The Blood Group problem!!!!

Richard L. Hall rhall at webmail.uvi.edu
Mon Jan 15 18:03:14 EST 2001


Hi Richard,

Thanks for noticing.  I sometimes wonder why general texts avoid 
exploring this topic in depth...it is such a nifty way to introduce 
all sorts of  concepts in cellular and molecular function.  Then 
again, the race to cover everything is akin to preferring thin ice to 
spaced, large chunks of thick ice.  Which situation do you think has 
the greater probability of getting you safely across the knowledge 
pond ?

Then again, I am an island guy.

rlh


>Richard Normal wrote:
>
>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
>superscript), and 'I-A'  and 'I-B' for the 'A' and 'B' alleles (the 
>A and B are
>superscripts).
>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,
>there are four phenotypes.  Every college level intro biology book has the
>complete 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 NOSPAMbtinternet.com> wrote in message
news:3A634E2C.30660582 at NOSPAMbtinternet.com...
>  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
>  >
>  > >Prof. writes:
>  > >
>  > > In human blood groups the AB blood type has a gene for type A blood
>  > > inherited 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 uvi.edu

"Live life on the edge...the view is always better"  rlh


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