Development of Natural Triploidy

Although scientists had been developing ways of inducing triploidy since the late 1970s and early 1980s, they continued to look for a better means of achieving better results. In 1993, scientists at Rutgers University invented a new type of polyploid oyster—a tetraploid—which contains four complete sets of chromosomes (4n). Importantly, unlike triploid shellfish, tetraploids are fully fertile, thus allowing them to be a parent for creating "natural" (genetic) triploids.

Using a proprietary, patented process, 4Cs Breeding Technologies, Inc., produces and nurtures tetraploid brood stock. Males are identified from our select brood stock lines and sacrificed for their sperm. The sperm from our tetraploid males have two sets of chromosomes (2C) instead of one (1C), as in diploid males. (See Cell Division Basics for more information on the normal cell division process.)

The resulting di-haploid sperm is used to fertilize haploid eggs from the customer's normal diploid brood stock. No induction treatment is used. The resulting zygotes are genetically triploid, with two sets of chromosomes contributed by the sperm and one set contributed by the egg.

4Cs Natural Triploids have all of the advantages of induced triploids, in the hatchery and in the field, with none of the drawbacks.

Licensing through 4Cs provides both brood stock for spawning and technical assistance in the hatchery. Contact us for more information.