🚀 go-pugleaf

Fragemann wrote:
> Hello,
>
> I have a few questions for people.
>
> 1. What is the current estimate for how many genes does the human
> genome have?
>


It keeps dropping. Recent estimates suggest as few as 25,000 genes:

<http://www.ornl.gov/sci/techresources/Human_Genome/faq/genenumber.shtml>


> 2. What is the current estimate for how many base pairs does the human
> genome have?
>

Almost 3 billion base pairs.

<http://www.ornl.gov/sci/techresources/Human_Genome/faq/compgen.shtml#genomesize>

This estimate is reasonably accurate and has not changed much in
awhile.

> 3. I was told that the more introns that you have, the greater your
> lifespan. But if all genes are at fixed loci, how can one human have
> more introns than another? It seems to me that loci positions would
> restrict intron length.


I'm afraid I don't follow the reasoning on this one.


Nick


--
Nick Theodorakis
nick_theodorakis@hotmail.com
contact form:
http://theodorakis.net/contact.html

On Tue, 12 Dec 2006, Fragemann wrote:

> 3. I was told that the more introns that you have, the greater your 
> lifespan. But if all genes are at fixed loci, how can one human have 
> more introns than another? It seems to me that loci positions would 
> restrict intron length.

Everyone has the same number of introns; every allele of a gene has the 
same pattern of introns and exons.

Well, more or less - there will be a few small mutations that interfere 
with splicing, and larger mutations that take out or duplicate entire 
genes or bits of genes, which will lead to variation, but not an awful 
lot.

Anyway, i know of no evidence for a correlation between number of introns 
and lifespan.

Unless, of course, you mean across species. Short-lived, fast-reproducing 
organisms tend to have fewer and smaller introns, since they slow down 
replication.

> 4. Lastly, in the current modern society, which person has more genetic 
> "fitness," the one who irresponsibly produces more children than they 
> can afford, or the one who has fewer because they spend their time 
> seeking a career, or because they are more responsible?

People who don't use usenet.

tom

-- 
this news group concentrate the debil of usenet -- uk.local.london motto

> 3. I was told that the more introns that you have, the greater your
> lifespan. But if all genes are at fixed loci, how can one human have
> more introns than another? It seems to me that loci positions would
> restrict intron length.
>

Your other questions were answered.

I think you're confusing introns with telomeres here. There's not really a 
direct connection between telomere length and lifespan, but it works like 
this:

Telomeres are repetetive sequences at the end of chromosomes. When a 
chromosome is replicated, the ends get lost, so the telomeres act as a sort 
of buffer of losable material.

When you run out of telomeres, your DNA will start missing vital stuff, 
eventually, and then you'll die from a lack of one or more vital proteins. 
This is a problem with animal clones. The cloned DNA has whatever telomere 
length the parent had, whereas an ovum fertilized from a sperm gets its own 
brand new set of telomeres.

I don't think this is a normal cause of death in people. I think organs 
usually give out, or disease develops, before your run out of telomeres, but 
I could be wrong.