RNA-Seq of adult chicken sickle feather tissues between male and female

Many animals can change their coats in response to different ages, sexes, or seasonal environmental changes. The hormones can also alter the size, shape, texture and color of the regenerated coat. Here we propose feather core branching morphogenesis module can be modulated by sex hormone or other environmental factors to change the form, texture or colors, thus generate a large spectrum of complexity for adaptation. We use sexual dimorphisms of the feather coat to explore the role of hormones in in coat morphogenesis and regeneration. A long-standing question is whether the sex-dependent feather morphologies are autonomously controlled by the male or female cell types, or extrinsically controlled and reversible. We have recently identified core feather branching molecular modules which control the anterior-posterior (BMP, Wnt gradient), medio-lateral (retinoic signaling, gremlin), and proximo-distal (sprouty, BMP) patterning of feathers. We hypothesize that modulatory signaling modules can be added upon these core branching modules to topologically tune the dimension of each parameter. Here we explore the involvement of hormones in generating sexual dimorphisms using exogenously delivered hormones. Our strategy is to mimic androgen levels by applying exogenous dihydrotestosterone and aromatase inhibitors to adult females and injecting exogenous estradiol to adult males. We also examine differentially expressed genes in the feathers of wildtype male and female chickens to identify potential downstream modifiers of feather morphogenesis. The data show male and female feather morphology and their color patterns can be modified extrinsically through molting and reseting the stem cell niche during regeneration.