Centipede Genes Offer Evolutionary Clues

 

Centipedes, those many-legged creatures that startle us in our homes and gardens, have been genetically sequenced for the first time. In a new study in the journal PLoS Biology, an international team of over 100 scientists today reveals how this humble arthropod’s DNA gave them new insight into how life developed on our planet.

Centipedes are members of the arthropods, a group with numerous species including insects, spiders and other animals. Until now, the only class of arthropods not represented by a sequenced genome was the myriapods, which include centipedes and millipedes. For this study, the researchers sequenced the genome of the centipede Strigamia maritima,because its primitive features can help us understand more complex arthropods.

According to Prof. Ariel Chipman, senior co-author of the study and project leader at the Hebrew University of Jerusalem's Alexander Silberman Institute of Life Science, the genetic data reveal how the creatures transitioned from their original dwelling-place in the sea to living on land.

“The use of different evolutionary solutions to similar problems shows that myriapods and insects adapted to dry land independently of each other,” said Chipman. “For example, comparing the centipede and insect genomes shows that they independently evolved different solutions to the same problem shared by all land-dwelling creatures — that of living in dry air.”

According to Chipman, the study found that despite being closely related to insects, the centipede lacks the olfactory gene family used by insects to smell the air, and thus developed its own air-sniffing ability by expanding other gene families not present in insects.

In addition, Chipman said, this specific group of centipedes lives underground and has lost their eyes, together with almost all vision genes and genes involved in the body’s internal clock. Instead, they maintain enhanced sensory capabilities enabling them to recognize their environment and capture prey.

Published in the latest edition of PLoS Biology, the research is a collaborative effort by over 100 scientists from 50 institutions. Thousands of human-hours went into looking at specific genes in the centipede genome, with each researcher looking at a limited set of genes or at specific structural characteristics to address specific questions.

In explaining the purpose of the research, Hebrew University's Chipman said: "If we have a better understanding of the biological world around us, how it operates, and how it came to be as it is, we will ultimately have a better understanding of ourselves.” According to Chipman, the research will have applications for other researchers ranging from conservation to dealing with crop pests.