Morpho-Regulation in Diverse Chicken Feather Formation: Integrating Branching Modules and Sex Hormone-Dependent Morpho-Regulatory Modules

The document presents a study on the influence of sex hormones on chicken feather morphogenesis, demonstrating that feather forms, textures, and colors can be extrinsically modified by hormones like estradiol and testosterone. The study involved injecting hormones into adult chickens and analyzing gene expression differences, with sample sizes of 14 wildtype males, 12 wildtype females, 12 males treated with estradiol, 15 females treated with testosterone, and 21 females treated with Femara. Results showed that estradiol significantly altered male feather morphology to resemble female feathers, while testosterone and Femara had less pronounced effects. The study also identified genes differentially expressed in male and female feathers, suggesting that hormones contribute to regional specificity in feather morphology, but local factors also play a significant role. The findings indicate that a core branching module produces basic feather morphology, with additional morpho-regulatory modules generating diverse forms. The study concludes that sex hormones, particularly estradiol, can override genetic identity to guide feather morphology and that further research is needed to understand the specific molecular mechanisms involved.