Question: how long does it take to recreate all the genomes

Scottish Wildcat answered on 21 Nov 2017:

Imagine that you have 30 copies of a book with hundreds of pages in each and you rip out all the pages, then shred them in a cross-cut shredder to produce tiny strips of paper on which you can just about read a few of the letters: Now, you have to ‘assemble’ all the pieces into the strips they came from, then all the strips into the pages, then all the pages into the books and check that each book is the same as all the others without making any mistakes!

This, as you might expect, is a difficult task especially if you don’t have a copy of the original book to refer to or a very similar book that has some of the same pages. The task of recreating the DNA sequence of a genome is similar, but many times more difficult, and requires the use of powerful computers to do the job. It can take a few hours or days to assemble a genome depending on the quality of the DNA reads and their length, and the speed and memory size of the computers used.

That is just the beginning of the task!

Now, you have to discover where all the genes are and what they do – This process is called genome annotation (literally adding notes) and it is very helpful to be able to refer to the annotations of genomes from other species when the DNA sequence of particular genes is the same or similar enough to guess that the gene-product does the same job. HUGELY powerful computers are needed to predict the shape of molecules coded by the DNA and translated into RNA and proteins. Quite similar DNA sequences can produce very differently shaped products!