NEW YORK (GenomeWeb News) — Researchers have sequenced the genome of the sea urchin and said they found similarities and differences between it and the human genome that could shed light on the evolution of both animals.
According to the Sea Urchin Genome Sequencing Project, analysis of a sequenced genome of a male California purple sea urchin revealed 23,000 genes comprising more than 814 megabases. The sequencing covered 90 percent of the genome.
The findings show that sea urchins and humans have a common ancestor, a marine creature that lived more than 540 million years ago and was an ancestor for the Deuterostomes, a super-phylum including both chordates — the phyla to which humans belong — and echinoderms, of which urchins are a part.
The researchers found that the sea urchin had most of the same gene families found in humans, although the genes were often larger in humans, a finding that researchers said reflects two different complete genome duplication events during vertebrate evolution that occurred well after the sea urchin and human lines split.
The research also shows that sea urchins have much larger innate immune system branches than humans, with as much as 10 to 20 times more genes controlling innate immunity as in humans.
Sea urchins do not have eyes or ears, but they do have genes for sensory proteins involved in vision and hearing in humans.
Baylor researchers sequenced the DNA, the California Institute of Technology prepared clones, and the Michael Smith Genome Sciences Center in Vancouver prepared a map of the genome.
The SUGSP Consortium, which is led by the Human Genome Sequencing Center at the Baylor College of Medicine, has published the analysis in the November issue of Science, though more extensive material will be published in the December issue of the journal Developmental Biology.