WHEN the going gets tough, bacteria get rid of the genes they don鈥檛 need,
biologists in Hungary have found.
Tibor Vellai and his colleagues at E枚tv枚s Lor谩nd University
in Budapest starved Escherichia coli for 55 days and found that the
population lost a gene for antibiotic resistance鈥攚hich the bacteria were
not using under the conditions of the experiment. Bacteria that were not starved
retained the gene (Proceedings of the Royal Society B, vol 266, p
1953).
鈥淭he loss of genetic information occurs at random within the whole genome,鈥�
says Vellai. The process kills individual cells if it disrupts essential genes,
but over several generations the gene pool becomes streamlined鈥攕aving
energy when genes are copied during reproduction.
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