Disomiclike

Disomiclike is a term used in genetics and cytogenetics to describe chromosomal states or inheritance patterns that resemble disomy, the presence of two homologous copies of a chromosome, in organisms where the overall chromosome set is higher than diploid (polyploid). A chromosome or chromosomal segment may be described as disomiclike when it behaves as if two copies are present with diploid-like segregation during meiosis, despite the organism carrying additional homeologous copies.

Disomiclike behavior is most often discussed in polyploid species, particularly allopolyploids undergoing diploidization. In these systems, pairing tends to occur between true homologs rather than between homeologs, producing a pattern of inheritance that mimics disomic segregation. This can simplify genetic analysis and breeding by yielding Mendelian-like segregation ratios at loci on the disomiclike chromosome, even though the plant or animal is polyploid.

As a descriptive term, disomiclike does not mandate a single mechanism; it can reflect preferential pairing, segmental disomy, or localized absence of recombination with homeologs. Its presence may be tissue- or locus-specific and can vary across individuals or developmental stages. Related concepts include disomy, disomic inheritance, polyploidy, diploidization, and allopolyploid genome evolution.