
American cockroaches thrive in cities thanks to their long genomes - rbanffy
http://www.sciencemag.org/news/2018/03/american-cockroaches-thrive-cities-thanks-their-incredibly-long-genomes
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jacob019
The article says that 60% of the DNA is made up of repeating sequences, but
then goes on to say that the reason American cockroaches thrive in cities is
due to their 150 scent receptors and 500 taste receptors. I'm don't see the
connection.

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moh_maya
Just based off the press release, and speculating a bit (note: this isn't
implied in the article; this is my attempt to link up the long genome /
repetitive elements and number of receptors)

Repetitive DNA can allow for increased frequency of DNA recombination;
depending on a host of factors (including the relative location of the
repetitive elements and the receptor genes, etc) this may facilitate
generation of new gene variants for the receptors, increasing the receptor
diversity, while preserving / retaining the parent genes.

Again, this is very simplistic speculative attempt to join the two dots.

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jobigoud
Which organism has the most complex genome on Earth? Let's say by defining a
complexity metric as the size of the compressed data or something.

And which organism has the biggest genome in terms of number of genes?

Is there a list of organisms ranked by genome complexity or size? And where
does Homo Sapiens fit on this list?

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RosanaAnaDana
I doubt that is going to work they way you think it will. DNA is not the same
as digital data in that its final use state is 3 dimensional, not 1d like a
tape (or digital file) or 2d like a raster or some other matrix. As well, this
3d form isn't fixed. So redundant sequences can have very different expression
and conformal changes despite being 'digitally' identical.

This is further complicated by some weird fricken shit, like in theses
cockroaches. Top of my head and can't remember the species or exact number,
but I remember some species of fern having between 100-1000 duplicate copies
of its genome in each cell. Pteridium I think? Any ways. It was bonkers.

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fastaguy88
The headline for this article is extremely misleading. Genome size has almost
nothing to do with the environmental adaptations -- the American cockroach has
about the same number of protein coding genes as the German cockroach and
termites. The extra DNA is in the introns.

The American cockroach does have additional odorant and taste receptors, but
those additional genes have very little effect on the genome size, because
only a small fraction of the genome (<2%) codes for protein.

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marojejian
I see no support for the title in the article. On the other hand, there is
evidence to suggest smaller genomes have been an asset to flowering plants:

[https://www.quantamagazine.org/with-downsized-dna-
flowering-...](https://www.quantamagazine.org/with-downsized-dna-flowering-
plants-took-over-the-world-20180111/)

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Symmetry
I suppose cockroaches are under enough selective pressure, in terms of the
ratio of individuals born to those who become parents, that they can maintain
a large genome despite presumably high mutation rates.

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wufufufu
Still a terrible name for a database

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robbyt
At least it's memorable!

