Abstract
Samia ricini, a gigantic saturniid moth, has the potential to be a novel
lepidopteran model species. Since S. ricini is much more tough and
resistant to diseases than the current model species Bombyx mori, the
former can be easily reared compared to the latter. In addition, genetic
resources available for S. ricini rival or even exceed those for B.
mori: at least 26 eco-races of S. ricini are reported and S. ricini can
hybridise with wild Samia species, which are distributed throughout
Asian countries, and produce fertile progenies. Physiological traits
such as food preference, integument colour, larval spot pattern, etc.
are different between S. ricini and wild Samia species so that those
traits can be the target for forward genetic analysis. In order to
facilitate genetic research in S. ricini, we determined the whole genome
sequence of S. ricini. The assembled genome of S. ricini was 458 Mb with
155 scaffolds, and the N50 length of the assembly was approximately 21
Mb. 16,702 protein coding genes were predicted in the assembly. Although
the gene repertoire of S. ricini was not so different from that of B.
mori, some genes, such as chorion genes and fibroin genes, seemed to
have specifically evolved in S. ricini.