Abstract Segmentation of a vertebrate embryo begins with the subdivision paraxial mesoderm into somites through not-well-understood process. Recent studies provided evidence that Notch-Delta and FGFR (fibroblast growth factor receptor) signalling pathways are required for segmentation. In addition, Mesp family bHLH transcription factors have been implicated in establishing segmental prepattern presomitic mesoderm. this study, we characterized zebrafish mesp-a mesp-b genes closely related to...

During vertebrate embryonic development, a unique pattern of neurogenesis emerges in the neural plate. Determination this depends on interaction among proneural genes and bHLH-O-type transcription factor (TF) genes, Hes/her, that suppress neurogenesis. In study, we focused mouse Hes1 orthologue, her6, to understand mechanism controls neurodevelopmental patterns developing brain zebrafish (Danio rerio). We first assessed expression her6 plate, confirming it was stably expressed entire...

Abstract Nuclear receptor subfamily 2 group F (Nr2f) proteins are essential for brain development in mice, but little is known about their precise roles and evolutionary diversification. In the present study, expression patterns of major nr2f genes ( nr2f1a , nr2f1b nr2f2 ) during early were investigated zebrafish. Comparisons revealed similar temporally spatially distinct after somite stages brain. Frameshift mutations three genes, achieved using CRISPR/Cas9 method, resulted a smaller...

Abstract The vertebrate telencephalic lobes consist of the pallium (dorsal) and subpallium (ventral). gives rise to basal ganglia, encompassing pallidum striatum. development this region is believed depend on Foxg1/Foxg1a functions in both mice zebrafish. This study aims elucidate genetic regulatory network controlled by foxg1a using zebrafish as a model. expression gradient within developing telencephalon was examined semi‐quantitatively initial investigations. Utilizing CRISPR/Cas9...

Abstract We isolated cDNA clones for the zebrafish gbx2 gene, which is implicated in establishment of midbrain–hindbrain boundary (MHB) other vertebrates. Spatially localized expression was observed at MHB from 90% epiboly through to hatching stage. Comparisons with otx2 , wnt1 and krox20 showed that expressed anterior hindbrain. Ectopic by mRNA injection caused cyclopia or truncation fore‐ midbrain severely affected isthmic cerebellar structures, while hindbrain formation not significantly...

Abstract In vertebrates, cranial sensory ganglia are mainly derived from ectodermal placodes, which focal thickenings at characteristic positions in the embryonic head. Here, we provide first description of early development epibranchial placode zebrafish embryos using sox3 as a molecular marker. By one‐somite stage, saw pair single ‐expressing domains appear lateral to future hindbrain. The domain, is referred here placode, segregated during phase segmentation form pax2a ‐positive medial...

Abstract Optical measurement of membrane potentials enables fast, direct and simultaneous detection from a population neurons, providing desirable approach for functional analysis neuronal circuits. Here, we applied recently developed genetically encoded voltage indicators, ASAP1 (Accelerated Sensor Action Potentials 1) QuasAr2 (Quality superior to Arch 2), zebrafish, an ideal model system studying neurogenesis. To achieve this, established transgenic lines which express the sensors, showed...

The larva of the sand dollar Peronella japonica lacks a mouth and gut, undergoes metamorphosis into juvenile without feeding. In present study, it was found that thyroid hormones accelerate P. larvae. contents in larvae increased gradually during development. Thiourea potassium perchlorate, inhibitors hormone synthesis, delayed larval simultaneously repressed an increase content thyroxine body. These results suggest has system for synthesis act as factors inducing metamorphosis.

We have specifically investigated the behavior of H3 and H4 histones during replication cycle MF–134SC cells. Mononucleosomes obtained from cells density–labeled with IDU or dense amino acids in presence appropriate radiolabeled precursors were applied to sucrose gradients containing 0.3 M NaC1 4M urea for rate zonal centrifugation. This allowed resolution normal subnucleosome particles composed DNA two molecules each without any measurable interparticle histone exchange. On labeling lysine,...

The expression of all four fgfr genes was extensively examined throughout early embryogenesis the zebrafish (Danio rerio). fgfr1 alone expressed maternally blastoderm, and then zygotically in anterior neural plate presomitic mesoderm. fgfr4 first detected late blastulae gradually restricted to brain. fgfr2 fgfr3 were initiated gastrulae, respectively; somitic mesoderm, whereas activated axial mesoderm midbrain During somitogenesis, each these a characteristic manner Using an FGF signal...

Abstract Zebrafish pou5f1 , also known as pou2 encodes a POU‐family transcription factor that is transiently expressed in the prospective midbrain and anterior hindbrain during gastrulation, governing brain development. In present study, we found main regulatory elements reside proximal upstream DNA sequence from −2.2 to −0.12 kb (the −2.2/−0.1 region). The electrophoretic gel mobility shift assay (EMSA) revealed four functional octamer sequences can associate with zebrafish Pou2/Pou5f1....

Fgf8 is among the members of fibroblast growth factor (FGF) family that play pivotal roles in vertebrate development. In present study, genomic DNA zebrafish fgf8 gene was cloned to elucidate regulatory mechanism behind temporally and spatially restricted expression embryos. Structural analysis revealed exon-intron organization highly conserved during evolution, from teleosts mammals. Close inspection sequence reverse transcription-polymerase chain reaction encodes two splicing variants,...

Zebrafish pou2 , encoding the class V POU transcription factor orthologous to mouse O ct‐3/4, has been implicated in different aspects of development, such as dorsoventral patterning, endoderm formation, and brain regionalization, by analyzing mutant embryos. In present study, we first conducted overexpression ‐modified genes m RNA injection, found that its active form ( vp‐ ) augmented mesoderm formation suppressed specification, whereas repressive en‐pou2 affected a manner. To avoid...

We report the characterization of a genomic clone containing portions two tandemly arranged genes that encode spicule matrix protein, SM30, sea urchin Strongylocentrotus purpuratus. The isolated 18.4-kilo-base contains complete sequence one SM30 gene, designated SM30-alpha, and portion another SM30-beta. Southern blot analysis shows protein is encoded by small gene family to four members. RNase protection assays indicate SM30-alpha expressed at time formation in embryo. In addition, mapping...