Mixedgenotype

Mixedgenotype, frequently rendered as mixed genotype or mixed-genotype in literature, refers to a situation in which an organism or a sample contains two or more genetically distinct cell lines or organisms. It is distinct from a uniform genotype across all cells. Mixed genotypes most commonly arise from mosaicism, where a post-zygotic mutation creates a lineage of cells with a different genotype within the same individual. Chimerism, the presence of two genetically distinct cell populations derived from different zygotes, can also produce a mixed genotype, such as in natural twin chimeras or after bone marrow or organ transplantation.

In infectious disease contexts, a host may harbor multiple genotypes of a pathogen, such as viruses or parasites, within the same body, complicating diagnosis and treatment. In population samples, mixed genotypes can result from admixture or contamination, where DNA from more than one genotype is present.

Detection and interpretation rely on genetic testing with sufficient resolution. Standard genotyping may show ambiguous signals at a locus, while deep sequencing and analysis of allele frequency distributions can estimate the proportions of each genotype. Interpreting mixed genotypes requires considering tissue source, sampling methods, and potential technical artefacts.

Implications vary by context. Mosaicism or chimerism may produce mosaic phenotypes and affect transplantation, pregnancy, and forensics. Pathogen mixtures can influence virulence, transmission dynamics, and drug resistance. In agriculture and plant breeding, mixed genotypes in a sample can affect trait selection and certification. Understanding mixed genotypes informs diagnostics, population genetics, and evolutionary studies.