When comparing genes from two sequenced genomes, how does one determine whether two genes are orthologous? What pitfalls arise when one or both of the genomes are not sequenced?

Key Concepts

Orthologous Genes

Orthologous genes are genes in different species that evolved from a common ancestral gene through speciation. They typically retain the same function across species, making them crucial for comparative genomics. Identifying orthologs helps in understanding evolutionary relationships and functional conservation.

Genome Sequencing

Genome sequencing is the process of determining the complete DNA sequence of an organism's genome. Accurate sequencing is essential for identifying genes and their relationships. If one or both genomes are not sequenced, it can lead to incomplete data, making it difficult to accurately determine orthology.

Pitfalls in Comparative Genomics

Pitfalls in comparative genomics include misidentifying orthologs due to incomplete or erroneous genome data, which can lead to false conclusions about gene function and evolutionary history. Additionally, gene duplication events can complicate ortholog identification, as paralogs (genes related by duplication) may be mistakenly compared instead of true orthologs.