genes relies on the existence of ovoD, a dominant female sterile mutation of the ovo gene, which is located near the middle of the acrocentric Drosophila X chromosome. Females that are ovoD/ ovo+ are...

genes relies on the existence of ovoD, a dominant female sterile mutation of the ovo gene, which
is located near the middle of the acrocentric
Drosophila X chromosome. Females that are ovoD/
ovo+ are sterile; ovoD-containing germ-line cells
cannot produce eggs.
a. Mutations in gene X are recessive lethals, so homozygotes for these mutations do not develop into
adults. Explain how researchers could use the ovoD
mutation in a mitotic recombination experiment to
determine (i) whether or not females might supply
the RNA or protein product of gene X to the eggs
they make in their ovaries, and (ii) whether this
maternally supplied product is needed for proper
development of their progeny. Where in the genome would gene X need to be located for this
approach to work?
b. The ovoD mutant gene has been cloned, so genomic
DNA for this mutant gene is available. How could
you use this cloned DNA to determine whether any embryonic lethal mutation located anywhere in the
genome was an allele of a maternal effect gene?
c. Regardless of its chromosomal location, how could
you distinguish in such an experiment whether the
gene in question was a maternal effect gene, as opposed to a gene whose product is needed for oogenesis in the female?
d. How can fly strains containing ovoD mutations be
maintained if females carrying these mutations are
sterile?