Basic Genetic Inheritance
By Bryan Chin (Pacific American Singers chapter)

First published in the American Singer Club newsletter, April 1997.

The American Singer Canary is a wonderful genetic combination of the Roller and Border Canary. By combining these two types of canaries we are constantly rearranging this gene pool by discarding the genetics we do not want and inserting genes we desire. Easier said than done, as we know and have experienced. By understanding basic genetic inheritance we can have a logical strategy for creating your ideal American Singer. I also plan to write a series of articles on breeding techniques referring to genetic terms so I hope that this will create a good base for you. This will only be the basic concepts without the exceptions and details.

Canaries have 42 chromosomes or 21 chromosomes pairs. These chromosomes carry the genetic code that effects everything about the canary including song. Chromosome pairs are like parallel lines that are spiraled. Let's look at one that is straightened out to show you the components.

[ Chromosome Pair ]

As you can see I have labeled the genes by letters. The capital letters and small letters of same type (i.e. A and a), represent a gene but with different traits. For example 'A' could represent a dominant trait that promotes the Chop phrase (more open beak phrases) where the 'a' trait represents a recessive trait that promotes Roll phrases (more closed beak phrases). The gene pair 'Aa' will show the trait of 'A' only since 'a' is recessive. You would have to have the gene pair 'aa' in a canary to have Roll phrases. I would like to emphasize there are dominant traits that are beneficial too. Not all recessive genes are desirable, for example hidden physical defects that pop up now and then are often recessive traits. There are also situations where either gene is dominant creating co-dominance, the results are intermediate result. One example of co-dominance is when a high range canary is crossed with a low range canary and you get a greater range than both, but not the highest or lowest notes of the respective parent.

So our endeavor is to pursue the American Singer that carries the traits we desire. So how is this done if we could see and identify each of the genes we want? Let's look at another example that shows us 3 genes pairs located on 3 different chromosome pairs. For explanation purposes only, let's assume the following (Please be aware that a canary has a total of 21 pairs of chromosomes!):

Gene 'A' is for open beak phrase (Dominant)
Gene 'a' is for closed beak phrase(Recessive)

Gene 'B' is for high notes (Co-dominant w/b)
Gene 'b' is for low notes (Co-dominant w/B)

Gene 'C' is for long song (Dominant)
Gene 'c' is for short song (Recessive)

Gene 'x' is for other traits

[ 3 Pairs ]

Eggs from the female will only contain half of the chromosomes so it can be joined with half of the chromosomes from the sperm of the male, giving the complete 42 chromosome to create a canary. When the eggs are formed and ready for fertilization, each egg will randomly pull one chromosome from each chromosome pair. The same will happen when sperm is generated. The random possibilities are:

[ Random Gene Combos ]

If the male had this same genetic make up his sperm would have the same random possibilities. If a male and female mated with the same genetic makeup (this is rare) as stated above what would be the odds of genetic combination of aaBcCc or aaBcCC? Both of these combination would give us closed beak phrases, wide voice range (since co-dominant), and long song. Let us look at how the odds are worked out by the following table.

Genetic code
Egg >
Sperm
ABC
 
AbC
 
ABc
 
Abc
 
aBC
 
aBc
 
abC
 
abc
 
ABC

AABBCC

AABbCC

AABBCc

AABbCc

AaBBCC

AaBBCc

AaBbCC

AaBbCc

AbC

AABbCC

AAbbCC

AABbCc

AAbbCc

AaBbCC

AaBbCc

AabbCC

AabbCc

ABc

AABBCc

AABbCc

AABBcc

AABbcc

AaBBCc

AaBBcc

AaBbCc

AaBbcc

Abc

AABbCc

AAbbCc

AABbcc

AAbbcc

AaBbCc

AaBbcc

AabbCc

Aabbcc

aBC

AaBBCC

AaBbCC

AaBBCc

AaBbCc

aaBBCC

aaBBCc

aaBbCC

aaBbCc

aBc

AaBBCc

AaBbCc

AaBBcc

AaBbcc

aaBBCc

aaBBcc

aaBbCc

aaBbcc

abC

AaBbCC

AabbCC

AaBbCc

AabbCc

aaBbCC

aaBbCc

aabbCC

aabbCc

abc

AaBbCc

AabbCc

AaBbcc

Aabbcc

aaBbCc

aaBbcc

aabbCc

aabbcc

The odds for aaBbCc is 4-to-64 or 1-to-16
The odds for aaBbCC is 2-to-64 or 1-to-32

Overall odds to get the results is the addition of both which is 6-to-64 or 3-to-32.

If we where looking for all recessive traits, aabbcc, the odds would be 1-to-64 odds.

By understanding genetics we can understand how to improve our American Singers. The first step is to understand in your strain what is recessive, dominant, and co-dominant. This can be done by pure observation. If one of your best Singers is cross with a female and certain good traits are lost in the babies you know that those traits are probably recessive. You will also understand that those babies carry your best Singer's genetics and can be recovered.

One real example in when is my line of birds they had very little freedom of song. I was able to purchase a male with excellent freedom and crossed with several females of mine. The results were great, all of my birds showed improved freedom. The freedom ranged from excellent to moderate freedom. This showed me that the male I used had a dominant genes for freedom for some of my birds and co-dominance for the others.

Copyright © 1997 Bryan Chin. All rights reserved.

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