This study was conducted to explore the regulatory role of methionine (Met) in feather follicle and feather development during the embryonic period of chicks. A total of 280 fertile eggs (40 eggs/group) were injected with 0, 5, 10, 20 mg of L-Met or DL-Met/per egg on embryonic day 9 (E9), and whole-body feather and skin tissues were collected on E15 and the day of hatching (DOH). The whole-body feather weight was determined to describe the feather growth, and the skin samples were subjected to hematoxylin and eosin staining and Western blotting for the evaluation of feather follicle development and the expressions of Wingless/Int (Wnt)/β-catenin signaling pathway proteins, respectively. The results showed that L- or DL-Met did not affect the embryo weight (P > 0.05), but increased the absolute and relative whole-body feather weights. Specifically, 5 and 10 mg of L-Met and 5, 10, and 20 mg of DL-Met significantly increased the absolute feather weight at E15 (P < 0.05), and 10 mg of L-Met and 5 and 10 mg of DL-Met significantly increased the absolute and relative feather weight on the DOH (P < 0.05). Moreover, a main effect analysis suggested that changes in the embryo and feather weights were related to the Met levels (P < 0.05) but not the Met source (P > 0.05). The levels of L- and DL-Met were quadratically correlated with the absolute and relative feather weights of chicks on the DOH (P < 0.05). Correspondingly, all doses of L- and DL-Met significantly increased the diameter and density of feather follicles on the DOH (P < 0.05), as well as the activity of Wnt/β-catenin on E15 and the DOH (P < 0.05). In conclusion, injection of either L- or DL-Met can improve feather follicle development by activating Wnt/β-catenin signaling, and thereby promoting feather growth; furthermore, no difference in feather growth was found between L- and DL-Met treatments. Our findings might provide a nutritional intervention for regulating feather growth in poultry production.

中文翻译：

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蛋氨酸通过激活Wnt /β-catenin信号传导改善鸡胚中的毛囊发育。

进行这项研究以探讨蛋氨酸（Met）在雏鸡胚胎期对卵泡和羽毛发育的调节作用。在胚胎第9天（E9），共向280个可育卵（每组40个卵）注射0、5、10、20 mg L-Met或DL-Met /每个卵，并注射全身羽毛和皮肤组织在E15和孵化当天（DOH）收集。确定全身羽毛的重量以描述羽毛的生长，并对皮肤样品进行苏木精和曙红染色和蛋白质印迹以评估羽毛的卵泡发育以及Wingless / Int（Wnt）/β-catenin信号传导的表达途径蛋白。结果表明，L-或DL-Met不会影响胚重（P> 0.05），但会增加绝对和相对的全身羽毛重量。具体来说，在E15时，5和10 mg的L-Met和5、10和20 mg的DL-Met显着增加了绝对羽毛重量（P <0.05），而10 mg的L-Met和5和10 mg DL -蛋氨酸显着增加了DOH的绝对和相对羽毛重量（P <0.05）。此外，一项主要效果分析表明，胚胎和羽毛重量的变化与Met水平有关（P <0.05），而与Met来源无关（P> 0.05）。L-和DL-Met的水平与DOH上雏鸡的绝对和相对羽毛重量呈二次相关（P <0.05）。相应地，所有剂量的L-和DL-Met均显着增加DOH上的毛囊直径和密度（P <0.05），以及Wnt /β-catenin对E15和DOH的活性（P <0.05） 。结论，注射L-或DL-Met可通过激活Wnt /β-catenin信号传导改善羽毛卵泡发育，从而促进羽毛生长。此外，在L-Met处理和DL-Met处理之间未发现羽毛生长差异。我们的发现可能为调节家禽生产中的羽毛生长提供营养干预。