Table 3.

Predictions About Which Combinations of Transgenes Can Be Distinguished from One Another by Their Fluorescence Patterns

	GloRFP	GloYFP	GloGFP	GloBFP	GloPFP
GloRFP	NO	YES*	YES	YES	NO
GloYFP		NO**	NO	YES	NO
GloGFP			NO	YES	YES
GloBFP				NO	YES
GloPFP					NO

^*“YES” means this would be a good cross to use in the classroom for using fluorescence to determine genotype. For instance, if you cross a Yellow (Glo^GFP) fish with a Blue (Glo^BFP) fish, this would be good choice. This is true because you can easily tell if an offspring contains both GFP and BFP because each these proteins will fluoresce under a different wavelength of light.

^**“NO” means this would not be a good cross to use. For instance, crossing a Yellow (Glo^RFP) with a Red (Glo^YFP) would be a bad choice. This is true because you cannot tell if an offspring contains both YFP and RFP because each of these proteins will fluoresce under 545 nm wavelength light. Therefore, cannot easily tell the difference between a fish that is only carrying the Glo^YFP and one carrying both Glo^YFP and Glo^RFP using the fluorescence in the body of the fish. Note that the answer would be “YES” for this cross if you were instead using fluorescence in the tail fin (see Fig. 3).

These predictions are based on the data in Figure 9, and provide a guide for which dihybrid crosses can be accurately assayed by fluorescence microscopy.