Outputs from RD-Analyzer in the validation set of Mtb isolates. (XLS 107 kb

Eryu Xia (2940318)

Jun Tan (46388)

Kiatichai Faksri (775893)

Rick Ong (3427067)

Yik-Ying Teo (159446)

Evolution

Life span differs between the sexes in many species. Three hypotheses to explain this interesting pattern have been proposed, involving different drivers: sexual selection, asymmetrical inheritance of cytoplasmic genomes, and hemizygosity of the X(Z) chromosome (the unguarded X hypothesis). Of these, the unguarded X has received the least experimental attention. This hypothesis suggests that the heterogametic sex suffers a shortened life span because recessive deleterious alleles on its single X(Z) chromosome are expressed unconditionally. In Drosophila melanogaster, the X chromosome is unusually large (approximate to 20% of the genome), providing a powerful model for evaluating theories involving the X. Here, we test the unguarded X hypothesis by forcing D. melanogaster females from a laboratory population to express recessive X-linked alleles to the same degree as males, using females exclusively made homozygous for the X chromosome. We find no evidence for reduced life span or egg-to-adult viability due to X homozygozity. In contrast, males and females homozygous for an autosome both suffer similar, significant reductions in those traits. The logic of the unguarded X hypothesis is indisputable, but our results suggest that the degree to which recessive deleterious X-linked alleles depress performance in the heterogametic sex appears too small to explain general sex differences in life span.Funding Agencies|Royal Physiographic Society in Lund; Swedish Research Council; Helge Ax:son Johnsons stiftelse</p

Brengdahl, Martin

Kimber, Christopher

Maguire-Baxter, Jack

Friberg, Urban

Digitala Vetenskapliga Arkivet - Academic Archive On-line

Sex differences in life span: Females homozygous for the X chromosome do not suffer the shorter life span predicted by the unguarded X hypothesis

Martin Brengdahl

Christopher M. Kimber

Jack Maguire-Baxter

Urban Friberg

Crossref

Lifespan differs between the sexes in many species. Three hypotheses to explain this interesting pattern have been proposed, involving different drivers: sexual selection, asymmetrical inheritance of cytoplasmic genomes, and hemizygosity of the X(Z) chromosome (the unguarded X hypothesis). Of these, the unguarded X has received the least experimental attention. This hypothesis suggests that the heterogametic sex suffers a shortened lifespan because recessive deleterious alleles on its single X(Z) chromosome are expressed unconditionally. In Drosophila melanogaster, the X chromosome is unusually large (~20% of the genome), providing a powerful model for evaluating theories involving the X. Here, we test the unguarded X hypothesis by forcing D. melanogaster females from a laboratory population to express recessive X-linked alleles to the same degree as males, using females exclusively made homozygous for the X chromosome. We find no evidence for reduced lifespan or egg-to-adult viability due to X homozygozity. In contrast, males and females homozygous for an autosome both suffer similar, significant reductions in those traits. The logic of the unguarded X hypothesis is indisputable, but our results suggest that the degree to which recessive deleterious X-linked alleles depress performance in the heterogametic sex appears too small to explain general sex differences in lifespan

Kimber, Christopher M.

Electronic Archiving System

Data from: Sex differences in lifespan: females homozygous for the X chromosome do not suffer the shorter lifespan predicted by the unguarded X hypothesis

Publikationer från Linköpings universitet

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Additional file 4: Table S4. of 
                     In silico region of difference (RD) analysis of Mycobacterium tuberculosis complex from sequence reads using RD-Analyzer

Lifespan differs between the sexes in many species. Three hypotheses to explain this interesting pattern have been proposed, involving different drivers: sexual selection, asymmetrical inheritance of cytoplasmic genomes, and hemizygosity of the X(Z) chromosome (the unguarded X hypothesis). Of these, the unguarded X has received the least experimental attention. This hypothesis suggests that the heterogametic sex suffers a shortened lifespan because recessive deleterious alleles on its single X(Z) chromosome are expressed unconditionally. In Drosophila melanogaster, the X chromosome is unusually large (~20% of the genome), providing a powerful model for evaluating theories involving the X. Here, we test the unguarded X hypothesis by forcing D. melanogaster females from a laboratory population to express recessive X-linked alleles to the same degree as males, using females exclusively made homozygous for the X chromosome. We find no evidence for reduced lifespan or egg-to-adult viability due to X homozygozity. In contrast, males and females homozygous for an autosome both suffer similar, significant reductions in those traits. The logic of the unguarded X hypothesis is indisputable, but our results suggest that the degree to which recessive deleterious X-linked alleles depress performance in the heterogametic sex appears too small to explain general sex differences in lifespan.Lifespan_Brengdahl_Kimber_et_alLifespan data from D. melanogaster (the Dahomey laboratory-adapted population), measured in vials. Note that Line and Vial numbers must be interpreted as specific to the Chromosome with which they occur. Numerical columns are days since start of experiment and their content is number of deaths since previous column.Viability_Brengdahl_Kimber_et_alEgg-to-adult viability data from D. melanogaster (the Dahomey laboratory-adapted population), measured in vials. Note that Line numbers must be interpreted as specific to the Chromosome with which they occur. Focal F is number of eclosed females and Focal M number of eclosed males. Ebony is number of eclosed competitor flies

ZENODO

Academic Archive On-line (Linköping University, Sweden)

Additional file 4: Table S4. of In silico region of difference (RD) analysis of Mycobacterium tuberculosis complex from sequence reads using RD-Analyzer

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