| Lueyang chicken is a local quality chicken variety of Lueyang country, Shaanxi Province,which has been selected in the condition of the unique geographical environment acclimatization and carefully breeding for a long time. With the trait of six ends in black which consists of comb, beak, toe, tongue, skin and stone, Lueyang chicken is a unique biological resource in Lueyang country. And because of its production in the Hei River basin,it is also known as Hei River chicken. Eating Lueyang chicken can lead to erythrocytosis and hemoglobin hyperplasia in human body due to the melanin in Lueyang chickens. It has a high tonic and medicinal value. Because of the importance of melanin in Lueyang chicken, it will be better if there is more melanin in the chicken body.In recent years, the trait of black in Lueyang chicken population was obviously degraded, which caused great economic losses in the production of chicken every year. At the same time, Lueyang chicken belongs to the local variety, growth rate and productivity is lower compared with broiler, which directly affects the farmers’ breeding enthusiasm. Then,purifying the black traits of the population and increasing the growth rate become the most important work. Illumina2000 sequencing technology was used to catalog the global gene expression profiles in the skin and muscle of the Lueyang chicken with white versus black skin. According to the results, we screened and analyzed the differently expressed gene in skin and muscle, picked out several genes which are related to the pigment deposition in skin such as ASIP, TYR, KIT, OCA2, TYRP1, KITLG, MITF, MC1 R et al. And we also picked out the MUSTN1 gene, which controls the regulation of muscle deposition. All of the differentially expressed genes were verified by qPCR. The results are as follows:1. A total of 81 genes were only detected in the black skin chicken while 82 only in the white ones. There are 506 genes detected in both.2. There are 18 608 and 22 563 genes were detected in muscle of the white and black skin chicken, and 28 genes of these are differentially expressed.3. In addition to the TYRP1 gene, the main genes that regulate pigmentation can be expressed in skin tissues(ASIP, TYR, KIT, OCA2, KITLG, MITF and MC1R).4. According to the result of qPCR, ASIP, TYR, KIT and OCA2 showed greater expression in the skin of black chickens(P < 0.05), KITLG, MITF and MC1 R showed no significant difference in expression between the black-skinned and white-skinned chickens(P > 0.05), and the expression of TYRP1 was not detected in either skin color. And the results of the qPCR were consistent with the RNA-seq.5. According to the result of the RNA-Seq of skin and muscle, the expression of MUSTN1 gene is closely related to the skin color, MUSTN1 showed extremely greater expression in the black chickens in the tissue of skin and muscle(P < 0.01).6. According to the result of qPCR, the expression of MUSTN1 gene in skin is significant higher than the expression in chest and leg muscle in 16 weeks old Lueyang chicken(P <0.05). Also in chest, the expression of MUSTN1 gene in the variety of white skin is significant higher than that in the black skin(P < 0.05).7. Through the re-filtering of the data, it is revealed that there is alternative splicing in the MITF gene in the two groups of Lueyang chicken, and the splicing exists between the 5’UTR region and the first exon.There exists important reference value of these results, it will be of great help to the selection of black traits and muscle traits in Lueyang chicken. At the same time it will provide a scientific basis for the further study of melanin deposition and muscle deposition mechanism. |
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