Alleles at the white Locus

 

There can be many different alleles of a single gene.  In fact, the actual number is infinite, as any particular base pair can be changed to any other, and any possible new DNA sequence can be inserted, and any amount can be deleted.  Some alleles will produce gene products with no function, others may produce products with partial function.  Even if several different mutant alleles are recessive to wild type, they may still be dominant to other alleles.  Usually, alleles that fully inactivate a gene are recessive in all heterozygous combinations, and alleles with only a slight loss of function are dominant to alleles with a more severe loss of function.  To see just how complicated this can all become, here is a partial list of mutant alleles at the white  locus of Drosophila melanogaster, taken from "Genetic Variations of Drosophila melanogaster" by D. L. Lindsley and E. H. Grell, Carnegie Institution of Washington Publication No. 627, 1968.  In 1968, there were 154 different alleles listed in the book; there were probably thousands that had been found but were not listed; more have been found since then.

 

w:  white

origin:  spontaneous

discoverer:  Morgan

references:  Morgan, Science 32: 120 (1910)

phenotype:  eyes pure white

wbf:  white-buff

origin:  spontaneous

discoverer: Safir

references:  Genetics 1: 584 (1916)

phenotype:  eyes light buff, lighter than we male. wbf male eyes somewhat lighter than female.

w+A: American wild-type allele of white

discoverer:  Timofˇef-Ressovsky

references:  Timofˇef-Ressovsky, Biol. Zentr. 52:

468 (1932)

phenotype:  eyes pinkish at eclosion, darken to  maroon, but never become a normal red.

wbl:  white-blood

origin:  spontaneous

discoverer:  Hyde

references:  Genetics 1: 535 (1916)

phenotype:  eyes yellowish ruby at hatching, darkening to sepialike with age; female

lighter than male.

w+O: Oregon-R wild-type allele of white

origin:  in Oregon-R wild type strain

discoverer:  Green

references:  Green, Proc. Natl. Acad. Sci. U. S. 45:

549 (1959)

phenotype:  amount of pigment in diploid w+O/w less than w+C/ w but difference is not readily detected visually.

wBwx:  white-Brownex

origin:  spontaneous

discoverer:  Mossige

references:  Dros. Info. Serv. 27: 59 (1953)

phenotype:  eye color like bw ; no sexual dimorphism

 

w+C:  Canton-S wild-type allele of white

origin:  In Canton-S wild type strain

discoverer:  Green

references:  Green, Proc. Natl. Acad. Sci. U. S. 45: 549 (1959)

phenotype:  (see description of w+O)

wcf:  white-coffee

origin:  Xray induced

discoverer:  Nicoletti

references:  Nicoletti, Dros. Info. Serv. 34: 52  (1960)

phenotype:  eyes deep ruby at hatching, but darken greatly with age.

wa:   white-apricot

origin:  spontaneous

discoverer:  Huestis, 1923

references:  Morgan, Bridges, and Sturtevant, Bibliog. Genet. 2: 218 (1925)

phenotype:  eyes of male yellowish with orange tone; female eyes yellower, somewhat lighter than male.

wch:  white-cherry

origin: spontaneous

discoverer:  Safir

references:  Biol. Bull. 25: 45 (1913)

phenotype:  eyes translucent pink, only slightly yellowish.

wa2

origin:  spontaneous

discoverer:  Bridges, 1929

references: Dros. Info. Serv. 9: 114 (1938)

phenotype:  eye color orange, slightly darker than wa.  Eyes of male darker than female.

 

 

we:  white-eosin

origin: spontaneous derivative of w

discoverer:  Morgan

references: Morgan and Bridges, Carnegie Inst. Wash. Publ. No. 237: 28 (1916)

phenotype:  eyes of female yellowish pink, male and we/ w  lighter.

wa3

origin: spontaneous

discoverer: Curry

references:  Dros. Info. Serv. 9: 114 (1938)

phenotype:  eyes brownish orange; slightly darker than either wa or wa2.  Very little sex difference

wm4:  white-mottled 4

origin:  Xray induced

discoverer:  Muller, 1929

references:  J. Genet. 22: 299 (1930)

phenotype:  eyes variegated