Table of Contents
Why do fruit flies have different eye colors?
Fruit Fly Eye Color Some fruit flies bred in the wild have red eyes. Brown and sepia eyes are a result of a recessive gene and only occur when two sepia-eyed flies mate. The white-eyed fruit fly gene is recessive and typically is eliminated after mating with dominant-eyed fruit flies for two generations.
Are white eyes in fruit flies sex-linked?
The appearance of white eyes in females shows that this trait is not lethal in females. All possible combinations of white eyes and sex are possible. The white-eye trait can be carried over to females when F1 females are crossed with white-eyed males.
Why are white eyed female fruit flies so rare in nature?
White eyes are very rare in natural fruit fly populations. Morgan realized that in these flies, eye color must somehow be tied to sex. From this and other evidence, Morgan deduced that the gene involved in this inheritance pattern is located only on the X chromosome. There is no corresponding eye color locus on the Y.
Why are fruit flies eyes red?
There are actually two types of pigment in the eye of the fruit fly. The first kind is a rusty-colored pigment called ommachrome pigment. The second is the reddish pigment, called pteridine, which gives the eye its bright red color. The optical insulation prevents light rays from scattering when they enter the eye.
How are eye colors inherited in fruit flies?
The eye color gene is located on the X chromosome (one of the sex determining chromosomes of Drosophila). White eye color is recessive. When a red eyed male mates with white eyed females, their daughters will have red eyes, but their sons will have white eyes. Click to see full answer.
Which is the dominant eye color in flies?
Thomas Hunt Morgan mapped this trait to the X chromosome in 1910. Like humans, Drosophila males have an XY chromosome pair, and females are XX. In flies, the wild-type eye color is red (X W) and it is dominant to white eye color (X w) (Figure 1).
What kind of eye color does a Drosophila fly have?
Like humans, Drosophila males have an XY chromosome pair, and females are XX. In flies, the wild-type eye color is red (X W) and it is dominant to white eye color (X w) (Figure 1). Because of the location of the eye-color gene, reciprocal crosses do not produce the same offspring ratios.
Which is a sex linked trait in Drosophila?
Reading: Sex-Linked Traits. Red eye color is wild-type and is dominant to white eye color. Eye color in Drosophila was one of the first X-linked traits to be identified. Thomas Hunt Morgan mapped this trait to the X chromosome in 1910. Like humans, Drosophila males have an XY chromosome pair, and females are XX.