The reason that male bees have no father has been discovered by an international team of scientists.
The finding solves a puzzle going back 150 years when a Polish priest said that male bees developed from unfertilised eggs, while females came from fertilised ones.
Researchers report the solution today in the journal Cell. Female bees have two copies of a gene called CSD — complementary sex determiner — one from each parent, that trigger female development.
Unfertilised eggs, which have only one copy of CSD from the mother, default to being males.
CSD comes in 19 versions and while females have two different types, males have only one. The team believes that the two different versions of CSD code for inactive prot- eins can pair up to make an active protein that drives female development.
But if only one type of CSD is made, no active protein is formed and the bee grows into a male.