The mouse Agouti gene encodes a paracrine signaling factor which promotes melanocytes to produce yellow instead of black pigment. It has been reported that Agouti mRNA is confined to the dermal papilla after birth in various mammalian species. In this study, we created and characterized a knockin mouse strain in which Cre recombinase was expressed in-frame with endogenous Agouti coding sequence. The Agouti–Cre mice were bred with reporter mice (Rosa26-tdTomato or Rosa26-ZsGreen) to trace the lineage of Agouti-expressing cells during development. In skin, the reporter was detected in some dermal fibroblasts at the embryonic stage and in all dermal fibroblasts postnatally. It was also expressed in all mesenchymal lineage cells in other organs/tissues, including eyes, tongue, muscle, intestine, adipose, prostate and testis. Interestingly, the reporter expression was excluded from epithelial cells in the above organs/tissues. In brain, the reporter was observed in the outermost meningeal fibroblasts. Our work helps to illustrate the Agouti expression pattern during development and provides a valuable mouse strain for conditional gene targeting in mesenchymal lineage cells in multiple organs.

小鼠Agouti基因编码一种旁分泌信号因子，可促进黑色素细胞产生黄色而不是黑色色素。据报道，多种哺乳动物出生后， Agouti mRNA 仅限于真皮乳头。在本研究中，我们创建并表征了一种敲入小鼠品系，其中 Cre 重组酶与内源Agouti编码序列符合读码框表达。 Agouti – Cre小鼠与报告小鼠（ Rosa26-tdTomato或Rosa26-ZsGreen ）交配，以追踪发育过程中表达 Agouti 的细胞的谱系。在皮肤中，在胚胎阶段的一些真皮成纤维细胞和出生后的所有真皮成纤维细胞中检测到报告基因。它还在其他器官/组织的所有间充质谱系细胞中表达，包括眼睛、舌头、肌肉、肠道、脂肪、前列腺和睾丸。有趣的是，报告基因表达被排除在上述器官/组织的上皮细胞之外。在大脑中，记者在最外层的脑膜成纤维细胞中观察到。我们的工作有助于阐明Agouti在发育过程中的表达模式，并为多个器官的间充质谱系细胞的条件基因靶向提供有价值的小鼠品系。