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The silkworm Z chromosome is enriched in testis-specific genes
K P Arunkumar1, Kazuei Mita, J Nagaraju
1Centre of Excellence for Genetics and Genomics of Silkmoths, Laboratory of Molecular Genetics, Centre for DNA Fingerprintingand Diagnostics, Tuljaguda, Nampally, Hyderabad, India.
Genetics
|April 1, 2009
Summary
The silkworm Z chromosome has more male-biased genes than autosomes, likely due to sexual antagonism and lack of dosage compensation. Gene duplication and translocation explain this Z chromosome gene accumulation.
Area of Science:
- Genetics
- Evolutionary Biology
- Genomics
Background:
- Sex determination relies on sex chromosomes, but their role in sexual dimorphism is under investigation.
- Sex-linked genes offer insights into sex chromosome evolution and sexual dimorphism.
Purpose of the Study:
- To investigate the role of Z chromosome genes in sexual dimorphism using the silkworm (Bombyx mori).
- To understand the evolutionary mechanisms driving gene accumulation on the Z chromosome.
Main Methods:
- Analysis of the silkworm (Bombyx mori) testis transcriptome.
- Comparative analysis of gene expression between Z chromosome and autosomes.
- Identification of testis-specific paralogous genes.
Main Results:
- The Z chromosome shows a significantly higher number of testis-expressed genes compared to autosomes.
- Evidence suggests sexual antagonism and absence of dosage compensation contribute to male-biased gene accumulation on the Z chromosome.
- Gene translocation and tandem duplication are identified as primary mechanisms for accumulating male-advantageous genes on the Z chromosome.
Conclusions:
- The silkworm Z chromosome is enriched with male-biased genes.
- Evolutionary pressures like sexual antagonism and lack of dosage compensation shape sex chromosome gene content.
- Translocation and duplication are key drivers of Z chromosome gene evolution in males.
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