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Please Need Help !!!!
I have used matK, rbcL and rpoC1 for my model plant (total 7 populations A-G collected from different places of Mexico, 6 samples for each population have been investigated). These 7 populations are a mixture of 4 different species of commun gender according to a recent taxonomic study.
Now results are here-
mat K shows all 7 populations have 100% identical sequences.
rbcL shows all populations have 100% identical sequences (but there is a single SNPs in one of the six samples of a population C).
rpoC1 shows 4 populations have 100% Identical sequences. Population C have 4 SNPs and other 2 populations A and B have 2 SNPs ( sharing same changes). (Wooo, What is this?)
So as a beginner in DNA barcoding, I am bit confused about these results.
Now my questions is,
What will be the conclusion?
According to matK and rbcL there is no genetic difference between all 4 species but rpoC1 reprsents few variation which i dont understand.
All comments are welcome !!!!! Please!!!!!!!
Ashutosh
Views: 9
Replies to This Discussion
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Permalink Reply by Camiel Doorenweerd on -
Dear Ashutosh,
I'm afraid your research questions and research methods don't quite match. There is the field of population genetics, there is DNA Barcoding, and there is taxonomy. Your sampling was for a population study, the methods you used are for DNA Barcoding, and the conclusions you are trying to draw are for taxonomy.
First off, the variation of the markers in question differs between different groups. It is therefore pretty much impossible to put a treshold on the amount of variation before you can call it a different species (they tried though, in the early days of barcoding). DNA barcoding is meant to distinguish species and to aid in describing them. If you want to do a taxonomic study and erect new species, you should read into the field of taxonomy more, because those guys have lots of rules before you can call something a new species. If you wanted to use DNA Barcoding to see if you can distinguish between the populations, then you have your answer already; apparantly for some populations you can, and for some you cannot.
The level at which species are named and at which populations are named is more or less arbitrary and dependant on the taxonomists working on it, but DNA Barcoding is mainly meant to distinguish species, not populations. That's the basis on which the markers were chosen.
Hope this helps you,
Camiel
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Permalink Reply by Ashutosh sharma on -
Dear Camiel,
Thanks for your beautiful answer. I m sorry for delayed response as i was out of station.
Well I should mention here that all the 7 populations of this plant are mixture of 4 different species according to a recent taxonomic study (earlier they were misinterpreted as the same species in Mexico).
Now my question is the same. I want to know more about it as matK and rbcL are 100% identical whereas rpoC1 represents some confusing changes in their nucleotide sequences. So, making a conclusion is geting difficult to me.
Thanks
Ashu
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