The regulation of transcriptional activity constitutes a primary layer of control over cellular function across diverse tissues and cell types. This regulatory transcriptional landscape is largely governed by epigenetic mechanisms, including DNA and histone modifications, the dynamic activity of epigenetic “writers” and “erasers,” and the influence of small regulatory molecules such as microRNAs (miRNAs). miRNAs are small non-coding RNA molecules that play critical roles in transcriptional and post-transcriptional gene regulation. By modulating the expression of transcription factors, kinases, and other regulatory proteins, miRNAs exert tight control over cellular processes and maintain homeostasis. Given the essential requirement for precise cellular coordination in reproductive biology, miRNAs have emerged as key regulators of reproductive function. They participate in multiple stages of reproductive processes, ranging from ovarian function to the establishment and maintenance of pregnancy, thereby influencing fertility outcomes across species. In this review, we summarize recent advances in understanding the roles of miRNAs in key reproductive events, including gametogenesis, oocyte maturation, embryonic genome activation, early embryonic development, implantation and pregnancy. We aim to highlight the principal miRNAs involved in the maintenance of reproductive function and fertility, and their molecular targets and the regulatory networks when known. Based on our review, we conclude that although their potential in clinical and/or agricultural applications still remains uncertain, their role in regulating fundamental aspects of cellular biology, particularly reproductive processes, is becoming increasingly clear.
This study evaluates ChromaLIVETM, a multichromatic, mix-and-read fluorescent marker developed for continuous live-cell imaging, in the context of embryology. The aim was to evaluate whether this marker is compatible with dynamic embryonic development up to the blastocyst stage, with minimal impact on embryo viability, integrity, or normal growth of mouse embryos at the 2-cell stage that were cultured to the blastocyst stage under time-lapse imaging conditions, either in the presence or absence of ChromaLIVETM. Results showed comparable blastocyst formation rates between ChromaLiveTM and the control group, as well as similar proportions of high-quality blastocysts. Although minor but statistically significant delays were noted in two kinetics events (t3 and tSB), other developmental timings remained unaffected. Time-lapse confocal fluorescence imaging demonstrated that ChromaLIVETM dye provided stable, bright, high-resolution 3D visualizations of cellular compartments including membranes, cytoplasm and embryonic structures such as trophectoderm, inner cell mass and blastocoel throughout development. Finally, transcriptomic analyses revealed a limited set of gene-expression differences between stained and unstained embryos; although these included developmental and metabolic pathways, embryos developed to the blastocyst stage comparably to controls.
Connecting the intestinal vasculature with the pre-existing systemic circulatory system is vital for nutrient absorption and blood transport for detoxification in the liver. However, the cellular processes underlying this connection remain unclear. Using genetically modified zebrafish models and in vivo imaging, we visualized that the supra-intestinal artery (SIA) connected to the pre-existing dorsal aorta (DA) in two distinct regions, the anterior and posterior. We found that endothelial cells migrated out of the DA and formed the anterior SIA-DA junction, whereas endothelial cells sprouted from SIA and connected to the DA in the posterior region. Pharmacological and genetic analyses revealed that activin receptor-like kinase 1 (ALK1) signaling was required for the SIA-DA connections. The present study provides new insights into the cellular phenomena and regulatory mechanisms of intestinal vascular development.
Both genetics and the environment affect the phenotypes of polycystic kidney diseases (PKD), such as autosomal dominant (AD) PKD, autosomal recessive (AR) PKD and nephronophthisis (NPH). Variable phenotypes, pleiotropy, divergent severity and progression, even in family members who inherited the same disease-causing mutation(s), signal the involvement of networked genes and modifiers. Several PKD-linked genes function in development and renal tubule morphogenesis. Cystic renal tissues feature metabolic remodeling, functional reprogramming and dysregulation of several shared factors and pathways. ADPKD, ARPKD and NPH partially phenocopy each other. Understanding the developmental arc of cystic kidney disease and its complex phenotypes would improve diagnostics and help develop effective personalized treatments. However, this is challenging to study in vertebrate systems due to genetic redundancy, functional overlap, and a dearth of genetic tools. Underused in this context, Drosophila melanogaster offers high genomic and pathway conservation, a wealth of genetic tools, and rapid generation times, making it a reliable and sustainable model for mechanistic, genome-wide, and precision medicine studies. Here, we surveyed ADPKD, ARPKD, and NPH, compared renal and extrarenal phenotypes, and examined the network of shared and unique contributors, their healthy and diseased functions and conservation from the perspective of mechanistic whole-animal modeling.
Based on updated information on tail regeneration in lizards, a hypothesis is introduced to explain why these reptiles evolved their regenerative ability. The hypothesis, supported by paleontological evidence, considers tail regeneration associated with autotomy since the Paleozoic in amphibian anthracosaurs of the Carboniferous Period. It is submitted that these ancient amphibians developed tails containing stem cells localized in autotomous planes and/or inter-muscle connective tissues, from which they could regenerate their tails, as some extant salamanders do. The process of stem cell distribution during vertebrate development in salamanders and lizards, however, remains to be demonstrated. It is here suggested that autotomy and regeneration were inherited in the reptiliamorph basal amniotes of the Upper Carboniferous, then in captorhinids of the Permian, in eosuchians of the Triassic, and in the derived Mesozoic lizards, allowing survival and radiation into numerous families. Only in a few lizard families, perhaps under specific ecological adaptations, was autotomy lost, reducing or eliminating tail regeneration. Transcriptome analysis of developing versus regenerating tail indicates numerous differences, suggesting that regeneration utilizes alternative developmental gene pathways from those activated during development. Clarification of gene networks evolved for lizard tail regeneration may indicate the essential steps necessary to regenerate organs also in other amniotes.
Background/Objectives: CRISPR/Cas9-mediated genome editing enables efficient generation of knockout mouse models; however, frameshift mutations do not always result in complete loss of function. The factors influencing functional inactivation following frameshift mutations remain incompletely understood. Here, we tested whether frameshift-dominant targeting of exon 1 is sufficient to generate a null allele of Fgf10, a gene essential for limb formation. Methods: Guide RNAs (gRNAs) were selected using a machine learning-based pipeline to favor microhomology-mediated end joining (MMEJ)-dominant repair. Editing efficiency and indel profiles were assessed via amplicon sequencing in mouse embryonic stem cells (mESCs) and preimplantation embryos. Edited embryos were transferred to surrogate females and analyzed at embryonic day 15.5 (E15.5). Results: Amplicon sequencing confirmed >97% editing efficiency and >80% frameshift alleles in both mESCs and preimplantation embryos, with a predominant 7 bp deletion. Despite highly efficient frameshift-dominant editing, most of the E15.5 embryos were morphologically normal, indicating that exon 1 targeting did not reliably produce null phenotypes. In silico analysis suggested the possible presence of alternative downstream translation initiation sites, and our secretion assay supported this possibility. Initiation from a downstream ATG in a +2 reading frame (e.g., 7 bp deletion) may restore the downstream coding sequence and partially preserve protein function. Conclusions: Frameshift mutations in exon 1 of Fgf10 do not consistently result in functional knockout. The functional outcome depends on the specific reading frame and may be influenced by alternative translation initiation and protein domain architecture. These findings highlight important considerations for designing genome editing strategies to achieve complete gene inactivation.
Warfarin is a coumarin-derived oral anticoagulant widely used for the prevention and treatment of thromboembolic disorders, particularly in patients with mechanical heart valves. The drug exerts its anticoagulant effect by inhibiting vitamin K epoxide reductase, thereby impairing γ-carboxylation of vitamin K-dependent coagulation factors. Despite its clinical efficacy, warfarin therapy is associated with a narrow therapeutic index, substantial interindividual variability in dose response, numerous drug interactions, and significant hemorrhagic risk. Maternal warfarin therapy during pregnancy is strongly associated with fetal warfarin syndrome (FWS), a characteristic pattern of embryopathy resulting from in utero exposure to the drug. This review summarizes current knowledge regarding the physicochemical properties, pharmacological mechanisms, dose variability, toxicity, and developmental effects associated with warfarin exposure. Evidence from human clinical studies and vertebrate animal models is discussed to elucidate conserved developmental and molecular mechanisms underlying warfarin teratogenicity. The review also examines the signaling pathways disrupted by warfarin exposure, highlighting that its teratogenic effects extend beyond anticoagulation to the disruption of vitamin K-dependent developmental signaling. Inhibition of γ-glutamyl carboxylation, together with alterations in Gas6/TAM, PXR, Ras, and Wnt/β-catenin signaling pathways, impairs skeletal, vascular, and neural development, contributing to the characteristic abnormalities of fetal warfarin syndrome. Collectively, this review integrates clinical, molecular, and experimental findings to provide a comprehensive understanding of warfarin-induced developmental toxicity. Current knowledge is insufficient to fully elucidate the complex mechanisms underlying warfarin-induced embryopathy and fetal toxicity. Further investigations are warranted to identify safer anticoagulant regimens during pregnancy and to inform the development of novel therapeutic strategies that minimize fetal risk while maintaining maternal anticoagulation.
Voltage-gated potassium channels (Kv) are a large family of potassium channels composed of 40 members across 12 subtypes. The KCNH genes encode three subfamilies of voltage-gated potassium channels: Kv10 (EAG, ether à go go), Kv11 (ERG, EAG-related gene), and Kv12 (ELK, EAG-like K). Kv channels play prominent roles in neuronal and cardiovascular systems. Mutations in Kv channels have been linked to many human diseases, such as epilepsy, heart arrhythmias, and cancers. Significant progress has been made in understanding protein structures, physiological functions, and pharmacological modifiers. However, the evolutionary history and gene expression of vertebrate KCNH genes during embryonic development remain largely unknown. We systematically identified and cloned 14 kcnh genes in zebrafish. Then, we examined the vertebrate KCNH channel evolution by phylogenetic and syntenic analyses. Our data reveal that the three subtypes of the KCNH gene family had already evolved in invertebrates, long before the emergence of vertebrates. The number of vertebrate KCNH genes increased, most likely due to whole-genome duplications (WGDs). In addition, we examined zebrafish kcnh gene expression during early embryogenesis by in situ hybridization. Each subgroup’s genes showed similar but distinct gene expression domains with some exceptions. Most of them were expressed in neural tissues. Notably, kcnh6a showed robust expression in the developing heart, consistent with its conserved role in cardiac repolarization. Additionally, a few kcnh genes were transiently expressed in non-neural tissues, such as somites and the notochord, suggesting they may have a unique role in embryonic development. Our phylogenetic and developmental analyses of KCNH channels shed light on their evolutionary history and potential roles during embryogenesis, in line with their physiological functions and human channelopathies.
Valproic acid (VPA) is a human developmental toxicant that causes neural tube defects and neurobehavioral deficits. Recent work has implicated VPA-induced oxidative stress in cell models of neurodifferentiation, where oxidative post-translational modifications (PTMs) in undifferentiated cells, primarily protein sulfenylation (Pr-SOH), were unique compared to differentiated neurons, primarily protein S-glutathionylation (Pr-SSG). Many of these effects could be mitigated by pretreatments with an Nrf2 inducer. However, it is unclear how early-stage mouse embryos (gestational day 8.5) respond to VPA treatments. Using whole embryo culture, mouse embryos were treated with VPA. A time course assessment of glutathione/glutathione disulfide redox potentials was performed via HPLC throughout 24 h of culture. At 6 h of VPA treatment, embryos were collected for the assessment of protein redox states and specific protein PTMs via various blotting techniques. Also, at 6 h of treatment, the localization of specific PTMs was determined via whole mount staining. Some embryos were pretreated with an Nrf2 inducer. Our data demonstrated that VPA caused a sharp oxidation of redox potentials, which were the greatest between 2 and 6 h, but reverted to control levels by 24 h. Preemptive Nrf2 activation prevented VPA-induced oxidation. Redox blotting showed that VPA caused oxidation of the proteome but this could be reversed by D3T pretreatment. More specifically, Pr-SOH levels increased but Pr-SSG levels were unchanged. Increased Pr-SOH could also be reversed with prior Nrf2 activation. We conclude that embryos at these early stages of development are highly sensitive to VPA and respond more like undifferentiated cells, promoting a more pro-oxidizing outcome for proteins, increasing Pr-SOH formation vs. Pr-SSG. These findings may support specific windows of development where embryos are more susceptible to VPA-induced oxidative injury. Further understanding of redox control and regulation at these susceptible states may serve to develop preventative strategies to reduce poor developmental outcomes after exposures.
Colony-stimulating factor-1 receptor (CSF1R) provides essential signals for macrophage and osteoclast proliferation, differentiation, and survival, but the roles of CSF1R+ macrophages and osteoclasts during limb morphogenesis are understudied. Here, we utilized a pharmacological model by feeding the CSF1R inhibitor PLX5622 to pregnant mice across gestation to examine how CSF1R disruption impacts embryonic limb development. CSF1R-expressing cells were significantly depleted in response to PLX5622 exposure, including a complete loss of embryonic osteoclasts and osteoclastic activity in the developing limb bones. Although the gross morphology of limb nerves, muscles, cartilage, and bone appeared intact between embryonic day 11.5 (E11.5) and E15.5, prenatal PLX5622 exposure resulted in a completely penetrant truncated phenotype for all postnatal day 1 (P1) limb bones analyzed, suggesting that CSF1R+ cells play important roles in mediating limb bone formation during late embryogenesis. Interestingly, strain-specific defects were observed in the heel, where most of the CD1 mice presented with absent talus and underdeveloped calcaneus bones, while the C57BL/6 mice presented with milder developmental disruptions in both bones. Taken together, our data demonstrate that PLX5622 effectively depletes CSF1R-expressing macrophages and osteoclasts in embryonic limbs and suggest an essential role for embryonic CSF1R+ cells in driving limb bone morphogenesis.
Regulation of the cell cycle is critical for maintaining genomic integrity. Therefore, cells have adapted several mechanisms to ensure that cell cycle events occur in a precise order. Some mechanisms regulate cell cycle progression by inhibiting cell cycle drivers, cyclin-dependent kinases (CDKs). The Wee1/Myt1 family of kinases regulate the G2-to-M phase transition by phosphorylating and inactivating Cdk1. Investigations of Wee1/Myt1 have mainly focused on its regulation of mitosis; the role of Wee1/Myt1 kinases in the meiotic cell cycle is less well understood. However, misregulation of Wee1/Myt1 during meiosis can have a range of fertility consequences from mild to severe, including human fertilization failure and infertility. Studies from several organisms reveal that the meiotic functions of Wee1/Myt1 kinases differ from mitosis depending on the species and sex. Here, we review how Wee1/Myt1 kinases regulate cell cycle progression in meiosis across species. We highlight current knowledge of Wee1/Myt1 in meiosis and discuss unanswered questions and new directions to advance the field of meiosis and reproduction. Understanding the molecular and cellular functions of Wee1/Myt1 homologs in these various systems may contribute to the discovery of the mechanisms underlying human infertility cases, better diagnoses, and clinical treatments.
Background: Hofbauer cells (HBCs) are the only immunocompetent cells within the stroma of chorionic villi and play a key role in immune regulation and placental development throughout gestation. Their phenotype, abundance, and proliferative activity change in accordance with the needs of the fetoplacental unit. Methods: Thirty healthy human placentas across all three trimesters were analyzed. Samples were processed using standard histological protocols and immunohistochemically stained with CD45, CD68, CD86, and Ki-67 markers. Morphometric analysis was performed to determine the following parameters: percentage of HBCs, numerical areal density, and proliferative index. Results: HBCs were immunoreactive for CD45 and CD68, while CD86 immunoreactivity was not observed in any trimester. The proportion of HBCs was highest in the second trimester and lowest in the third. Numerical areal density was highest in the second trimester (22.21 ± 3.86) and lowest in the first (8.27 ± 4.18). The proliferative index was highest in the first trimester (82.45 ± 10.19%), decreased significantly in the second, and was completely absent in the third trimester. Conclusions: During physiological placental development, Hofbauer cells maintain a predominantly non-M1 macrophage phenotype, accompanied by a gradual reduction in proliferative activity.
Epigenetic regulation is pivotal in reproductive processes, such as oocyte maturation and pre-implantation embryonic development, and it impacts gene expression without altering DNA sequence through mechanisms including DNA methylation, histone modifications, and non-coding RNAs. Primarily, microRNA-21 is involved in meiotic progression, apoptosis, and cumulus cell function, which are necessary for oocyte competency. miR-21 dysregulation can lead to improper oocyte maturation and poor embryonic development, ultimately causing developmental defects. During pre-implantation embryonic development, DNA methylation and histone modifications contribute to cellular reprogramming, ensuring proper gene activation and repression. Environmentally, endocrine disruptors affect miR-21 expression, potentially disrupting pathways involved in reproductive health and developmental programming. Overall, this review explores the correlation between epigenetics, miRNA regulation, and environmental factors, emphasizing the intricacies of oocyte maturation and pre-implantation embryonic development. This highlights the need for additional mechanistic and translational research in reproductive epigenetics.
The gut microbiome plays a pivotal role in modulating multiple physiological processes from the earliest stages of life. However, the complete scope of its effects during childhood is yet to be fully elucidated, which underscores the importance of enhancing the understanding of this emerging area of research. This narrative review provides an overview of the influence of the gut microbiome in early human ontogeny by examining its role in brain and immune development, as well as its involvement in neurodevelopmental disorders and early-life mental health. The gut microbiome contributes to shaping the development and function of both the brain and the immune system. Its influence appears to be primarily mediated through the synthesis of neurotransmitters and microbial metabolites, as well as through the activation of specific pathways within the hypothalamic–pituitary–adrenal axis. Nevertheless, the exact mechanisms through which the gut microbiome exerts these effects, and the full extent of its impact on neurodevelopmental and immune health, remain incompletely understood and continue to be active areas of research and scientific debate. Ultimately, advances revealing how the gut microbiome shapes early brain and immune system development will create new opportunities for innovative interventions and predictive strategies aimed at transforming pediatric health outcomes.
Lung organogenesis is orchestrated by dynamic epithelial-mesenchymal interactions during embryogenesis, yet the gene regulatory programs and signaling dynamics governing these processes in the pseudoglandular stage remain incompletely understood. In this study, we integrated spatial and single-cell transcriptomic data across embryonic developmental stages to systematically characterize epithelial and mesenchymal dynamics during lung development. To achieve more refined cell types at single-cell resolution in spatial transcriptomic data, we developed a bin-based deconvolution strategy that enabled high-precision cell-type assignment. We subsequently constructed a 3D spatiotemporal landscape of lung development and elucidated the molecular regulatory mechanisms underlying epithelial-mesenchymal maturation during lung morphogenesis. In addition, we analyzed transcription factor module activity, intercellular communication signaling, and predicted downstream target genes, while integrating public GWAS metadata to link developmental programs with lung cancer-related features. We observed pronounced stage-specific functional heterogeneity between the pseudoglandular and late embryonic stages. Notably, E13.5 emerged as a critical transition window, during which progenitor states shifted toward more mature cellular phenotypes. We reconstructed epithelial-mesenchymal interactions and uncovered coordinated rewiring of ligand-receptor signaling and transcriptional networks across developmental stages. Regulatory network analysis further identified temporally coordinated transcription factor modules centered on Tbx3, Tbx5, Gli1, Gata4/5, Foxa1/2, and Cebpa, which collectively orchestrated branching morphogenesis, epithelial patterning, and tissue stabilization. Integration with lung cancer genome-wide association data demonstrated that embryonic lung progenitor states exhibit strong associations with lung cancer-related transcriptional programs, particularly involving epithelial-mesenchymal plasticity and RNA-splicing pathways. Furthermore, TP53/HNRNP-mutant lung adenocarcinomas displayed embryonic-like molecular features associated with cytoskeletal remodeling and progenitor-state reactivation. Together, our study provided a spatiotemporally resolved framework of embryonic lung development and identifies a critical transition window linking lung morphogenesis, regulatory network remodeling, and cancer-associated epithelial plasticity.
Feto-maternal microchimerism (Mc) refers to the exchange of cells between the fetus and mother, and fetal–fetal Mc to the exchange between fetuses during pregnancy. This phenomenon occurs across mammalian species, including humans, mice, and cattle. Key data on Mc cells and theoretical considerations regarding the presence of fetal-derived material, such as trophoblast cells, cell-free fetal DNA (cffDNA), and exosomes in maternal blood are summarized. This review aims to first, synthesize current knowledge on feto-maternal and fetal–fetal Mc across mammals, second, address three core questions: how and where Mc has been demonstrated in animals, what techniques have been used over time to detect fetal-derived material and Mc, and how placental structures influence the frequency of Mc. Finally, it aims to identify gaps in the literature for species such as horses, goats, and pigs. This article concludes that Mc is a widespread phenomenon among mammals, but detection methods and reported frequencies vary significantly by species and placental type. A biological model is presented in this article in which multinucleated trophoblast cells undergo apoptosis, releasing cffDNA that enters the maternal blood circulation after multinucleated trophoblast invasion. Advances in molecular biology technology have improved the ability to detect fetal-derived material, cells, DNA, and exosomes in maternal blood. However, notable research gaps remain for Mc in horses, goats, and pigs, highlighting the need for targeted studies to better understand species-specific patterns or a general biological model.
The proportion of spermatozoa with progressive motility is widely used to evaluate the quality of a single ejaculate. However, the cellular and physiological mechanisms underlying this trait remain unclear. The present study examined the association between the progressive motility of bovine spermatozoa, their quality and their fertilization competence in vitro, and subsequently the association with the developmental morphokinetics of the formed embryos. Fresh ejaculates were classified and divided into groups with high (HPM), medium (MPM), or low (LPM) progressive motility. Then, spermatozoa were evaluated for their morphology, plasma membrane integrity, mitochondrial membrane potential, oxidative status, and acrosome integrity. The findings revealed that spermatozoa from HPM ejaculates enhanced motility in association with higher mitochondrial membrane potential relative to the LPM group, suggesting higher metabolic potential. No differences were recorded in fertilization competence among groups; however, the developmental kinetics of the formed embryos, determined by a time-lapse system, differed; embryos derived from HPM spermatozoa cleaved earlier to the two-, three-, and four-cell stages than embryos derived from MPM spermatozoa, suggesting that HPM-derived embryos are of good quality. Our findings suggest that progressive motility is not only a motility characteristic; it also reflects cellular quality of spermatozoa and the formed embryo.
The poly(A) tail has long been known to play a central role in mRNA stability, storage, and translational competence, making it a potential key regulator during hypometabolic states. During seasonal torpor, hibernating mammals must frequently enter these hypometabolic states to survive. In this study, we examined protein abundance changes in key enzymes involved in poly(A) tail synthesis, binding, and removal during torpor in the brown adipose tissue of the 13-lined ground squirrel, Ictidomys tridecemlineatus, using immunoblots. BAT during late torpor exhibited significantly reduced abundance of the catalytic cleavage enzyme CPSF73, but increased abundance of poly(A) polymerase PAPOLA. In contrast, poly(A)-binding proteins and major complex subunits of deadenylases, including CCR4-Not, exhibited no significant changes. Furthermore, despite unchanged levels of the translation initiation factor eIF4E, the phosphorylated variant of 4E-BP1, a potent inhibitor of the initiation factor when hypophosphorylated, was significantly reduced during late torpor. Overall, constrained mRNA maturation, preserved transcript stability, and reversible translational inhibition suggest that an important role exists for poly(A) tail regulatory machinery in hypometabolic survival throughout the torpid state.
Microtia-atresia is a rare craniofacial malformation primarily affecting the first and second pharyngeal arches, leading to the deformity of the auricle and atresia of the external ear canal. Its etiology is heterogenous and largely unknown, including both genetic and environmental factors. The HOXA4 gene has been identified as potentially pathogenetic for microtia-atresia in three twin families. A hoxa4a mosaic knockdown zebrafish model was constructed using CRISPR/Cas9. hoxa4a was expressed in the mandible during early development in zebrafish, while the F0 mosaic knockdowns exhibited craniofacial malformations with abnormal chondrocyte morphologies. Specifically, hoxa4a knockdown reduced cranial neural crest cell proliferation while increasing apoptosis, markedly downregulating chondrogenic markers sox9a and col2a1a. Consequently, pharyngeal arch chondrocytes exhibited disorganized arrangement and morphological abnormalities, resulting in mandibular hypoplasia. Our findings provide important insights into the role of hoxa4a in zebrafish mandibular development and the pathology of microtia-atresia caused by HOXA4 gene mutations in humans.
In osteopetrotic mice with homozygous inactivating mutations in the colony stimulating factor 1 (Csf1op/op) or its receptor (Csf1r-/-) gene, teeth fail to erupt due to severe reduction in osteoclastogenesis. Dental abnormalities have been described in the unerupted teeth of these models, but it remains unclear whether these defects arise from direct roles of CSF1R in odontogenesis or indirectly from impaired bone remodeling associated with failed eruption. Here, we examined the spatiotemporal expression of CSF1R during tooth development and inhibited CSF1R pharmacologically in utero using PLX5622 during early stages of tooth morphogenesis. Teeth and surrounding bone were analyzed at embryonic and postnatal stages using histology and high-resolution micro-computed tomography. Embryonic CSF1R inhibition resulted in reproducible abnormalities in incisor and molar morphology that were evident before and after birth and were associated with loss of normal bone remodeling at the tooth-bone interface. In contrast, postnatal CSF1R inhibition did not affect the structure or continuous growth of adult incisors. Together, these findings demonstrate a temporally restricted, indirect role for CSF1R in odontogenesis that is independent of tooth eruption and associated with remodeling of the bony crypts surrounding developing teeth by CSF1R-dependent cells.
