Cloning And Expression Analysis Of Fibroin Heavy Chain Gene From Actias Selene Hubner

Silk contains two main parts, sericin and fibroin.Sericin produced in mid-silk glang encapsulates fibroin which takes up 25% of the total weight. Fibroin produced in post-silk gland is the main part of silk which takes up 70% of the total weight.Fibroin-H as the main part of silk,fibroin-L and P25 with a 6:6:1 molar ratio make up the fundamental structural unit of fibroin.Rearch of fibroin-H has important theoretical and practical value. From theoretical sense, we can ascertain the homology and evolution relationship of different species. From practical possibilities ,we can increase output and quality of silk, produce special silk product,raise silkworm ablility of resistance to disease and the ability to resist bad environment and development new applications.This experiment cloned Fibroin-H gene sequence of the 5'flanking from Actias selene firstly. This sequence of 2801bp long contains start codon and encodes 933 amino acids with Fibroin-H conservative structural characteristics.We have found that the sequence has a high homology with that of Antheraea pernyi,Antheraea yamamai,Saturnia japonica,Anthereaea mylitta, especially Saturnia japonica.It shows the result is right.The accesssion number is GU212855.1. Through expression analysis of semi-quantitative PCR towards fibroin-H of different time in the fifth instar, we have found expession of fibroin-H from the first day,third day, sixth day, ninth day and twelfth day in the fifth instar of A.selene in post-silk gland increases day by day.It is credible.Through analysis we have detected fibroin-H from the first day,third day, sixth day, ninth day and twelfth day in the fifth instar of A.selene in mid-silk gland and the trend is:low-high-low-high.We have not detected fibroin-H in fat body.It shows expression of fibroin-H has organization specificity which is in accord with previous study.