Scientists claim sea urchin DNA decoded

An international team of nearly 250 scientists reported Friday that they had determined the exact order of all 814 million letters of DNA code that carry the instructions for making and maintaining a sea urchin.

If you think that’s relevant only to scuba divers and sea otters, you’re wrong. Among life-forms that lack backbones, these spiky critters – which are kissing cousins of starfish and can live for more than 100 years – are our closest relatives. They are more similar to us than fruit flies or worms, those classic laboratory workhorses that for decades have provided insights into human biology and genetics.

Sea urchins, it turns out, have 23,300 genes, only slightly fewer than humans have. Many are similar to genes that cause human diseases, including Huntington’s disease and muscular dystrophy. That means urchins may provide a new venue for studying the molecular origins of those ailments.

Surprisingly, urchins have 979 genes that, by the looks of them, are involved in sensing light or odors.