Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: thedoc on 02/06/2016 22:50:01
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David Williams asked the Naked Scientists:
Does the caterpillar and it's butterfly and it's egg have the same DNA formulation?
What do you think?
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Does the caterpillar and it's butterfly and it's egg have the same DNA formulation?
I would say "yes", if you put the three stages in a slightly different sequence: egg, caterpillar and butterfly*.
The DNA stores the instructions for all stages of the butterfly's life.
But different genes in the DNA are expressed at different stages of the butterfly's life, and these active genes then activate the next (currently inactive) genes.
There are various ways that genes can be activated and deactivated, via the action of regulatory genes.
https://en.wikipedia.org/wiki/Regulation_of_gene_expression
* The reason I reordered the lifecycle phases is that the eggs laid by a butterfly do have different DNA than either the mother or father butterfly.
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All three phases of the butterfly, have the same DNA. However, each phase, will use a different combinations of genes.
Picture the DNA as a Rubik's Cube. You always have the same cube, with the same number of color facets. By rotating the sides, one can come up with a bunch of color combinations. In the case of the butterfly, the sequence of steps from eggs to butterfly reflects a path for rotating the sides of the cube. This is done by following a potential gradient.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fthecube.guru%2Fwp-content%2Fuploads%2Frubiks-cube-step1-1.jpg&hash=d098bd30fba8db5a9eecbd79841d4d35)
Most of the DNA is called junk genes. These are not junk, but rather is part of the mechanism that defines the mechanism of the DNA Rubik's cube and how it is able to move between specific states, that allow the exposed coding genes to coordinate.