White (mutation): Difference between revisions
m italics |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:White-eyed Drosophila.jpg|thumb|A white-eyed ''Drosophila'']] |
[[Image:White-eyed Drosophila.jpg|thumb|A white-eyed ''Drosophila'']] |
||
''' ''white'' ''' was the first [[sex-linked]] [[mutation]] ever discovered in ''[[Drosophila melanogaster]]''. In 1910 [[Thomas Hunt Morgan]], (or, legend has it, his wife) collected a single [[male]] [[white-eyed]] [[mutant]] from a [[population]] of ''[[Drosophila melanogaster]]'' [[fruit flies]], which usually have bright [[red]] [[eyes]]. Upon [[Reproduction|breeding]] this male with [[wild-type]] [[female]] flies he found that the offspring did |
''' ''white'' ''' was the first [[sex-linked]] [[mutation]] ever discovered in ''[[Drosophila melanogaster]]''. In 1910 [[Thomas Hunt Morgan]], (or, legend has it, his wife) collected a single [[male]] [[white-eyed]] [[mutant]] from a [[population]] of ''[[Drosophila melanogaster]]'' [[fruit flies]], which usually have bright [[red]] [[eyes]]. Upon [[Reproduction|breeding]] this male with [[wild-type]] [[female]] flies he found that the offspring did conform to the expectations of [[Mendelian inheritance]].<ref> |
||
Morgan, TH: (1910) "Sex Limited Inheritance in Drosophila." ''Science'', 32(812):120-122</ref> The first generation (the F1) produced 1,237 red-eyed offspring and three white-eyed flies, all males. The second generation (the F2) produced 2,459 red-eyed females, 1,011 red-eyed males, and 782 white-eyed males. Further experimental crosses led Morgan to the conclusion that this mutation was somehow physically connected to the "factor" that determined [[gender]] in ''Drosophila''. Morgan named this trait ''white'', now abbreviated ''w''. <ref>As the field of [[genetics]] developed, names for [[gene]]s were [[Italic type|italicized]], and [[dominant allele]]s were [[capitalized]] while [[recessive allele]]s (such as ''white'') were made [[lower case]]. Names of commonly used mutations were shortened, and since ''white'' was one of the first named, it was shortened to a single letter.</ref> Flies carrying the ''white'' [[allele]] are frequently used to introduce high school and college students to genetics. |
Morgan, TH: (1910) "Sex Limited Inheritance in Drosophila." ''Science'', 32(812):120-122</ref> The first generation (the F1) produced 1,237 red-eyed offspring and three white-eyed flies, all males. The second generation (the F2) produced 2,459 red-eyed females, 1,011 red-eyed males, and 782 white-eyed males. Further experimental crosses led Morgan to the conclusion that this mutation was somehow physically connected to the "factor" that determined [[gender]] in ''Drosophila''. Morgan named this trait ''white'', now abbreviated ''w''. <ref>As the field of [[genetics]] developed, names for [[gene]]s were [[Italic type|italicized]], and [[dominant allele]]s were [[capitalized]] while [[recessive allele]]s (such as ''white'') were made [[lower case]]. Names of commonly used mutations were shortened, and since ''white'' was one of the first named, it was shortened to a single letter.</ref> Flies carrying the ''white'' [[allele]] are frequently used to introduce high school and college students to genetics. |
||
Revision as of 09:19, 23 February 2010
white was the first sex-linked mutation ever discovered in Drosophila melanogaster. In 1910 Thomas Hunt Morgan, (or, legend has it, his wife) collected a single male white-eyed mutant from a population of Drosophila melanogaster fruit flies, which usually have bright red eyes. Upon breeding this male with wild-type female flies he found that the offspring did conform to the expectations of Mendelian inheritance.[1] The first generation (the F1) produced 1,237 red-eyed offspring and three white-eyed flies, all males. The second generation (the F2) produced 2,459 red-eyed females, 1,011 red-eyed males, and 782 white-eyed males. Further experimental crosses led Morgan to the conclusion that this mutation was somehow physically connected to the "factor" that determined gender in Drosophila. Morgan named this trait white, now abbreviated w. [2] Flies carrying the white allele are frequently used to introduce high school and college students to genetics.
The protein made by white functions as an ATP-binding cassette (ABC) transporter. It carries the precursors of the red and brown eye color pigments, guanine and tryptophan, into the developing eyes during pupation.[3] The human version of white is ABCG1, and is involved in transporting lipids and cholesterol into cells.
Notes and references
- ^ Morgan, TH: (1910) "Sex Limited Inheritance in Drosophila." Science, 32(812):120-122
- ^ As the field of genetics developed, names for genes were italicized, and dominant alleles were capitalized while recessive alleles (such as white) were made lower case. Names of commonly used mutations were shortened, and since white was one of the first named, it was shortened to a single letter.
- ^ Mackenzie, S. M.; Brooker, M. R.; Gill, T. R.; Cox, G. B.; Howells, A. J.; Ewart, G. D. (1999) Mutations in the white gene of Drosophila melanogaster affecting ABC transporters that determine eye colouration. Biochimica et Biophysica Acta (BBA) - Biomembranes 1419: 173-185.