The Blood Group problem!!!!

Richard Norman rsnorman at
Mon Jan 15 16:54:19 EST 2001

The classical notation, using upper case for dominant and lower case for
recessive, is to use 'i' or 'i-O' for the 'O' allele (where the O is a
and 'I-A'  and 'I-B' for the 'A' and 'B' alleles (the A and B are
It is a standard example of multiple alleles.  With three alleles there are
6 different genotypes.  Since i is recessive to either of the other two,
are four phenotypes.  Every college level intro biology book has the
poop.   Richard Hall's info below describes the cellular machinery that
implements system (converts genotype to phenotype) and is usually NOT
found in the texts!

"Andrew T. Austin" <slightlynervous at> wrote in message
news:3A634E2C.30660582 at
> So, if i may translate it goes a bit like this (i might be wrong, it has
happened before):
> Parent with blood type `A` (really is `AO`) breeds with parent `B` (`BO`)
they can produce a child with groups `A` (`AO`) or `B` (`BO`) or `O` (`OO`).
> Parents with blood groups `A` (`AO`) and `O` (`OO`) can produce only child
with groups `A` (`AO`) or `O` (`OO`).
> Parents with groups `B` (`BO`) and `O` (`OO`) can only produce a child
with either `B` (`BO`) or `O` (`BO`).
> Parents with groups `AB` and `AB` will produce either a child with `A`
(`AA`) or `B` (`BB`) or `AB`.
> Parents with groups `O` (`OO`) and `O` (`OO`) will only produce a child
with groups `O` (`OO`)
> Parents with groups `AB` and `A` (AO) will produce........
> And so on.
> Regards,
> Andrew "tries to remember biology class" Austin.
> "Richard L. Hall" wrote:
> > Good Morning,
> >
> > Wrong! Everybody has the "O-gene."
> >
> > Genes are expressed as polypeptides or proteins. The A and B antigens
are NOT proteins but rather glycolipids found on the membranes of most human
cells. The proteins produced by "A and B genes" are enzymes that catalyze
the addition of specific sugars (either N-acetylgalactosamine or
D-galactose) to a glycolipid consisting of L-fucose: D-galactose:
N-acetylglucosamine: D-galactose: N-acetylgalactosamine:lipid. The five
sugar glycolipid is sometimes called the 'H-antigen" although it is actually
non-antigenic. The A or B antigens are formed by the addition of either
N-acetylgalactosamine or D-galactose to the H-antigen.
> >
> > The so called "O gene" produces the glycosylating enzyme (or enzymes)
producing the "H-antigen." There are "A-genes, B-genes, and "O genes" as
well as an A-antigen, a B-antigen, and a "H-antigen" and they are apparently
inherited in a Mendelian fashion.
> >
> > rlh
> >
> >      In human blood groups the AB blood type has a gene for type A blood
> >      from one parent and a gene B inherited by the other parent, so you
see there
> >      are no O genes in blood group AB therefore a baby with blood type O
can not
> >      form.....
> >
> >      Prof.
> >
> > Richard L. Hall, Ph.D.
> > Comparative Animal Physiologist
> >
> > University of the Virgin Islands
> > 2 John Brewers Bay
> > St. Thomas, U.S.V.I. 00802
> >
> > 340-693-1386
> > 340-693-1385 FAX
> >
> > rhall at
> >
> > "Live life on the edge...the view is always better" rlh

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