Developmental Biology

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Official Journal of the Society for Developmental Biology www.sciencedirect.com/journal/developmental-biology

Expression patterns of eya1 and its candidate interaction partners at mid-tailbud stage. Xenopus laevis embryos after whole-mount in situ hybridization at stage 27, in lateral views (anterior is to the left). The schematic drawing (A) shows the distribution of placodes in a mid-tailbud stage embryo. Arrows indicate expression in placodes and display the colour code used in the drawing (yellow: profundal placode; dark green: trigeminal placode; light green: olfactory placode, pink: otic placode; brown: lateral line placode; orange: epibranchial placodes). For placodes derived from the posterior placodal area, only the otic placode and one lateral line placode are indicated in panels C–L. Arrowheads and asterisks indicate other areas of expression. Pink arrowhead: somites; white asterisks: pharyngeal pouches. Blue asterisks (neural crest streams) and arrowheads indicate expression in areas where eya1 is not expressed. Panels D, F, H, J, L are magnifications of panels C, E, G, I, K, respectively. Abbreviations: B, blood islands; E, prospective eye, including lens (L) placode; EB, epibranchial placodes; F: forebrain; H: hindbrain; LL, lateral line placodes; LPM, lateral plate mesoderm; M: midbrain; Ol, olfactory placode; Ot, otic placode; P, pronephros; Pr, profundal placode; V, trigeminal placode.
Gail Martin looking at the camera, sitting on a bench in front of a lily pad pond in her garden in Berkeley. Photo from Brigid Hogan.
Depletion of miR-196a expands neural plate progenitors at the expense of neural crest specification and neuronal differentiation. Embryos were injected into one dorsal blastomere at the 4-cell stage of development with 300 pg of GFP mRNA or of lacZ developed with Red-gal. In all panels the injected side is to the right. Whole mount in situ hybridisation of zic1, (stage 14), zic3, (stage 14), msx2, (stage 14), sox2, (stage 14), pax6, (stage 15) hairy1, (stage 18), eng2, (stage 15) n-tub (stage 18) and elrc1, (stage 18), following MO mediated miRNA KD. Embryos are positioned in dorsal view with anterior at the top. Whole mounts are shown as well as transverse sections (i). Injection of the MO caused an expansion in the NPB markers Zic1 (n = 28/30) and Zic3 (n = 34/37) but a loss in the anterior region of the NPB marker Msx2 (n = 18/19) (A–C). The neural marker Sox2 was expanded in a lateral direction and appeared to lose the intense dark region of expression seen in the control side (see black arrow) (n = 37/37) (D). Expression of the neural marker Pax6 was slightly enlarged across the anterior neural fold (lens primordia) (see white arrow) but reduced in the position of the forebrain stripe (see black arrow) (n = 18/24) (E). The downstream target of Notch – Hairy1 had a reduced but broadened expression (n = 22/25) (F) Eng2 showed a reduced and broadened expression as well as a shift more posterior (n = 19/25) (G). Both neuronal differentiation markers N-tub (n = 24–30) and ELRC (n = 23/24) were reduced following miR-196aMO injection although this was restricted to the anterior most part of the NP (see black arrows). The expression of these two markers in the trigeminal placodes had extended in both an anterior and posterior direction (see white arrows) (H,I).
Neuron layer of E12.5 Togaram1 KO cortex is thin and irregular. (A) Control E12.5 cortical section shows a thick layer of Pax6+ NSCs in the ventricular zone topped by daughter cells forming layers of basal progenitors (Tbr2+) and neurons (Tubb3+). (B-D) Examples of different neuron layer abnormalities found in Togaram1 KOs. (B) KO #1 displays a deep ventricular indent and a small neuron cluster to the left of the indent. Neuron layer is thinner above the indent, but is continuous. (C) KO #2 has a very thin patchy neuron layer with a large neuron cluster. (D) KO #3 has a ventricular indent with a thin neuron layer with a gap above the indent. White dashed line marks ventricle, yellow dashed lines outline ectopic neuron clusters, yellow arrowheads indicate breaks in the neuronal layer. Scale bars: 100um.
Model. (A) Early wound signaling activates expression of nrg-1 in muscle near the wound site by 6 hours and subsequently in the distal blastema region from 1 to 5 days. As regeneration progresses, nrg-1 expressed from muscle signals through egfr-1, and receiving cells of this signaling could either be neoblasts (gray arrows), muscle, or other cell types. A downstream consequence of the signaling results in localization of neoblast proliferation near the blastema region, which correlates in space and time approximately with the locations of nrg-1's late expression phase. The activity of nrg-1 and egfr-1 promotes blastema outgrowth. (B) Regulatory model identifying a critical role for nrg-1 and egfr-1 functionally downstream of egr. Wounding activates immediate early expression of egr, which is responsible for transcriptional activation of nrg-1 and runt-1. nrg-1 is functionally required for regeneration and acts through egfr-1, and these factors exert critical responses downstream of egr in order to localize proliferation to wound sites and also cause blastema outgrowth. Gray lines: contributions from nrg-1 signal feedback and/or roles for pre-existing NRG-1 protein in the wound activation process (see text). (C) Phylogeny showing the conserved use of Neuregulin and/or EGFR signaling to functionally promote regeneration. Acoels are believed to be either early-branching Deuterostomes within Xenacoelomorpha or form a sister group to all Bilaterian animals (dotted lines).
Perturbation of Cxcl14 specifically in placode cells disrupts trigeminal ganglion development. A. Schematic illustrating the in ovo experimental design to perturb Cxcl14, specifically targeting placode cells. Experimental (red) reagents were delivered unilaterally into the ectoderm of HH11 (13 somites) chick embryos. B-E″. Either a Cxcl14 specific gRNA-CRISPR/Cas9 construct (B-C′) or Cxcl14 MO (D-E′) were introduced onto the right side of the embryo. Immunolabeling of SOX10 (magenta) and TUJ1 (green) reveals the effects of loss of Cxcl14 within the trigeminal ganglion, specifically in placode cells at HH16. Arrows indicate position of neural crest-derived cells. Arrowheads indicate position of placode-derived cells.
Schematic of workflow. Public datasets re-analysis; processing (UMAPs shown); integration and downstream analysis (cartoon of cell fate trajectories and cell-cell interactions); generation of a reference atlas (annotated UMAP); application by sequencing new data and automatically embedding in the atlas and annotating cell types.
===== Alt text TSK is expressed in the cortical plate of the developing mouse neocortex. (A to E) Immunofluorescence with an anti-β-gal antibody (A, B), or X-gal staining (C to E), in coronal brain sections of E14.5 (A), P0 (B, C), P14 (D), or adult (E) TSK+/- mice, showing β-gal expression (green in (A, B); light blue in (C to E)) in the cortical plate between E.14.5 and P14. Hoechst nuclear staining is shown in blue (A, B). Scale bars, 500 μm (A, B) or 1000 μm (C to E). (F to O) Double immunofluorescence in coronal brain sections of E14.5 TSK+/- mice with an anti-β-gal antibody (green staining) and anti-PAX6 (F, K), anti-Nestin (G, L), anti-TBR2 (H, M), anti-βIII-Tubulin (I, N) or anti-TBR1 (J, O) antibodies (red staining), showing β-gal expression in the cortical plate, partially overlapping with the TBR1+ domain. Images in (K to O) show magnifications of the boxed areas in (F to J). Hoechst nuclear staining is shown in blue. Scale bars, 500 μm.
scube mutants display Hh loss-of-function phenotypes. Loss of slow muscle fibres in scube mutant families at 30 hpf. In wild-type zebrafish, slow muscle fibres form a regular array with clearly defined V-shaped somites. In scube1−/−, scube3−/−, and scube1−/−scube3−/−, morphology of slow muscle fibres are comparable to wild-type siblings. In contrast, scube2−/−, scube1−/−scube2−/−, scube2−/−scube3−/−, and the triple scube mutant show severe disruption of slow muscle fibres along the body, including fibre loss (white arrows), abnormal fibre shapes (yellow arrows), and the presence of U-shaped somites (indicated by white dashed lines). The triple mutant shows the most severe phenotype, characterised by the near-complete loss of slow muscle fibres and pronounced abnormalities in the remaining fibres.
Formation of the Ch foramen by bone deposition. Bone, cartilage and endothelial cells are labeled in cyan, green and magenta, respectively. (E′) A single optical section of the boxed region in E. Channel for green and magenta fluorescence is shown in the right panel. n = 3. Anterior is to the left.
Cartoon of wild type and tat-5 mutant mature sperm and cell membrane. Wild type sperm is motile and functional thanks to internalised PtdEth in the membrane. Mutant spermatocytes lose membrane asymmetry without tat-5 activity, losing their activation an motility.
Bundled yolk microtubule array structures in dchs triple mutants A. Confocal images at 50% epiboly of WT and dchs triple mutants stained with DAPI (blue) and for DM1α (microtubules, green). Arrowhead indicates microtubule bundling. B. Quantification of yolk microtubule bundling through measurement of bare yolk areas lacking microtubules at 50% epiboly. ∗∗p < 0.01. WT N = 25 embryos, MZdchs1a−/−; Zdchs1b−/−; MZdchs2−/− N = 32 embryos. C. Confocal images of yolk microtubule meshwork marked with DM1α, just vegetal of YSL of WT and dchs triple mutants at 50% epiboly. D. Quantification of yolk microtubule alignment coherency. ∗∗∗∗p < 0.0001. WT N = 25 embryos, MZdchs1a−/−; Zdchs1b−/−; MZdchs2−/− N = 32 embryos.
(E) Schematic showing DD and DA neuron organization along the VNC. (F) Representative images of anterior DA and DD neurons in pal-1(zy117), sex-1(zy130) and double mutants. Asterisks mark dorsally mispositioned neurons. Scale bar = 20 μm. (G) Quantification of worms with dorsally mispositioned neurons at L1. Statistics: (C) one-way ANOVA with Tukey's Post-hoc Comparisons, and (G) Chi-squared test with Monte Carlo simulation for 10,000 replicates, followed by a pairwise analysis using Fisher's exact test with Monte Carlo simulation for 10,000 replicates and adjusted with Holm corrections.
Parallel reporter analysis reveals cell-type–specific CRM activity in sorted vascular endothelial cells. Activity of barcoded reporters was quantified in sorted vascular endothelial cells relative to the inactive control (C120). Reporters containing the fli CRM showed the strongest activation in this cell type. ubb-containing reporters were significantly activated over controls, but to a lesser extent than in whole embryos. dll4in3 reporter activity was elevated relative to baseline, although the difference from C120 was not statistically significant. Each CRM was tested using two independent barcoded reporters across four biological replicate experiments. Individual points represent barcode-specific measurements from independent biological replicates.
Cmtr1 KOs exhibit sex specific differences (a) Whole mount E7.5 male and female control and KO embryos. (B) Quantification of embryo size from E7.5 litters using ImageJ. (C) Principal component analysis (PCA) indicating male and female KOs cluster separately. (D) Normalized counts for select non-X or –Y linked differentially expressed genes which are higher in male KOs than female KOs. (E) Normalized counts (DESeq2) for select differentially expressed non-X or –Y linked genes which are higher in female KOs than male KOs. (F) RT-PCR validation of male/female differential expression in mutant embryos
Dynamic GRNs associated with inferred transcriptional progression between progenitor-like and chondrogenic states. (A) Heatmap of genes dynamically expressed along the chondrocyte trajectory. Epoch divides cells (columns) and genes (rows) into stages or epochs. Results of enrichment analysis of genes up-regulated in each epoch are shown to the right of the heatmap. The Epoch algorithm also reconstructs dynamic gene regulatory networks (GRNs). The top regulators of each epoch, determined by the network importance metrics of centrality and betweenness, are listed to the right of the enrichment results. (B) Sub-networks of that exemplify genes specific to the early (Clec3b) and late (Col9a3 and Prg4), and their regulators.
PrE signaling before and after implantation. A) During preimplantation development, spontaneous differences in FGF4/FGFR1,2/MEK signaling sort PrE from EPI. B) After implantation and prior to gastrulation, the anterior visceral endoderm (AVE) secretes antagonists of BMP/Nodal/WNT signaling to direct anterior/posterior patterning.
Elevated H3K27me3 levels in camk2g1 crispants. Increased levels of H3K27me3 are observed in the dorsal aorta (DA, white arrows) but not the posterior cardinal vein (PCV, green arrows) of camk2g1 fli1:GFP positive morphants (n = 24-30) compared to control embryos (n = 29-30)
Schematic of the function of common protein degradation systems DeGradFP, AID, dTAG, and PROTAC.
Loss of Kcnj2 affects transcription in Osr1 positive mesenchyme 4 cells. Immunohistochemistry shows that Asporin expression is expanded into more cells in Kcnj2KO/KO palatal shelves. A white line shows where fluorescence was quantified and the arrow shows the region of highest asporin expression.
GFP-Tmbim4 localizes to the membrane in Xenopus
The neural tube course based undergraduate research experience Scientific goal. Spina bifida: congenital defect, worldwide impact. Candidate human bifida genes --> validate candidate genes in chick embryos. Course gaols. Developmental biology, research & society, techniques, science communication. Student outcomes. Self-evaluations show significant gains in concepts, techniques, literature, writing, presenting, self-efficacy. Experimental workflow. sgRNA/Cas9 in HH4 and HH10 chick embryo, look for neural tube defects.
mt-ER complexes in postovulatory oocytes and early embryos. Postovulatory oocytes in the lumen of the ovary. Note numerous stick-like mt-ER complexes distributed in the ooplasm among lipid droplets and yolk spheres. Semi-thin sections stained with methylene blue. Ultrastructure of mt-ER complexes seen at the longitudinal (B) and cross (C) sections. TEM Early embryo. Note that most mt-ER complexes fill the cytoplasm of micromeres (enlarged in inset). Semi-thin sections stained with methylene blue. The cytoplasm of blastomeres contains numerous mt-ER complexes, free mitochondria (encircled by a dotted line) (enlarged in inset E) and folded membranes of endoplasmic reticulum (encircled with a dashed line). TEM. Abbreviations: c – mt-ER complexes; g, glycogen granules; ld, lipid droplet; oo, oocyte; ow, ovarian wall; solid arrowhead, longitudinal section of mitochondrion; hollow arrowhead, cross section of mitochondrion.
The subphylum Tunicata
Spindle orientation during C. elegans germ cell mitosis positions the cytokinetic ring to favour cytoplasmic bridge duplication. The spatiotemporal pattern of LIN-5/NuMA (blue) cortical localization promotes spindle orientation parallel to the rachis surface in germ cells. This ensures that the cytokinetic ring forms in the orthogonal plane, allowing the cytokinetic ring to interact with the germ cell's rachis face and/or the stable cytoplasmic bridge during ring closure and thus favoring cytoplasmic bridge duplication.
Polarized germline cysts are formed in Drosophila, Xenopus and mice
ShH10 minimally infects cells in the brain and contralateral ear. In mice injected with ShH10 at P1, GFP expression (green) is not seen in the brain at or P21. In contrast, high levels of GFP expression are seen in the brain of AAV-ie-K558R injected mice, including nearly 100 % of Purkinje cells in the cerebellum at P21. Cell nuclei are stained with DAPI in the brain sections (blue). Scale bar 50 μm.
SCRT2 represses ISLET1 expression in the dorsal domain
Endodermal tissue deformations at the AIP during foregut elongation. (A) Velocity fields quantified from time lapse of cell movements between HH stages 8+ and 10+. Orientation and magnitude of arrows indicate orientation and speed of cell movements, respectively; underlying heat map indicates speed (n = 3); scale = 200 μm. (B) Principal strain rates computed from velocity fields in (A), where major and minor cruciform axes represent maximum and minimum principal strain rates D1 and D2, respectively, and their orientations represent the associated principal directions. Negative/compressive principal strain rates are indicated in blue, and positive/extensional strain rates are indicated in red; strain rate scale = 0.01 %/s; spatial scale is as in (A). (C) Maximum and minimum principal strain rates calculated from velocity fields at HH stage 8, following electroporation with 3 nls-GFP RNA control (left) and DeAct-GFP RNA (right) (n = 3);
Increased expression of Scl is detected 24 h after Nkx2.5 overexpression, which was followed by vascular changes 48 h after electroporation
Visualization of the coronary arteries in E18.5 mice. (A, B) 3D surface rendering of the main left and right coronary arteries (CA) in frontal views. The yellow letters indicate that the right coronary artery and the septal artery share a common origin, while the white letters indicate the left coronary artery and its septal artery branches. (C–F) 2D serial slices in different planes along the Z-axis, identifying the coronary arteries, interventricular septal branches, and some anatomical landmarks. rca, right coronary artery; lca, left coronary artery; sa(p), posterior septal artery; sa(a), anterior septal artery; sa(l), septal artery covering left septum; Scale bars: 200 μm.
PRDM13 expression in the developing cerebellum in E12.5 and loss in Ptf1a null mice
Images of differentiated cells migrating from d5 EBs; Left, middle, and right columns show immunofluorescence images for each marker protein (Map2, GFAP, aSMA, AFP), DAPI-stained images, and merged images, respectively. D5 EBs were cultured for 4 days in DMEM-FBS. Images of d4 EBs stained with antibody for each marker protein and DAPI
Critical periods for FGFR2b/1b ligands in controlling cochlear epithelial and ganglion development fall between E11.5-E13.5 and E11.5-E14.5, respectively.
Model of mouse somitogenesis in WT and Epop KO conditions. In WT, PRC2 and Epop interact to keep the expression of certain Hox genes silenced the presomitic mesoderm (PSM). Epop KOs result in a faster Hox clock and a rostral shift in the axial skeleton formation.
CRISPR/Cas9 mediated mutagenesis of Bl-Ascl1/2.1 induces decrease of ESN in Branchiostoma lanceolatum
An extended KA1 domain recapitulates MELK localization A. The structure of MELK and deletion constructs expressed in embryos. White box (1–13): MELK-specific N-term region, orange box: kinase domain, red box: Threonine-Proline (TP) rich domain, blue box: KA1 domain. Asterisk indicates the lysine (K) to arginine (R) mutation (KR) in the MELK catalytic domain. Reg.: Regulatory Sequence, MLS: Mitosis Localization Signal. The extended KA1 domain consists of the KA1 domain together with the MLS. B. Identification of Mitosis Localization Signal (MLS) via localization of GFP-expressing proteins coded by constructs. Dividing cells are marked by asterisks. Arrows point to the nuclei expressing GFP-MELK constructs-derived proteins. Scale bar: 10 μm.
Detection of HOXA5 and HOXA5-FLAG proteins by immunofluorescence for E15.5 wt (B) and Hoxa5FLAG/FLAG mouse embryos (C-F).
The spb mutant phenotype. A Utrophin transgene with a GFP reporter labels the cell membrane.
Reduced BMP signaling in Poglut2/3 DKO limb bud development
Infographic comparing a ketogenic diet and ketone supplementation: therapeutic ketogenic vs standard high-carb diet with added ketones, showing impacts on cellular autophagy, body size, reduced fertility, and delayed development in fruit flies.
DIC images of hermaphrodite reproductive tracts of N2 that have embryos in their uterus (A) and spe-21(syb4299) that have only unfertilized oocytes in their uterus (B). Visualizing sperm loss after the start of ovulation in day 1 and day 3 adult spe-21(syb4299) (D, F) and N2 (C, E) worms raised at 20 °C. The positions of the spermathecae are marked by yellow boxes. Sperm nuclei are visualized using DAPI staining as small, bright puncta due the presence of highly condensed nuclear material.
Percentage of PCs undergoing cell proliferation is not changed but the percentage of PCs undergoing apoptosis is increased upon CDK1 and PLK1 inhibition. (A) PCs were immunolabeled with the Sp1 antibody shown in red. Dividing cells at the gastrula stage are shown in green and DNA is shown in blue. Scale bar = 50 μm. Orthogonal projection of images shown.
Pibf1m1Bei variant results in excision of exon9 resulting in loss of the coil-coiled domain in PIBF1 protein
Prediction of liquid–liquid phase separation in key regulators of skeletal muscle development
Summary of Artificial Development System Models
Classification of RNA biosensors by function, mechanism, delivery, and cellular context
Tg(elavl3:mCherry-CAAX) labels axons within the larvae spinal cord
Genomic rearrangement of the Hox cluster in a dung beetle species with derived cephalic horn morphology
Hand-traced cell tracking of convergent extension cell movements in the Xenopus mesoderm.
Lineage tracing of NPCs in developing kidney reveals Rac1 required for NPCs formation. (A) Frozen section of Six2Cre;R26RtdT and Rac1fl/fl;Six2Cre;R26RtdT at E16.5 counterstained with DAPI. TdTomato expression labels all Six2+NPC derivatives. Blank arrowheads point to NPCs in cap mesenchyme. Green arrowheads point to SSB. Yellow arrowheads point to glomeruli. Scale bar, 100um.
PROX1 directs Type II SGN axon turning non-cell autonomously. Peripheral axons of Type II SGNs immunolabeled for Neurofilament (NF-H, green) in Emx2-Cre; Prox1 cKOs or littermate controls, and Bhlhe22-Cre; Prox1 cKOs and littermate controls. Arrowheads indicate incorrectly turning axons.
Generation of endogenously tagged Nup96-mEGFP and Impβ-mScarlet-I to visualize the nuclear morphology and transport machinery in Drosophila
Early asymmetric cleavage and distribution of serotonin in early Ilyanassa embryos. (A) Schematic figures of the first three asymmetric macromere divisions (4, 8, and 12-cell stages) of the Ilyanassa embryo. Four macromeres are generated during the first two division cycles. During each successive cleavage cycle, each macromere undergoes an asymmetric division and produces a smaller daughter cell (micromere) with a distinct cell fate. The macromeres divide at an oblique angle, clockwise from the animal-vegetal axis, and generate the first micromere daughter cells. In the next cleavage, macromeres divide at a similar oblique angle, counterclockwise from the animal-vegetal axis, and generate the second micromere daughter cells. (B-D′) Serotonin distribution during the 4-cell stage. Co-staining with serotonin (red) and β-tubulin (green) antibodies and DAPI-stained DNA (blue) is shown. During interphase serotonin was detected in the center of the array of microtubules (arrowheads) and the macromere cortex. During prometaphase, an apical section shows that serotonin is concentrated in the apical cytoplasm (C, arrowhead). During metaphase, serotonin is localized to the surface of the macromere and concentrated around the apical spindle pole.
ippk-1 mutants display neuron intercalation and VNC extension defects. (A) Brightfield images of embryos and corresponding deconvolved fluorescence images of the VNC at 1.5 fold in WT and mutants, with the cytoplasm of DD neurons labeled with unc-30p::gfp and the membranes of DD and DA neurons labeled with cnd-1p::PH::mCherry. The magenta box indicates the approximate area of the middle panels. Schematics of the corresponding middle panel VNC show DD neurons highlighted in green.
Schematic drawing of human early development, from pre-implantation to gastrulating embryo, and the extra-embryonic and placental signalling to it.
Transgenic mouse Robo1 and Robo2 (mRobo1/2) can signal midline repulsion in Drosophila neurons. (A–K) Ventral nerve cords from Drosophila embryos carrying elav-GAL4 and the indicated HA-tagged UAS-Robo transgenes, stained with anti-HRP (magenta; labels all axons) and anti-FasII (green; labels a subset of longitudinal axon pathways) (A–F) or anti-HA (G–K). Embryos carrying elav-GAL4 alone (A) display a wild type ventral nerve cord with a ladder-like axon scaffold, two commissures per segment, and three distinct FasII-positive longitudinal pathways on either side of the midline. Misexpression of Robo1 with elav-GAL4 (B) inhibits midline crossing, and commissures are thin or absent (arrowhead with asterisk). In embryos misexpressing mRobo1 (C) or mRobo2 (D) with elav-GAL4, many segments have reduced or absent commissures (arrowhead with asterisk), and in some segments FasII-positive axons ectopically cross the midline (arrow with asterisk). FasII-positive longitudinal pathways also appear disorganized in (B–D). Embryos misexpressing mRobo3.1 (E) or mRobo3.2 (F) appear wild type. (G–K) HA-tagged Robo1 and mRobos are expressed on longitudinal axons (arrows), and mRobo proteins are also detectable on midline crossing axons when present (arrowheads in H-K).