查看更多>>摘要：The specification of germ cells in zebrafish mostly relies on an inherited mechanism by which localized maternal determinants,called germ plasm,confer germline fate in the early embryo.Extensive studies have partially allowed the identification of key regulators governing germ plasm formation and subsequent germ cell development.RNA-binding proteins,acting in concert with other germ plasm components,play essential roles in the organization of the germ plasm and the specification,migration,maintenance,and differentiation of primordial germ cells.The loss of their functions impairs germ cell formation and causes sterility or sexual conversion.Evidence is emerging that they instruct germline development through dif-ferential regulation of mRNA fates in somatic and germ cells.However,the challenge remains to decipher the complex interplay of maternal germ plasm components in germ plasm compartmentalization and germ cell specification.Because failure to control the developmental outcome of germ cells disrupts the for-mation of gametes,it is important to gain a complete picture of regulatory mechanisms operating in the germ cell lineage.This review sheds light on the contributions of RNA-binding proteins to germ cell development in zebrafish and highlights intriguing questions that remain open for future investigation.
查看更多>>摘要：The hindbrain,which develops from the anterior end of the neural tube expansion,can differentiate into the metencephalon and myelencephalon,with varying sizes and functions.The midbrain-hindbrain boundary(MHB)and hindbrain myelencephalon/ventral midline(HMVM)are known to be the source of the pro-genitors for the anterior hindbrain and myelencephalon,respectively.However,the molecular networks regulating hindbrain morphogenesis in these structures remain unclear.In this study,we show that reti-noblastoma 1(rb1)is highly expressed at the MHB and HMVM in zebrafish.Knocking out rb1 in mice and zebrafish results in an enlarged hindbrain due to hindbrain neuronal hyperproliferation.Further study reveals that Rb1 controls the hindbrain morphogenesis by suppressing the expression of Gbx1/Gbx2,essential transcription factors for hindbrain development,through its binding to E2f3/Hdac1,respectively.Interest-ingly,we find that Gbx1 and Gbx2 are expressed in different types of hindbrain neurons,suggesting distinct roles in hindbrain morphogenesis.In summary,our study clarifies the specific role of RB1 in hindbrain neural cell proliferation and morphogenesis by regulating the E2f3-Gbx1 axis and the Hdac1-Gbx2 axis.These findings provide a research paradigm for exploring the differential proliferation of neurons in various brain regions.
查看更多>>摘要：MicroRNAs(miRNAs)play a significant role in axon regeneration following spinal cord injury.However,the functions of numerous miRNAs in axon regeneration within the central nervous system(CNS)remain largely unexplored.Here,we elucidate the positive role of microRNA-2184(miR-2184)in axon regeneration within zebrafish Mauthner cells(M-cells).The upregulation of miR-2184 in a single M-cell can facilitate axon regeneration,while the specific sponge-induced silencing of miR-2184 leads to impeded regeneration.We show that syt3,a downstream target of miR-2184,negatively regulates axon regeneration,and the regeneration suppression modulated by syt3 depends on its binding to Ca2+.Furthermore,pharmaco-logical stimulation of the cAMP/PKA pathway suggests that changes in the readily releasable pool may affect axon regeneration.Our data indicate that miR-2184 promotes axon regeneration of M-cells within the CNS by modulating the downstream target syt3,providing valuable insights into potential therapeutic strategies.
查看更多>>摘要：Mitochondrial dysfunction is a critical factor leading to a wide range of clinically heterogeneous and often severe disorders due to its central role in generating cellular energy.Mutations in the TUFM gene are known to cause combined oxidative phosphorylation deficiency 4(COXPD4),a rare mitochondrial disorder characterized by a comprehensive quantitative deficiency in mitochondrial respiratory chain(MRC)com-plexes.The development of a reliable animal model for COXPD4 is crucial for elucidating the roles and mechanisms of TUFM in disease pathogenesis and benefiting its medical management.In this study,we construct a zebrafish tufm--mutant that closely resembles the COXPD4 syndrome,exhibiting compro-mised mitochondrial protein translation,dysfunctional mitochondria with oxidative phosphorylation defects,and significant metabolic suppression of the tricarboxylic acid cycle.Leveraging this COXPD4 zebrafish model,we comprehensively validate the clinical relevance of TUFM mutations and identify probucol as a promising therapeutic approach for managing COXPD4.Our data offer valuable insights for understanding mitochondrial diseases and developing effective treatments.
查看更多>>摘要：Laterality is a crucial physiological process intricately linked to the cilium-centrosome complex during embryo development.Defects in the process can result in severe organ mispositioning.Coiled-coil domain containing 141(CCDC141)has been previously known as a centrosome-related gene,but its role in left-right(LR)asymmetry has not been characterized.In this study,we utilize the zebrafish model and hu-man exome analysis to elucidate the function of ccdc141 in laterality defects.The knockdown of ccdc141 in zebrafish disrupts early LR signaling pathways,cilia function,and Kupffer's vesicle formation.Unlike ccdc141-knockdown embryos exhibiting aberrant LR patterns,ccdc1 41-null mutants show no apparent abnormality,suggesting a genetic compensation response effect.In parallel,we observe a marked reduction in α-tubulin acetylation levels in the ccdc141 crispants.The treatment with histone deacetylase(HDAC)inhibitors,particularly the HDAC6 inhibitor,rescues the ccdc141 crispant phenotypes.Furthermore,exome analysis of 70 patients with laterality defects reveals an increased burden of CCDC141 mutations,with in-vivo studies verifying the pathogenicity of the patient mutation CCDC141-R123G.Our findings highlight the critical role of ccdc141 in ciliogenesis and demonstrate that CCDC141 mutations lead to abnormal LR patterns,identifying it as a candidate gene for laterality defects.
查看更多>>摘要：Unraveling the lineage relationships of all descendants from a zygote is fundamental to advancing our understanding of developmental and stem cell biology.However,existing cell barcoding technologies in zebrafish lack the resolution to capture the majority of cell divisions during embryogenesis.A recently developed method,a substitution mutation-aided lineage-tracing system(SMALT),successfully recon-structed high-resolution cell phylogenetic trees for Drosophila melanogaster.Here,we implement the SMALT system in zebrafish,recording a median of 14 substitution mutations on a one-kilobase-pair bar-coding sequence for one-day post-fertilization embryos.Leveraging this system,we reconstruct four cell lineage trees for zebrafish fin cells,encompassing both original and regenerated fin.Each tree consists of hundreds of internal nodes with a median bootstrap support of 99％.Analysis of the obtained cell lineage trees reveals that regenerated fin cells mainly originate from cells in the same part of the fins.Through multiple times sampling germ cells from the same individual,we show the stability of the germ cell pool and the early separation of germ cell and somatic cell progenitors.Our system offers the potential for recon-structing high-quality cell phylogenies across diverse tissues,providing valuable insights into development and disease in zebrafish.
查看更多>>摘要：Maintaining chromosome euploidy in zebrafish embryonic cells is challenging because of the degradation of genomic integrity during cell passaging.In this study,we report the derivation of zebrafish cell lines from single blastomeres.These cell lines have a stable chromosome status attributed to BMP4 and exhibit continuous proliferation in vitro.Twenty zebrafish cell lines are successfully established from single blas-tomeres.Single-cell transcriptome sequencing analysis confirms the fidelity of gene expression profiles throughout long-term culturing of at least 45 passages.The long-term cultured cells are specialized into epithelial cells,exhibiting similar expression patterns validated by integrative transcriptomic analysis.Overall,this work provides a protocol for establishing zebrafish cell lines from single blastomeres,which can serve as valuable tools for in vitro investigations of epithelial cell dynamics in terms of life-death balance and cell fate determination during normal homeostasis.
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