Research article

Systematic cloning and analysis of autophagy-related genes from the silkworm Bombyx mori

Xuan Zhang¹ , Zhan-Ying Hu² , Wei-Fang Li¹ , Qing-Rong Li² , Xiao-Juan Deng² , Wan-Ying Yang² , Yang Cao² and Cong-Zhao Zhou¹

¹Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei Anhui 230027, PR China

²Department of Sericulture science, College of Animal Science, South China of Agricultural University, Guangzhou 510642, PR China

author email corresponding author email

BMC Molecular Biology 2009, 10:50doi:10.1186/1471-2199-10-50

Published:	27 May 2009

Abstract

Background

Through the whole life of eukaryotes, autophagy plays an important role in various biological events including development, differentiation and determination of lifespan. A full set of genes and their encoded proteins of this evolutionarily conserved pathway have been identified in many eukaryotic organisms from yeast to mammals. However, this pathway in the insect model organism, the silkworm Bombyx mori, remains poorly investigated.

Results

Based on the autophagy pathway in several model organisms and a series of bioinformatic analyses, we have found more than 20 autophagy-related genes from the current database of the silkworm Bombyx mori. These genes could be further classified into the signal transduction pathway and two ubiquitin-like pathways. Using the mRNA extracted from the silkgland, we cloned the full length cDNA fragments of some key genes via reverse transcription PCR and 3' rapid amplification of cDNA ends (RACE). In addition, we found that the transcription levels of two indicator genes BmATG8 and BmATG12 in the silkgland tend to be increased from 1^st to 8^th day of the fifth instar larvae.

Conclusion

Bioinformatics in combination with RT-PCR enable us to remodel a preliminary pathway of autophagy in the silkworm. Amplification and cloning of most autophagy-related genes from the silkgland indicated autophagy is indeed an activated process. Furthermore, the time-course transcriptional profiles of BmATG8 and BmATG12 revealed that both genes are up-regulated along the maturation of the silkgland during the fifth instar. These findings suggest that the autophagy should play an important role in Bombyx mori silkgland.