Biomaterial Database

Lack of experimental evidence for frequency-dependent selection at the alcohol dehydrogenase locus in Drosophila melanogaster. 1979

H Yoshimaru, and T Mukai

Two experiments were conducted for testing frequency-dependent selection at the alcohol dehydrogenase locus (Adh; map position, 2--50.1), where two types of alleles, AdhF and AdhS, have been found to be polymorphic in natural populations. First, a competition experiment was carried out between inversion-free AdhF/AdhF and AdhS/AdhS genotypes at five gene frequency levels (those of AdhF = 0.83, 0.67, 0.5, 0.33, and 0.17). First-instar larvae of the two homozygous types in various ratios were placed in a vial, and the frequency of adult flies of each genotype was determined. However, the relative viabilities of these two types did not change with the change in the frequencies of genotypes or genes. The second test was performed by using the results of viability tests with the Cy method of Wallace, using the results of inversion-free crosses only. Although there was variation in the gene frequencies among the vials in testing the viability of individuals consistng of random combinations of two second chromosomes, no difference was found in average viabilities among the vials in which the gene frequencies were different. Thus, no evidence for frequency-dependent selection was obtained.

UI	MeSH Term	Description	Entries
D007446	Chromosome Inversion	An aberration in which a chromosomal segment is deleted and reinserted in the same place but turned 180 degrees from its original orientation, so that the gene sequence for the segment is reversed with respect to that of the rest of the chromosome.	Inversion, Chromosome,Inversion, Chromosomal,Chromosomal Inversion,Chromosomal Inversions,Chromosome Inversions,Inversions, Chromosomal,Inversions, Chromosome
D007527	Isoenzymes	Structurally related forms of an enzyme. Each isoenzyme has the same mechanism and classification, but differs in its chemical, physical, or immunological characteristics.	Alloenzyme,Allozyme,Isoenzyme,Isozyme,Isozymes,Alloenzymes,Allozymes
D004331	Drosophila melanogaster	A species of fruit fly frequently used in genetics because of the large size of its chromosomes.	D. melanogaster,Drosophila melanogasters,melanogaster, Drosophila
D005787	Gene Frequency	The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.	Allele Frequency,Genetic Equilibrium,Equilibrium, Genetic,Allele Frequencies,Frequencies, Allele,Frequencies, Gene,Frequency, Allele,Frequency, Gene,Gene Frequencies
D005838	Genotype	The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.	Genogroup,Genogroups,Genotypes
D000429	Alcohol Oxidoreductases	A subclass of enzymes which includes all dehydrogenases acting on primary and secondary alcohols as well as hemiacetals. They are further classified according to the acceptor which can be NAD+ or NADP+ (subclass 1.1.1), cytochrome (1.1.2), oxygen (1.1.3), quinone (1.1.5), or another acceptor (1.1.99).	Carbonyl Reductase,Ketone Reductase,Carbonyl Reductases,Ketone Reductases,Oxidoreductases, Alcohol,Reductase, Carbonyl,Reductase, Ketone,Reductases, Carbonyl,Reductases, Ketone
D000483	Alleles	Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.	Allelomorphs,Allele,Allelomorph
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012641	Selection, Genetic	Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.	Natural Selection,Genetic Selection,Selection, Natural