Survival rates. For comparison of survival rates (Table 1), eggs
were collected from crosses between two hemizygous gfp and rfp
transgenic zebrafish. About 25% of individuals with each of the four
genotypes were obtained: wild type, gfp, rfp, and gfp/rfp. The genotypes/
phenotypes were determined in fry of 3–4 day postfertilization
when both RFP and GFP expression can be easily detected. These
offspring from the same pair of parents were cultured in the same tank
and counted again at the adult stage.
Reproduction success. Reproduction success was measured by
counting the numbers of embryos produced from a pool of equal
number of the following four types of spawning fish of similar size:
wild-type males, wild-type females, gfp transgenic males, and gfp
transgenic females. Each fish selected was pre-tested individually to
ensure that it spawned actively. Eggs were collected for 7–8 consecutive
days and the embryos were examined under a fluorescent microscope.
The penetrance of phenotype is always 100%, as confirmed by PCR
analysis.
Selectivity value