Effects of Estradiol on Expression of Estrogen Receptor and Collagen mRNAs in Chick Skin

Abstract

Skin thickness and strength differ between male and female chickens. This study aimed to clarify the effects of estradiol on the expression of estrogen receptors and collagen mRNA in chicken skin. Estradiol was administered to male chicks for 3 weeks, then cryosections of skin collected from the cervical, thoracic, dorsal, and pelvic limb regions were stained with hematoxylin and eosin, and dermal thickness was measured.Estrogen receptor and collagen mRNA expression was assessed using real-time RT-PCR, and collagen contents were determined. Estradiol did not alter dermal thickness or the collagen content of the skin from any tested region. Among the estrogen receptors, significantly more ESR1 mRNA was expressed in the thoracic skin of chicks administered with estradiol compared with vehicle (control), and in the thoracic skin compared with skin from other regions within each group. Estradiol did not affect ESR2, GPER, and COL1A1 mRNA expression. These results suggested that estradiol stimulates ESR1 expression in thoracic skin, but does not affect collagen synthesis in skin from any other region of male chicks.

Collagen Content and Collagen Fiber Architecture in the Skin of Shamo Chicken, a Japanese Game Fowl

“…In both sexes, leg skin had higher collagen content than that of the cervical, thoracic, and dorsal skin. The same tendency has been observed in our previous study using male Rhode Island Red chicks [4]. In addition, the thoracic skin had higher collagen content than that of the cervical skin.…”

“…In this study, even in the femoral skin, there was no significant difference in collagen content between the sexes of 10-week-old chicks. Our previous study indicates that the administration of estradiol in male chicks does not affect the dermal thickness, COL1A1 expression, or collagen content of the skin[ 4 ]. These results suggest that the sex difference in collagen content in the femoral skin of mature Shamo chickens is not an effect of sex hormones, such as estradiol, but due to other factors.…”

“…[ 2 ] report that collagen content and collagen type I gene expression levels in the breast skin of broiler chicks increases with growth and are higher in males than in females in the early developmental stage. Regarding sex differences in skin collagen, Rhode Island Red cocks have higher collagen content than hens[ 3 ], but estradiol does not affect collagen content in the skin[ 3 , 4 ]. Rhode Island Red and White Leghorn cocks have similar skin collagen content[ 3 ].…”