Morphogenesis Of Macrotrichium And Expression Pattern Of β-catenin And Sonic Hedgehog In Bos Grunniens Embryos

The study selected Bos grunniens embryo as hair follicle developmental model under extreme ecological environment. We systematically analysis hair follicle morphogenesis in Bos grunniens embryos during Ed 35 ~ 255 by conventional histological section, tissue microarray technology, HE and collagen staining . And the expression pattern of signaling moleculeβ-catenin and SHH(sonic hedgehog) were detected by immunohistochemistry. The results showed that:1. Morphogenesis of Bos grunniens hair follicle can be divided into pre-placode stage, hair placode stage, hair germ stage, hair peg stage and hair follicle stage by morphological changes. And these stages can be divided into several sub-stages, in particular, the hair placode stage can be divided into four sub-stages. Bos grunniens macrotrichium follicles occur earlier than the other pelage follicles and also get higher density and more synthesis of collagen.2. Bos grunniens hair follicle morphogenesis is accompanied by the occurrence of sweat gland and sebaceous gland. After stage of placode, germ, peg, shaping and differentiation, sweat gland mature. And sebaceous gland has also experienced a period of morphogenesis stage, cell differentiation stage and maturation stage before the maturity. Eventually a typical hair follicle - sweat gland - sebaceous unit form.3. At the pre-plcode stage,β-catenin expressed in the epidermal keratinocytes and dermal mesenchymal cells, At the hair placode stage,β-catenin strongly expressed in the epidermis of placode and dermal condensate. After a expression decrease during hair germ and peg stage,β-catenin again expressed in the hair matrix region at the hair follicle stage.4. At the pre-placode stage, SHH expressed in the epidermal basal cells. After the formation of hair placode SHH expressed in the epithelial department of placode. Then at the hair germ stage, SHH expressed in anterior extremity of the epithelial cord before a transient expression disappearance until hair follicle stage. After hair follicle form and begin differentiation and maturation, SHH was seen again in the hair follicle root sheath, sebaceous gland cells, hair matrix and dermal papilla region.