Globetrotting black rat genes reveal spread of humans and diseases

Feb 01, 2008
Globetrotting black rat genes reveal spread of humans and diseases
Black rats collected in a single night in a small village in northern Laos. Credit: Angela Frost, University of Queensland, Australia

DNA of the common Black Rat (Rattus rattus) has shed light on the ancient spread of rats, people and diseases around the globe.

Studying the mitochondrial DNA of 165 Black Rat specimens from 32 countries around the world, an international team of scientists has identified six distinct lineages in the Black Rat’s family tree, each originating from a different part of Asia.

“Black Rats are carriers of many different human diseases, including plague, typhus and leptospirosis,” says CSIRO mammal expert Dr Ken Aplin, lead author of the study.

“It has been unclear why certain rodent-borne diseases are more common in some places than others, but our work raises the possibility that the different lineages of Black Rats each carry a different set of diseases, which is something medical science now needs to consider.

“We need to know more about what types of Black Rats are moving around the world and what disease risks each of them might pose.”

The six different lineages originated in India, East Asia, the Himalayas, Thailand, the Mekong Delta, and Indonesia.

The Indian lineage spread to the Middle-East around 20,000 years ago, then later to Europe. It reached Africa, the Americas and Australia during the Age of Exploration.

The East Asian lineage moved from Taiwan to Japan, the Philippines, and Indonesia, arriving in Micronesia only 3,500 years ago.

The other four lineages have not become so widespread but they could be set to expand their ranges in the future.

“Our findings also show a good match between the historic spread of each lineage and ancient routes of human migration and trade, but there are a few surprises that raise new questions about human prehistory,” Dr Aplin says.

“The genetic evidence points strongly to there being more than one species of black rat, but more work is needed before we can say exactly how many species there are.”

The Black Rat is one of the most common of the world’s 56 Rattus species, and is also known as the house, roof or ship rat. It is found throughout Africa, Asia, Australia, Europe and the Americas.

Dr Aplin will present the results of his team’s research at the Archaeological Science Conference in Canberra, Australia on Monday.

Source: CSIRO Australia

Explore further: 221 new species described by the California Academy of Sciences in 2014

add to favorites email to friend print save as pdf

Related Stories

All in a flap: Seychelles fears foreign bird invader

Oct 17, 2014

It was just a feather: but in the tropical paradise of the Seychelles, the discovery of parakeet plumage has put environmentalists in a flutter, with a foreign invading bird threatening the national parrot.

Physicist Stephen Hawking visits LA stem cell lab

Apr 10, 2013

Stephen Hawking toured a stem cell laboratory Tuesday where scientists are studying ways to slow the progression of Lou Gehrig's disease, a neurological disorder that has left the British cosmologist almost ...

How the 'street pigeon' got its fancy on

Jan 19, 2012

Pigeons display spectacular variations in their feathers, feet, beaks and other physical traits, but a new University of Utah study shows that visible traits don't always coincide with genetics: A bird from ...

Recommended for you

Ninety-eight new beetle species discovered in Indonesia

4 hours ago

Ninety-eight new species of the beetle genus Trigonopterus have been described from Java, Bali and other Indonesian islands. Museum scientists from Germany and their local counterparts used an innovative approa ...

Bacteria are wishing you a Merry Xmas

5 hours ago

A bacterium has been used to wish people a Merry Xmas. Grown by Dr Munehiro Asally, an Assistant Professor at the University of Warwick, the letters used to spell MERRY XMAS are made of Bacillus subtilis, ...

Pragmatic approach to saving what can be saved

5 hours ago

How can biodiversity be preserved in a world in which traditional ecosystems are increasingly being displaced by "man-made nature"? Biologists at the TU Darmstadt and ETH Zurich have developed a new concept ...

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.