The Glowing Green Sperm

Research from Oxford, with potential implications for understanding male infertility:

A new way of studying sperm function has been developed which will aid research into male infertility.
In work published in this month’s edition of the journal Biology of Reproduction, an international team led by Oxford researchers has shown for the first time that it is possible to introduce a synthetic gene (a transgene) directly into a normal, live animal in such a way that the gene is expressed in mature sperm.
The new method could be extremely important for fertility research because it allows many different aspects of gene function in sperm to be studied. This means that scientists can begin to understand the details of how the sperm works and how infertility may result when things go wrong.
The new approach is particularly important because although many cells of the body can be cultured in a petri dish and genetically modified there, this is not possible for sperm cells because of their small size and unusual shape, and because they only live for a short time outside the body.
The study showed that the gene coding for a fluorescent green protein, originally taken from a jellyfish, could be introduced into sperm precursor cells within the testicles of a hamster, resulting in green, glowing sperm. Hamsters were used in the study because their sperm have many attributes in common with those of humans, and thus offer an excellent model for studying human sperm development and how defects in this process might result in infertility.
The scientist leading the study, Dr John Parrington of the Department of Pharmacology, said: ‘We created green sperm to show this approach could work. But our real aim is to use this technique to study the function of genes that are important during fertilization and that may cause infertility if they become defective. That’s an important goal given that a recent study found that one in seven British couples have fertility problems and a third of these have an unknown cause…’
Picture: Hamster sperm expressing a fluorescent green protein. Only the section between the head and the tail is glowing, as the protein targets the mitochondria, which in sperm are located in the midpiece. The fluorescence is only visible under a particular wavelength of light under a microscope.

From the University of Oxford news page…