Mrf-2基因缺陷老鼠之顱顏分析

Cephalometric Analysis for Mice Deficient in Mrf-2

賴泰廷(Tai-Ting Lai) ； 莊廷熙(Ting-Hsi Chuang) ； 羅思敏(Clarice Law)

《中華牙醫學雜誌（中文版）》 24卷4期 (2005/12) Pp. 240-248

https://doi.org/10.7106/CJD.200512.0240

摘要

基因標的(Gene targeting)導致在去氧核醣核酸結合蛋白(DNA binging protein)上Mrf-2(modulater recognition factor 2)基因缺陷的老鼠其遺傳表型(phenotype)呈現出瘦小及生長遲緩的特徵。然而，由外表觀察得知這些突變老鼠有較短的鼻子(snout)和較小的頭顱腔(cranial vault)。實驗目的：我們假設Mrf-2基因缺陷的相同體(homologue)老鼠乃會在骨骼與顱顏發育上產生特殊組織缺陷。因此，本實驗的目的乃在找出Mrf-2-/-突變種(mutant)和Mrf-2+/+野生型(wild type)之間其骨骼和顱顏構造及發育上的差異。實驗方法：老鼠分成兩組：Mrf-2-/-突變種(mutant)和Mrf-2+/+野生型(wild type)。每一老鼠各照一張側方測顏及前後測顱放射片，並將影像輸入電腦數位化，並標上界標(landmark)記錄。一系列的線性及角度測量。以統計軟體加以分析。結果：根據顱顏分析，在突變種及野生型老鼠之間，在鼻子顱骨長度及寬度，皆在統計學上有顯著差異。其差異隨著年齡增加而增加。結論：這Mrf-2基因缺陷老鼠不尋常的顱顏表現型態，乃在顱顏構造上並非成等比例縮小，可推測Mrf-2基因在不同的顱顏構造上有不同的作用。

關鍵字

基因標的 ； Mrf-2 ； 遺傳表型

並列摘要

Gene targeting has resulted in a mutant mouse deficient in modulator recognition factor-2 (Mrf-2), a DNA binding protein. The primary phenotype of the Mrf-2-/- mouse is leanness and growth retardation. However, visual inspection of these mutants revealed unusual craniofacial characteristics, with blunted snouts and relatively small cranial vaults. We hypothesized that a deficiency in the Mrf-2 homologue in mice would result in a tissue-specific defect in skeletal and craniofacial development. Therefore, the objective of this study was to localize and quantify the structural differences in the craniofacial complex when comparing Mrf-2 (-/-) mutants and Mrf-2 (+1+) wildtype mice. Mice were divided into 2 different groupings: Mrf-2 (-/-) mutants and MrI-2 (+/+) wildtype mice, Radiographs were made of each subject's head from the superior and lateral views. Images were digitized and landmarks were identified. A series of linear and angular measurements was recorded, and a statistical analysis was carried out. According to the cephalometric analysis, there were statistically significant differences in nasal length, cranial vault length, and cranial vault width between the mutant and wildtype mice. These differences increased with age. The unusual craniofacial phenotype of the Mrf-2 deficient mutant mouse is a result of disproportionate size discrepancies in selected craniofacial structures. These structural differences may have resulted from the loss of specific activity of Mrf-2 on craniofacial or skeletal tissues.

並列關鍵字

gene targeting ； Mrf-2 ； phenotype