A question from Cloning

[koyal]

Hello biohazard,
So, that means there is no chance for the insect egg to cross fertilize that way, even if it results in a weird organism?
Thank you and MrMistery for your valuable opinions, I will come back with new threads as and when I may have some other doubts.
Hey I forgot to add one more thing, if that Piggy experiment succeeds, that will nutralise the undue advantage that females have over males in cloning? Also it will give the females a clean exit path from labour pains and other inconveniences associated with pregnancy? Only unfortunate thing I feel is that the future human offsprings will all have a piggy mother in the present sense, but may not matter so long as it is the order of the day !!

Regards,
Koyal

[biohazard]

Well, I hadn't thought quite that far: having pigs as surrogate mothers. But who knows, it might even be possible in some odd future scenario :P

[koyal]

Hello,
In the early attempts of cloning, it was reported that an attempt to clone a frog using a frog's cell nucleus did not progress beyond the stage of tadpole. Does it mean that the code required to switch the development from tadpole to frog is not present in the nucleus of a frog's standard cell? Any idea in which cell part that info is available?

Also if the same cloning technique is applied to a butterfly does it mean that the cloned product will not proceed beyond larval stage?

Regards,
Koyal

[MrMistery]

to the first one: no, i think the epigenetics was what stopped the researchers there.

to the second one: you can't really make a prediction until you try it, but i would think not, since i presume metamorphosis has different genetic backgrounds in the two very distantly related organisms. Or it might stall at the same stage but not because of the same reasons.

[koyal]

Hi,
Thank you MrMistery for the clarifications. However, I have still some doubts regarding the first part of the answer.When you mentioned Epigenetics, do you mean environmental factors or some other known factors, can you kindly elaborate?
Do you mean Metamorhosis is controlled by factors beyond DNA sequence? If so, any further development of even a successfully cloned emryo, such as development of teeth,brain, development during puberty and mental development etc., ( which may not be stricly metamorhosis) may also get affected?

What I had in mind was cloning assumes :

(Sperm cell + Egg's nucleus) + Bioreaction of nucleus fusion = Nucleus of a standard cell

Since a naturally fertilized frog cell is able to go successfully through the process of metamorhosis, don't you think there could be something wrong in the above assumption.
Also what about the Age factor of the nucleus of a standard cell, which might have gone through a number of divisions in its life time, where as the Sperm cell and Egg cells are specialised cells freshly manufactured in the Nature's lab.

Regards,
Koyal

[koyal]

Hi,
Please clarify, I have one more doubt:
What is the minimum matching criteria between the nuclei of two species for interspecies reproduction ? To elaborate further, how much are the cell nuclei of a horse and a donkey matching as mules are naturally cross produced between them?

Regards,
Koyal

[MrMistery]

well I don't think an answer to your question can exist, as I doubt there is an actual way in which you can quantify the degree of similarity between two nuclei. if there is, I don't know what it is.

[koyal]

Hi,
Well, MrMistery,first of all thank you for your reply.I was under the impression that an organism is entirely defined by the number of chromosomes in the nucleus and the DNA sequence and biologically that is what is preventing interspecies reproduction. But in the case of a horse having 64 chromosomes and a Donkey having 62 chromosomes, still cross reproduction is possible though most of the mules are sterile. I wanted to know is there any criteria interms of allowable mismach of chromosomes that defines possibility of successful interspecies reproduction.
Also, I assume that for any organism,it should be possible to have interspecies reproduction with its immediate cousins in the evolutionary ladder.What you experts think of this assumption?

Regards,
Koyal

[MrMistery]

well, yes, but numbers of chromosomes are not a very indicative thing, what genes are different is a much more important aspect. chromosomes can fuse/break apart, so two organisms could theoretically have very similar genes but a very different number of chromosomes. I know in my general biology days I read about some rodents in which (in the same species) in which different organisms have different numbers of chromosomes due to these robertsonian translocation mechanisms.

And please, remember something else: we define a species by the virtue of the fact that organisms inside the species can breed with one another but not with other organisms. When you are talking about interspecies reproduction this is the exception, not the rule.

Also note that there are many barriers to this kind of reproduction, pre- and post-zygotic. For example, it is possible that bindin-like proteins on the sperm of one organism do not match the receptors on the egg of another, so the sperm cannot get inside the egg

[jeenpeek]

I have a question about cloning a construct with multiple stop codons on my insert. I am trying to clone this in a GFP vector and my insert has more than 1 stop codon and also the stop codon is less than half way through my insert. Will this make a difference in cloning into my GFP vector. And also how do I do in frame cloning? I am beginner. Please help.

[JackBean]

If you have there several STOP codons, you won't get whole protein, it will be terminated.
I just don't understand, why are you cloning sequence with SEVERAL stop codons? What is that sequence?

[zami'87.]

@JackBean
hm..maybe if you insert (gene for) mutated tRNA that can recognize stop codon? It will compete with release factor of course but anyway you would get a product...one can also use mutated tRNA to change reading frame...