The race for life, in which millions of sperm swim quickly towards the egg, is neither fair nor noble: rather a ruthless race in which even There are manipulative sperm that are careful to poison their competition..
In what points out a new study published in PLOS Genetics by researchers at the Max Planck Institute for Molecular Genetics (MPIMG) in Berlin.
The research studied mouse sperm cells under a microscope to better understand the effects of a particular DNA sequence known as the t haplotype. The team knew from previous research that sperm that carry this sequence they tend to swim straighter (instead of going in circles) and faster on average than competing sperm without it.
He haplotype t is a series of linked genes that occupy chromosome 17 in house mice around the world. (Unlike humans, who have 23 pairs of chromosomes, mice only have 20.) What happens is that sperm with the t haplotype manage to disable sperm without it.
Specifically, the t haplotype 'poisons' all sperm during the early phases of sperm production, injecting each cell with certain genes that inhibit its ability to regulate movement. It is not until a later phase, when each cell divides in half, that the 'antidote' comes into play. After splitting, half of sperm inherit the genes of the t haplotype on chromosome 17.
For lucky sperm, the t haplotype provides new genetic variants that reverse the inhibitory effects of the 'poison' that all cells consumed during the previous phase of development. According to explains the co-author of the study, Bernhard Herrmann, director of MPIMG:
The trick is that the t haplotype 'poisons' all the sperm, but at the same time produces an antidote, which acts only on the t sperm (those with the t haplotype) and protects them. The result is a kind of marathon in which all participants receive poisoned drinking water, but only some of the runners have access to the antidote.
In their study, the researchers saw that many sperm without the antidote literally swam in circles until they died, while their t-haplotype competitors swam directly forward.
–
The news
Some sperm literally poison their competition in the race to fertilize an egg
was originally published in
Xataka Science
by
Sergio Parra
.