Supressors part 1

In my hobby hatchery I play with few genes that can be called supressors. Supressor gene means lower expression of a certain trait. In this little series I will present supressors of tail fin. So genes that supress tail shape – from big tail fin to short tail fin – in my breeding program from delta tail to round tail. In next posts I will describe other genes that can help switch from big tail to short tail. This change of course works both directions – so by removing a supressor/supressors from genotype you can have nice big tails from short tails (round, corf, spear tails). First supressor I’m going to write about is so called Translucent Scale (sometimes called transparent scale). It lowers the synthesis levels of guanine within the body. For keeping things simple I call all reflective cells guanine. It is worth remembering tho that there are few kinds of reflective cells within a guppy body. Transparent scale is probably lowering one kind of reflective cells levels. This one which is responsible for most delta tails. To better understand what kind of reflective cells I’m talking about take a look at splendid phenotype of Philip Shaddock.

P. Shaddock

On above photo you can clearly see guanine shine on a tail fin. So in hypothesis about Transparent Scale being a supressor of tail fin shape – this guanine layer is important component of common delta tail phenotype. So if we add a gene which is lowering levels of this important component we receive a phenotype with smaller tail fin. My crossings show that delta tail from which we are starting is important for the shape we will receive after adding a transparent scale supressor. So if you want as a result a nice, broad roundtails, my experience shows that you should use nice broad, floawing broad tails without sharp edges. So like below male:

Halfblack neon broad tail

Beautiful, flowing broad tail with curly, round edges is a key to achieve nice roundtails. If you use sharp edges broad tail you will receive more spade like tails. So how to recognise this Transparent Scale gene? Pretty easy once you know what you are looking for. Please take a look at picture of a female. It has lowered guanine levels in whole body so you can clearly see the inside of a belly and guanine from gill covers is also removed. In males expression is the same but usually masked by other pigment cells.

For some training below few males from my lines.

partial guanine removal on gill covers
Lower male has guanine removal masked by other colors
this boy shows nice guanine losses when seen from below
guanine loss easly seen on gill covers

Of course it is possible to achieve broad tail with transparent scale supressor gene. If such is a desire you have to build genotype that way tail fin is built mostly from cells which are not affected by a supressor. Can be done and effects are nice. Transparent scale is removing/lowering one kind of guanine layer. Guanine is mostly reflective factor to our eye (leucophores are white and not necessary reflective but it is another subject and we want to keep our thinking simple and not complicated ;)). Therefore if you remove reflective factor from phenotype you achieve unpolished, mat, dull phenotype. There are for sure breeders which favour this kind of a look. So you just want to build a genotype from cells which are not a kind of guanine transparent scale is affecting. Examples below (not mine so I kindly ask authors for a message :))

mat male with nice broadtail built mainly by red selection.
nice, flowing broad tail built mostly from white leucophores which compensate guanine removal