What's the difference between a human and a fruit fly?

May 12, 2008

Fruit flies are dramatically different from humans not in their number of genes, but in the number of protein interactions in their bodies, according to scientists who have developed a new way of estimating the total number of interactions between proteins in any organism.

The new research, published today in the Proceedings of the National Academy of Sciences journal, shows that humans have approximately 10 times more protein interactions than the simple fruit fly, and 20 times as many as simple, single-cell yeast organisms.

This contradicts comparisons between the numbers of genes in different organisms, which yield surprising results: humans have approximately 24,000 genes, but fruit flies are not far behind, with approximately 14,000 genes.

The interaction between different proteins is behind all physiological systems in the human body. When the body digests food, responds to a change in temperature, or fights off an infection, numerous combinations of protein interactions are involved. However, until now it has been impossible to calculate the numbers of interactions that take place within different organisms.

Professor Michael Stumpf from Imperial College London’s Department of Life Sciences, one of the paper’s authors, explains the significance of the new study, saying:

“Scientists have believed for some time that the complexity of an organism’s protein interactions determine its biological complexity, but until now it’s been impossible to put a number on the size of one organism’s interaction network compared to another, as relatively little work has been done to identify and map these interactions.”

Scientists refer to the total number of protein interactions in the body as the “human interactome”, likening it to the human genome, which is most commonly associated with giving us our human traits.

Professor Stumpf adds: “Understanding the human genome definitely does not go far enough to explain what makes us different from more simple creatures. Our study indicates that protein interactions could hold one of the keys to unraveling how one organism is differentiated from another.”

The researchers devised a mathematical tool which allows them to predict the total size of an organism’s protein interaction network based on currently available, incomplete data.

The researchers’ next steps will be to make much more detailed predictions based on careful comparisons between species. This will be crucial in order to understand, for example, why some fungal species, such as baker’s yeast are important in the production of bread and beer, while other closely related species cause fungal infections with high mortality rates.

Source: Imperial College London

Explore further: Sheep flock to Eiffel Tower as French farmers cry wolf

add to favorites email to friend print save as pdf

Related Stories

Team conducts unprecedented analysis of microbial ecosystem

Nov 26, 2014

An international team of scientists from the Translational Genomics Research Institute (TGen) and The Luxembourg Centre for Systems Biomedicine (LCSB) have completed a first-of-its-kind microbial analysis of a biological ...

Signaling molecule crucial to stem cell reprogramming

Nov 20, 2014

While investigating a rare genetic disorder, researchers at the University of California, San Diego School of Medicine have discovered that a ubiquitous signaling molecule is crucial to cellular reprogramming, a finding with ...

Recommended for you

Genomes of malaria-carrying mosquitoes sequenced

10 hours ago

Nora Besansky, O'Hara Professor of Biological Sciences at the University of Notre Dame and a member of the University's Eck Institute for Global Health, has led an international team of scientists in sequencing ...

Bitter food but good medicine from cucumber genetics

10 hours ago

High-tech genomics and traditional Chinese medicine come together as researchers identify the genes responsible for the intense bitter taste of wild cucumbers. Taming this bitterness made cucumber, pumpkin ...

New button mushroom varieties need better protection

15 hours ago

A working group has recently been formed to work on a better protection of button mushroom varieties. It's activities are firstly directed to generate consensus among the spawn/breeding companies to consider ...

User comments : 0

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.