The secret behind silkworm's hardy stomachs

May 27, 2008
Silkworm
Silkworm eating mulberry leaf. Credit: Toru Shimada

Silkworms have a unique ability to eat toxic mulberry leaves without feeling ill, and researchers have come one step closer to understanding why: silkworms contain a special digestive enzyme that is not affected by mulberry’s toxic chemicals.

Mulberry leaves contain an extremely high amount of alkaloids that inhibit enzymes that break down sucrose (sugar), and thus are potentially quite toxic. However, one type of sucrase called beta-fructofuranosidase is not affected by these alkaloids.

Until now, this enzyme has not been found in any animals, but Toru Shimada and colleagues believed this might explain the silkworm’s unique diet.

The researchers scanned the silkworm genome and discovered two fructofuranosidase genes, although only one was actually expressed in the worm. This gene (BmSuc1) was, as expected, concentrated in the worm’s gut, although surprisingly was also prevalent in the silk gland. When they isolated the enzyme from silkworms, the researchers found it could effectively digest sucrose.

Article URL: www.jbc.org/cgi/content/full/283/22/15271
The article appears in the May 30 Journal of Biological Chemistry.

Source: American Society for Biochemistry and Molecular Biology

Explore further: Biotech firm's GM mosquitoes to fight dengue in Brazil

add to favorites email to friend print save as pdf

Related Stories

The difficult question of Clostridium difficile

Aug 19, 2014

The bacterium Clostridium difficile causes antibiotic-related diarrhoea and is a growing problem in the hospital environment and elsewhere in the community. Understanding how the microbe colonises the hu ...

Tattoo biobatteries produce power from sweat

Aug 13, 2014

In the future, working up a sweat by exercising may not only be good for your health, but it could also power your small electronic devices. Researchers will report today that they have designed a sensor ...

Ingested nanoparticles may damage liver

Aug 12, 2014

(Phys.org) —Nanoparticles in food, sunscreen and other everyday products have many benefits. But Cornell biomedical scientists are finding that at certain doses, the particles might cause human organ damage.

Recommended for you

Walking fish reveal how our ancestors evolved onto land

30 minutes ago

About 400 million years ago a group of fish began exploring land and evolved into tetrapods – today's amphibians, reptiles, birds, and mammals. But just how these ancient fish used their fishy bodies and ...

The roots of human altruism

2 hours ago

Scientists have long been searching for the factor that determines why humans often behave so selflessly. It was known that humans share this tendency with species of small Latin American primates of the ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

zevkirsh
not rated yet May 28, 2008
i want some of dat stuff