IN the future, expectant parents could choose the sex of their babies ahead of time, thanks to a new discovery by Japanese scientists.
Girl babies carry two “X” chromosomes in their cells, while boys have one “X” and one “Y”.
A new, simplified, method of separating the two as part of the IVF process could lead to ‘designer families’ with the parents’ exact gender preferences.
The discovery was revealed in scientific journal Plot Biology.
One of the paper’s co-authors, Masayuki Shimada, from Hiroshima University, said “This is first study to scientifically [show] the functional differences, [ie] fertilisation ability, between X-sperm and Y-sperm.”
While scientists have able to separate the chromosomes for some time, this new method makes the process far simpler and a good deal quicker.
While the research may one day have an impact on human society, the scientists say their work’s main application will, alas, at first be agriculture.
“In a dairy farm, the value of a female dairy cow is much higher than male, because milk is only produced by female cows,” said Shimada.
“In the case of beef meat production, the speed of growing is much higher in males after castration than females.”
Shimada says there are moral questions to be answered before the technology is applied to human babies.
“Use of this method in human reproductive technology is speculative at the moment, and involves significant ethical issues unaffected by the utility of this new technique.”
Professor Robin Lovell-Badge, an expert in developmental biology at the Francis Crick Institute in London, warned that further testing is needed before the technique is declared safe.
He told the Guardian: “While the mice born after the sperm sorting apparently appeared normal, it would be essential to verify that there were no long-term effects of activating these receptors prior to fertilisation,” he said.
“In other words, do not try this at home in attempts to bias the likelihood of having a boy or a girl.”
Professor Allan Pacey, Professor of Andrology at the University of Sheffield, said: “There have been many attempts over the years to develop techniques to separate X from Y chromosome bearing sperm and thereby influence the sex of farm animals or humans born.
“We also know that nature is pretty ingenious in how it can influence the sex of offspring born in response to specific environmental or social conditions.
However, to date, the mechanism by which it does this is poorly understood.
“Therefore, this paper is very interesting because it highlights inherent physiological differences between X and Y chromosome bearing sperm in the laboratory.
Dr Peter Ellis, lecturer in Molecular Biology and Reproduction, University of Kent School of Biosciences, added: “This study makes the startling claim that there are cell surface markers on X- and Y-bearing sperm cells that ‘label’ these and selectively affect their function.
“This type of marker has been sought for many years in many different species, but thus far without success. “
“If this study were to be replicated – and in particular if it holds true in species other than mice – then the implications could be colossal for both animal and human artificial insemination and assisted reproduction, but we are certainly not at that stage yet.”