Mutation of a Cuticle Protein Gene,BmCPG10,is Responsible for Silkworm Non-Moulting in the 2nd Instar Mutant
In the silkworm,metamorphosis and moulting are regulated by ecdysone hormone and juvenilehormone.The subject in the present study is a silkworm mutant that does not moult in the 2nd instar(nm2).Genetic analysis indicated that the nm2mutation is controlled by a recessive gene and is homozygous lethal.Based on positional cloning,nm2 waslocated in a region approximately 275 kb onthe 5th linkage group by eleven SSR polymorphism markers.In this specific range,according tothe transcriptional expression of thirteen genes and cloning,the relative expression level oftheBmCPG10 gene that encodes a cuticle protein was lower than the expression level of the wild-type gene.Moreover,this gene”sstructurediffers from that of the wild-type gene: there is a deletion of 217 bp in its open reading frame,which resulted in a change in the protein it encoded.The BmCPG10 mRNA was detectable throughout silkworm development from the egg to the moth.This mRNA was low in the pre-moulting and moulting stages of each instar but was high in the gluttonous stage and in newly exuviated larvae.The BmCPG10 mRNA showed high expression levels in the epidermis,head and trachea,while the expression levelswere low in the midgut,Malpighian tubule,prothoracic gland,haemolymph and ventral nerve cord.The ecdysonetitrewas determined by ELISA,and the resultsdemonstrated that the ecdysonetitreof nm2 larvae was lower than that of the wild-type larvae.The nm2mutant could be rescued by feeding 20-hydroxyecdysone,cholesterol and 7-dehydrocholesterol(7dC),but the rescued nm2 only developed to the 4th instar and subsequently died.The moulting time of silkworms could be delayed by BmCPG10 RNAi.Thus,we speculated that the mutation of BmCPG10 was responsible forthe silkworm mutant that did not moult in the 2nd instar.
Bombyx mori non-moulting in the 2nd instar positional cloning BmCPG10 cuticle protein ecdysone
Fan Wu Pingyang Wang Qiaoling Zhao Lequn Kang Dingguo Xia Zhiyong Qiu Shunming Tang Muwang Li Xingjia Shen Guozheng Zhang
School of Biotechnology,Jiangsu University of Science and Technology,Zhenjiang,212018,China;The Seri School of Biotechnology,Jiangsu University of Science and Technology,Zhenjiang,212018,China;The Seri
国内会议
武汉
英文
324-337
2017-08-21（万方平台首次上网日期，不代表论文的发表时间）