Involvement of homeobox transcription factor Mohawk in palatogenesis

Abstract

Palatogenesis is affected by many factors, including gene polymorphisms and exposure to toxic chemicals during sensitive developmental periods. Cleft palate is one of the most common congenital anomalies, and ongoing efforts to elucidate the molecular mechanisms underlying palatogenesis are providing useful insights to reduce the risk of this disorder. To identify novel potential regulators of palatogenesis, we analyzed public transcriptome datasets from a mouse model of cleft palate caused by selective deletion of transforming growth factor-β (TGFβ) receptor type 2 in cranial neural crest cells. We identified the homeobox transcription factor Mohawk (Mkx) as a gene downregulated in the maxilla of TGFβ knockout mice compared with wild-type mice. To examine the role of mkx in palatogenesis, we used CRISPR/Cas9 editing to generate zebrafish with impaired expression of mkxa and mkxb, the zebrafish homologs of Mkx. We found that mkx crispants expressed reduced levels of gli1, a critical transcription factor in the Sonic hedgehog (SHH) signaling pathway that plays an important role in the regulation of palatogenesis. Furthermore, we found that mkxa À/À zebrafish were more susceptible than mkxa +/+ zebrafish to the deleterious effects of cyclopamine, an inhibitor of SHH signaling, on upper jaw development. These results suggest that Mkx may be involved in palatogenesis regulated by TGFβ and SHH signaling, and that impairment in Mkx function may be related to the etiology of cleft palate.

Analysis of Gene-Environment Interactions Related to Developmental Disorders

“…Advances in genome editing technologies have enabled us to edit any gene of interest in various experimental models, including zebrafish and induced pluripotent stem (iPS) cells generated from human samples ( Adachi et al, 2022 ; Whiteley et al, 2022 ). Public databases focusing on genes, biological samples, and chemicals related to various diseases including DDs, have been expanding ( Al-Jawahiri and Milne, 2017 ; Reilly et al, 2017 ; Lombardo et al, 2019 ; Davis et al, 2021 ).…”

Repositioning of Lansoprazole as a Protective Agent Against Cisplatin-Induced Ototoxicity

“…CRISPR RNA (crRNA) targeting zgc:64,076 or zgc:175,176, transactivating crRNA (tracrRNA), and recombinant Cas9 protein were obtained from FASMAC (Kanagawa, Japan) (sequences shown in Supplementary Table S1). Crispant zebrafish for zgc:64,076 or zgc:175,176 were generated according to methods described previously (Adachi et al, 2021). Briefly, the larvae exhibiting bright fluorescence of lissamine were selected at 1 day-post fertilization (dpf).…”