Blind Scottish centipede found WITHOUT a body clock - and the discovery could unlock clues to how millions of insects evolved

Home »Blind Scottish centipede found WITHOUT a body clock - and the discovery could unlock clues to how millions of insects evolved

Blind Scottish centipede found WITHOUT a body clock - and the discovery could unlock clues to how millions of insects evolved

Posted by sciencetech-blog on Tuesday, November 25, 2014 Label:

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For decades, scientists have been trying to discover the origins of many insect species by studying the Blind Brora centipede.

With ancestors dating back over 400 million years, the centipede, also known as Strigamia maritima, is mainly used to study the differences across invertebrates.

Now experts have revealed that the myriapod is missing an internal body clock, as well as vital light receptors seen across the animal kingdom by sequencing its genome for the first time.

Researchers from Cambridge University have sequenced the first full myriapod genome from the Strigamia maritima, which is of interest because they believe the creature could shed light on the ancestor of beetles and crabs, as well as some other invertebrates

Researchers from the Universities of St Andrews and Cambridge uncovered these findings after they sequenced the first full myriapod genome - a complete set of DNA - from the centipede.

Strigamia is part of the myripod family - a group that includes the centipedes and millipedes - which can be used to explore the genetic basis of centipede biology and the evolution of arthropods, including crabs and beetles.

The team, whose findings are published in the journal Plos Biology, used this sequence to recreate many features of the genetic make-up of the ancestral arthropod.

For example, they discovered it has a large number of near-identical segments, with one or two pairs of legs on each.

The type of centipede is favoured by scientists for the accessibility of its nests, from which embryos can be gathered for research purposes (pictured). Experts have revealed that the myriapod is missing an internal body clock, as well as vital light receptors seen across the animal kingdom

WHY HAVE SCIENTISTS SEQUENCED A CENTIPEDE GENOME?

The genome sequence of the centipede Strigamia maritima has allowed scientists to reconstruct many features of the genetic make-up of the ancestral arthropod.

They hope to learn more about the evolution of insects, crustaceans, chelicerates such as spiders and myriapods - centipedes and millipedes - from it.

The evolution of the huge biodiversity of these, animals and the information encoded in their genomes, is poorly understood.

While a number of studies have been done on the fruit fly, Drosophila melanogaster, the Strigamia genome could demonstrate that much has changed during the evolution of the fly genome, as well as insect genomes more generally.

This makes a strong case for studying a wider range of species to develop a deeper understanding of animal biology.

This centipede genome also provides examples of differences in how insects and myriapods independently conquered the land. For example, their sense of smell is achieved by different sets of molecules.

Lead author Dr David Ferrier, of St Andrews University in Scotland, said: 'This genome of Strigamia has proved to be particularly valuable in deducing the content of important gene families in the ancestral arthropod, this ancestor being the starting point for the evolution of the huge diversity of arthropods that we currently see today.

'There has been a high turn-over in arthropod gene and genome organisation, with lots of rearrangements and plenty of gene losses during the evolution of animals, like the insects.

'The sorts of reconstructions that have been made possible by this new myriapod genome provide a foundation for delving more deeply into the biology of these genetic changes.'

Perhaps one of the most surprising findings is that these centipedes seem to have lost the genes programming the known light receptors used by animals, as well as the genes controlling the body's internal clock.

Professor Michael Akam, of Cambridge University, said: 'Strigamia 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.

'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.'

He began making trips to Brora on the Scotland coast, to hunt out Strigamia a decade ago.

Research at the Brora beach is likely to continue for years.

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