Allotetraploidsus

Allotetraploidsus is a coined term used in genetics to refer to an allotetraploid organism or lineage characterized by four complete sets of chromosomes derived from two distinct ancestral species. The term is not widely used in formal taxonomic nomenclature and is not associated with a specific, officially named taxon.

Formation of an allotetraploidsus would involve hybridization between two species followed by genome doubling, producing two subgenomes that are homoeologous but distinct. This genome structure, known as an allotetraploid arrangement, can arise when unreduced gametes or somatic chromosome duplication occur after hybridization. In plants, allopolyploidization is a common mechanism of speciation; in animals, it is comparatively rare but has been documented in a few groups.

Detection and analysis rely on cytogenetics to observe chromosome sets, flow cytometry to estimate genome size, and genomic sequencing with subgenome phasing to assign sequences to the respective progenitors. Gene expression studies can reveal subgenome dominance or differential expression patterns between the two subgenomes.

Biology and ecology of an allotetraploidsus would include potential gains from combining traits of both progenitors, such as increased heterozygosity and novel phenotypes, as well as challenges in meiotic pairing that can affect fertility. Stabilization through chromosome doubling can restore fertility and establish a new lineage.

Relation to real-world polyploidy: Allopolyploidy and resultant tetraploids are well documented in crops like wheat and cotton. Allotetraploidsus, however, remains an informal or hypothetical label rather than an accepted taxon in current scientific nomenclature.