发信人: biz (古怪), 信区: Biology
标 题: Re: questions about the latest version of human genome
发信站: The unknown SPACE (Thu Feb 15 13:34:31 2001), 站内信件


【 在 bigbans (smile) 的大作中提到: 】
: 1.one gene can direct the synthesis of many proteins?
yes/no.

a gene directs the synthesis of one polypeptide. a protein may
contain more than two different polypeptides and require more
than two genes.

in some cases a gene may contain more than two introns (inter-
rupted sequences) and exon (expressed sequences). an RNA
transcribed from such a gene may undergo splicing, that is, the
re-combination of introns and exons, resulting several mRNAs from
one single gene. these mRNAs may then be translated into a group
of proteins. usually such proteins are structurally and functionally
similar.

: 2.Based on a combination of computer data and human
: analysis, there is some evidence that the genome may contain
: another 12,731 or so genes, but it is too early to know for
: sure.----from Celera site.
: What does this mean?We didn't discover the complete
: human genome?

we have finished the sequencing of human genome. namely, we now
know the complete(?) nucleotide pair sequences of human genome (
or more exactly genome of those people whose DNAs were used in
the human genome project.) what we don't completely yet know:
variations of nucleotides at billions of loci within genome, what
fragments of the human genome have what functions. for a comparison,
you have decoded a secret telegram and had all the numbers, and
you have found out that some combinations of numbers stand for
certain words, yet you still have quite a lot of numbers you don't
know how to combine them and what words the possible combinations
may stand for.

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※ 来源:．The unknown SPACE bbs.mit.edu．[FROM: 128.104.69.146]