Researchers at the University of California, Davis, have sequenced the genome of Aptostichus stephencolberti, a trapdoor spider about the size of a quarter, and found that it is roughly 50% larger than the human genome. The spider is the first member of its family to have its genome sequenced, according to corresponding author Jason Bond. The study appears in the Journal of Heredity.
“At 4.6 gigabases, or 4.6 billion DNA base pairs, it’s not the largest genome among the spiders, but it’s significant,” said Bond.
The genome is also complex, with 52 chromosomes compared with 23 in humans. Most of its size, 77%, comes from repetitive sequences copied many times across the genome rather than from extra genes. Like all spiders, this one has no telomere repeats, the sequences that protect chromosome ends. That absence may account for why spider chromosomes evolve faster than those of vertebrates.
“It lends itself to broadening our understanding of spider genome composition and consequently how genomes have evolved across the animal Tree of Life,” Bond said.
The spider got its name in 2008. Comedian Stephen Colbert found out that Bond had named a trapdoor spider after rock musician Neil Young and, on his “Who’s Not Honoring Me Now?” segment of “The Colbert Report,” demanded a spider of his own. Bond agreed.
A. stephencolberti lives only in coastal dunes in Central California, from the San Francisco Bay to Monterey, where beachgoers often come near it without knowing. Females spend their whole lives in silk-lined burrows sealed by a hinged, camouflaged door, rushing out to grab prey that come too close. The spider’s venom poses no danger to humans. Bond noted that only 30 to 50 of the more than 50,000 known spider species have venom known to be toxic to people.
The sequencing is part of the California Conservation Genomics project, a state-funded effort to build a genomic dataset for conservation science. Trapdoor spiders seldom travel far, and their dune habitat is fragmented, so genomic data can help identify distinct populations that may need protection. Rising sea levels threaten their narrow range.
“At 4.6 gigabases, or 4.6 billion DNA base pairs, it’s not the largest genome among the spiders, but it’s significant,” said Bond.
The genome is also complex, with 52 chromosomes compared with 23 in humans. Most of its size, 77%, comes from repetitive sequences copied many times across the genome rather than from extra genes. Like all spiders, this one has no telomere repeats, the sequences that protect chromosome ends. That absence may account for why spider chromosomes evolve faster than those of vertebrates.
“It lends itself to broadening our understanding of spider genome composition and consequently how genomes have evolved across the animal Tree of Life,” Bond said.
The spider got its name in 2008. Comedian Stephen Colbert found out that Bond had named a trapdoor spider after rock musician Neil Young and, on his “Who’s Not Honoring Me Now?” segment of “The Colbert Report,” demanded a spider of his own. Bond agreed.
A. stephencolberti lives only in coastal dunes in Central California, from the San Francisco Bay to Monterey, where beachgoers often come near it without knowing. Females spend their whole lives in silk-lined burrows sealed by a hinged, camouflaged door, rushing out to grab prey that come too close. The spider’s venom poses no danger to humans. Bond noted that only 30 to 50 of the more than 50,000 known spider species have venom known to be toxic to people.
The sequencing is part of the California Conservation Genomics project, a state-funded effort to build a genomic dataset for conservation science. Trapdoor spiders seldom travel far, and their dune habitat is fragmented, so genomic data can help identify distinct populations that may need protection. Rising sea levels threaten their narrow range.