Transcriptomic profiling of tissue environments critical for post-embryonic patterning and morphogenesis of zebrafish skin

Abstract

Regulation of neural crest derived pigment cells and dermal cells that form skin appendages is broadly similar across vertebrate taxa. In zebrafish, organized pigment stripes and an array of calcified scales form simultaneously in the skin during post-embryonic development. Understanding mechanisms that regulate stripe patterning and dermal morphogenesis may lead to discovery of fundamental mechanisms that govern development of animal form. To learn about cell types and potential signaling interactions that govern skin patterning and morphogenesis we generated and analyzed single cell transcriptomes of skin with genetic or induced defects in pigmentation and squamation. These data reveal a previously undescribed population of ameloblast-like epidermal cells, suggest hormonal control of epithelial-mesenchymal signaling, clarify the signaling network that governs scale papillae development, and identify the hypodermis as a crucial pigment cell support environment. These analyses provide new insights into the development of skin and pigmentation and highlight the utility of zebrafish for uncovering essential features of post-embryonic development in vertebrates.

col1a2 + fibroblasts/muscle progenitors finetune xanthophore countershading by differentially expressing csf1a/1b in embryonic zebrafish

“…However, we found that the xanthoblasts/xanthophore pattern of embryonic zebrafish was not affected in iridophore mutants. Adult csf1b mutants have recently been noted to exhibit a reduction in dorsal xanthophores (62), a phenotype akin to what we observed in embryonic csf1b mutants. It is possible that Csf1b executes similar function in both stages.…”

“…Previous studies reported Csf1a and Csf1b expression in iridophores of juvenile and adult zebrafish ( 30 ). Csf1b was also identified in hypodermis of juvenile/adult zebrafish ( 62 ). Different from the juvenile and adult stage, we found that embryonic Csf1a and Csf1b were differentially expressed in col1a2 + fibroblast and muscle progenitors instead.…”

“…It would be intriguing to explore whether the Csf1b-expressing hypodermis in adults shares a common origin with embryonic Col1a2 + fibroblasts and muscle progenitors. On the other hand, csf1ra mutant, but not single csf1a or csf1b mutant, completely disrupted the adult stripe ( 62 ). Given the fact that both csf1a and csf1b are expressed by iridophore in adult zebrafish and iridophore plays an essential role in adult stripe pattern formation ( 30 ).…”

Effects and phenotypic consequences of transient thyrotoxicosis and hypothyroidism at different stages of zebrafishDanio rerio(Teleostei; Cyprinidae) skeleton development

“…The effects of the excess of THs are being studied in transgenic and/or pharmacologically treated with THs animals (Shkil et al, 2012, Keer et al, 2019, Keer et al, 2022, Aman et al, 2023, Deal and Volkoff, 2020. Such studies have yielded a wealth of data of all sort of effects of THs on the development of cartilages, bones, scales and dentition in fish.…”

“…The TH deficiency is acquired via a transgene-mediated ablation of thyroid follicles and/or the pharmacological treatment of organism with the goitrogens - chemical agents suppressing synthesis of thyroid hormones or disrupting HPT axis. The effects of the excess of THs are being studied in transgenic and/or pharmacologically treated with THs animals (Shkil et al, 2012, Keer et al, 2019, Keer et al, 2022, Aman et al, 2023, Deal and Volkoff, 2020). Such studies have yielded a wealth of data of all sort of effects of THs on the development of cartilages, bones, scales and dentition in fish.…”