Life begins. . .

Thanks for proving this subforum needs a moderator:)

Not that I will be in the running, but it will be cool when it gets a moderator anyway, which it certainly will, now.
Good work:)
 
As there is no moderator I WILL NOW JAM THIS SPAM SO FAR UP COOLSKILL'S NOSE THAT HE WILL LATER FIND IT'S NEGATIVE IMPRINTED ON HIS UNDERWEAR!
 
I don't really see what is wrong with the thread though. It raises a valid biological question. Does life start with the fusion of sperm and egg?
 
Who says it is a question. I believe he forgot to post the rest of his intended content and then forgot about the the thread alltogether.

This forum does need a moderator. This sort of threads are a rarity here, no moderater action is needed here, this place is civil on its very own.
 
It's a pretty good question.

I was trying to fertilise some echinoderm eggs (with echinoderm sperm mind you) the other week and even though I got the sperm to fuse with the eggs they didn't divide, presumably the chromosomes didn't hook up. I don't know, even enucleated sperm can fuse with an egg, so maybe it takes a little more.
 
Was it of the same species? I know if there are any sort of incompatability the cell kinda crashes. (like a program written in cobol if you try to run it on basic) This could be one chromasome is missing or is the wrong shape. It could be because one of the gametes was damaged during preparation or was just "bad" to begin with.

This brings up a point. Are not the egg and sperm 'alive' at least as much as the bacteria they resemble? If so, does not life begin at their formation and not when they fuse?

You are murdering millions of sperm every day and one egg every month you don't have sex so grab your wife quick.
 
Originally posted by skyederman
It's a pretty good question.

I was trying to fertilise some echinoderm eggs (with echinoderm sperm mind you) the other week and even though I got the sperm to fuse with the eggs they didn't divide, presumably the chromosomes didn't hook up. I don't know, even enucleated sperm can fuse with an egg, so maybe it takes a little more.
Click to expand...

maybe it is necessary to mature the egg or even the sperm.
 
When a sperm fuses with a egg,

Ahh lets see I’m not a developmental biologist would be nice if the one that’s actually here would sober up and actually try to reply in detail.
- the tail breaks off, this is why the sperm contributes not mitochondria to the next generation,
- The head swells and fuses with the egg nucleus
- Chromosome count is now diploid (46) over haploid (23) from each gamate.
- The cell begins to develop, specific genes are activated in specific order and rate of production, this is why cloning has so many problems.
 
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Originally posted by spuriousmonkey
maybe it is necessary to mature the egg or even the sperm.
Click to expand...

more detail

I think we matured our Patella vulgata sperm with a pH treatment, but I can't find my old master thesis. Sue me for not having a good memory.

Basically we cut open the sides of males and females, with the notification that you can't tell a male from a female before you cut them. You collect the eggs or the sperm. Then wash them in millipore filtered seawater. And I think you needed to give the sperm a pH treatment to mature them before they could fertilize the egg.

I imagine you might need to do something similar with echinoderms.

it is all described in Serras and Speksnijder, 1991. F-actin localization during trochoblast differentiation in patella vulgata embryos. Development 112, 833-845.

Fetus will send you a copy.
 
Re: When a sperm fuses with a egg,

Originally posted by Neuromancer
Ahh lets see I’m to a developmental biologist would be nice if the one that’s actually here would sober up and actually try to reply in detail.
Click to expand...
you forgot some things
for sea urchin:
- possibly first sperm attraction
- sperm contacts the jelly layer
- the acrosome reaction in which enzymes of the acrosomal process are released. They eat through the jelly.
-digestion of the layer
- binding of receptors to the vitelline envelope
- fushion of acrosomal process membrane and egg membrane.
- fast block to prevent polyspermy
- slow block

and I didn't go into detail
Originally posted by Neuromancer

- the tail breaks off, this is why the sperm contributes not mitochondria to the next generation,
- The head swells and fuses with the egg nucleus
- Chromosome count is now diploid (46) over haploid (23) from each gamate.
- The cell begins to develop, specific genes are activated in specific order and rate of production, this is why cloning has so many problems.
Click to expand...


one of the reasons not to go into details is that there are many species specific differences which would make it impossible to turn generalizations into details. obviously
 
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By the way, is it possible for an ovum to be fertilized (or at least penetrated) by multiple sperms? Just asking.....
 
there are mechanisms in place to prevent it, but god once fertilized an egg without sperm, so why not multiple sperms fertilizing a single egg.

the egg will probably die soon though. It is usually not very beneficial to have extra copies of genes and the nuclear divisions will probably go alllllll wrong.
 
yes there is a mechanism to prevent more the one sperm entering at a time, the ovum membrane hardness very quickly after a sperm enters. Sometimes it does happen and the embryo dies, sometimes it even grows into a fetus but triploid feti are horribly disfigured freaks and none have survived long after birth.
 
Originally posted by Neuromancer
yes there is a mechanism to prevent more the one sperm entering at a time, the ovum membrane hardness very quickly after a sperm enters. Sometimes it does happen and the embryo dies, sometimes it even grows into a fetus but triploid feti are horribly disfigured freaks and none have survived long after birth.
Click to expand...

I have...
 
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