Researchers in the US have discovered that a gene called Boule has been uniquely required for sperm production in animals ranging from sea urchins to humans for 600 million years.
Dr Eugene Xu, who led the study at Northwestern University in Chicago, said: "This is the first clear evidence that suggests our ability to produce sperm is very ancient, probably originating at the dawn of animal evolution 600 million years ago. This finding suggests that all animal sperm production likely comes from a common prototype."
Scientists believe Boule's key role in reproduction may provide a potential target for a male contraceptive drug, and it may also open up new ways of combating pest-borne diseases with controlled breeding.
The gene was discovered by Dr Xu in 2001, but at the time no-one suspected that sperm from so many animal species had a common origin as different genes often produce similar functions.
Dr Xu's team investigated the sperm of a sea urchin, a chicken, a fruit fly, a fish and a human, and Boule was present in every sample.
Their research is reported in the online journal Public Library of Science (PLoS) Genetics.
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