Laser microdissection coupled with RNA-seq profiling of the E11.5 mouse mandibular epithelium along the dorsoventral axis
How the dorsal-ventral axis of the vertebrate jaw, particularly the position of tooth initiation site, is established remains a critical and unresolved question. Tooth development starts with the formation of the dental lamina, a localized thickened strip within the maxillary and mandibular epithelium. To identify transcriptional regulatory networks (TRN) controlling the specification of dental lamina from the naïve mandibular epithelium, we utilized Laser Microdissection coupled low-input RNA-seq (LMD-RNA-seq) to profile gene expression of different domains of the mandibular epithelium along the dorsal-ventral axis in wild type mouse and two loss-of-function mouse models of domain specific transcription factors. Overall design: To identify genes that are critical for mandibular epithelial patterning, we applied Laser Microdissection (LMD) coupled Smart-Seq2 RNA-seq to generate transcriptome profiles of four domains along the dorsal-ventral axis of the E11.5 mouse mandibular epithelium (also known as the oral-aboral axis). The four domains, from dorsal to ventral, included: 1) a posterior/dorsal domain; 2) a Dental Lamina (DL) domain; 3) an anterior domain; and, 4) an aboral/ventral domain. To determine the role of domain specific TFs in mandibular epithelium patterning and DL formation, we also generated transcriptome profiles of two loss-of-function mouse models: 1) DL specific transcription factor: Pitx2; 2) Aboral domain specific transcription factor: Tfap2a and Tfap2b.