Wild, Wild Red

Wild Full Red

It is always an exciting time in the Design Lab when the experimental crosses I am doing begin to color up. There is always surprises in store. Many people think this is due to guppy genetics, but the truth is any properly designed scientific experiment should produce surprises. Why else would you do it?

About seven months ago I decided to explore Full Red genetics by doing two reciprocal crosses...one with my wild type guppies and another with my Midnight Black Moscows. There was a few ideas I want to explore. One was that the Full Red is actually a mosaic of red color cells, put together like a patchwork quilt. The other is that there is a full red gene that causes the guppy to become entirely red, suppressing the expression of other color genes.

The Full Red strain I used came from Ed Chiasson, via Darryl Tsutsui in Hawaii.

Take a look at the male in the above picture. First of all it is an F1 male at about 3 months. It is well on its way to becoming a Full Red male. So that is surprise no. 1. He is really, really red, something I did not suspect in an outcross. Surprise no. 2 is that this male's father is not Full Red. The father is a wild male. It is the mother who is Full Red. What about the reciprocal cross, where the Full Red is the father and the wild female is the mother? The father was the wild guppy phenotype. No red genes! So surprise no. 3 is that the Chiasson Full Reds I have are entirely X-linked, although I will have to go to an F2 generation to see if there is an autosomal red gene as well.

Big bonus in my fish room. I have an X-linked full red line. Extremely valuable for my experimental crosses.

Will I get a Red Moscow in the F1 generation from the cross with my Midnight Black Moscows? The males from this cross show the same X-linked red color, but I suspect I will have to wait for the second generation to see a good Full Red Moscow.

The F2 generation is going to be totally fascinating because I should see segregation of the color genes.

I have been collecting all the results of my experiments and my general notes on guppy mutations into a new book, the "Guppy Design Lab."