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Haploids can be a useful genetic tool. They can shorten the number of generations required in order to do a screen. Also in the future, we hope that haploids will improve our abililty to identify the gene locus where a mutation is producing an interesting phenotype.

In our experience, haploids can be generated relatively easily. However the production of high quality haploids appears to depend greatly on the mother. A good mother can produced haploids that are virtually indistinguishable from diploid embryos through early 20 stages. In the late 20's, the haploid phenotype begins to become more obvious with shortening of the body axis. By the mid-30's the haploid phenotype is clearly obvious with shortened body axis and significant ventral edema. Certainly for late stages, haploids will be unsuitable for screening developmental defects. However, at earlier stages they may become an important tool.

In order to produce haploids, males and females are primed and boosted as usual.

Place the 900 µl of sperm suspension in a glass pyrex dish (small one) and then into a Stratalinker (Stratagene) (bottom lined with aluminum foil) and zap with 500 on energy setting (50,000 µJ). This dose may need to be titered based on your Stratalinker

Split the irradiated sperm to fertilize all your aliquots of embryos.

Diploid Embryo
Haploid Embryo

This protocol contributed by Tim Grammer and Mustafa Khokha