Japanese researchers have found a method to select spermatozoids with X and Y chromosomes in mice, in order to determine the sex of a fetus.
The method, researched on mice, allows the selection and separation of spermatozoids carrying X chromosomes from those carrying Y chromosomes, which opens the possibility of choosing the gender of the future baby in the event that they are used in in vitro fertilization procedures.
The geneticists who created this method were working on a project trying to identify and understand the differences between spermatozoids carrying Y chromosomes and those carrying X chromosomes. They noted that the latter carry more genes compared to the former.
“This is the first study to identify the functional differences between spermatozoids with X chromosomes and those with Y chromosomes,” said Masayuki Shimida, co-author of the method and researcher at Hiroshima University.
Dr. Shimida is of the opinion that his method may prove extremely useful in cattle breeding, where, by manipulating spermatozoids, more females for milk or more males for meat may be born, depending on the specifics of the farms and the needs of farmers.
Currently, there is a method of sperm selection, cytometry, which allows the measurement of the characteristics of some cells, starting from the average size of the spermatozoids; this proves to be expensive. The researchers argue that their method is based on the different way in which the two types of spermatozoids move, thus allowing lower costs.
Dr. Shimada, along with his colleagues, found that spermatozoids with X chromosomes carry multiple genes, which means they can produce a wider range of proteins, including certain receptors that bind to certain substances. Using this feature, the researchers selected an antiviral and antitumor drug that highlights two specific receptors: TLR7 and TLR8.
When they exposed the spermatozoids of the mice to a solution containing this drug, the speed of some spermatozoids diminished. The researchers explained that this method can be used to influence the chances that a female will have a baby with a certain gender.