London: It is not only the sperm of men but mothers may also influence the sex of her offspring. A significant study has now revealed that the reproductive system of female pigs can recognise the sex of the sperm.
"What this shows is that mothers are able to differentiate between the sperm that makes boys and girls,” said Alireza Fazeli, a professor at University of Sheffield.
In lab experiments on pigs, researchers found that the reproductive systems of female pigs recognise whether a sperm will produce a boy or a girl before it reaches and fertilises the egg, and their oviduct (fallopian tubes) change in response.
Different genes are active in female pigs' reproductive system cells in experimental conditions when all X (female) or all Y (male) sperm are present, the findings showed.
To find out whether females can differentiate between female and male sperm, they inseminated female pigs with sperm that was either all X or all Y.
They then analysed the pig oviduct gene expression - the genes that were switched on in the oviduct cells.
They found that 501 genes consistently produced proteins in differing amounts depending on whether X or Y sperm was present.
If females can recognise the sex of sperm and change in response, they might be able to create an environment that favours boys or girls, researchers indicated.
The study appeared in the journal BMC Genomics.