Animal welfare and use of silkworm as a model animal

Abstract

Sacrificing model animals is required for developing effective drugs before being used in human beings. In Japan today, at least 4,210,000 mice and other mammals are sacrificed to a total of 6,140,000 per year for the purpose of medical studies. All the animals treated in Japan, including test animals, are managed under control of "Act on Welfare and Management of Animals". Under the principle of this Act, no person shall kill, injure, or inflict cruelty on animals without due cause. "Animal" addressed in the Act can be defined as a "vertebrate animal". If we can make use of invertebrate animals in testing instead of vertebrate ones, that would be a remarkable solution for the issue of animal welfare. Furthermore, there are numerous advantages of using invertebrate animal models: less space and small equipment are enough for taking care of a large number of animals and thus are cost-effective, they can be easily handled, and many biological processes and genes are conserved between mammals and invertebrates. Today, many invertebrates have been used as animal models, but silkworms have many beneficial traits compared to mammals as well as other insects. In a Genome Pharmaceutical Institute's study, we were able to achieve a lot making use of silkworms as model animals. We would like to suggest that pharmaceutical companies and institutes consider the use of the silkworm as a model animal which is efficacious both for financial value by cost cutting and ethical aspects in animals' welfare.

Molecular cloning and characterization of presenilin gene in Bombyx mori

“…The silkworm, Bombyx mori (B. mori), is widely used in genetics and molecular biology and has numerous beneficial traits as a model compared with mammals or other insects. In particular, the whole genome of the silkworm has been sequenced, which allows for genetic manipulation, and there are already a number of ongoing research projects that utilize transgenic and genetically modified silkworms (33,34). Of note, a number of previous studies have demonstrated the possibility of applying the results obtained in silkworms to mammals (33,34).…”

Influence of clove oil and eugenol on muscle contraction of silkworm (<i>Bombyx mori</i>)

“…The further investigation is required to challenge with other fish anesthetic agents. It might be possible to use silkworm as model animals for screening new anesthetic agents for fish, since the use of silkworm is low cost, easy breeding, simple handle, and reproducible obtained results (32).…”

Uncovering Staphylococcus aureus genes with roles in pathogenicity by silkworm infection model

“…RH2180-5 (23–25), GPI0363(26), compound 5(27) and iminothiadiazolo-pyrimidinone derivatives(28). Additionally, silkworms have large enough body size to allow administration of precise inoculum and dosage, are economical, easy to handle, and associated with less ethical issues as well as less biohazard potential(29, 30). The number of bacterial cells required to kill silkworms can be quantitatively determined by the administration of precise inoculum of the bacteria.…”