Paralogspecific

Paralog-specific refers to properties, functions, or regulations of a gene that are unique to one member of a paralogous gene family. Paralogous genes arise via duplication within a genome, and subsequent divergence can lead to paralog-specific expression, activity, interactions, or regulation. The term is used when a feature cannot be generalized across all paralogs in the family.

Paralog-specific features may include tissue- or condition-specific expression, distinct promoter elements, or differences in protein–protein interaction networks. In contrast to core shared functions, paralog-specific changes contribute to subfunctionalization or neofunctionalization after duplication.

Assessing paralog specificity requires comparative analyses: phylogenetic reconstruction to establish paralog relationships, transcriptome profiling to map expression, proteomics to assess interactions, and functional genetics to test individual paralogs by knockouts or knockdowns.

Examples of paralog-specific divergence include the human MYC gene family, where C-MYC, N-MYC, and L-MYC have distinct expression patterns and roles in development and tumorigenesis, illustrating paralog-specific functions. In the globin gene family, alpha-like and beta-like paralogs show tissue- and developmental-stage-specific expression, reflecting paralog specialization.

See also: paralog, gene duplication, subfunctionalization, neofunctionalization.