I tried both the World of Ball Pythons and Morph Market genetics calculators. Both were right as far as they go, but neither broke the results down by sex and by whether the banana male was a male maker or female maker. Here is what I got.
Mating:
female ghi cinnamon x male banana (aka coral glow)
This is a three gene pair problem. Ghi, cinnamon and banana are all codominant (AKA incompletely dominant) to the corresponding normal genes. The banana mutant gene is sexlinked, but we do not know whether the banana gene is on the male's X chromosome (a female maker) or on the male's Y chromosome (a male maker). As none is a super, each gene pair with a mutant gene is assumed to have a mutant gene paired with a normal gene.
Female gene pairs:
Gene pair 1: A ghi gene and a normal gene
Gene pair 2: A cinnamon gene and a normal gene.
Gene pair 3: Two normal genes.
Male gene pairs:
Gene pair 1: Two normal genes.
Gene pair 2: Two normal genes.
Gene pair 3: A banana gene and a normal gene.
Punnett square (ghi x normal) result:
1/2 (50%) ghi mutant gene and normal gene (= ghi)
1/2 (50%) two normal genes (= normal)
Punnett square (cinnamon x normal) result:
1/2 (50%) cinnamon mutant gene and normal gene (= cinnamon)
1/2 (50%) two normal genes (= normal)
Sometimes the male's banana gene crosses over from the Y chromosome to the X chromosome (in male maker ball pythons) or from the X chromosome to the Y chromosome (in female maker ball pythons). This seems to happen in 5-10% of the sperm. Using 10% in the following Punnett squares.
Punnett square (male-maker banana male x normal female) result:
~45% banana mutant gene (on Y chromosome) and normal gene (on X chromosome) (= male banana)
~5% two normal genes (both X and Y chromosomes) (= male normal)
~5% banana mutant gene (one X chromosome) and normal gene (other X chromosome) (= female banana)
~45% two normal genes (both X chromosomes) (= female normal)
Final result for female ghi cinnamon x male banana (male maker):
~11.25% male banana ghi cinnamon
~11.25% male banana ghi
~11.25% male banana cinnamon
~11.25% male banana
~1.25% male ghi cinnamon
~1.25% male ghi
~1.25% male cinnamon
~1.25% male normal
~1.25% female banana ghi cinnamon
~1.25% female banana ghi
~1.25% female banana cinnamon
~1.25% female banana
~11.25% female ghi cinnamon
~11.25% female ghi
~11.25% female cinnamon
~11.25% female normal
Punnett square (female-maker banana male x normal female) result:
~5% banana mutant gene (on X chromosome) and normal gene (on Y chromosome) (= male banana)
~45% two normal genes (both X and Y chromosomes) (= male normal)
~45% banana mutant gene (on X chromosome) and normal gene (on X chromosome) (= female banana)
~5% two normal genes (both X chromosomes) (= female normal)
Final result for female ghi cinnamon x male banana (female maker):
~1.25% male banana ghi cinnamon
~1.25% male banana ghi
~1.25% male banana cinnamon
~1.25% male banana
~11.25% male ghi cinnamon
~11.25% male ghi
~11.25% male cinnamon
~11.25% male normal
~11.25% female banana ghi cinnamon
~11.25% female banana ghi
~11.25% female banana cinnamon
~11.25% female banana
~1.25% female ghi cinnamon
~1.25% female ghi
~1.25% female cinnamon
~1.25% female normal
The final results are the expected odds. The actual results may be more or less different from the expected.
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