In a study conducted at the Max Planck Institute for Plant Breeding Research
in Cologne, Germany, scientists established a system to generate clonal sex
cells in tomato plants and used them to design the genomes of offspring. The
fertilization of a clonal egg from one parent by a clonal sperm from another
parent produced plants containing the complete genetic information of both
parents.



In the system that Underwood and his team developed, meiosis was replaced by
mitosis, a simple cell division, in tomato. In the so-called MiMe system
(Mitosis instead of Meiosis) the cell division mimics a mitosis, thus
sidestepping genetic recombination and segregation, and produces sex cells
that are exact clones of the parent plant. For the first time, researchers
were able to harness clonal sex cells to engineer offspring through a
process called "polyploid genome design."



The researchers performed crosses where the clonal egg from one MiMe tomato
plant was fertilized by a clonal sperm from another MiMe tomato plant. The
resulting tomato plants contained 48 chromosomes and the complete genetic
repertoire of both parents.



[www.mpg.de]