"Sperm with a longer service life resulting in a healthier offspring, according to research at Uppsala university. The find is believed to be of great importance in the artificial fertilization."
"In a regular ejaculation (ejaculate) is tens of millions of sperm, but only one of them will fertilize the egg. Does it matter which?"
"Normally this is no problem, because the nature takes care about this in connection with sexual intercourse. It will be the way it is, so to say. At fertilization, however, the question is much more relevant since there will be other opportunities to choose which sperm to have a chance to blend together with the egg, and thus form a new individual."
" You've known for a long time that the sperm may look different, but until now, it has been assumed that it is not so much matter which sperm cell it ultimately becomes that fertilizes the egg, it just gets stimulated. In this case, should the offspring be viable. About so have you thought about, but now we can show that there are large differences between the different sperm in a single ejaculate and that this affects the offspring, " says Ghazal Alavioon, researchers at the evolutionary biology centre at Uppsala university."
"Together with researchers at the University of East Anglia in the Uk she has been studying zebrafish. Among other things, shared they in several attempts a ejaculate from a hanfisk in two halves. In one half there was sperm with a longer life span, while sperm longevity in the other was shorter."
"the Sperm from the different halves were then fertilize the eggs of a honfisk."
"– First, we estimated the sperm's lifespan. Then we waited to fertilize one half, that half of the sperm in this half had died. The other half fertilized at one time, so there was a mixture of the sperm with long and short life, " says Ghazal Alavioon."
"the Offspring was then followed for two years."
"– Surprisingly enough turned out that the offspring from the sperm with longer life was much more viable. There were more individuals, they aged more slowly and lived longer, " says Ghazal Alavioon."
"There is a difference between sperm and spermatozoa, but why some sperm is better than other researchers would not know."
"– we must try to find out now. Obviously there is something in these sperm which results in a more viable offspring, but what this is we know very little about."
"Whether the same thing also applies to us humans, scientists don't either."
" It's not impossible and if this is also true for us humans can imagine it can be of great importance in in vitro fertilization (artificial insemination). In that case, one can think that developing methods to find the best sperm, " says Ghazal Alavioon."
"The current research presented in the journal Evolution Letters."
"the Sperm is the male germ cells and is formed inside the channels in the testes. Each day is formed about 100 million new sperm."
"Essential for a man's fertility is the number of live, healthy sperm in the semen and their mobility. The man's semen normally contains 20-250 million sperm per milliliter, with an average concentration of 65 million sperm per milliliter. Over 20 million per milliliter are considered "
"the Sperm is much smaller than the egg. In connection with the conception melts the egg and sperm merge to form a fertilized egg (zygote) then starts to divide to form a new individual."