Genomic Features of Parthenogenetic Animals

Area of Science:

• Evolutionary Biology
• Genomics
• Reproductive Biology

Background:

• Asexual reproduction, or parthenogenesis, is predicted to significantly impact animal genomes.
• Previous studies on individual parthenogenetic species suggested common genomic alterations like high heterozygosity or unique gene content.

Purpose of the Study:

• To systematically investigate genomic features across multiple independent transitions to parthenogenesis in animals.
• To determine if previously reported genomic patterns are general consequences of asexual reproduction or lineage-specific.

Main Methods:

• Analysis of published genome data from 26 parthenogenetic animals.
• Representation of at least 18 independent evolutionary transitions to asexuality.
• Systematic characterization of genomic features such as heterozygosity, gene content, and transposable elements.

Main Results:

• No single genomic feature was consistently found across the majority of parthenogenetic lineages studied.
• High heterozygosity was observed only in parthenogens of hybrid origin; non-hybrid parthenogens were largely homozygous.
• The expected dramatic genome-wide effects of absent recombination were not observed.

Conclusions:

• Previously reported genomic patterns associated with parthenogenesis are likely lineage-specific.
• The origin of parthenogenesis (hybrid vs. non-hybrid) is a key factor influencing genomic characteristics.
• Factors including lineage-specific patterns, origin of parthenogenesis, and survivorship bias may explain the limited general impact of asexual reproduction on genomes.