Tetrad (meiosis)

The tetrad is the four spores produced after meiosis of a yeast or other Ascomycota, Chlamydomonas or other alga, or a plant.

The meiotic products, spores, remain packaged in the parental cell body to produce the tetrad.

Non-parental ditype (NPD) is a spore that contains only the two recombinant-type ascospores (assuming two segregating loci).

Tetrad analysis can be used to confirm whether a phenotype is caused by a specific mutation, construction of strains, and for investigating gene interaction.

Tetrad analyses have also contributed to detection and study of the phenomena of gene conversion and post-meiotic segregation.