简介：Six1转录因子在颅感觉器官的发育中发挥着重要作用，点突变是颅面部出生缺陷的基础。由于 Six1 的转录活性可以通过相互作用蛋白进行调节，因此我们之前筛选了候选相互作用蛋白，并通过其包含几个具有真正的辅因子 Sine oculis 结合蛋白 (Sobp) 的结构域，鉴定了含锌指 MYM 的蛋白 4 (Zmym4)。 。尽管 Zmym4 与调节早期大脑发育和某些癌症有关，但其在颅面发育中的作用此前尚未被描述。方法：我们在培养细胞中使用免疫共沉淀和荧光素酶报告基因检测来测试 Zmym4 和 Six1 之间的相互作用。我们利用胚胎中 Zmym4 的敲低和过表达来测试其对早期外胚层基因表达、神经嵴迁移和颅面软骨形成的影响。结果：我们没有发现任何证据表明 Zmym4 在培养细胞中与 Six1 发生物理或转录相互作用。尽管如此，胚胎中内源性 Zmym4 的敲低导致了早期颅骨基因表达的改变，包括那些在神经缘、神经板、神经嵴和前基板外胚层中表达的基因。实验性增加 Zmym4 水平对神经边缘或神经板基因影响较小，但改变了神经嵴和前基板基因的表达。在幼虫阶段，耳囊和鳃弓中表达的基因在 Zmym4 突变体中表现出表达减少。尽管我们没有检测到神经嵴迁移到鳃弓的缺陷，但 Zmym4 的缺失导致了几个颅面软骨的异常形态。讨论：虽然 Zmym4 似乎不具有 Six1 转录辅助因子的功能，但它在调节对正常颅面发育至关重要的组织中胚胎颅骨基因的表达方面发挥着重要作用。版权所有 © 2023 Jourdeuil, Neilson, Cousin, Tavares, Majumdar, Alfandari和穆迪。

Introduction: The Six1 transcription factor plays important roles in the development of cranial sensory organs, and point mutations underlie craniofacial birth defects. Because Six1's transcriptional activity can be modulated by interacting proteins, we previously screened for candidate interactors and identified zinc-finger MYM-containing protein 4 (Zmym4) by its inclusion of a few domains with a bona fide cofactor, Sine oculis binding protein (Sobp). Although Zmym4 has been implicated in regulating early brain development and certain cancers, its role in craniofacial development has not previously been described. Methods: We used co-immunoprecipitation and luciferase-reporter assays in cultured cells to test interactions between Zmym4 and Six1. We used knock-down and overexpression of Zmym4 in embryos to test for its effects on early ectodermal gene expression, neural crest migration and craniofacial cartilage formation. Results: We found no evidence that Zmym4 physically or transcriptionally interacts with Six1 in cultured cells. Nonetheless, knockdown of endogenous Zmym4 in embryos resulted in altered early cranial gene expression, including those expressed in the neural border, neural plate, neural crest and preplacodal ectoderm. Experimentally increasing Zmym4 levels had minor effects on neural border or neural plate genes, but altered the expression of neural crest and preplacodal genes. At larval stages, genes expressed in the otic vesicle and branchial arches showed reduced expression in Zmym4 morphants. Although we did not detect defects in neural crest migration into the branchial arches, loss of Zmym4 resulted in aberrant morphology of several craniofacial cartilages. Discussion: Although Zmym4 does not appear to function as a Six1 transcriptional cofactor, it plays an important role in regulating the expression of embryonic cranial genes in tissues critical for normal craniofacial development.Copyright © 2023 Jourdeuil, Neilson, Cousin, Tavares, Majumdar, Alfandari and Moody.