Expression Levels of WNT Signaling Pathway Genes During Early Tooth Development

Abstract

It is known to all that Wnt signaling pathway plays an important role in the early development of tooth. Our previous research found that Wnt signaling pathway played crucial roles in dental development, and mutations in antagonist of Wnt signaling pathway may lead to the formation of supernumerary teeth. However, the expression pattern of Wnt signaling molecules in early development of tooth, especially genes with stage specificity, remains unclear. Hence, we applied RNA-seq analysis to determine the expression levels of wnt signal molecules at five different stages of rat first molar tooth germ. In addition, after literature review we summarized the function of Wnt signaling molecules during tooth development and the relationship between Wnt signaling molecules variation and tooth agenesis. Our research may have implications for exploring the role of Wnt signaling molecules in different stages of tooth development.

Unraveling the structure, chemical composition, and conserved signaling in leech teeth

“…Specifically, genes shared with the mouse showed 67.6% (4113 + 864/7362) and 66.3% (4113 + 1080/7826) in Hirudo teeth and Helobdella proboscis, respectively ( Figure 2 (B), Dataset 1). From these datasets, we selected potential candidate genes for tooth formation based on specific criteria: (i) expression in tooth-forming tissues in mice and Hirudo teeth ( Figure 4 (B); Nishikawa and Kawamoto 2015 ; de Sousa-Romero and Moreno-Fernández 2016 ; Neupane et al 2023 ; Song et al 2023 ) and (ii) lack of expression in the toothless leech ( Helobdella proboscis). Following these criteria, we identified three genes – protein tyrosine phosphatase receptor type O ( Ptpro ), prickle planar cell polarity protein 2 ( Prickle2 ), and wnt family protein 16 ( Wnt16 ) (TPM > 1.5) ( Figure 3 (A) and Figure 4 (B)).…”

“…We used embryonic mice tooth germs, Hirudo jaws, and Helobdella proboscises to examine conserved signaling pathways for tooth development for the first time, employing de novo transcriptome analysis. This aimed to better understand the development of dental tissue in non-chordate animals and compare it with mice teeth ( Figure 4 ; Nishikawa and Kawamoto 2015 ; de Sousa-Romero and Moreno-Fernández 2016 ; Neupane et al 2023 ; Song et al 2023 ). The transcriptome data from the toothless leech, Helobdella , was analyzed to deduce the signaling molecules present in toothless leeches.…”

“…The high-throughput analysis of leech teeth and proboscis revealed significant numbers of odontogenic genes shared with vertebrate tooth development ( Figure 4 ; Nishikawa and Kawamoto 2015 ; de Sousa-Romero and Moreno-Fernández 2016 ; Neupane et al 2023 ; Song et al 2023 ). A previous study demonstrated deep genetic homology in specific tissue development among bilaterians (Tarazona et al 2016 ), suggesting possible homology between mouse and Hirudo teeth regarding genetic factors.…”

“…The knockdown of Ptpro resulted in retarded tooth development, while overexpression facilitated the process (Neupane et al 2023 ), and Prickle2 and Wnt16 have been reported to be involved in dental hard tissue development and morphogenesis (Nishikawa and Kawamoto 2015 ; de Sousa-Romero and Moreno-Fernández 2016 ; Song et al 2023 ). Additionally, Prickle2 has been implicated in neurite formation during brain development (Okuda et al 2007 ), enamel rod decussation (Nishikawa and Kawamoto 2015 ), the Wnt and planar cell polarity pathway, and pluripotency (Tao et al 2012 ), suggesting that Prickle2 and Wnt16 might share similar signaling functions during tooth and proboscis formation in leeches.…”

“…Therefore, to shed some light on the evolutionary perspective of odontogenesis, we conducted de novo transcriptome analysis of mouse, toothed leech ( Hirudo nipponia ) and toothless leech ( Helobdella austinensis ). We selected potential candidate genes for tooth formation based on commonly expressed genes in mice and leeches as revealed by transcriptome analyses, along with genetic information obtained from previous studies (Nishikawa and Kawamoto 2015 ; de Sousa-Romero and Moreno-Fernández 2016 ; Neupane et al 2023 ; Song et al 2023 ). Additionally, using electron microscopy, the present study revealed the chemical composition of leech teeth, along with identifying conserved signaling molecules associated with tooth formation.…”