Molecular genetics

Definition

The study of how DNA structure, sequence variation, and gene expression produce phenotypic differences among organisms; encompasses methods for mapping, sequencing, and manipulating genes to infer function, inheritance, and evolutionary relationships.

Etymology

From Latin 'molecula' (small mass) and Greek 'genetikos' (generative).

Example

Molecular genetics revealed that knockdown resistance (kdr) mutations in the voltage-gated sodium channel gene underlie pyrethroid resistance in Anopheles gambiae mosquitoes, enabling targeted surveillance of insecticide resistance in malaria vector populations.

Related Terms

• population genetics
• Genomics
• transcriptomics
• Gene expression
• quantitative trait locus
• CRISPR
• Phylogenetics
• Genetic marker
• linkage mapping

Usage Notes

Distinguish from 'classical genetics,' which infers gene behavior from crosses and phenotypic ratios without direct DNA analysis. In entomology, molecular genetics bridges taxonomy (DNA barcoding), ecology (gene flow in fragmented habitats), and applied pest management (resistance monitoring, sterile insect technique genetics). Often used interchangeably with 'molecular biology' in casual speech, though the latter is broader, encompassing non-genetic mechanisms such as protein biochemistry and cell signaling.