Second Chromosome viability Genetic Load and Lethal Allelic Frequency in Drosophila melanogaster in Lagos

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Date
2001
Authors
Adekoya, K.O.
Williams, G.O.
Journal Title
Journal ISSN
Volume Title
Publisher
University of Lagos, Nigeria
Abstract
The frequencies of recessive lethal, semilethal, subvital and quasinormal chromosomes-2 in Drosophila melanogaster from 5 sites in Lagos and one near Lagos, were determined by making one chromosome-2 from each trapped male homozygous. The frequency of allelism, among the lethal chromosomes isolated, was also determined. Heterogeneity chi-square tests among the sites were inconclusive. The results were more suggestive of free gene flow among the sites , especially as the difference between the intrasite and intersite frequencies of allelism was not significant. The very low frequencies indicated a large population. The frequencies of lethal, semilethal, subvital, quasinormal and normal chromosomes in the population were 13.1%, 5.8%, 19.4%, 52.7% and 9.0% in that order. Although the frequency of lethals was lower than expected for a lowland population located close to equator, the proportion of lethals among drastics (lethal + semilethals) was not different from values for a number of populations in higher latitudes. Also, comparisons with previous data on chromosome -3 suggest that generalizations on genetic load in populations must be based on data of all the major chromosomes in the species.
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Keywords
genetic load, allelism, drastics, detrimentals, viability
Citation
Adekoya, K.O and Williams, G.O. (2001): Second Chromosome viability Genetic Load and Lethal Allelic Frequency in Drosophila melanogaster in Lagos Nigeria. J. of Sci, Tech. and Environ. 1 (1) : 77-84.