DEVELOPMENTAL DYNAMICS

Analysis pipeline to quantify uterine gland structural variations
Khan S, Shen M, Bhurke A, Alessio A and Arora R
Technical advances in whole tissue imaging and clearing have allowed 3D reconstruction of exocrine uterine glands deep-seated in the endometrium. However, there are limited gland structure analysis platforms to analyze these imaging data sets. Here, we present a pipeline for segmenting and analyzing uterine gland shape.
ARHGAP29 promotes keratinocyte proliferation and migration in vitro and is dispensable for in vivo wound healing
Rhea L, Reeb T, Adelizzi E, Garnica B, Stein A, Kollash A, Dunnwald E and Dunnwald M
RhoA GTPases play critical roles in actin cytoskeletal remodeling required for controlling a diverse range of cellular functions including cell proliferation, adhesion, migration and changes in cell shape, all required for cutaneous wound healing. RhoA cycles between an active GTP-bound and an inactive GDP-bound form, a process regulated by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). ARHGAP29 is a GAP expressed in skin keratinocytes and is decreased in the absence of interferon regulator factor 6, a critical regulator of cell proliferation, migration, and wound healing. However, the role for ARHGAP29 in keratinocyte biology is unknown.
Spatiotemporal distribution of neural crest cells in the common wall lizard Podarcis muralis
Pranter R and Feiner N
Neural crest cells (NCCs) are migratory embryonic stem cells that give rise to a diverse set of cell types. Here we describe the dynamic distribution of NCCs in developing embryos of the common wall lizard Podarcis muralis inferred from 10 markers. Our aim is to provide insights into the NCC development of lacertid lizards and to infer evolutionary modifications by comparisons to other tetrapods.
foxe1 mutant zebrafish show indications of a hypothyroid phenotype and increased sensitivity to ethanol for craniofacial malformations
Raterman ST, Wagener FADTG, Zethof J, Cuijpers V, Klaren PHM, Metz JR and Von den Hoff JW
FOXE1 mutations in humans are associated with cleft palate and hypothyroidism. We previously developed a foxe1 mutant zebrafish demonstrating mineralization defects in larvae. In the present study, we investigate the thyroid status and skeletal phenotype of adult foxe1 mutants.
Seasonal heterochrony of reproductive development and gene expression in a polymorphic salamander
Herrboldt MA, Wright CNC and Bonett RM
Life cycle evolution includes ecological transitions and shifts in the timing of somatic and reproductive development (heterochrony). However, heterochronic changes can be tissue-specific, ultimately leading to the differential diversification of traits. Salamanders exhibit alternative life cycle polymorphisms involving either an aquatic to terrestrial metamorphosis (biphasic) or retention of aquatic larval traits into adulthood (paedomorphic). In this study, we used gene expression and histology to evaluate how life cycle evolution impacts temporal reproductive patterns in males of a polymorphic salamander.
Functional significance of earthworm clitellum in regulating the various biological aspects of cell survival and regeneration
Selvan Christyraj JD, Vaidhyalingham AB, Sengupta C, Rajagopalan K, Vadivelu K, Suresh NK and Venkatachalam B
Earthworms are a highly abundant species in nature, with nearly 7000 different species being discovered. Despite the similarities in morphology among earthworm species, their regeneration capabilities vary based on the clitellum. The clitellum plays a crucial role in the clitellum-dependent worms, as it is involved in the processes of regeneration and reproduction in earthworms. The fascinating characteristic of the clitellum, which serves as a hub for stem cells in clitellum-dependent worms, plays a crucial role in various biological processes that require further exploration. This review focuses on the overall physiological functions and uncovers the lesser-known roles of the clitellum that have been documented in various research articles. In recent times, numerous studies have been conducted using the earthworm model to explore various areas. In that regard, the clitellum's different roles in regulating and controlling stem cells, the regeneration process, regulation of organogenesis, stress response, aging, autotomy, and various features have been briefly discussed. Ultimately, we emphasized the unique and versatile role of the clitellum in the animal model, making it an ideal choice for studying development, regeneration, stem cells, organogenesis, toxicology, autotomy, and aging response.
A network of transient domains for breaking symmetry during anterior-posterior axis formation in the porcine embryo
Plöger R, Tsikolia N and Viebahn C
Breaking radial symmetry for anterior-posterior axis formation is one of the key developmental steps of vertebrate gastrulation and is established through a succession of transient domains defined by morphology or gene expression. Three such domains were interpreted recently in the rabbit to be part of a "three-anchor-point model" for axis formation. To answer the question as to whether the model is generally applicable to mammals, the dynamic expression patterns of four marker genes were analyzed in the pig, where gastrulating epiblast forms from half the inner cell mass: EOMES and PKDCC transcripts display decreasing expression intensities in the anterior hypoblast and-together with WNT3-increasing intensity in the anterior streak domain and the node; TBX6 expression changes from an initial central expression to exclusive expression in the posterior extremity of the primitive streak. The anterior streak domain has thus a molecular footprint similar to the one in the rabbit, the end node shares TBX6 between the species, while the anterior hypoblast-mirroring specific porcine epiblast derivation and fate-is marked by PKDCC instead of WNT3. The molecular similarities in transient domains point to conserved mechanisms for establishing the mammalian anterior-posterior axis and, possibly, breaking radial symmetry.
Elp1 function in placode-derived neurons is critical for proper trigeminal ganglion development
Hines MA and Taneyhill LA
The trigeminal nerve is the largest cranial nerve and functions in somatosensation. Cell bodies of this nerve are positioned in the trigeminal ganglion, which arises from the coalescence of neural crest and placode cells. While this dual cellular origin has been known for decades, the molecular mechanisms controlling trigeminal ganglion development remain obscure. We performed RNA sequencing on the forming chick trigeminal ganglion and identified Elongator acetyltransferase complex subunit 1 (Elp1) for further study. Mutations in ELP1 cause familial dysautonomia (FD), a fatal disorder characterized by the presence of smaller trigeminal nerves and sensory deficits. While Elp1 has established roles in neurogenesis, its function in placode cells during trigeminal gangliogenesis has not been investigated.
EphB2, EphB4, and ephrin-B1 expression and localization in postnatal developing epididymis in mice
Gofur MR and Ogawa K
Eph receptors and ephrin ligands, the transmembrane proteins, function as a mechanism of communication between cells. Therefore, we intended to explore the expression array of EphB2 and EphB4 receptors and ephrin-B1 ligand in postnatal developing mouse epididymis during 1 day to 8 weeks using RT-PCR amplification and immunofluorescence staining.
Spatiotemporal characteristics of eustachian tube development in C57BL/6 mice: Correlation between morphological and functional maturation
Yu X, Zhang H, Li H, Shen X, Yu W, Li T, Chen X, Zong S and Xiao H
The eustachian tube (ET), a critical conduit connecting the middle ear and nasopharynx, is essential for normal middle ear function. However, it remains one of the least understood anatomical structures due to its complexity and the challenges of in vitro manipulation. Historically, these challenges have hindered research into the morphology and function development of the ET. This study elucidates the spatiotemporal relationship of ET morpho-functional maturation in mice, identifying key periods and factors that lay the theoretical foundation for exploring the molecular mechanisms of ET-related diseases.
Stat stimulates histone H3K4 methylation via KDM5 inhibition in adult stem cells of budding tunicates
Kimura-Nagano Y, Kishimoto K, Sekida S and Kawamura K
The branchial epithelium is one of the main tissues in which histone H3K4 trimethylation (H3K4me3) occurs in the budding tunicate, Polyandrocarpa misakiensis. It contains proliferating and undifferentiated cell aggregates at the bottom of each pharyngeal cleft, providing the nest for the adult stem cell niche. We examined the sustainable mechanism enabling epigenetic histone methylation in adult stem cells.
Analysis of Meis2 knockout mice reveals Sonic hedgehog-mediated patterning of the cochlear duct
Koo HY, Oh JH, Durán Alonso MB, Hernández IL, González-Vallinas M, Alonso MT, Tena JJ, Gil-Gálvez A, Giraldez F, Bok J and Schimmang T
The mechanisms underlying the formation of complex structures such as during the outgrowth of the cochlear duct are still poorly understood.
Hypoxia regulate developmental coronary angiogenesis potentially through VEGF-R2- and SOX17-mediated signaling
Vitali HE, Kuschel B, Sherpa C, Jones BW, Jacob N, Madiha SA, Elliott S, Dziennik E, Kreun L, Conatser C, Bhetwal BP and Sharma B
The development of coronary vessels in embryonic mouse heart involves various progenitor populations, including sinus venosus (SV), endocardium, and proepicardium. ELA/APJ signaling is known to regulate coronary growth from the SV, whereas VEGF-A/VEGF-R2 signaling controls growth from the endocardium. Previous studies suggest hypoxia might regulate coronary growth, but its specific downstream pathways are unclear. In this study, we further investigated the role of hypoxia and have identified SOX17- and VEGF-R2-mediated signaling as the potential downstream pathways in its regulation of developmental coronary angiogenesis.
Developmental cochlear defects are involved in early-onset hearing loss in A/J mice
Kui L, Ma P, Zhao W, Yan B, Kuang X, Li B, Geng R, Zheng T and Zheng Q
A/J mice exhibited a severe hearing loss (HL) at juvenile stage. Up-to-date, studies on HL in A/J mice have mostly focused on the damage or dysfunction of hair cells (HCs), spiral ganglion neurons (SGNs), and stereocilia. We examined A/J mice at the early postnatal stage and found that the damage and the loss of outer hair cells (OHCs) are not severe enough to explain the profound HL observed at this age, which suggests that other cochlear defects may be responsible for HL. To better understand the mechanisms of early-onset HLin A/J mice, we characterized the pathology of the cochlea from postnatal day 3 to day 21.
Stage-by-stage exploration of normal embryonic development in the Arabian killifish, Aphanius dispar
Alsakran A, Minhas R, Hamied AS, Wilson RW, Ramsdale M and Kudoh T
Arabian killifish, Aphanius dispar, lives in marine coastal areas of the Middle East, as well as in streams that experience a wide range of salinities and temperatures. It has been used as a mosquito control agent and for studying the toxicities of environmental pollutants. A. dispar's eggshell (chorion) and embryos are highly transparent and are suitable for high resolution microscopic observations, offering excellent visibility of live tissues.
Effects of life history strategies and habitats on limb regeneration in plethodontid salamanders
Bothe V, Müller H, Shubin N and Fröbisch N
Salamanders are the only tetrapods that exhibit the ability to fully regenerate limbs. The axolotl, a neotenic salamander, has become the model organism for regeneration research. Great advances have been made providing a detailed understanding of the morphological and molecular processes involved in limb regeneration. However, it remains largely unknown how limb regeneration varies across salamanders and how factors like variable life histories, ecologies, and limb functions have influenced and shaped regenerative capacities throughout evolution.
BMP signaling pathway member expression is enriched in enteric neural progenitors and required for zebrafish enteric nervous system development
Moore JA, Moreno-Campos R, Noah AS, Singleton EW and Uribe RA
The vertebrate enteric nervous system (ENS) consists of a series of interconnected ganglia within the gastrointestinal (GI) tract, formed during development following migration of enteric neural crest cells (ENCCs) into the primitive gut tube. Much work has been done to unravel the complex nature of extrinsic and intrinsic factors that regulate processes that direct migration, proliferation, and differentiation of ENCCs. However, ENS development is a complex process, and we still have much to learn regarding the signaling factors that regulate ENCC development.
Ventral body wall closure: Mechanistic insights from mouse models and translation to human pathology
Formstone C, Aldeiri B, Davenport M and Francis-West P
The ventral body wall (VBW) that encloses the thoracic and abdominal cavities arises by extensive cell movements and morphogenetic changes during embryonic development. These morphogenetic processes include embryonic folding generating the primary body wall; the initial ventral cover of the embryo, followed by directed mesodermal cell migrations, contributing to the secondary body wall. Clinical anomalies in VBW development affect approximately 1 in 3000 live births. However, the cell interactions and critical cellular behaviors that control VBW development remain little understood. Here, we describe the embryonic origins of the VBW, the cellular and morphogenetic processes, and key genes, that are essential for VBW development. We also provide a clinical overview of VBW anomalies, together with environmental and genetic influences, and discuss the insight gained from over 70 mouse models that exhibit VBW defects, and their relevance, with respect to human pathology. In doing so we propose a phenotypic framework for researchers in the field which takes into account the clinical picture. We also highlight cases where there is a current paucity of mouse models for particular clinical defects and key gaps in knowledge about embryonic VBW development that need to be addressed to further understand mechanisms of human VBW pathologies.
Expression analysis of genes including Zfhx4 in mice and zebrafish reveals a temporospatial conserved molecular basis underlying craniofacial development
Liu S, Xu L, Kashima M, Narumi R, Takahata Y, Nakamura E, Shibuya H, Tamura M, Shida Y, Inubushi T, Nukada Y, Miyazawa M, Hata K, Nishimura R, Yamashiro T, Tasaki J and Kurosaka H
Embryonic craniofacial development involves several cellular and molecular events that are evolutionarily conserved among vertebrates. Vertebrate models such as mice and zebrafish have been used to investigate the molecular and cellular etiologies underlying human craniofacial disorders, including orofacial clefts. However, the molecular mechanisms underlying embryonic development in these two species are unknown. Therefore, elucidating the shared mechanisms of craniofacial development between disease models is crucial to understanding the underlying mechanisms of phenotypes in individual species.
Knockout of rbm24a and rbm24b genes in zebrafish impairs skeletal and cardiac muscle integrity and function during development
Saquet A, Ying Z, Shi DL and Grifone R
Skeletal and cardiac muscles are contractile tissues whose development and function are dependent on genetic programs that must be precisely orchestrated in time and space. In addition to transcription factors, RNA-binding proteins tightly regulate gene expression by controlling the fate of RNA transcripts, thus specific proteins levels within the cell. Rbm24 has been identified as a key player of myogenesis and cardiomyogenesis in several vertebrates, by controlling various aspects of post-transcriptional regulation, including pre-mRNA alternative splicing and mRNA stabilization. In zebrafish, knockdown of rbm24a or rbm24b also causes skeletal and cardiac muscle phenotypes, but how their combined loss affects muscle integrity and function remains elusive.
Patterns of early embryogenesis and growth in the olfactory system of chick (Gallus gallus domesticus) based on iodine-enhanced micro-computed tomography
Hogan AVC, Cerio DG and Bever GS
The vertebrate olfactory system entails a complex set of neural/support structures that bridge morphogenetic regions. The developmental mechanisms coordinating this bridge remain unclear, even for model organisms such as chick, Gallus gallus. Here, we combine previous growth data on the chick olfactory apparatus with new samples targeting its early embryogenesis. The purpose is to illuminate how early developmental dynamics integrate with scaling relationships to produce adult form and, potentially, evolutionary patterns. Olfactory structures, including epithelium, turbinate, nerve, and olfactory bulb, are considered in the context of neighboring nasal and brain structures.