Evolution of the Drosophila melanogaster-sigma virus system in a natural population from Tübingen

1992 ◽  
Vol 85-85 (2-3) ◽  
pp. 186-189 ◽  
Author(s):  
A. Fleuriet ◽  
D. Sperlich
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Population ◽  
Sigma Virus ◽  
Virus System

scholarly journals GENETIC LOAD IN NATURAL POPULATIONS: IS IT COMPATIBLE WITH THE HYPOTHESIS THAT MANY POLYMORPHISMS ARE MAINTAINED BY NATURAL SELECTION?

Genetics ◽  
1974 ◽  
Vol 77 (3) ◽  
pp. 569-589
Author(s):  
Martin L Tracey ◽  
Francisco J Ayala
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Selection ◽  
Natural Population ◽  
Natural Populations ◽  
Genetic Load ◽  
Structural Genes ◽  
Invertebrate Species ◽  
Average Proportion ◽  
Mean Fitness ◽  
The Mean

ABSTRACT Recent studies of genetically controlled enzyme variation lead to an estimation that at least 30 to 60% of the structural genes are polymorphic in natural populations of many vertebrate and invertebrate species. Some authors have argued that a substantial proportion of these polymorphisms cannot be maintained by natural selection because this would result in an unbearable genetic load. If many polymorphisms are maintained by heterotic natural selection, individuals with much greater than average proportion of homozygous loci should have very low fitness. We have measured in Drosophila melanogaster the fitness of flies homozygous for a complete chromosome relative to normal wild flies. A total of 37 chromosomes from a natural population have been tested using 92 experimental populations. The mean fitness of homozygous flies is 0.12 for second chromosomes, and 0.13 for third chromosomes. These estimates are compatible with the hypothesis that many (more than one thousand) loci are maintained by heterotic selection in natural populations of D. melanogaster.

Seasonal changes in recombination characteristics in a natural population of Drosophila melanogaster

Heredity ◽  
2021 ◽  
Author(s):  
Dau Dayal Aggarwal ◽  
Sviatoslav Rybnikov ◽  
Shaul Sapielkin ◽  
Eugenia Rashkovetsky ◽  
Zeev Frenkel ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Population ◽  
Seasonal Changes

scholarly journals A SURVEY OF ISOZYME POLYMORPHISM IN A DROSOPHILA MELANOGASTER NATURAL POPULATION

Genetics ◽  
1975 ◽  
Vol 80 (4) ◽  
pp. 761-771
Author(s):  
H T Band
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Population ◽  
Published Data ◽  
The South ◽  
Biochemical Polymorphism ◽  
Metabolizing Enzymes ◽  
Animal Populations ◽  
Isozyme Polymorphism ◽  
The Right

ABSTRACT A survey of biochemical polymorphism among glucose- and non-glucose-metabolizing enzymes was carried out on the June 1973 collection from the South Amherst, Mass. Drosophila melanogaster natural population. Polymorphic levels are among the highest recorded for this species; polymorphism among glucose-metabolizing enzymes did not differ significantly from that among non-glucose-metabolizing enzymes. Two loci, G6Pd on the × and Est-6 on the 3rd chromosome, displayed significant excesses of heterozygotes. Adh on the 2nd and Idh, Odh and Ao on the 3rd chromosome showed significant heterozygote deficiencies. Idh is ten map units to the left of Est-6, Odh twelve map units to the right and Ao is seven units beyond Odh. Temperatures in the two-week June period prior to collection were exceedingly variable. Daily high/low ranged between 76°/40° and 97°/65°F. These results support the findings of Frydenberg and Simonsen (1973) that in some populations glucose-metabolizing enzymes tend to be as polymorphic as non-glucose-metabolizing ones. They also add to the evidence obtained from other plant and animal populations that increased biochemical polymorphism is associated with more variable and/or colder climates. The increase may in part be due to increased polymorphism among glucose-metabolizing enzymes. Comparisons utilizing published data on other D. melanogaster populations and on D. robusta indicate a clinal increase in heterozygosity among glucose-metabolizing enzymes as one moves northward.

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