International team completes genome sequence of centipede

November 25, 2014, Baylor College of Medicine
Strigamia maritima
Strigamia maritima. Credit: ArthropodBase wiki

An international collaboration of scientists including Baylor College of Medicine has completed the first genome sequence of a myriapod, Strigamia maritima - a member of a group venomous centipedes that care for their eggs - and uncovered new clues about their biological evolution and unique absence of vision and circadian rhythm.

Over 100 researchers from 12 countries completed the project. They published their work online today in the journal PLOS Biology.

"This is the first myriapod and the last of the four classes of arthropods to have its genome sequenced," said Dr. Stephen Richards, assistant professor in the Human Genome Sequencing Center at Baylor, where the sequencing of the project was completed, and the corresponding author on the report. "Arthropods are particularly interesting for scientific study because they diverged into more species than any other animal group as they adapted in many ways to conquer the planet. The genome of the myriapod in comparison with previously completed genomes of the other arthropod classes gives us an important view of the evolutionary changes of these exciting species."

Dr. Ariel Chipman, of the Hebrew University of Jerusalem in Israel, Dr. David Ferrier, of The University of St. Andrews in the United Kingdom, and Dr. Michael Akam of the University of Cambridge in the UK, together with Richards served as key players in the collaboration.

"The arthropods have been around for over 500 million years and the relationship between the different groups and early evolution of the species is not really well understood," said Chipman, associate professor at the Hebrew University. "We have good sampling of insects but this is the first time a , one of the more simple arthropods - simple in terms of body plan, no wings, simple repetitive segments, etc.—has been sequenced. This is a more conservative genome, not necessarily ancient or primitive, but one that has retained ancient features more than other groups."

"From fossil evidence, we know the myriapods are one of three independent arthropod invasions of the land (from the sea), in addition to the insects and spiders. So they had to find a way to smell chemicals in air, rather then taste them in water. The team identified large gene expansions of the gustatory (taste) receptors suspected to fill the olfactory role that olfactory (smell) receptors play in insects," Richards said. "This is a nice example of parallel evolution where different group of genes expanded, providing a different solution to the same problem."

One interesting finding revolved around this particular centipede group losing its eyes at least 200 million years ago.

No genes related solely to vision were found in the genome, and interestingly, genes related to the were also missing. The circadian clock regulates sleep and causes jetlag and also relies on light input to synchronize with day and night.

"This teaches us about how evolution works and how things change, how things can be conserved and others lost," said Chipman. "In general, this just gives us a better understanding of biology and how it works over long periods of time."

"Strigamia (centipedes) live underground and have no eyes, so it is not surprising that many of the genes for light receptors are missing, but they behave as if they are hiding from the light. They must have some alternative way of detecting when they are exposed," says Akam, head of zoology at Cambridge and one of the lead researchers.

"It's curious, too, that this creature appears to have no body clock - or if it does, it must use a system very different to other animals."

The centipede's is of more than just scientific interest, said Akam.

"Some of its genes may be of direct use. All centipedes inject venom to paralyse their prey," he explains. "Components of venom often make powerful drugs, and the centipede will help researchers find these venom genes."

Explore further: First widespread look at evolution of venomous centipedes

More information: hipman AD, Ferrier DEK, Brena C, Qu J, Hughes DST, et al. (2014) The First Myriapod Genome Sequence Reveals Conservative Arthropod Gene Content and Genome Organisation in the Centipede Strigamia maritima. PLoS Biol 12(11): e1002005. DOI: 10.1371/journal.pbio.1002005

Related Stories

Fly genome could help us improve health and our environment

October 13, 2014

The house fly might be a worldwide pest, but its genome will provide information that could improve our lives. From insights into pathogen immunity, to pest control and decomposing waste, the 691 Mb genome has been sequenced ...

House fly sex may reveal one key to controlling them

November 18, 2014

The quest of University of Houston professor Richard Meisel to understand how and why males and females differ may one day lead to a more effective means of pest control - namely, the pesky house fly.

Glanville fritillary genome sequenced

September 5, 2014

The Glanville fritillary has long been an internationally known model species for ecology and evolutionary biology, whose population biology has been studied on the Åland Islands for more than twenty years. Now the species ...

Recommended for you

Scientists ID another possible threat to orcas: pink salmon

January 19, 2019

Over the years, scientists have identified dams, pollution and vessel noise as causes of the troubling decline of the Pacific Northwest's resident killer whales. Now, they may have found a new and more surprising culprit: ...

Researchers come face to face with huge great white shark

January 18, 2019

Two shark researchers who came face to face with what could be one of the largest great whites ever recorded are using their encounter as an opportunity to push for legislation that would protect sharks in Hawaii.

Why do Hydra end up with just a single head?

January 18, 2019

Often considered immortal, the freshwater Hydra can regenerate any part of its body, a trait discovered by the Geneva naturalist Abraham Trembley nearly 300 years ago. Any fragment of its body containing a few thousands cells ...

0 comments

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.