Formation of the calvaria is a multi-staged process and is regulated by multiple genetic factors. Disruption of normal calvarial development usually causes craniosynostosis, a prevalent birth defect characterized by premature fusion of calvarial bone. Recent studies have identified mutations of KMT2D allele in patients with craniosynostosis, indicating a potential role for Kmt2d in calvarial development. KMT2D mutations have also been implicated in Kabuki syndrome, which features a distinct facial appearance, skeletal abnormality, growth retardation and intellectual disability. However, the expression pattern of Kmt2d has not been fully elucidated. In the present study we examined the expression pattern of Kmt2d at multiple stages of embryo development in mice, with a focus on the craniofacial tissues. Our in situ hybridization results showed that Kmt2d mRNA is expressed in the developing calvarial osteoblasts, epithelia and neural tissues. Such an expression pattern is in line with the phenotypes of Kabuki syndrome, suggesting that Kmt2d plays an intrinsic role in normal development and homeostasis of these craniofacial tissues.

颅盖骨的形成是一个多阶段的过程，并受多种遗传因素的调节。正常颅盖骨发育的破坏通常会导致颅突肿大，这是一种普遍存在的出生缺陷，其特征是颅盖骨骨过早融合。最近的研究已经确定了颅前突病患者的KMT2D等位基因突变，表明Kmt2d在颅骨发育中具有潜在作用。KMT2D突变也与歌舞uki综合症有关，该特征具有明显的面部外观，骨骼异常，生长迟缓和智力残疾。但是，Kmt2d的表达模式尚未完全阐明。在本研究中，我们检查了Kmt2d的表达模式在小鼠胚胎发育的多个阶段，重点放在颅面组织上。我们的原位杂交结果表明，Kmt2d mRNA在发育中的颅骨成骨细胞，上皮细胞和神经组织中表达。这种表达模式与歌舞uki综合症的表型一致，表明Kmt2d在这些颅面组织的正常发育和体内平衡中起着固有的作用。