Axial specification for sensory organs versus non-sensory structures of the chicken inner ear

A mature inner ear is a complex labyrinth containing multiple sensory organs and nonsensory structures in a fixed configuration. Any perturbation in the structure of the labyrinth will undoubtedly lead to functional deficits. Therefore, it is important to understand molecularly how and when the position of each inner ear component is determined during development. To address this issue, each axis of the otocyst (embryonic day 2.5, E2.5, stage 16–17) was changed systematically at an age when axial information of the inner ear is predicted to be fixed based on gene expression patterns. Transplanted inner ears were analyzed at E4.5 for gene expression of BMP4 (bone morphogenetic protein), SOHo-1 (sensory organ homeobox-1), Otx1 (cognate of Drosophila orthodenticle gene), p75NGFR (nerve growth factor receptor) and Msx1 (muscle segment homeobox), or at E9 for their gross anatomy and sensory organ formation. Our results showed that axial specification in the chick inner ear occurs later than expected and patterning of sensory organs in the inner ear was first specified along the anterior/posterior (A/P) axis, followed by the dorsal/ventral (D/V) axis. Whereas the A/P axis of the sensory organs was fixed at the time of transplantation, the A/P axis for most non-sensory structures was not and was able to be re-specified according to the new axial information from the host. The D/V axis for the inner ear was not fixed at the time of transplantation. The asynchronous specification of the A/P and D/V axes of the chick inner ear suggests that sensory organ formation is a multi-step phenomenon, rather than a single inductive event.

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The Key Transcription Factor Expression in the Developing Vestibular and Auditory Sensory Organs: A Comprehensive Comparison of Spatial and Temporal Patterns

Neural Plasticity ◽

10.1155/2018/7513258 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Shaofeng Liu ◽

Yunfeng Wang ◽

Yongtian Lu ◽

Wen Li ◽

Wenjing Liu ◽

...

Keyword(s):

Transcription Factors ◽

Inner Ear ◽

Hair Cells ◽

Expression Patterns ◽

Organ Of Corti ◽

Sensory Organ ◽

Sensory Organs ◽

Supporting Cells ◽

Cell Fate Decisions ◽

Temporal And Spatial

Inner ear formation requires that a series of cell fate decisions and morphogenetic events occur in a precise temporal and spatial pattern. Previous studies have shown that transcription factors, including Pax2, Sox2, and Prox1, play important roles during the inner ear development. However, the temporospatial expression patterns among these transcription factors are poorly understood. In the current study, we present a comprehensive description of the temporal and spatial expression profiles of Pax2, Sox2, and Prox1 during auditory and vestibular sensory organ development in mice. Using immunohistochemical analyses, we show that Sox2 and Pax2 are both expressed in the prosensory cells (the developing hair cells), but Sox2 is later restricted to only the supporting cells of the organ of Corti. In the vestibular sensory organ, however, the Pax2 expression is localized in hair cells at postnatal day 7, while Sox2 is still expressed in both the hair cells and supporting cells at that time. Prox1 was transiently expressed in the presumptive hair cells and developing supporting cells, and lower Prox1 expression was observed in the vestibular sensory organ compared to the organ of Corti. The different expression patterns of these transcription factors in the developing auditory and vestibular sensory organs suggest that they play different roles in the development of the sensory epithelia and might help to shape the respective sensory structures.

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Shaping of inner ear sensory organs through antagonistic interactions between Notch signalling and Lmx1a

eLife ◽

10.7554/elife.33323 ◽

2017 ◽

Vol 6 ◽

Cited By ~ 13

Author(s):

Zoe F Mann ◽

Héctor Gálvez ◽

David Pedreno ◽

Ziqi Chen ◽

Elena Chrysostomou ◽

...

Keyword(s):

Inner Ear ◽

Notch Signalling ◽

Sensory Organ ◽

Sensory Organs ◽

Functional Diversification ◽

Dynamic Nature ◽

Embryonic Chicken ◽

Mechanisms Of Formation ◽

Sensory Patch ◽

Antagonistic Interactions

The mechanisms of formation of the distinct sensory organs of the inner ear and the non-sensory domains that separate them are still unclear. Here, we show that several sensory patches arise by progressive segregation from a common prosensory domain in the embryonic chicken and mouse otocyst. This process is regulated by mutually antagonistic signals: Notch signalling and Lmx1a. Notch-mediated lateral induction promotes prosensory fate. Some of the early Notch-active cells, however, are normally diverted from this fate and increasing lateral induction produces misshapen or fused sensory organs in the chick. Conversely Lmx1a (or cLmx1b in the chick) allows sensory organ segregation by antagonizing lateral induction and promoting commitment to the non-sensory fate. Our findings highlight the dynamic nature of sensory patch formation and the labile character of the sensory-competent progenitors, which could have facilitated the emergence of new inner ear organs and their functional diversification in the course of evolution.

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Confocal imaging of sensory organ formation during Xenopus inner ear development

The Journal of the Acoustical Society of America ◽

10.1121/1.4744288 ◽

2001 ◽

Vol 109 (5) ◽

pp. 2357-2357

Author(s):

Elba E. Serrano ◽

Quincy A. Quick

Keyword(s):

Inner Ear ◽

Confocal Imaging ◽

Sensory Organ ◽

Ear Development ◽

Organ Formation ◽

Inner Ear Development

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Meis gene expression patterns in the developing chicken inner ear

The Journal of Comparative Neurology ◽

10.1002/cne.22508 ◽

2010 ◽

Vol 519 (1) ◽

pp. 125-147 ◽

Cited By ~ 17

Author(s):

Luis Óscar Sánchez-Guardado ◽

José Luis Ferran ◽

Lucía Rodríguez-Gallardo ◽

Luis Puelles ◽

Matías Hidalgo-Sánchez

Keyword(s):

Gene Expression ◽

Inner Ear ◽

Expression Patterns ◽

Gene Expression Patterns

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A Model of Waardenburg Syndrome Using Patient-Derived iPSCs With a SOX10 Mutation Displays Compromised Maturation and Function of the Neural Crest That Involves Inner Ear Development

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.720858 ◽

2021 ◽

Vol 9 ◽

Author(s):

Jie Wen ◽

Jian Song ◽

Yijiang Bai ◽

Yalan Liu ◽

Xinzhang Cai ◽

...

Keyword(s):

Gene Expression ◽

Neural Crest ◽

Inner Ear ◽

Expression Patterns ◽

Interaction Network ◽

Patient Specific ◽

Waardenburg Syndrome ◽

Differentiation Potential ◽

Ear Development ◽

Inner Ear Development

Waardenburg syndrome (WS) is an autosomal dominant inherited disorder that is characterized by sensorineural hearing loss and abnormal pigmentation. SOX10 is one of its main pathogenicity genes. The generation of patient-specific induced pluripotent stem cells (iPSCs) is an efficient means to investigate the mechanisms of inherited human disease. In our work, we set up an iPSC line derived from a WS patient with SOX10 mutation and differentiated into neural crest cells (NCCs), a key cell type involved in inner ear development. Compared with control-derived iPSCs, the SOX10 mutant iPSCs showed significantly decreased efficiency of development and differentiation potential at the stage of NCCs. After that, we carried out high-throughput RNA-seq and evaluated the transcriptional misregulation at every stage. Transcriptome analysis of differentiated NCCs showed widespread gene expression alterations, and the differentially expressed genes (DEGs) were enriched in gene ontology terms of neuron migration, skeletal system development, and multicellular organism development, indicating that SOX10 has a pivotal part in the differentiation of NCCs. It’s worth noting that, a significant enrichment among the nominal DEGs for genes implicated in inner ear development was found, as well as several genes connected to the inner ear morphogenesis. Based on the protein-protein interaction network, we chose four candidate genes that could be regulated by SOX10 in inner ear development, namely, BMP2, LGR5, GBX2, and GATA3. In conclusion, SOX10 deficiency in this WS subject had a significant impact on the gene expression patterns throughout NCC development in the iPSC model. The DEGs most significantly enriched in inner ear development and morphogenesis may assist in identifying the underlying basis for the inner ear malformation in subjects with WS.

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Immunohistochemical and gene expression analysis of autologous platelet rich fibrin for distal limb wound defects healing in donkeys (Equus asinus).

Mansoura Veterinary Medical Journal ◽

10.35943/mvmj.2020.21.107 ◽

2020 ◽

Vol 21 (1) ◽

pp. 46-55

Author(s):

Mohamed Albahrawy ◽

Khaled Abouelnasr ◽

Mohamed Hamed ◽

Mohamed EL-Adl ◽

Esam Mosbah ◽

...

Keyword(s):

Gene Expression ◽

Growth Factor ◽

Expression Patterns ◽

Growth Factor Receptor ◽

Immunohistochemical Analysis ◽

Tissue Growth ◽

Control Group ◽

Distal Limb ◽

Platelet Rich Fibrin ◽

Significant Difference

Objective: To evaluate the effect of platelet-rich fibrin (PRF) in the promotion of distal limb wound defects healing in donkeys. Design: A randomized experimental design Animals: Twelve clinically healthy male donkeys, weighing, 130–230 kg and aged 4 –5 years were allocated into three groups(4 animals/each) and undergo a 6cm2 (2cm X 3cm) 2 wound defects on the dorsolateral surface of right metacarpal and metatarsal regions for each donkey. Control (group A): the wound defects were left for spontaneous healing. In groups B and C, the wound defects were treated with either one application of PRF (B) or with three consecutive applications of PRF (a week interval) (C). Wound defects healing were evaluated clinically, histologically and immunohistochemically, in addition to gene expression patterns of angiogenic and myofibroblastic genes vascular endothelial growth factor (VEGF-A), collagen type 3 α1 (COL3α1), and fibroblast growth factor 7 (FGF-7) and tissue growth factor β1 (TGFβ1) were performed. Results: The healing percentage of single and three PRF applications was significantly higher (P <0.05) (84.6%, and 93.7% respectively) than in control one (66.7%). The number of days needed for complete wound healing was considerably shorter in repeated PRF treated wound defects (63.2±2.8) compared with single PRF and untreated wound defects (71.6±3 and 86.3±3, respectively). Semi-quantitative evaluation of histological sections at 15 and 45 days post-operative showed a significant difference (P<0.05) in epithelization, PMNL, fibroblasts, tissue macrophages, neo-angiogenesis and new collagen scores in both PRF groups compared to control one. Qualitative analysis of immunohistochemical views of the wound defects showed a significant immunostaining difference against EGFR, VEGF, and TGFβ stain between both PRF treated groups and control one. Immunohistochemical analysis of cells stained for epidermal growth factor receptor (EGFR), VEGF, and TGFβ at 15 and 45 days after interference was higher in both PRF treated groups compared to control one, but three PRF application showed the highest rates. The relative expression of FGF-7, TGFβ1, VEGF-A, and COL3α1 genes was higher in both PRF groups compared to control one, but the triple PRF group revealed the highest expression. Conclusion and clinical relevance: Application of PRF could improve the healing of distal limb wound defects in donkeys.

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Transcriptomic analysis of sea star development through metamorphosis to the highly derived pentameral body plan with a focus on neural transcription factors

DNA Research ◽

10.1093/dnares/dsaa007 ◽

2020 ◽

Vol 27 (1) ◽

Cited By ~ 1

Author(s):

Maria Byrne ◽

Demian Koop ◽

Dario Strbenac ◽

Paula Cisternas ◽

Regina Balogh ◽

...

Keyword(s):

Gene Expression ◽

Molecular Mechanisms ◽

De Novo ◽

Expression Patterns ◽

Body Plan ◽

Sea Star ◽

Neural Genes ◽

Transcription Factor Genes ◽

Juvenile Stages ◽

Sensory Structures

Abstract The Echinodermata is characterized by a secondarily evolved pentameral body plan. While the evolutionary origin of this body plan has been the subject of debate, the molecular mechanisms underlying its development are poorly understood. We assembled a de novo developmental transcriptome from the embryo through metamorphosis in the sea star Parvulastra exigua. We use the asteroid model as it represents the basal-type echinoderm body architecture. Global variation in gene expression distinguished the gastrula profile and showed that metamorphic and juvenile stages were more similar to each other than to the pre-metamorphic stages, pointing to the marked changes that occur during metamorphosis. Differential expression and gene ontology (GO) analyses revealed dynamic changes in gene expression throughout development and the transition to pentamery. Many GO terms enriched during late metamorphosis were related to neurogenesis and signalling. Neural transcription factor genes exhibited clusters with distinct expression patterns. A suite of these genes was up-regulated during metamorphosis (e.g. Pax6, Eya, Hey, NeuroD, FoxD, Mbx, and Otp). In situ hybridization showed expression of neural genes in the CNS and sensory structures. Our results provide a foundation to understand the metamorphic transition in echinoderms and the genes involved in development and evolution of pentamery.

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