Yamashita Ryo, Takegawa Yumiko, Sakumoto Machiko, Nakahara Mai, Kawazu Haruna, Hoshii Takayuki, Araki Kimi, Yokouchi Yuji, Yamamura Ken-ichi
Division of Developmental Genetics, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan.
Dev Dyn. 2009 Apr;238(4):993-1000. doi: 10.1002/dvdy.21900.
Leucine-rich repeat (LRR) -containing G protein coupled receptor (LGR) family members are characterized by the presence of a seven-transmembrane domain and LRR motifs. We describe a new function for Lgr4 in the development of the gall bladder and cystic duct and in the epithelium-mesenchyme interaction. Lgr4 expression was observed in the gall bladder epithelium when the gall bladder primordium elongated ventrally. Although Lgr4 hypomorphic mutant (Lgr4(Gt/Gt)) embryos developed a normal gall bladder bud at embryonic day (E) 10.25, no further elongation was observed at later stages. At E12.5, the mesenchyme surrounding the gall bladder had completely disappeared in Lgr4(Gt/Gt) embryos, while the gall bladder remained unelongated. Neighboring tissues such as liver and pancreas were unaffected, as revealed by expression of marker genes. This is the first report of a mutant mouse that lacks a gall bladder and cystic duct without affecting the other tissues that derive from the same hepatic diverticulum.
富含亮氨酸重复序列（LRR）的G蛋白偶联受体（LGR）家族成员的特征是存在七跨膜结构域和LRR基序。我们描述了Lgr4在胆囊和胆囊管发育以及上皮-间充质相互作用中的新功能。当胆囊原基向腹侧伸长时，在胆囊上皮中观察到Lgr4表达。尽管Lgr4低表达突变体（Lgr4(Gt/Gt)）胚胎在胚胎第（E）10.25天发育出正常的胆囊芽，但在后期未观察到进一步伸长。在E12.5时，Lgr4(Gt/Gt)胚胎中围绕胆囊的间充质完全消失，而胆囊仍未伸长。如标记基因表达所示，肝脏和胰腺等邻近组织未受影响。这是关于一种突变小鼠的首次报道，该小鼠缺乏胆囊和胆囊管，而不影响源自同一肝憩室的其他组织。
