorphology. These results identify a previously unappreciated role of capn8 and calcium-dependent proteolysis during embryogenesis. Taken together, our findings highlight the distinct and overlapping roles of dact1 and dact2 in embryonic craniofacial development, providing new insights into the multifaceted regulation of Wnt signaling.

A systematic review and meta-analysis of the traumatogenic phenotype hypothesis of psychosis.

Developmental trauma increases psychosis risk and is associated with poor prognosis. It has been proposed that psychosis in survivors of developmental trauma gives rise to a distinct 'traumatogenic' phenotype. Given the implications for personalised treatment, we sought to explore the traumatogenic psychosis phenotype hypothesis in a systematic review and meta-analysis of studies comparing psychotic presentations between adults with and without developmental trauma histories. We registered the systematic review on PROSPERO (CRD42019131245) and systematically searched EMBASE, Medline and PsycINFO. The outcomes of interests were quantitative and qualitative comparisons in psychotic symptom expression (positive, negative, cognitive) and other domains of psychopathology, including affect regulation, sleep, depression and anxiety, between adults with and without experience of developmental trauma. Of 34 studies included (N = 13 150), 11 were meta-analysed (n = 2842). A significant relationship was found between developmental trauma and increased symptom severity for positive (Hedge's g = 0.27; 95% CI 0.10-0.44; P = 0.002), but not negative symptoms (Hedge's g = 0.13; 95% CI -0.04 to 0.30; P = 0.14). Developmental trauma was associated with greater neurocognitive, specifically executive, deficits, as well as poorer affect, dissociation and social cognition. Furthermore, psychotic symptom content thematically related to traumatic memories in survivors of developmental trauma. Our findings that developmental trauma is associated with more severe positive and affective symptoms, and qualitative differences in symptom expression, support the notion that there may be a traumatogenic psychosis phenotype. However, underdiagnosis of post-traumatic stress disorder may also explain some of these findings. More research is needed to explore this further.

Transcriptional programs of Pitx2 and Tfap2a/Tfap2b controlling lineage specification of mandibular epithelium during tooth initiation.

How the dorsal-ventral axis of the vertebrate jaw, particularly the position of tooth initiation site, is established remains a critical and unresolved question. Tooth development starts with the formation of the dental lamina, a localized thickened strip within the maxillary and mandibular epithelium. To identify transcriptional regulatory networks (TRN) controlling the specification of dental lamina from the naïve mandibular epithelium, we utilized Laser Microdissection coupled low-input RNA-seq (LMD-RNA-seq) to profile gene expression of different domains of the mandibular epithelium along the dorsal-ventral axis. We comprehensively identified transcription factors (TFs) and signaling pathways that are differentially expressed along mandibular epithelial domains (including the dental lamina). Specifically, we found that the TFs Sox2 and Tfap2 (Tfap2a/Tfap2b) formed complimentary expression domains along the dorsal-ventral axis of the mandibular epithelium. Interestingly, both classic and novel dental lamina specific TFs-such as Pitx2, Ascl5 and Zfp536-were found to localize near the Sox2:Tfap2a/Tfap2b interface. To explore the functional significance of these domain specific TFs, we next examined loss-of-function mouse models of these domain specific TFs, including the dental lamina specific TF, Pitx2, and the ventral surface ectoderm specific TFs Tfap2a and Tfap2b. We found that disruption of domain specific TFs leads to an upregulation and expansion of the alternative domain's TRN. The importance of this cross-repression is evident by the ectopic expansion of Pitx2 and Sox2 positive dental lamina structure in Tfap2a/Tfap2b ectodermal double knockouts and the emergence of an ectopic tooth in the ventral surface ectoderm. Finally, we uncovered an unappreciated interface of mesenchymal SHH and WNT signaling pathways, at the site of tooth initiation, that were established by the epithelial domain specific TFs including Pitx2 and Tfap2a/Tfap2b. These results uncover a previously unknown molecular mechanism involving cross-repression of domain specific TFs including Pitx2 and Tfap2a/Tfap2b in patterning the dorsal-ventral axis of the mouse mandible, specifically the regulation of tooth initiation site.

Network Pharmacology-Based Virtual Screening of Chemical Constituents from Vitexnegundo Linn's Discovered Novel Molecular Targets for Breast Cancer Treatment.

The Chinese chaste tree Vitexnegundo (VN) is a popular herb in South and Southeast Asia that has several health benefits, including the ability to inhibit tumor growth and induce apoptosis in multiple tumors. Literature revealed scanty research on breast cancer, with little focus on the molecular mechanism of the disease and an emphasis on targets, biological networks, and active components. Exploring natural compounds as possible therapeutic options is an old but still promising approach for drug discovery and development. This study used a thorough computational and statistical method to screen potential drug candidates. The active ingredients and targets of VN were identified using SwissADME, SwissTargetPrediction, STITCH, IMPPAT database, KNapSAcK database, and literature. The OMIM and GeneCards databases were searched for possible targets related to breast cancer. The PASS online server was used to check the probability of active metabolite (Pa) against breast cancer. To build protein-protein interactions (PPI) networking, the intersection of disease and drug targets was uploaded to the STITCH database. Cytoscape software was used to analyze the topology parameters of networking to identify hub targets. Gene Ontology (GO) was analyzed using Metascape and ShinyGO, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed using the David database and SR plot, and the site of expression and protein domain were studied using FunRich. We employed AutoDockvina, Discovery Studio, and UCSF ChimeraX software and auxiliary tools for molecular docking and analysis. Zincpharmer was used for pharmacophore mapping. ADMET analysis was conducted using ADMETsar, Swiss ADME, ADMETLab servers, and mypresto using GROMACS for molecular dynamics simulation (MDS). A total of 65 targets and 21 active ingredients were identified. Further investigation was conducted on 20 hub targets selected through PPI networking construction. The enrichment analysis results indicated that the key factors were P, amyloid-beta response, cellular response to amyloid- beta, Pos. reg. of G2/M transition of the mitotic cell cycle, and response to a toxic substance. The molecular docking, pharmacophore mapping, and MD simulation results indicated that apigenin, kaempferol, and luteolin positively interacted with CDK1 and CDK6 proteins. This study is the first to use network pharmacology, molecular docking, pharmacophore mapping, and MD simulation to identify the active ingredients, molecular targets, and critical biological pathways responsible for VN anti-breast cancer. The study provides a theoretical basis for further research in this area.

A spatial-temporal map of glutamatergic neurogenesis in the murine embryonic cerebellar nuclei uncovers a high degree of cellular heterogeneity.

The nuclei are the main output structures of the cerebellum. Each and every cerebellar cortical computation reaches several areas of the brain by means of cerebellar nuclei processing and integration. Nevertheless, our knowledge of these structures is still limited compared to the cerebellar cortex. Here, we present a mouse genetic inducible fate-mapping study characterizing rhombic lip-derived glutamatergic neurons of the nuclei, the most conspicuous family of long-range cerebellar efferent neurons. Glutamatergic neurons mainly occupy dorsal and lateral territories of the lateral and interposed nuclei, as well as the entire medial nucleus. In mice, they are born starting from about embryonic day 9.5, with a peak between 10.5 and 12.5, and invade the nuclei with a lateral-to-medial progression. While some markers label a heterogeneous population of neurons sharing a common location (BRN2), others appear to be lineage specific (TBR1, LMX1a, and MEIS2). A comparative analysis of TBR1 and LMX1a distributions reveals an incomplete overlap in their expression domains, in keeping with the existence of separate efferent subpopulations. Finally, some tagged glutamatergic progenitors are not labeled by any of the markers used in this study, disclosing further complexity. Taken together, our results obtained in late embryonic nuclei shed light on the heterogeneity of the excitatory neuron pool, underlying the diversity in connectivity and functions of this largely unexplored cerebellar territory. Our findings contribute to laying the groundwork for a comprehensive functional analysis of nuclear neuron subpopulations.

CXCL12 drives natural variation in coronary artery anatomy across diverse populations.

To efficiently distribute blood flow to cardiac muscle, the coronary artery tree must follow a specific branching pattern over the heart. How this pattern arises in humans is unknown due to the limitations of studying human heart development. Here, we leveraged a natural variation of coronary artery anatomy, known as coronary dominance, in genetic association studies to identify the first known driver of human coronary developmental patterning. Coronary dominance refers to whether the right, left, or both coronary arteries branch over the posterior left ventricle, but whether this variability is heritable and how it would be genetically regulated was completely unknown. By conducting the first large-scale, multi-ancestry genome-wide association study (GWAS) of coronary dominance in 61,043 participants of the VA Million Veteran Program, we observed moderate heritability (27.7%) with ten loci reaching genome wide significance. An exceptionally strong association mapped DNA variants to a non-coding region near the chemokine CXCL12 in both European and African ancestries, which overlapped with variants associated with coronary artery disease. Genomic analyses predicted these variants to impact CXCL12 levels, and imaging revealed dominance to develop during fetal life coincident with CXCL12 expression. Reducing Cxcl12 in mice to model the human genetics altered septal artery dominance patterns and caused coronary branches to develop away from Cxcl12 expression domains. Cxcl12 heterozygosity did not compromise overall artery coverage as seen with full deletion, but instead changed artery patterning, reminiscent of the human scenario. Together, our data support CXCL12 as a critical determinant of human coronary artery growth and patterning and lay a foundation for the utilization of developmental pathways to guide future precision 'medical revascularization' therapeutics.

Ectopic Activation of Fgf8 in Dental Mesenchyme Causes Incisor Agenesis and Molar Microdontia.

Putatively, tooth agenesis was attributed to the initiation failure of tooth germs, though little is known about the histological and molecular alterations. To address if constitutively active FGF signaling is associated with tooth agenesis, we activated Fgf8 in dental mesenchyme with Osr-cre knock-in allele in mice (Osr2-creKI; Rosa26R-Fgf8) and found incisor agenesis and molar microdontia. The cell survival assay showed tremendous apoptosis in both the Osr2-creKI; Rosa26R-Fgf8 incisor epithelium and mesenchyme, which initiated incisor regression from cap stage. In situ hybridization displayed vanished Shh transcription, and immunostaining exhibited reduced Runx2 expression and enlarged mesenchymal Lef1 domain in Osr2-creKI; Rosa26R-Fgf8 incisors, both of which were suggested to enhance apoptosis. In contrast, Osr2-creKI; Rosa26R-Fgf8 molar germs displayed mildly suppressed Shh transcription, and the increased expression of Ectodin, Runx2 and Lef1. Although mildly smaller than WT controls prenatally, the Osr2-creKI; Rosa26R-Fgf8 molar germs produced a miniature tooth with impaired mineralization after a 6-week sub-renal culture. Intriguingly, the implanted Osr2-creKI; Rosa26R-Fgf8 molar germs exhibited delayed odontoblast differentiation and accelerated ameloblast maturation. Collectively, the ectopically activated Fgf8 in dental mesenchyme caused incisor agenesis by triggering incisor regression and postnatal molar microdontia. Our findings reported tooth agenesis resulting from the regression from the early bell stage and implicated a correlation between tooth agenesis and microdontia.

An updated model of shoot apical meristem regulation by ERECTA family and CLAVATA3 signaling pathways in Arabidopsis.

The shoot apical meristem (SAM) gives rise to the aboveground organs of plants. The size of the SAM is relatively constant due to the balance between stem cell replenishment and cell recruitment into new organs. In angiosperms, the transcription factor WUSCHEL (WUS) promotes stem cell proliferation in the central zone of the SAM. WUS forms a negative feedback loop with a signaling pathway activated by CLAVATA3 (CLV3). In the periphery of the SAM, the ERECTA family receptors (ERfs) constrain WUS and CLV3 expression. Here, we show that four ligands of ERfs redundantly inhibit the expression of these two genes. Transcriptome analysis confirmed that WUS and CLV3 are the main targets of ERf signaling and uncovered new ones. Analysis of promoter reporters indicated that the WUS expression domain mostly overlaps with the CLV3 domain and does not shift along the apical-basal axis in clv3 mutants. Our three-dimensional mathematical model captured gene expression distributions at the single-cell level under various perturbed conditions. Based on our findings, CLV3 regulates cellular levels of WUS mostly through autocrine signaling, and ERfs regulate the spatial expression of WUS, preventing its encroachment into the peripheral zone.

Developing a tool to assess the health-related quality of life in calves with respiratory disease: tool refinement and construct validity testing

Bovine respiratory disease (BRD) is a major source of morbidity and mortality in calves and detection of the disease can be challenging. Diagnostic tools for BRD are typically based on the assessment of clinical signs. As experience of disease is associated with a poor quality of life and this poor emotional experience can be expressed in observable behaviour patterns, a quality-of-life approach might identify new indicators of disease. Health-related quality of life (HRQOL) approaches are widely used in human medicine but are rarely used in livestock. This study aimed to refine and validate an HRQOL tool for calves with BRD that had been created in a previous study. The tool contained 13 items/indicators across two domains (clinical signs and behavioural expression). One hundred preweaned dairy-bred calves were scored daily using the HRQOL tool and also using the industry-recognised Wisconsin health score as a ‘gold standard’. The score assigned to each of the 13 items of the HRQOL tool was summed to give an accumulated HRQOL score for each calf/day. To refine the tool, the items within the tool were compared to each other to identify high levels of correlation or redundancy. This resulted in the retention of three items within the clinical signs domain (body and head posture, respiratory effort and ear carriage) and four within the behavioural expression domain (vigour, movement to feed, motivation at feed and volume of feed consumed). To determine whether the refined HRQOL tool could successfully differentiate sick from healthy animals, the Wisconsin score was used to create two matched groups of 28 ‘sick’ and 28 ‘healthy’ calves. There was a significant difference in the HRQOL scores between the two groups (H = 14.09, df = 1, P = 0.000) suggesting that the new tool could differentiate between ‘healthy’ and ‘sick’ calves. In terms of the two domains, there was a significant difference (P < 0.001) between the ‘healthy’ and ‘sick’ calves for the overall HRQOL tool score for the clinical signs domain, but there was no significant difference (P = 0.154) between ‘healthy’ and ‘sick’ calves in the overall HRQOL score for the behavioural expression domain; however, the combined tool was the most accurate. Overall, this study has demonstrated that the new HRQOL tool can differentiate between sick and healthy calves. Some or all of the indicators could be used alongside existing disease-detection tools for preweaned calves. However, future work would be needed to validate this HRQOL tool in other production systems.

TBX3 is essential for establishment of the posterior boundary of anterior genes and upregulation of posterior genes together with HAND2 during the onset of limb bud development.

During limb bud formation, axis polarities are established as evidenced by the spatially restricted expression of key regulator genes. In particular, the mutually antagonistic interaction between the GLI3 repressor and HAND2 results in distinct and non-overlapping anterior-distal Gli3 and posterior Hand2 expression domains. This is a hallmark of the establishment of antero-posterior limb axis polarity, together with spatially restricted expression of homeodomain and other transcriptional regulators. Here, we show that TBX3 is required for establishment of the posterior expression boundary of anterior genes in mouse limb buds. ChIP-seq and differential gene expression analysis of wild-type and mutant limb buds identifies TBX3-specific and shared TBX3-HAND2 target genes. High sensitivity fluorescent whole-mount in situ hybridisation shows that the posterior expression boundaries of anterior genes are positioned by TBX3-mediated repression, which excludes anterior genes such as Gli3, Alx4, Hand1 and Irx3/5 from the posterior limb bud mesenchyme. This exclusion delineates the posterior mesenchymal territory competent to establish the Shh-expressing limb bud organiser. In turn, HAND2 is required for Shh activation and cooperates with TBX3 to upregulate shared posterior identity target genes in early limb buds.

Relationship between sleep disturbance and developmental status in preschool-aged children with developmental disorder

BackgroundSleep has been known to affect childhood development. Sleep disturbance is likely more common in children with developmental delay (DD) than in typical development. There are few studies on the correlation between sleep disturbance and developmental features in children with DD. Therefore, this study aimed to evaluate the associations between the two in children with DD.MethodsA total of 45 children (age range 27.0 ± 11.1) with DD were recruited and evaluated using the Sleep Disturbance Scale for Children (SDSC) and Bayley Scales of Infant and Toddler Development (BSID-III). The outcomes are expressed as means and standard deviations. The correlation between SDSC and BSID-III was assessed using Spearman’s rank correlation test. Multiple regression analysis was performed to investigate the relationship between BSID-III domains and SDSC questionnaire subscales. Statistical significance was set at p < 0.05.ResultsBased on the correlation analysis and subsequent hierarchical regression analysis, cognition and socio-emotional domains of BSID-III were significantly associated with the DOES subscale of the SDSC questionnaire. In addition, the expressive language domain of the BSID-III was found to be associated with the DA subscale of the SDSC questionnaire. It seems that excessive daytime sleepiness might negatively affect emotional and behavioral problems and cognitive function. Also, arousal disorders seem to be related to memory consolidation process, which is thought to affect language expression.ConclusionThis study demonstrated that DA and DOES subscales of the SDSC questionnaire were correlated with developmental aspects in preschool-aged children with DD. Sleep problems in children with DD can negatively affect their development, thereby interfering with the effectiveness of rehabilitation. Identifying and properly managing the modifiable factors of sleep problems is also crucial as a part of comprehensive rehabilitation treatment. Therefore, we should pay more attention to sleep problems, even in preschool-aged children with DD.

ALTERED MERISTEM PROGRAM1 sustains cellular differentiation by limiting HD-ZIP III transcription factor gene expression.

Plants show remarkable developmental and regenerative plasticity through the sustained activity of stem cells in meristems. Under certain conditions, pluripotency can even be reestablished in cells that have already entered differentiation. Mutation of the putative carboxypeptidase ALTERED MERISTEM PROGRAM1 (AMP1) in Arabidopsis (Arabidopsis thaliana) causes a set of hypertrophic phenotypes, indicating a defect in the suppression of pluripotency. A role of AMP1 in the miRNA-mediated inhibition of translation has previously been reported; however, how this activity is related to its developmental functions is unclear. Here, we examined the functional interaction between AMP1 and the Class III homeodomain-leucine zipper (HD-ZIP III) transcription factors, which are miRNA-controlled determinants of shoot meristem specification. We found that the HD-ZIP III transcriptional output is enhanced in the amp1 mutant and that plant lines with increased HD-ZIP III activity not only developed amp1 mutant-like phenotypes but also showed a synergistic genetic interaction with the mutant. Conversely, the reduction of HD-ZIP III function suppressed the shoot hypertrophy defects of the amp1 mutant. We further provide evidence that the expression domains of HD-ZIP III family members are expanded in the amp1 mutant and that this misexpression occurs at the transcriptional level and does not involve the function of miRNA165/166. Finally, amp1 mutant-specific phenotypes cannot be mimicked by a general inhibition of miRNA function in the AMP1 expression domain. These findings lead us to a model in which AMP1 restricts cellular pluripotency upstream of HD-ZIP III proteins, and this control appears to be not directly mediated by the canonical miRNA pathway.

Development of node architecture and emergence of molecular organizer characteristics in the pig embryo.

The avian node is the equivalent of the amphibian Spemann's organizer, as indicated by its ability to induce a secondary axis, cellular contribution, and gene expression, whereas the node of the mouse, which displays limited inductive capacities, was suggested to be a part of spatially distributed signaling. Furthermore, the structural identity of the mouse node is subject of controversy, while little is known about equivalent structures in other mammals. We analyzed the node and emerging organizer in the pig using morphology and the expression of selected organizer genes prior to and during gastrulation. The node was defined according to the "four-quarter model" based on comparative consideration. The node of the pig displays a multilayered, dense structure that includes columnar epithelium, bottle-like cells in the dorsal part, and mesenchymal cells ventrally. Expression of goosecoid (gsc), chordin, and brachyury, together with morphology, reveal the consecutive emergence of three distinct domains: the gastrulation precursor domain, the presumptive node, and the mature node. Additionally, gsc displays a ventral expression domain prior to epiblast epithelialization. Our study defines the morphological and molecular context of the emerging organizer equivalent in the pig and suggests a sequential development of its function.

Unfolding the ventral nerve center of chaetognaths

BackgroundChaetognaths are a clade of marine worm-like invertebrates with a heavily debated phylogenetic position. Their nervous system superficially resembles the protostome type, however, knowledge regarding the molecular processes involved in neurogenesis is lacking. To better understand these processes, we examined the expression profiles of marker genes involved in bilaterian neurogenesis during post-embryonic stages of Spadella cephaloptera. We also investigated whether the transcription factor encoding genes involved in neural patterning are regionally expressed in a staggered fashion along the mediolateral axis of the nerve cord as it has been previously demonstrated in selected vertebrate, insect, and annelid models.MethodsThe expression patterns of genes involved in neural differentiation (elav), neural patterning (foxA, nkx2.2, pax6, pax3/7, and msx), and neuronal function (ChAT and VAChT) were examined in S. cephaloptera hatchlings and early juveniles using whole-mount fluorescent in situ hybridization and confocal microscopy.ResultsThe Sce-elav+ profile of S. cephaloptera hatchlings reveals that, within 24 h of post-embryonic development, the developing neural territories are not limited to the regions previously ascribed to the cerebral ganglion, the ventral nerve center (VNC), and the sensory organs, but also extend to previously unreported CNS domains that likely contribute to the ventral cephalic ganglia. In general, the neural patterning genes are expressed in distinct neural subpopulations of the cerebral ganglion and the VNC in hatchlings, eventually becoming broadly expressed with reduced intensity throughout the CNS in early juveniles. Neural patterning gene expression domains are also present outside the CNS, including the digestive tract and sensory organs. ChAT and VAChT domains within the CNS are predominantly observed in specific subpopulations of the VNC territory adjacent to the ventral longitudinal muscles in hatchlings.ConclusionsThe observed spatial expression domains of bilaterian neural marker gene homologs in S. cephaloptera suggest evolutionarily conserved roles in neurogenesis for these genes among bilaterians. Patterning genes expressed in distinct regions of the VNC do not show a staggered medial-to-lateral expression profile directly superimposable to other bilaterian models. Only when the VNC is conceptually laterally unfolded from the longitudinal muscle into a flat structure, an expression pattern bearing resemblance to the proposed conserved bilaterian mediolateral regionalization becomes noticeable. This finding supports the idea of an ancestral mediolateral patterning of the trunk nervous system in bilaterians.

Muscular remodeling and anteroposterior patterning during tapeworm segmentation.

Tapeworms are parasitic flatworms that independently evolved a segmented body plan, historically confounding comparisons with other animals. Anteroposterior (AP) patterning in free-living flatworms and in tapeworm larvae is associated with canonical Wnt signaling and positional control genes (PCGs) are expressed by their musculature in regionalized domains along the AP axis. Here, we extend investigations of PCG expression to the adult of the mouse bile-duct tapeworm Hymenolepis microstoma, focusing on the growth zone of the neck region and the initial establishment of segmental patterning. We show that the adult musculature includes new, segmental elements that first appear in the neck and that the spatial patterns of Wnt factors are consistent with expression by muscle cells. Wnt factor expression is highly regionalized and becomes AP-polarized in segments, marking them with axes in agreement with the polarity of the main body axis, while the transition between the neck and strobila is specifically demarcated by the expression domain of a Wnt11 paralog. We suggest that segmentation could originate in the muscular system and participate in patterning the AP axis through regional and polarized expression of PCGs, akin to the gene regulatory networks employed by free-living flatworms and other animals.

Emotion detection from handwriting and drawing samples using an attention-based transformer model.

Emotion detection (ED) involves the identification and understanding of an individual's emotional state through various cues such as facial expressions, voice tones, physiological changes, and behavioral patterns. In this context, behavioral analysis is employed to observe actions and behaviors for emotional interpretation. This work specifically employs behavioral metrics like drawing and handwriting to determine a person's emotional state, recognizing these actions as physical functions integrating motor and cognitive processes. The study proposes an attention-based transformer model as an innovative approach to identify emotions from handwriting and drawing samples, thereby advancing the capabilities of ED into the domains of fine motor skills and artistic expression. The initial data obtained provides a set of points that correspond to the handwriting or drawing strokes. Each stroke point is subsequently delivered to the attention-based transformer model, which embeds it into a high-dimensional vector space. The model builds a prediction about the emotional state of the person who generated the sample by integrating the most important components and patterns in the input sequence using self-attentional processes. The proposed approach possesses a distinct advantage in its enhanced capacity to capture long-range correlations compared to conventional recurrent neural networks (RNN). This characteristic makes it particularly well-suited for the precise identification of emotions from samples of handwriting and drawings, signifying a notable advancement in the field of emotion detection. The proposed method produced cutting-edge outcomes of 92.64% on the benchmark dataset known as EMOTHAW (Emotion Recognition via Handwriting and Drawing).