What is "reciprocal cross"

n. hybridization involving a pair of crosses that reverse the sexes associated with each genotype [syn: reciprocal]

In genetics, a reciprocal cross is a breeding experiment designed to test the role of parental sex on a given inheritance pattern. All parent organisms must be true breeding to properly carry out such an experiment. In one cross, a male expressing the trait of interest will be crossed with a female not expressing the trait. In the other, a female expressing the trait of interest will be crossed with a male not expressing the trait.

For example, suppose a biologist wished to identify whether a hypothetical allele Z, a variant of some gene A, is on the male or female sex chromosome. She might first cross a Z-trait female with an A-trait male and observe the offspring. Next, she would cross an A-trait female with a Z-trait male and observe the offspring. Via principles of dominant and recessive alleles, she could then (perhaps after cross-breeding the offspring as well) make an inference as to which sex chromosome contains the gene Z, if either in fact did.

Such types of experiments are unlikely to actually be carried out in the contemporary era of DNA sequencing and molecular genetics.