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Cornsnake Morph Guide ® | Advanced Genetics | Charles Pritzel |
If we use a small z to show the sex chromosome carrying a recessive mutant, the expected results are shown in Figure 3.
Parents |
Cross being performed |
Mutant offspring |
Normal male Normal female |
ZZ x ZW ZZ, ZW |
None |
Normal male Mutant female |
ZZ x zW Zz, ZW |
None |
Normal (het) male Normal female |
zZ x ZW zZ, ZZ, zW, ZW |
50% of Females |
Normal (het) male Mutant female |
zZ x zW zz, zZ, zW, ZW |
50% of Females 50% of Males |
Mutant male Normal female |
zz x ZW zZ, zW |
100% of Females |
Mutant male Mutant female |
zz x zW zz, zz, zW, zW |
All Offspring |
Figure 3 - results of breedings involving a recessive Z-linked trait. |
In figure 4 we explore the results expected from a dominant Z-linked trait. This time, the underlined z represents a dominant mutant.
Parents |
Cross being performed |
Mutant offspring |
Normal male Normal female |
ZZ x ZW ZZ, ZW |
None |
Normal male Mutant female |
ZZ x zW Zz, ZW |
100% of Males |
Mutant (het) male Normal female |
zZ x ZW zZ, ZZ, zW, ZW |
50% of Females 50% of Males |
Mutant (het) male Mutant female |
zZ x zW zz, zZ, zW, ZW |
50% of Females 100% of Males |
Mutant male Normal female |
zz x ZW zZ, zW |
All Offspring |
Mutant male Mutant female |
zz x zW zz, zz, zW, zW |
All Offspring |
Figure 4 - results of breedings involving a dominant Z-linked trait. |
If the trait is codominant, there will be three phenotypes in the males, as usual. However, since there are only two possible genotypes in the female, there would only be two phenotypes in the females.
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