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: Fishes' innate food choice could change with the environment

add to favorites email to friend print save as pdf

Related Stories

Nano-antioxidants prove their potential

Feb 09, 2015

Injectable nanoparticles that could protect an injured person from further damage due to oxidative stress have proven to be astoundingly effective in tests to study their mechanism.

Toxic fruits hold the key to reproductive success

Dec 09, 2014

In the course of evolution, animals have become adapted to certain food sources, sometimes even to plants or to fruits that are actually toxic. The driving forces behind such adaptive mechanisms are often ...

Recommended for you

Lifeline extended for critically endangered porpoise

1 hour ago

Mexico's recent decision to buy-out gillnet fisheries in the upper Gulf of California may give one of the world's rarest species the breathing space it needs to survive. Time is still ticking, but the move ...

New 'enigma' moth helps crack evolution's code

2 hours ago

Aenigmatinea glatzella – which has iridescent gold and purple wings – is a 'living dinosaur' that represents an entirely new family of primitive moths. This is the first time since the 1970s that a new ...

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.