The Biosphere

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6:24 AM

@TanMath I think people might comment on interesting papers, or biological/scientific concepts. I think that's not necessarily a bad thing - there is no point in pushing for mandatory chat when we could be discussing things we want to talk about. For me biology discussion could be for discussing something like this: goo.gl/LjrPdv rather than how to force people to chat more.

AMR

6:49 AM

Has shovel, keeps digging. People stay away from chat because there are a hundred threads to go through about complaining about how no one is chatting before you can get to a post that might be even remotely related to Biology. All the attention seeking pushes the posts with legitimate chat topics off the board so that no one else can see them.

7 hours later…

Resonating

2:16 PM

@GoodGravy Oh man, that's amazing! She's a neuropsychologist. Be the change you want to see in the world, I guess

5 hours later…

TanMath

7:18 PM

@GoodGravy I am not forcing people, I am encouraging people to chat more

Resonating

@TanMath Like 30% of the things you say are about how much people don't talk eough. Nobody wants to talk about how much people don't talk enough, it's super boring.

If you want to talk about CRISPR-CAS systems or the evolution of the archaea I'd love to

Eocyte hypothesis

The Eocyte hypothesis is a biological classification that indicates eukaryotes evolved from the prokaryotic Crenarchaeota (formerly known as eocytes), a phylum within the archaea. This hypothesis was originally proposed by James A. Lake and colleagues in 1984 based on the discovery that the shapes of ribosomes in the Crenarchaeota and eukaryotes are more similar to each other than to either bacteria or the second major kingdom of archaea, the Euryarchaeota. The eocyte hypothesis gained considerable attention after its introduction due to the interest in determining the origin of the eukaryotic...

This is kind of interesting but I don't buy it, mostly for emotional reasons but partly because it doesn't fit the observed gene distribution patterns as well as a HGT hypothesis

MattDMo

7:59 PM

@canadianer so anyways, I almost always run reducing gels, so adding DTT and boiling are pretty much a standard procedure for me.

canadianer

8:23 PM

@MattDMo At the time I did this, I was running combinations of reducing or non-reducing and native or SDS. I remember not boiling a sample of pure streptavidin just to see what its stability was like. Almost all of it ran as the tetramer (at least I assume that's what it was) with only a small proportion appearing monomeric/denatured. Thinking harder, there was probably BME in the loading buffer, though SAV doesn't naturally have any disulfide bonds.

TanMath

8:41 PM

@Resonating OK.. Let's talk about crispr!

Resonating

8:57 PM

@TanMath CRISPR is totally rad. There's an igem team trying to build a crispr array that deterministically lays down dna segments like breadcrumbs

but it kind of sucks and doesn't work right, so who cares

but it coudl theoretically work, you just need a crispr target and homologous patch that recreates the target + a tracer

TanMath

@Resonating explain crispr.. I forgot how it works

Resonating

CRISPR relies on these guide RNAs that bind crispr

TanMath

That is soooo descriptive!

Resonating

so half the RNA binds crispr, the other half binds dna somewhere in the chromosome, bringing crispr alogn with it. If the guide RNA finds a sequence that binds the RNA strand + NGG it cuts it in half

which is why the guide RNAS don't get cut up by CRISPR on the host genome

it's adaptive immunity for prokaryotes. Viral DNA gets hacked up and put between these spacers which stop CRISPR from murderign the library, but the library can then target viruses

Humans put in guide RNA that bind elsewhere on the chromosome and little bits of dsDNA for homologous repair so we can patch whatever we want into the chromosome

TanMath

@Resonating but from some pictures it seems that crispr only cuts out DNA

Resonating

9:08 PM

@TanMath what? I mean, that's a really weird way to phrase it

It cuts any DNA

anywhere*

TanMath

@Resonating but it can't put in. DNA

Resonating

*3 nt upstream of NGG. Results not typical.

Yeah, so you put in a homologous repair template