A research team headed by a scientist in Athenry has discovered key genes that could boost lamb production. The work may also help identify genes associated with human reproduction.
Dr Seamus Hanrahan of Teagasc's Athenry, Co Galway, research centre led the group, which included scientists from NUI Galway, France and New Zealand. They identified three gene mutations that have a strong influence on ovarian function in sheep.
The team used advanced DNA technology to make the discovery. One gene can only be inherited from the mother and a second can be inherited from either parent, Dr Hanrahan said. "We are the first group of researchers in the world to have discovered that this second gene affects ovulation rate in sheep," he stated.
"Ewes that inherit a single copy of any of the three mutations have a significantly higher ovulation rate."
The mutation increased the likelihood of twins being delivered. "The effect could be an increase in litter size of between 0.5 and one lamb per ewe. Only improvements at the lower end of the scale would be practical under Irish sheep production conditions," he added.
Inheriting two of the mutations has the opposite effect, causing sterility in the ewes, he said. "This profound effect on ovarian function makes this discovery of major potential significance to medical research on fertility control in women," he said. "It is likely that what we have discovered on how follicle development [which influences egg production] is controlled in sheep will provide important insights for human fertility."