College of Cat Genetics: Seminar 1
by Patricia Turner
Answer: The expressions Champion's blood and diluting out
are based upon misconceptions because they date from the times when it
was believed that characteristics were inherited in the blood and were
blended. There is no such thing as blended inheritance and this was
demonstrated by Gregor Mendel in his classic work with garden peas.
Some genes have very small effects and only change the characteristics
of a cat when they are added to many other small genes. This can
give the impression of blended inheritance. The characteristics of
a kitten are inherited in the gametes or sex cells.
Answer: The instructions governing the nature of the chemical
ingredients from which the cat is made and the nature of
the chemical changes in its body during its life are carried in the nucleus
of the cells by chromosomes inheirted from the parents.
Answer: The use of the symbol y
(once used to denote the sex-linked colour gene producing red) has been
discontinued because there was so often confusion between it and the Y
symbol for the Y sex chromosome and
as the colour gene concerned is not recessive in inheritance the use of
a lower case letter was not ideal. The symbol O
was proposed to replace it and is now in use in all formal genetic texts.
The name of the colour gene is now orange and not yellow.
Answer: The gene symbolized Pd is inherited as a dominant and the information on its dominance is given by the use of a capital letter symbol (capital letters describe dominant genes and lower case letters describe recessives).