By Tia Ghose
A single gene may act like a genetic dimmer switch, fine-tuning leaf variation between tomato plants. The gene reveals another way evolution can increase natural variation, and hints at the genetic basis of species distinction.
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Plant biologist Neelima Sinha and her colleagues looked at two tomato plants from the Galapagos Islands. The leaves of the tomato plant Solanum galapagense look like snowflakes — branching and forking into a series of smaller leaflets. A close relative Solanum cheesemaniae boasts more demure leaves that branch only once.
The team found that the intricate leaf pattern of S. galapagense is caused by a single deletion from its genetic code, says Sinha of the University of California, Davis. The snipped gene spurs S. galapagense to produce more of a protein needed for new leaf formation, the team reports in the May Current Biology.