Hamidi Kordiyeh, Darvish Jamshid, Matin Maryam M, Javanmard Athar Sadat, Kilpatrick C William
Department of Biology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran.
Research Group of Rodentology, Institute of Applied Zoology, Ferdowsi University of Mashhad, Mashhad, Iran.
Anat Rec (Hoboken). 2017 Dec;300(12):2138-2149. doi: 10.1002/ar.23678. Epub 2017 Sep 9.
To date, no studies have examined the tooth formation during developmental stages of brush-tailed mice (Calomyscidae) and true hamsters (Cricetidae). Herein, we compared the timing of tooth morphogenesis and FGF4 expression pattern during development of the first lower molar in Goodwin's brush-tailed mouse, Calomyscus elburzensis with two other muroid rodents; the house mouse, Mus musculus (Muridae), model organism for tooth morphogenesis, and the golden hamster, Mesocricetus auratus which shares great similarities in cusp pattern with brush-tailed mice. All three species were bred in captivity and developing embryos were isolated at different embryonic days (E). Histological evaluation of lower molars was performed and spatiotemporal pattern of FGF4 expression was determined by immunohistochemistry. Results indicated that morphogenesis of the tooth cusps starts at the beginning of the cap stage of the first lower molar (E14 in house mouse, about E11.5 in golden hamster and E22 in Goodwin's brush-tailed mouse). During the cap to bell stage (E15 in house mouse, E12 in golden hamster and at about E24 in Goodwin's brush-tailed mouse), a decrease in the expression of FGF4 was observed in the mesenchyme, except for the cusp tips. According to our observations, the developmental process of the first lower molar formation in Goodwin's brush-tailed mouse began much later as compared with the other two species. Despite the differences in the temporal pattern of molar development between these three members of the same superfamily (Muroidea), the correlation in the expression of FGF4 with specific stages of tooth morphogenesis supported its regulatory function. Anat Rec, 300:2138-2149, 2017. © 2017 Wiley Periodicals, Inc.
迄今为止，尚无研究考察帚尾鼠（仓鼠科）和真仓鼠（仓鼠科）发育阶段的牙齿形成过程。在此，我们比较了古氏帚尾鼠（Calomyscus elburzensis）第一下臼齿发育过程中牙齿形态发生的时间和FGF4表达模式，以及另外两种鼠形啮齿动物；家鼠（Mus musculus，鼠科），牙齿形态发生的模式生物，和金黄仓鼠（Mesocricetus auratus），其牙尖模式与帚尾鼠有很大相似性。所有三个物种均在圈养条件下繁殖，并在不同胚胎日（E）分离发育中的胚胎。对下臼齿进行组织学评估，并通过免疫组织化学确定FGF4表达的时空模式。结果表明，牙尖的形态发生始于第一下臼齿帽状期开始时（家鼠为E14，金黄仓鼠约为E11.5，古氏帚尾鼠为E22）。在帽状期到钟状期（家鼠为E15，金黄仓鼠为E12，古氏帚尾鼠约为E24），除牙尖外，间充质中FGF4的表达下降。根据我们的观察，与其他两个物种相比，古氏帚尾鼠第一下臼齿形成的发育过程开始得要晚得多。尽管同一总科（鼠总科）的这三个成员在臼齿发育的时间模式上存在差异，但FGF4表达与牙齿形态发生特定阶段的相关性支持了其调节功能。《解剖学记录》，300:2138 - 2149，2017年。©2017威利期刊公司。
