Worker gene controls class

Researchers have discovered that termite 'caste' is influenced by genetic inheritance, a finding which could lead to new ways of combating this hugely damaging pest.

Termites cause billions of dollars worth of damage across the globe each year but it is the sterile workers which feed and build the colony that do most of this damage.

Until recently it was believed that termite caste was determined by environmental factors, however no details about the process were known.

In a paper entitled 'Sex-linked genetic influence on caste determination in a termite ' which appears in Science this week, a team of researchers from the University of Sydney's School of Biological Sciences and Ibaraki University in Japan have discovered the gene, named 'worker', that controls whether a termite egg becomes royal or working class.

"Depending on which version of the gene an offspring inherits, it will either be hard-wired to become a worker, or potentially develop into a king or queen," Sydney University's Dr Nathan Lo, said.

"Up until now, it was believed that such a genetic system was non-existent, with caste being determined purely by uncharacterised environmental stimuli acting on a totipotent genome.

"Interestingly, when royal genotypes mate, they give rise to worker genotypes, which are far less able to engage in selfish reproduction, which would reduce colony efficiency.

"However, occasion brother-sister worker matings appear to be required for further royal genotypes to be produced, resulting in a neat symmetry.

"This is a major step in understanding the mystery of how termite eggs can turn into offspring with such different morphologies, and it should eventually help us to find highly specific compounds that do things like turn workers into royals, which would cause havoc in the colony."

He said the royals are costly to raise, and if there are too many of them the efficiency of the colony will drop dramatically.

Source: University of Sydney