muchado

Hypothetically there should be 61 types of tRNA. However, to this date reports from various eukaryotic organisms suggest there are far less then 61 types of tRNA. The reason behind that is the ability to wobble base pair and the presence of modified bases. Wobble base pairing means that one of the three bases in a given codon does not have to follow watson-crick base pairing rule. We also have non-conventional base like inosine that can base pair with A, U, or C. So how many you ask? Most people will just say >20 to stay on the safe side:)

Here is another source... http://www.wehi.edu.au/education/wehi-tv/dna/index.html You will find neat animations here on replications, transcription, and translation. There is one animation of the cell that is completely mind blowing. I think this is the best animation I have seen to this date. Makes you just fall in love. This is totally perfect to show in introductory classes in college and in high school. http://aimediaserver.com/studiodaily/harvard/harvard.swf Hope you enjoy it. Thanks to the harvard folks who conceived it.

Hi everyone! I love to think/discuss science which is why I am here. Hmm..let's see..finished my BA in creative writing a year ago...hoping to do masters in fine arts. That's about it I guess. cheers!

You are right about the fact there are way more people 'specializing' now then ever before...but you are definitely misguided to think they are narrow minded. Many of the 'specialists' will advice people to be aware of as many thing as you can while focusing in your tiny corner...both are necessary...you can formulate much about you specialty without having broad picture... you won't have enough audience nor money(funding) if you just apply what you learn to your specialize field. I think this trend for a mix of specific and general have really evolved in the last 10 years. Now a days a biologist or geneticist does not just really on molecular/biochemical/genetics for solution then turn to mathematician...computational modeling and to do science at this level you really need broad picture as well as information about little stuff.

Our experience shapes our identity and how we react..this is specially true in context to how we relate/connect to a piece of literature...for me Virginia Woolf's Mrs Dalloway and Joyce' Portrait of a Young Man as artist are two of the best examples of Stream-of-cons. About HP...it is a piece of literary work...how good? only time will answer that question...but i don't believe it will go down next to ulysses or such...she imitated too many previous authors in her books in trying to establish her own style... Nonetheless, I have read each one of those books at least 5times, why? because I think its relaxing...she asks her readers to stress their imagination while still keeping feet with modern society..which is enjoyable...when I take few hours away from my work to let it loosely exercise..i find its refreshing to come back to critical thinking...but that just me These kind of works should be read by adults because they raise important question that we should think about...the fact she was and still are able to captivate a generation for 10yrs is rather amazing...we should read the text to try to understand why it has such a tremendous social impact...understanding the culture/society we live in is always important..after all those of use who loves science loves it because we are so curious about ourselves..the nature.

Hahaha.. IN GENERAL... gene cloning can be good and bad good because without gene cloning technologies we probably have a heck of time trying to figure out functions, structure, etc. bad because cloning process most definitely can introduce mutation..some will tell you that these technology can turn people into Dr. frankenstein who will try to create some sort of superhero:)...all these can certainly raise ethical debates...in respect to economical implication...may be money for technological advancement....environment...hmm..well cloning can involve use of bacterial organisms..which will need to properly disposed off..if mutation are introduced during the process you don't that to be exposed to environment either...etc etc.

Oh, the examples are plentiful...like the Ku proteins that have role in DSB and telomere biology. ...But I was looking to read about the subject from a historical prospective....there is plenty of stuff available on Garrod's one gene one enzyme hypothesis but not how it evolved since then. The earliest solid evidence I can find in eukaryote is ilv1 gene which encodes thereonine deaminase (from 1974). Anyways, thanks for your suggestion.

I was going to suggest something along this line..random primer extension...its sounds like the most simple approach. There is a paper from David Bartel's lab in MIT ...check their protocols...here is the reference for the paper...Science vol 294 no. 5543..oct 26 2001 pg. 858-862. There lab web site once had this protocol for cloning miRNA..http://web.wi.mit.edu/bartel/pub/protocols/miRNAcloning.pdf might give you some idea. Cheers!

Interesting discussion...it is really important to be open minded when talking about actual cause of cancer....many in the field will tell you that telomere dysfunction (i.e. shortening, missing proteins in the 'cap'), which leads to end-to-end fusion of chormosome and self perpetuating bridge-fusion-break cycles, is the main cause of cancer and genome instability. Since these events lead to amplification, deletion, and addition of different parts in the genome. As for the original question..turning back telomerase will not give you immortality. As Prewitt pointed out before, telomerase is selectively turned off in our cells. This feedback mechanism is extremely important for tumorgenesis..while telomerase must be turned on to develop tumor, it must be turned off before a tumor can take its mature form. There are plentiful of literatures supporting this. Ask for reference if you are interested. Cheers!

I think those papers (two in Nature by Yamanaka's and Jaenisch's groups and a third in first edition of Cell Stem Cell by Hochedlinger's group) were totally mind blowing. Nonetheless, there seem to be alot of obstacles that we have to overcome specially tumor formation after transplantation.

First of all thanks for asking a critical question. It is really important for us to think about such issues given the rapid pace at which science is advancing. The will probably become reality more quickly than we think. Having said that, I agree with SkepticLance that current understanding and technologies are mostly at its infancy, so we have a long way to go before we can apply them to human. Is germline gene therapy technically easier to do somatic gene therapy? I don't know enough about this topic to comment but I do want to point out three studies that just came out in Nature (very highly accredited scientific journal) showing that somatic cells can be reengineered into embryonic stem cells by controlling expression of four transciption factors. Three separate groups came to the same conclusion showing that re-engineered 'stem cells' have the potential to transmit germline, fully contribute to development, and differentiate into numerous types of cells in culture. Yes, this needs to be studied further but these studies definitely show that one day it might be possible to take cells from a patient, culture and engineered them in vitro, and transplant them back into organs (i.e. liver, heart) that are damage. I think if this technology is successfully establish we can put behind numerous ethical debate about use of germline/embryo in treatment. If you are interested in reading/glancing at the articles they are in July 19th edition of Nature. cheers!

One gene can generate products that are involved in multiple distinct processes/pathways. Examples of this are plentiful. I was wondering if someone with experties on the area can direct me to literature source where I can find 1. the first example of a single gene/protein with multiple function 2. How such phenomenon complicate how we use genetics to decipher function of a gene. Thanks!! Muchado