Identification, expression, and artificial selection of silkworm epigenetic modification enzymes

Area of Science:

• Genomics
• Epigenetics
• Animal Breeding

Background:

• Phenotypic variation during domestication is of significant interest.
• Epigenetic modification enzymes (EMEs) may influence these variations.
• The domesticated silkworm (Bombyx mori) serves as a model for studying EME roles in domestication.

Purpose of the Study:

• To identify EMEs in the silkworm genome.
• To investigate the role of EMEs in silkworm domestication and breeding traits.
• To understand the genetic basis of phenotypic changes during domestication.

Main Methods:

• Homology searching to identify 44 EMEs in the silkworm genome.
• Phylogenetic analysis and gene expression pattern comparison across species.
• Gene-related selective sweeping to identify artificially selected BmEMEs.

Main Results:

• Identified 44 EMEs with conserved expression patterns across species, highly expressed in brain, embryo, and gonads.
• Discovered five BmEMEs under artificial selection, including BmSuv4-20 and BmDNMT2.
• Found mutations in BmSuv4-20 and BmDNMT2 affecting transcription factor binding sites, with altered expression in domesticated vs. wild silkworms.

Conclusions:

• Silkworm domestication involved artificial selection on epigenetic modification markers, potentially driving phenotypic evolution.
• This research offers a new perspective on the genetic underpinnings of animal domestication and breeding.