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Teramoto, M.

Publications and source records attributed to Teramoto, M..

4 recordsLinked to original sources

Fgf10 mutant newts can regenerate normal limbs despite severe developmental hindlimb defects

In the amniote limb, FGF10 is essential for limb bud initiation and outgrowth. However, whether this function is broadly conserved in tetrapods and/or involved in adult limb regeneration remains unknown. To tackle this question, we established an Fgf10 null mutant line in the newt Pleurodeles waltl which have amazing regenerative ability. While Fgf10 mutant forelimbs develop normally, the hindlimbs exhibit severe digit reduction, fail to ossify the zeugopod, and downregulate FGF target genes like Sall1, Runx1 and Hoxa11/d11. Despite these developmental defects, Fgf10 mutants were able to regenerate near-normal hindlimbs. Together, our results suggest an important role for Fgf10 in hindlimb digit formation and zeugopod ossification during development, but little or no function in regeneration, suggesting that different mechanisms operate during limb regeneration versus development.

developmental biology↗

DrosoPhyla: genomic resources for drosophilid phylogeny and systematics

The vinegar fly Drosophila melanogaster is a pivotal model for invertebrate development, genetics, physiology, neuroscience, and disease. The whole family Drosophilidae, which contains over 4000 species, offers a plethora of cases for comparative and evolutionary studies. Despite a long history of phylogenetic inference, many relationships remain unresolved among the groups and genera in the Drosophilidae. To clarify these relationships, we first developed a set of new genomic markers and assembled a multilocus data set of 17 genes from 704 species of Drosophilidae. We then inferred well-supported group and species trees for this family. Additionally, we were able to determine the phylogenetic position of some previously unplaced species. These results establish a new framework for investigating the evolution of traits in fruit flies, as well as valuable resources for systematics.

evolutionary biology↗

Live imaging of avian embryos revealing a new head precursor map and the role for the anterior mesendoderm in brain development

We investigated the initial stages of head development using a new method to randomly label chicken epiblast cells with enhanced green fluorescent protein, and tracking the labeled cells. This analysis was combined with grafting mCherry-expressing quail nodes, or node-derived anterior mesendoderm (AME). These live imagings provided a new conception of the cellular mechanisms regulating brain and head ectoderm development. Virtually all anterior epiblast cells are bipotent for the development into the brain or head ectoderm. Their fate depends on the positioning after converging to the AME. When two AME tissues exist following the ectopic node graft, the epiblast cells converge to the two AME positions and develop into two brain tissues. The anterior epiblast cells bear gross regionalities that already correspond to the forebrain, midbrain, and hindbrain axial levels shortly after the node is formed. Therefore, brain portions that develop with the graft-derived AME are dependent on graft positioning.

developmental biology↗

The absence of SOX2 in the anterior foregut alters the esophagus into trachea and bronchi in both epithelial and mesenchymal components

In the anterior foregut (AFG) of mouse embryos, the transcription factor SOX2 is expressed in the epithelia of the esophagus and proximal branches of respiratory organs comprising the trachea and bronchi, whereas NKX2.1 is expressed only in the epithelia of respiratory organs. Previous studies using hypomorphic Sox2 alleles have indicated that reduced SOX2 expression causes the esophageal epithelium to display some respiratory organ characteristics. In the present study, we produced mouse embryos with AFG-specific SOX2 deficiency. In the absence of SOX2 expression, a single NKX2.1-expressing epithelial tube connected the pharynx and the stomach, and a pair of bronchi developed in the middle of the tube. Expression patterns of NKX2.1 and SOX9 revealed that the anterior and posterior halves of SOX2-deficient AFG epithelial tubes assumed the characteristics of the trachea and bronchus, respectively. In addition, we found that mesenchymal tissues surrounding the SOX2-deficient NKX2.1-expressing epithelial tube changed to those surrounding the trachea and bronchi in the anterior and posterior halves, as indicated by the arrangement of smooth muscle cells and SOX9-expressing cells and by the expression of Wnt4 (esophagus specific), Tbx4 (respiratory organ specific), and Hoxb6 (distal bronchus specific). The impact of mesenchyme-derived signaling on the early stage of AFG epithelial specification has been indicated. Our study demonstrated an opposite trend where epithelial tissue specification causes concordant changes in mesenchymal tissues, indicating a reciprocity of epithelial-mesenchymal interactions.

developmental biology↗