Research Highlights

• Subject Categories:
  • Genetics
  • Biotechnology
  • Ecology & evolution

Published online: 16 September 2009 | doi:10.1038/nchina.2009.183

Genomics: Silkworm secrets

Felix Cheung

Introduction

© (2009) istockphoto.com

Silkworms may be small, but they have a major part in Chinese history. People began farming silkworms for silk production at around 3,500 BC, but there is much debate on how silkworm domestication came about. What were the ancestors of domesticated silkworms like? Did people artificially select silkworms that can produce silk many times a year? Do domesticated silkworms have mixed geographic heritage?

Zhonghuai Xiang at Southwest University in Chongqing, Jun Wang at the Beijing Genomics Institute in Shenzhen and co-workers¹ have now sequenced the genomes of 40 domesticated and wild silkworms. They constructed a genetic variation map that can answer all of the above questions.

The genetic variation map contains 16 million single-nucleotide polymorphisms, and many indels and structural variations. The researchers found that the domesticated silkworms are genetically different from the wild varieties, but have maintained high levels of genetic variability. The finding suggests that silkworm domestication happened quickly, and probably involved a large number of silkworms.

The researchers also identified 354 candidate genes that may have evolved during domestication, some of which have enriched expression in the silk gland, midgut and testis. These data help explain the domestication processes, and may have applications in devising pest control strategies.

The authors of this work are from:
Key Sericultural Laboratory, Ministry of Agriculture, College of Biotechnology, Southwest University, Chongqing, China; Institute of Agronomy and Life Sciences, Chongqing University, Chongqing, China; Beijing Genomics Institute, Shenzhen, China; Department of Biology, University of Copenhagen, Copenhagen, Denmark; Departments of Integrative Biology and Statistics, University of California, Berkeley, California, USA; Chongqing Normal University, Chongqing, China.

Reference

1. Xia, Q. et al. Complete resequencing of 40 genomes reveals domestication events and genes in silkworm (Bombyx). Science doi:10.1126/science.1176620 (2009). | Article | OpenURL