scholarly journals Recurrent evolution of cross-resistance in response to selection for improved post-infection survival in Drosophila melanogaster

2021 ◽  
Author(s):  
Aparajita Singh ◽  
Aabeer Basu ◽  
Biswajit Shit ◽  
Tejashwini Hegde ◽  
Nitin Bansal ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Bacterial Pathogen ◽  
Host Population ◽  
Host Susceptibility ◽  
Cross Resistance ◽  
Response To Selection ◽  
Host Sex ◽  
Determining Factors ◽  
Selection For

The host susceptibility to one pathogen can decrease, increase, or remain unaffected by virtue of the host evolving resistance towards a second pathogen. Negative correlations between a host susceptibility to different pathogens is an often-cited explanation for maintenance of genetic variation in immune function determining traits in a host population. In this study, we investigated the change in susceptibility of Drosophila melanogaster flies to various novel bacterial pathogens after being experimentally selected for increased resistance to one particular bacterial pathogen. We independently selected flies to become more resistant towards Enterococcus faecalis and Pseudomonas entomophila, and baring a few exceptions the evolved populations exhibited cross-resistance against the range of pathogens tested in the study. Neither the identity of the native pathogen nor the host sex was major determining factors in predicting the pattern of cross-resistance exhibited by the selected populations. We therefore report that a generalized cross-resistance to novel pathogens can repeatedly evolve in response to selection for resistance against a single pathogen.

scholarly journals Sexual antagonism for resistance and tolerance to infection in Drosophila melanogaster

2014 ◽  
Vol 281 (1788) ◽  
pp. 20140987 ◽  
Author(s):  
Crystal M. Vincent ◽  
Nathaniel P. Sharp
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Sexual Dimorphism ◽  
Bacterial Pathogen ◽  
Ecological Factors ◽  
Evolutionary Genetics ◽  
Antagonistic Pleiotropy ◽  
Sexual Antagonism ◽  
Heritable Variation ◽  
Dioecious Populations

A critical task in evolutionary genetics is to explain the persistence of heritable variation in fitness-related traits such as immunity. Ecological factors can maintain genetic variation in immunity, but less is known about the role of other factors, such as antagonistic pleiotropy, on immunity. Sexually dimorphic immunity—with females often being more immune-competent—may maintain variation in immunity in dioecious populations. Most eco-immunological studies assess host resistance to parasites rather than the host's ability to maintain fitness during infection (tolerance). Distinguishing between resistance and tolerance is important as they are thought to have markedly different evolutionary and epidemiological outcomes. Few studies have investigated tolerance in animals, and the extent of sexual dimorphism in tolerance is unknown. Using males and females from 50 Drosophila melanogaster genotypes, we investigated possible sources of genetic variation for immunity by assessing both resistance and tolerance to the common bacterial pathogen Pseudomonas aeruginosa. We found evidence of sexual dimorphism and sexual antagonism for resistance and tolerance, and a trade-off between the two traits. Our findings suggest that antagonistic pleiotropy may be a major contributor to variation in immunity, with implications for host–parasite coevolution.

scholarly journals The genetic analysis of the direct and correlated response to selection for chaetae in Drosophila melanogaster

1973 ◽  
Vol 22 (1) ◽  
pp. 1-7
Author(s):  
W. R. Scowcroft
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Genetic Correlation ◽  
Statistical Approach ◽  
Correlated Response ◽  
Minor Importance ◽  
Response To Selection ◽  
Genetic Changes ◽  
Selection For ◽  
Selection Of

SUMMARYThe direct and correlated response to selection of scutellar microchaetae and scutellar bristles has been analysed by determining the contribution of the three major chromosomes, alone and in combination with each other, to the overall response. The results of the analysis confirm a previous finding, based on a formal statistical approach, that response to selection for microchaetae had highly pleiotropic effects on scutellar bristles. In lines selected, each for high and low microchaetae, genetic changes in the 2nd and 3rd chromosomes are pre-eminent and essentially equal. Inter-chromosomal interactions are of relatively minor importance in interpreting the response to selection for microchaetae but assume greater importance with respect to the correlated character. The results are discussed in terms of the genetic correlation between fitness and the character measured.

scholarly journals Heritability of Directional Asymmetry in Drosophila melanogaster

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Ashley J. R. Carter ◽  
Elizabeth Osborne ◽  
David Houle
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variation ◽  
Artificial Selection ◽  
Natural Variation ◽  
The Other ◽  
Directional Asymmetry ◽  
Consistent Difference ◽  
Selection Experiment ◽  
Response To Selection ◽  
Powerful Technique

Directional asymmetry (DA), the consistent difference between a pair of morphological structures in which the same side is always larger than the other, presents an evolutionary mystery. Although many paired traits show DA, genetic variation for DA has not been unambiguously demonstrated. Artificial selection is a powerful technique for uncovering selectable genetic variation; we review and critique the limited number of previous studies that have been performed to select on DA and present the results of a novel artificial selection experiment on the DA of posterior crossvein location in Drosophila wings. Fifteen generations of selection in two genetically distinct lines were performed and none of the lines showed a significant response to selection. Our results therefore support and reconfirm previous findings; despite apparent natural variation and evolution of DA in nature, DA remains a paradoxical trait that does not respond to artificial selection.

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