How come we have five antigen by rh with only two genes?

Debate and discussion of any biological questions not pertaining to a particular topic.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
north3rner
Garter
Garter
Posts: 3
Joined: Sun Oct 25, 2015 8:26 am

How come we have five antigen by rh with only two genes?

Post by north3rner » Tue Nov 10, 2015 4:03 pm

I don't grasp the Rh blood group system. Scanned textbook below.

50 antigens, lots of combinations (alleles), two genes. Five we care about especially: D, C, c, E, e. "D" defines Rh positive or negative.
Fine.

But then textbook says:
Because the Rh alleles are inherited in groups of paired antigens, and each person has two chromosomes for the Rh antigens, each person has a total of five Rh antigens


Why five antigens ? With two genes and assuming both codominant that would make max four not five.
And what of two chromosomes? Each gene carried on separate chromosomes ?
I read somewhere all of it is carried on chromosome 1.


Image

Post Reply

Who is online

Users browsing this forum: No registered users and 24 guests