Heterogonesis describes the segregation of parental genomes into distinct cell lineages in the dividing zygote.[1][2]
Fertilisation occurs when an ovum fuses with a sperm, forming a zygote. Normally, the genomes of the two parents assort into two diploid bi-parental daughter cells. In a heterogoneic cell division, the genome of only one parent assorts into a single daughter cell following the formation of a tripolar (rather than the normal bipolar) spindle apparatus.[3] Heterogonesis allows for chromosomal segregation to occur in a dispermic fertilisation which may subsequently result in chimerism or sesquizygosis.
The term heterogonesis was coined in 2016 by Destouni and Vermeesch who observed the phenomenon in bovine zygotes.[1] The word is derived from the Greek meaning "different parental origin".