Questions regarding neuralation/gastrulation

[sven222]

Hey guys,

I have a few questions, if you can help me out it would be great. First year bio by the way, so don't get too complex on me. I'm a chemistry major, so excuse my ignorance when it comes to anything biological.

During neuralation, the verterbrate nerve cord is a tube whereas in inverterbrates it is a rod. Why exactly is this?

Also, How do the cells of the dorsal blastopore lip know in which direction to go when they invaginate?

Any help would be great guys :)

 

[Another God]

hmmm...Way over my head. Way too macro for me

If no one gets back to you, i'll try my biology textbook andsee what I can come up with, but until then, I'll leave this to someone else.

 

[sven222]

Originally posted by Another God
hmmm...Way over my head. Way too macro for me

If no one gets back to you, i'll try my biology textbook andsee what I can come up with, but until then, I'll leave this to someone else.

Thanks, I know exactly what you mean. I much prefer dealing with things on a smaller scale :D

Any help would be much appreciated.

 

[Monique]

Hi Sven! I

Originally posted by sven222
During neuralation, the verterbrate nerve cord is a tube whereas in inverterbrates it is a rod. Why exactly is this?

I didn't know it was a rod in invertebrates.. it must be a different mechanism that forms then. In vertebrates the neural tube forms by the the action of nochord cells which are present along the the central body axis. These cells express Brachyury (Greek for short-tail, the mutant), the mesoderm on top will start to thicken, rolls up into a tube and pinches off from the rest of the cell sheet, thus creating the neural tube.

This notochord is not present in invertebrates.

Also, How do the cells of the dorsal blastopore lip know in which direction to go when they invaginate?

Well, each part of the blastopore is chemically defined, different genes are expressed at posterior, anterior, terminal or dorsoventral sides. This gradient of chemical signals will tell the cell how to grow.

 

[iansmith]

Originally posted by sven222
During neuralation, the verterbrate nerve cord is a tube whereas in inverterbrates it is a rod. Why exactly is this?

It due to their anatomy. Vertebrate and invertebrates are dissimilar to great extend due to their evolution parttern. In invertebrate, the major nerve are on the ventral (are ventral ectoderm) and not vertebrae are around the nerve whereas in vertebrate the major nerves on dorsal (derived from dorsal ectoderm) and surrounded by vertenbrae

Also what does to the invertebrate rod becomes versus the nervous tube of invertebrate.

 

[sven222]

Thanks guys :)