Study On Skin Follicle Morphogenesis, Development And Annual Cycle Changes Of Liaoning Cashmere Goats

Cashmere is a marrowless animal fiber, and was regarded as a precious raw material for textiles. For improving the cashmere production under the same process scale, the first step was researching the cashmere goat's skin particularly and thoroughly, then described the mechanism of cashmere growth in skin, and the final purpose was controling and enhancing the quantity and quality of cashmere. In this research, the skin follicle morphogenesis, development and annual cycle changes of Liaoning Cashmere Goats was studied and summarized, which can provide the retionale for succedent study, such as molecular regulation mechanism and mechanism of cashmere's perennial growth of Lianning Cashmere Goats.Two main methods were involved in this study:1. Sacpic staining was used for measuring the thickness of dermis and epidermis, and depth, hair bulb's breadth, density and the activity state of primary follicles (PF) and secondary follicles(SF).2. The expression of VEGF and the distribution of microvessel was detected by using immunohistochemisty. Likewise the expression of Bax and Bcl-2 was detected, which the apoptotic could be distinguished preliminary.The results of skin follicle morphogenesis of Liaoning Cashmere Goats was described as follow:at 45th day embryonic age, these was no evidence of hair follicle's morphogenesis; at 60th day embryonic age, a arch-structure called hair germ made of dermis lobus intermedius cells was fromed; at 75th day embryonic age, hair germ extended into dermis and formed a columnar structure; at 90th day embryonic age, a large number of bulbous pegs was observed in longitudinal section of skin; at 105th day embryonic age, PF has matured, and the evidence of SF initial was shown at some point beneath the epidermis, and the aebaceous gland and sweat gland was detected first time; at 120th day embryonic age, hair fiber produced by PF came out of skin surface, and the SF has matured partially; at 135th day embryonic age, the skin was extremely similar to adult.During the fetel development process of Liaoning Cashmere Goats, the depth and breadth of two kinds of hair follicle increased all the time; thickness of dermis, epidermis and the ratio between them increased through the process either; density of PF decreased day by day, while the SF's density increased, thus the ratio between SF to PF increased either; the activity state of two kinds of follicles maintained a very high level.During the fetel development process of Liaoning Cashmere Goats, the mean optical density of VEGF and microvessel density (MVD) changed with the increasingly tendency, and the correlation between them was extremely positive. Bax and Bcl-2 positive was detected at PF and SF, epidermis, aebaceous gland and sweat gland; the Bax's mean optical density of two kinds of follicles was constant long-trem after an initial stage's raise, while the Bcl-2's was increased all the time, thus the ratio of Bax/Bcl-2 decreased time by time, suggested the apoptosis on these two kinds of follicles was tapering when the follicles matured gradually. By study the Liaoning Cashmere Goat's adult female monthly in a whole year, the depth of PF minimized at February and maximized at August; while the SF's minimized at May and maximized at August. Breadth of hair bulb of PF minimized at November and resembled among the other months; while SF's minimized at February and maximized at May. Thickness of epidermis minimized at September and maximized at February, while dermis'minimized at May and maximized at August, thus the ratio of dermis/epidermis minimized at May and maximized at July. The density of PF and SF and the ratio of S/P changed unremarkable among months. It could be emphasized that two phenomena has been detected in this research, including the PF's concomitance of dead and newborn, and SF's fusion made by several SFs. The activity state of PF minimized during March to May and maximized at August; SF's minimized at April and maximized at August.By study the Liaoning Cashmere Goat's adult female monthly in a whole year, VEGF-positive was detected in PF and SF's hair bulb, inner root sheath, outer root sheath, and aebaceous gland, sweat gland, pidermis. Changes of mean optical density of VEGF on PF was bimodal pattern, the former was shown during March to May, the latter shown at August. Same as SF's first crest value shown at May and the second at August. Interestingly, the change of MVD in dermis was bimodal pattern too, with two peaks at May and August. By Pearson correlation analysis, the expression of VEGF in PF and MVD was mezzo positive correlation, while SF's and MVD was hadro-positive correlation.By study the Liaoning Cashmere Goat's adult female monthly in a whole year, Bax and Bcl-2-positive was detected in PF and SF's hair bulb, inner root sheath, outer root sheath, and aebaceous gland, sweat gland, pidermis, similar to VEGF. Expression of Bax in PF minimized at June and maximized at July, while Bcl-2's changed unremarkable among months, thus the ratio of Bax/Bcl-2 in PF minimized at June and maximized at July. Expression of Bax in SF was bimodal pattern with two peaks at May and September, while Bcl-2's only peak shown at May, thus the ratio of Bax/Bcl-2 in SF minimized at October and maximized at April, but with another high level at July.The cycle changes of hair follicles was going round and beginning again, meanwhile a variety of cellular factors expressed with a cyclical variation, including several of them such as VEGF could cause MVD changed circularly. Therefore, the complex changing was taken place circularly in skin of Liaoning Cashmere Goats.