Research On The Function Of BMP4and FGF5in Goose Feather Follicles And Feathers Development

In this paper, embryonic and postnatal Jilin White Geese were chosen as the experimental material, from which we collected10-130days old geese back feathers and observed growth and development of feather and feather morphological changing. In addition, Collecting the goose dorsal skin of E20to E30and P10to P130, using immunohistochemical and fluorescence quantitative PCR to study the expression position and levels of BMP4and FGF5at the different developmental stages in geese skin, discussing the function and effect of feather development.The research results of goose feather growth and development regular were as follows, goose feather development experience three stages:, juvenile plumage, adult plumage, and adult plumage include feather and down. Goose was born with yellow lanugo of the whole body, lanugo appeared in baby geese back when they were15days old, till35days old the yellow lanugo completely drained away, white feathers and down appeared in body surface, and in80days old baby feather were replaced by them, then rapidly grow to mature in120days old. Small hooks appeared in38days old, about70days old feather sticks integraded basically. With the age increases,the diameter and length of fragment feather and plumule and barbules was increasing. The length and diameter of feathers and barbules growed fast at40-90day age,90day-old growth slowed, after110days,the growth rate stabilize. The feather got mature in about120days of age. Combination of the record of the daily illumination time, temperature, and humidity during sampling in this study, and correlation analysis with feather development, it revealed that the growth and development of goose feather was effected by age and genes significantlygreater than environmental factors.The results of localized expression and the function on goose feather development of BMP4and FGF5were as follows. BMP4and FGF5two genes were expressed in the whole process of feathers and hair follicle development.In about E27, BMP4expressed mainly in the medullary parts at the base and dermal papilla of the primary feather follicle. At P10, the positive expression of BMP4decreased in the primary feather follicles, and had a strong positive expression in dermal papilla and the entire medullary parts of the secondary feather follicle. With the age increasing, BMP4expression extended gradually from the base to upward. From E21to P40, BMP4expression was at a low level; P40-70BMP4expression was detected in the barb ridge and rachis ridge parts in the primary feather follicle, the medulla site has not detected BMP4positive expression, also secondary feather follicles did not find positive expression of BMP4in the rachis ridge and the barb ridge parts, while the amount of BMP4gene expression in P40-70showing a suddenly rapid increase in the trend, coupled with the branch to make this time piece barbs fusion, revealing that BMP4promoted feather branching, and may promoted the occurrence and development of feather barbs and hooks. After P90, BMP4positive expression could be detected in the dermal papilla, a very small amount of positive expression in the medulla, but at P120and P130BMP4-positive expression basically was not detected in the secondary feather follicle. At P120, the feathers had got mature, the amount of expression of BMP4were at a high level, revealing that BMP4played a role in feather follicles transformation process from telogen to anagen.The positive expression of FGF5in E27was detected the base of the primary feather follicle, that is, the dermal papilla and medullary parts of the base, but not detected in the secondary feather follicle; At P30, FGF5positive expressed continuely in the medullary parts of the base of the primary feather follicle, and gradually extended upward, and detected a small amount of positive expression in the medullary parts of the middle region, also weak positive expression was detected in dermal papilla, and medullary parts of the secondary feather follicle; At P60, positive expression was not detected in the primary feather follicle, secondary follicle medulla parts found strong positive expression of FGF5; At P90, FGF5-positive expression was detected in the feather follicle outer root sheath parts, and a very small amount of positive expression in the medulla; At P120, FGF5positive expressed at the medulla and dermal papilla of the primary feather follicle a small amount, but was not detected in the secondary feather follicle. In the feathers rapid development of40-90days, the expression of FGF5increased rapidly, and the expression levels peaked in90days, inferring that FGF5mainly restrained the development of feather follicle, and mainly impacted the feathers length changes, revealing that FGF5played a role during the feather follicle from anagen to telogen.Analysising the overall changing trend of BMP4and FGF5two gene expression, before P40, the changing trend of two genes expression was basically same, and was at low expression level, while the feather follicles and feathers developed actively, suggesting that the two genes played a negative regulatory role; after P40, the two gene expression began to differ, BMP4expression increased in the period of feather branching, the expression levels decreased after branching, and increased when feather follicles change into the catagen, revealing that BMP4promoted feather branching and maintained feather follicles in catagen; The expression of FGF5increased from anagen to catagen, and the expression decreased when changed into the catagen, revealing that FGF5promoted feather follicles transforming from anagen to catagen.