Washington: A new research finds that sperm that live longer before fertilising an egg produce healthier offspring. The study was conducted by researchers from the University of East Anglia and Uppsala University in Sweden and shows that longer-lived sperm in an ejaculate of a zebrafish male produce offspring with longer and healthier lifespans – who in turn produce more and healthier offspring themselves – than the shorter-lived sperm in the same ejaculate.
Lead researcher Dr Simone Immler, from UEA’s School of Biological Sciences, said, “One male produces thousands to millions of sperm in a single ejaculate but only very few end up fertilising an egg.”The research team performed in vitro fertilisations by collecting gametes from males and females. They then split the ejaculate of a male into two halves. In one half, they selected for shorter-lived sperm and in the other for longer lived sperm. They then added the sperm to two half clutches from a female to fertilise the eggs and reared the offspring into adulthood. According to Dr Immler, the longer-lived sperm within the ejaculate of male zebrafish, the resulting offspring is much fitter than their full siblings sired by the shorter-lived sperm of the same male.