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: Galapagos volcano calms, pink iguanas out of danger

Related Stories

Q&A: Why are antibiotics used in livestock?

1 hour ago

Wal-Mart, the world's biggest retailer, is the latest company to ask its suppliers to curb the use of antibiotics in farm animals. Here's a rundown of what's driving the decision: ...

Recommended for you

South American parrot in trouble: researchers

6 hours ago

A South American parrot with a wine-colored chest is in deep trouble, with its population down to some 3,000 and a habitat reduced to a speck of what it once was, researchers said Tuesday.

Protecting South America's iconic golden dorado fish

7 hours ago

A new study launched this month by University of Massachusetts Amherst fisheries biologist Andy J. Danylchuk, in collaboration with Argentina's Ministry of Environment and regional partners including Juramento ...

Galapagos volcano calms, pink iguanas out of danger

9 hours ago

A volcano in the Galapagos Islands whose fiery eruption raised fears for the world's only population of pink iguanas has calmed, sparing the unique critters from danger, officials said Tuesday.

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

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.