Dominant gene traits

Ezekial mic2mcb at gps0.leeds.ac.uk
Tue Mar 22 09:28:26 EST 1994


Karla L. Nohalty (nohalty at newsserver.read.tasc.com) wrote:
: Hi, this is a general question that came up between myself and some
: friends.  I would appreciate any e-mail (to klnohalty at tasc.com) that
: can shed some light on the subject.

: A friend of ours has brown eyes, but she has to light (blue and green
: I think) eyed parents.  From what I remember of my bio, the light colored
: eyes are a product of a recessive gene trait. So, when to recessive genes
: are crossed with two other recessive genes, all combinations come out
: recessive (or so we thought!)  Are there some cases when a dominant
: gene (i.e., brown eyes) may be present in an individual, yet not assert
: itself?

: Thanks in advance!


As I understand it a dominant gene is by definition one that will always be
expressed. However animal genetics is seldom simple enough to be described
in terms as simple as dominant or recessive. Several genes may influence a
trait (and I honestly don't know if this is true of human eye colour) or
two alleles of the same gene may BOTH affect the trait. This is called
co-dominance.

Hope this is some help,
Matt



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