In humans the presence of a functional SRY gene on the Y chr

In humans, the presence of a functional SRY gene on the Y chromosome results in male genitalia. Thus, individuals with a nonfunctional SRY gene are phenotypically female. If a male acquired a SRY mutation in the germ cells that give rise to sperm and then subsequently had children with a colorblind female (colorblindness is a recessive X-linked trait), what would be the potential genotypes and phenotypes of the male and female children? Please define each allele, write the genotype of the male and female, and draw a punnet square to show your work.

Solution

Answer:

XY= normal male

XYs= srm mutation

Xc= Colorblind allele

X= normal allele

Parents: XYs (srm mutation male) x XcXc (color blind female)

Punnet suare

Xc

Xc

X

XXc (carrier female)

XXc (carrier female)

Ys

XcYs (color blind female)

XcYs (color blind female)

Explanation:

Color blindness is X linked recessive inheritance.

two copies of a disease allele on the X chromosome are required for an individual with two X chromosomes (a female) to be affected with an X-linked recessive disease.

Since males genotype children have mutation in SRY gene they are phenotypically females

	Xc	Xc
X	XXc (carrier female)	XXc (carrier female)
Ys	XcYs (color blind female)	XcYs (color blind female)