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Fruit flies (Drosophila) are vital in genetic studies due to their small size, ease of handling, and short generation time of 10-12 days. With 4 pairs of chromosomes, they offer a unique opportunity for observing mutations and gene mapping. Thomas Hunt Morgan pioneered their use in 1907 and discovered consistent banding patterns, leading to the development of chromosome maps. In 1921, H. J. Muller demonstrated that genes could mutate, showcasing the significance of fruit flies in genetics. These organisms possess genes similar to humans, making them valuable for research.
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Chromosomes Analysis Fruit Fly
Why Fruit Flies? • Small size • Easy to handle • Short generation time (10 – 12 days) • Many offspring • Many variations or mutations • 4 pairs of chromosomes • 100 times larger than human chromosomes
Chromosome Mapping • Thomas Hunt Morgan 1st used fruit flies in 1907 and in 1911 he recognized that the banding patterns were constant in their location and number. • Morgan also noticed that any irregularity in the banding pattern was reflected in abnormal fruit flies • After many years of research geneticists chromosome maps were constructed
Mutations • 1921 – H. J. Muller discovered that genes can mutate • He induced mutations in fruit flies by exposing them to x-rays.
Drosophila Chromosomes • 4 chromosomes • The 1st chromosome is the X chromosome • Chromosome numbers 1- 3 are large and chromosome number 4 is extremely small • The chromosomes contain thousands of gene of which only 48 will be included in our map • Many of these genes are also found in humans
X chromosome – chromosome 1 • White Eye • Vermillion Eye • Bar Eye • Hexokinase
Chromosome 2 • Dumpy Wing • Black Body • Cinnabar Eye • Vestigial Wing
Chromosome 3 • Sepia Eye • Scarlet Eye • Hairless • Ebony Body
Chromosome 4 • Eyeless
