All worldwide Mycobacterium leprae strains analyzed so far, more than 400 in total, have been found to have
essentially identical genomes, or be clonal.
The core problem in the study of the development of multicellular organisms is: Why do cells that start out with
identical genomes do different things in different environments?
«That was a big mystery because if there are two
identical genomes coming together, the end product should be the same as if the fungi had just cloned itself through asexual reproduction,» said Heitman.
The cells in our body have
almost identical genomes, but differ from each other because different genes are active (expressed) in different types of cells.
«You're able to see what happens when you reprogram cells
with identical genomes but divergent epigenomes, and figure out what is happening because of genetics, and what is happening due to other mechanisms.»
Another is how cells in a single organism take on different functions despite having
identical genomes.
Just as no two people possess the same genetic makeup, a recent study has shown that no two single tumor cells in breast cancer patients have
an identical genome.
But the analysis of marbled crayfish DNA from across Europe and Africa, he says,» shows that all these crayfish are clones — with
identical genomes the world over.»
But the fascinating finding was that the sets of identical twins — with
identical genomes — reported the same exact levels of fidelity, while fraternal twins and regular siblings didn't.
In the case of chimpanzees (Pan troglodytes), our evolutionary siblings (99 %
identical genome), fruits are consumed early in the morning thereby providing fructose and other sugars needed to replenish fasting serum glucose levels.