The Study On BECN1 Gene Expression In Qianhua Mutton Merino Hair Follicle

Mutton Wool is one of the main products of sheep breeding,its yield and quality affect the economic benefits of wool textile industry,high-grade wool products need high-quality fine wool,therefore,the cultivation of high-quality fine wool sheep has become a hot spot at present.Qianhua meat Merino sheep is an original sheep^[1]variety bred by the introduction of South African meat.The male parent is Merino sheep,while the female parent is northeast fine wool sheep.According to progressive hybrid,cross fixation and breeding improvement,which has excellent meat production performance and 66～70 homogeneous fine wool breeds,which belongs to typical fleshy fine wool sheep.Sheep skin hair follicles are the basis of wool production traits.There is a periodic development law in sheep hair follicles,that is,the process of alternation between rest period,growth period and retrogression stage^[2],which has an important influence on the occurrence of wool.Some studies have shown that there is autophagy in mammal hair follicles.BECN1 gene is the gene that initiates autophagy.A large number of studies have called BECN1 autophagy gene or autophagy protein.In order to understand the structure and periodic changes of hair follicles in dried Chinese meat Merino sheep,the changes of hair follicles tissue structure in different stages of hair follicles development in dry Chinese meat Merino sheep were observed,and the differences of hair follicles tissue structure in different developmental stages were found out.On this basis,the autophagy promoter gene BECN1 was located and expressed on the hair follicles at the corresponding development stage.From the spatial point of view,the changes of hair follicle cell autophagy in dried Chinese meat Merino sheep were indirectly revealed,which provided a theoretical basis for expounding the wool production performance and the periodic development mechanism of hair follicles in dried Chinese meat Merino sheep.The results are as follows:1.The tissue structure of hair follicles of dried Chinese meat during the growing period（August）,retrogression（December）and rest was observed by tissue section and HE staining,respectively.it was found that the morphology and size of hair papilla and hair bulb in the hair follicles of the three periods changed significantly,and the hair nipples and hair balls gradually atrophied until the rest period from the pear shape and oval shape of the growing period to the recess stage.The number of hair sheath cells decreased from multi-layer to monolayer.2.Immunohistochemical test showed that the expression of BECN1 gene was the most obvious in the skin tissue of dry Chinese meat Merino sheep and hybrid sheep,and expressed in inner root sheath,outer root sheath and hair parent material,but not in hair parent material during growth,but not in inner root sheath and outer root sheath.The BECN1 gene of dry Chinese meat was expressed in a very small part of the resting stage of Merino sheep,most of which were not expressed in the outer root sheath,and the BECN1 gene of the hybrid sheep was not obviously expressed in the outer root sheath at the rest stage.3.The expression of BECN1 gene in hair follicles of dry Chinese meat Merino and its hybrid generation was detected by fluorescence quantitative PCR.The results showed that BECN1 gene was expressed in retrogression（12 months）,rest（April）and growth（August）,and there were differences in different cycles of hair follicles and between the two kinds of sheep.The main results were as follows:（1）the expression of BECN1 gene in merino wool bursa for dry Chinese meat was significantly higher in retrogression than in growth（P<0.05）,significantly higher in retrogression than in rest（P<0.05）,but there was no significant difference between growth and rest（P>0.05）,showing the regularity of retrogression>growth>rest.The expression of BECN1 gene in hybrid wool capsule was significantly higher than that in growth stage（P<0.05）,and that in retrogression stage was significantly higher than that in rest stage（P<0.05）,but there was no significant difference between growth period and rest period（P>0.05）,which was consistent with that of dried Chinese meat Merino sheep.（2）the expression of BECN1 gene in hybrid sheep was significantly higher than that in dry Chinese meat Merino sheep（P<0.05）,but there was no significant difference between the two sheep during the growth period and the rest stage（P>0.05）.The expression of m RNA in both breeds at the same time was hybrid sheep>dried Chinese meat Merino sheep.4.The expression of BECN1 gene in hair follicles of dry Chinese meat Merino sheep and its hybrid generation was detected by immunoblotting.The results showed that BECN1 gene was expressed in retrogression（12 months）,rest（April）and growth（August）,and there were differences between different hair follicles and different breeds.The main results were as follows:（1）the expression of BECN1 gene in dry Chinese meat Merino sheep was significantly higher in retrogression than in growth,and significantly higher in retrogression than in rest,but there was no significant difference between growth and rest（P>0.05）.The expression of BECN1 gene in hybrid wool capsule was significantly higher than that in rest（P<0.01）.The regression stage was significantly higher than that in the growth period（P<0.01）,but there was no significant difference between the growth period and the rest period（P>0.05）.The expression pattern of the two kinds of sheep was the same,both of them were retrogression>growth>rest.（2）the expression of BECN1 gene in crossbred sheep was significantly higher than that in dry Chinese meat Merino sheep at the same time,but there was no significant difference between the two breeds at the growth stage and the rest stage.The expression of BECN1 protein in both kinds of sheep at the same time was hybrid sheep>dried Chinese meat Merino sheep.In summary,the structure of hair follicles is different in different hair follicles development cycles.BECN1 gene was expressed in the hair follicles of both sheep skin,showing the regularity of retrogression>growth>rest.BECN1 gene may be involved in the periodic changes of hair follicles of Merino sheep for dry Chinese meat.The expression of autophagy gene BECN1 in hair follicles showed regularity,indicating that autophagy may play an important role in the periodic changes of Merino hair follicles used in dried Chinese meat.