Integrating sex-bias into studies of archaic introgression on chromosome X
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View abstract on PubMed
Summary
This summary is machine-generated.Ancient hominin DNA segments are mostly found on human autosomes, not the X chromosome. This study reveals a 7:1 ratio, with male-biased ancient populations explaining the low X chromosome coverage.
Area Of Science
- Human evolution
- Paleogenetics
- Population genetics
Background
- Interbreeding between archaic hominins and modern humans is evidenced by archaic haplotype segments ('archaic coverage') in current human genomes.
- Most archaic coverage is found on autosomes, with significantly less retained on the X chromosome.
Purpose Of The Study
- To summarize published estimates of archaic coverage on autosomes and the X chromosome.
- To investigate the impact of sex-biased archaic introgression on the retention of archaic coverage.
Main Methods
- Analysis of published archaic coverage estimates from extant human samples.
- Extensive simulation studies modeling sex-bias in archaic introgressors.
Main Results
- On average, 7 times more archaic coverage exists on autosomes compared to the X chromosome.
- Continental patterns show the highest autosome-to-X ratio in European samples and the lowest in South Asian samples.
- Increasing male sex-bias in archaic populations correlates with reduced archaic coverage on the X chromosome.
Conclusions
- Sex-bias, specifically a male-biased sex ratio among archaic introgressors, likely explains the scarcity of archaic coverage on the human X chromosome.
- This study provides the first explicit model of sex-bias's role in shaping archaic DNA patterns on sex chromosomes.
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