NOTE. SYMBOLS of alleles: Dominant alleles: M - the presence of melanin (black pigment) G - the presence of guanine (сonditionally blue pigment) E - the presence of astaksantin (red pigment) X - the presence of lutein (yellow piment) Recessive alleles: m -the lack or g - the lack or e - the lack or x - the lack or
reduction of melanin quantity (black pigment) reduction of guanine quantity (сonditionally blue pigment) reduction of astaksantin quantity (red pigment) reduction of lutein quantity (yellow piment)
4 pigments and two basic rules: 1. Recessive alleles of each gene reduces the amount of color pigment granules, which are coded by the formation of these same genes, and the phenotype of color almost does not occur.
2. The more recessive alleles of genes in the color genotype, the smaller the quantity of pigment cells.
Hi, lucasrock!!! 4 genes = 4 base color (black, red, yellow and blue/white) Classical mendelian inheritance inheritance for each gene - dominant (M, G, E, X) and recessive (m, g, e, x) and interaction between these genes. For example, if we have cross between 5-7 pairs with genotypes "MM GG ee xx" and "mm gg EE XX" in F2 we recieve ALL 16 variants of colors genotype.
genes/colors and their location: Body colors (all autosomal) are: - grey - dominant over all over body colors - gold/tiger/bronze - recessive - blond/gold - recessive - albino/rrea – recessive, there are two different genes which cause the albino phenotype and which can’t be differentiated
- lutino/wrea – recessive - there are three types of blau: one blau –gene shows no red and no yellow another blau gene could show reduced red but no yellow and the other blau gene (this one is called “hellblau”, this is a German word which means light blue) could show yellow e.g. snake skin - pink is something special because of its peculiarities, it has a reduced number of the big black colour cells (melanophores) and it looks like tiger in its pure manifestation (without the hb). In the combination with the Nigrocaudatus 2 gene (it’s the gene for half black/tuxedo) the back becomes pink, that was the reason for the name “pink”, because the first guppies with this body colourwhere pink half blacks. It is suspected that they have also an increased number of iridophores. - cream - double recessive, gold + tiger - white - double recessive, blau + gold - silver - double recessive, blau + tiger - “super white” – triple recessive, blau + gold + albino - you can breed more combinations but only for these double and triple recessive body colours exists a specific name Some (not all!) colors: 1. colors for the fore-body (the belly, until the beginning of dorsal in their original appearance): - coral is a metallic red which is in most cases y-linked but there should be one x-linked strain in Germany too. In Germany we call it “neon” . In the combination with one of the blau genes it becomes light blue. - moscow is a y-linked gene in most cases but there are some x-linked strains too. It is a metallic silver until dark blue colour. The intensity depends of the mood of the male. You can find this gene in metal heads (y-linked moscow + y-linked snake skin) or moscow blues (y-linked moscow + y-linked blue + x-linked blue) or in moscow greens and moscow purples - Schimmelpfennig Metall (this is the original German name) or platinum is a metallic white/yellow/bright purple/bright blue. It is y-linked in most cases but there are some xlinked strains e.g. in Japan too. - lazuli is a light blue which is y-linked (I don’t know it for sure, because only the Japanese breed it and in Europe there are no lines of this strain, so I had to use a online-translation which could be wrong) 2. colors for the lower-back: - half black (it is the Nigrocaudatus 2 gene) is a x-linked gene in most cases but there are some y-linked strains too. It is a more or less black colour. It could become dark blue too after some selective breeding ( you have to increase the number of iridophores which lay above the melanophores) . In combination with the platinum it seems to be greenish. - japan blue/aquamarine is a light blue which is a y-linked gene in most cases but there are some x-linked strains too. - Störzbach (Stoerzbach) metal is a recessive and autosomal metallic blue, but in combination with other colour-genes it makes them a metallic colour e.g. Mikarif (Stoerzbach metal + snake skin)
There a lot of colours which consists of several different genes for example full reds. There are 6 (perhaps more) different genes for red and they can be y-linked, x-linked and autosomal, some are dominant and others are recessive, so it’s very difficult to talk about reds and full reds. Some colours are shown on the whole body e.g. snake skin. And some colors are shown on the body and the fins e.g. blues (in blue delta IFGA strains), parrish and hutter greens, snake skins, reds, purples, 3/4 blacks etc. The problem is that some body-colours or normal colours also effect the form of the caudal e.g. you cannot create a half blackdouble sword. There are some genes which are not really a colour like red, but the effect the caudal form too. The x-linked gene "cp" is such a gene. It causes a dark pigmentation of the caudal and together with the “double sword-gene” it causes a delta tail. The delta tail always consists of two or more genes. There has to be the “double sword-gene” (which can be y- or x-linked) and a colour gene for the caudal. Sometimes the male has both necessary genes or the female has both genes or each sex has only one of these genes, but in all these case you got a delta tail. I hope you can see that the genetic of the guppy is very complex and to create a new strain is a lot of hard work and a great challenge.
For example when your cross a grey guppy (GG) with a gold guppy(gg), your will get guppy of these four different genotype (GG), (Gg), (gG) & (gg). All 3 fish with genotype (GG), (Gg), (gG) will turn out to be a grey guppy, in this case gene (G) is considered dominant over other gene (g). Recessive - A gene in which the trait it represent will not show because its dominanted by another gene it pair with is considered recessive. Refer to the example above, those guppy with genotype(Gg) will turn out to be grey instead of gold because the gold gene (g) is recessive. Only instance when you can have a gold body guppy is when the guppy have this genotype (gg). Homozygous - Paired genes that are the same at the same locus(location). Using the above example we can say that a gold body guppy have homozygous gold body trait. Heterozygous - Paired genes that are different. Referring to the example above, the grey guppy with (Gg) & (gG) genotype are heterozygous. We commonly refer a heterozygous guppy as one that does not breed true We commonly refer a homozygous guppy as one that breed true genes/colors and their location: Body colors (all autosomal) are: - grey - dominant over all over body colors - gold/tiger/bronze - recessive - blond/gold - recessive
- albino/rrea – recessive, there are two different genes which cause the albino phenotype and which can’t be differentiated - lutino/wrea – recessive - there are three types of blau: one blau –gene shows no red and no yellow another blau gene could show reduced red but no yellow and the other blau gene (this one is called “hellblau”, this is a German word which means light blue) could show yellow e.g. snake skin - pink is something special because of its peculiarities, it has a reduced number of the big black colour cells (melanophores) and it looks like tiger in its pure manifestation (without the hb). In the combination with the Nigrocaudatus 2 gene (it’s the gene for half black/tuxedo) the back becomes pink, that was the reason for the name “pink”, because the first guppies with this body colourwhere pink half blacks. It is suspected that they have also an increased number of iridophores. - cream - double recessive, gold + tiger - white - double recessive, blau + gold - silver - double recessive, blau + tiger - “super white” – triple recessive, blau + gold + albino - you can breed more combinations but only for these double and triple recessive body colours exists a specific name Some (not all!) colors: 1. colors for the fore-body (the belly, until the beginning of dorsal in their original appearance): - coral is a metallic red which is in most cases y-linked but there should be one x-linked strain in Germany too. In Germany we call it “neon” . In the combination with one of the blau genes it becomes light blue. - moscow is a y-linked gene in most cases but there are some x-linked strains too. It is a metallic silver until dark blue colour. The intensity depends of the mood of the male. You can find this gene in metal heads (y-linked moscow + y-linked snake skin) or moscow blues (y-linked moscow + y-linked blue + x-linked blue) or in moscow greens and moscow purples - Schimmelpfennig Metall (this is the original German name) or platinum is a metallic white/yellow/bright purple/bright blue. It is y-linked in most cases but there are some xlinked strains e.g. in Japan too. - lazuli is a light blue which is y-linked (I don’t know it for sure, because only the Japanese breed it and in Europe there are no lines of this strain, so I had to use a online-translation which could be wrong) 2. colors for the lower-back: - half black (it is the Nigrocaudatus 2 gene) is a x-linked gene in most cases but there are some y-linked strains too. It is a more or less black colour. It could become dark blue too after some selective breeding ( you have to increase the number of iridophores which lay above the melanophores) . In combination with the platinum it seems to be greenish. - japan blue/aquamarine is a light blue which is a y-linked gene in most cases but there are some x-linked strains too. - Störzbach (Stoerzbach) metal is a recessive and autosomal metallic blue, but in combination with other colour-genes it makes them a metallic colour e.g. Mikarif (Stoerzbach metal + snake skin)
There a lot of colours which consists of several different genes for example full reds. There are 6 (perhaps more) different genes for red and they can be y-linked, x-linked and autosomal, some are dominant and others are recessive, so it’s very difficult to talk about reds and full reds. Some colours are shown on the whole body e.g. snake skin. And some colors are shown on the body and the fins e.g. blues (in blue delta IFGA strains), parrish and hutter greens, snake skins, reds, purples, 3/4 blacks etc. The problem is that some body-colours or normal colours also effect the form of the caudal e.g. you cannot create a half blackdouble sword. There are some genes which are not really a colour like red, but the effect the caudal form too. The x-linked gene "cp" is such a gene. It causes a dark pigmentation of the caudal and together with the “double sword-gene” it causes a delta tail. The delta tail always consists of two or more genes. There has to be the “double sword-gene” (which can be y- or x-linked) and a colour gene for the caudal. Sometimes the male has both necessary genes or the female has both genes or each sex has only one of these genes, but in all these case you got a delta tail. I hope you can see that the genetic of the guppy is very complex and to create a new strain is a lot of hard work and a great challenge. Feel free to ask me f you have any problems concerning the basic genetic of you guppy. Only the male can show y-linked traits. But they can also show x-linked taits or a mix of yand of x-linked traits. Y-linked means that the gene(s) for this trait are on the Ychromosome. It's the same with x-linked. Females can't show all traits because there is a lack of some special colorcells in their skin. They have all kinds of colorcells but they have less cells of certain kinds than the males. If a y-linked gene becomes x-linked because of a crossing-over the appearance of the phenotype of this trait on the females could be the same as on the males. But sometimes there are some changes in the appearance e.g. japan blue. Females with x-linked japan blue don't show any blue on the body, they only show sometimes some blue on the caudal. Don't ask me why they don't show it. Full gold females show that females have enough iridophores to show metalic colors. You see the same genotype (same genes) doesn't mean the same phenotype (this what you can see with your eyes if you look on the fsih) at both sexes. It's like every science: there are more questions than answers and even if got the answer to one question there two new questions in this one answer. Outcrosses When making outcrosses you want to cross with lines that you are pretty sure are going to give the desired results. Somewhere around 80% to 90% of outcrosses produce fish that are inferior to both parents. When you are selecting which strains of fish you would like to work with, it is advantageous to select lines that can be used to improve each other. Over the years I nave Kept a mental catalog of the crosses that have worked well. Today, these crosses are the backbone of my breeding program. Below are some of the crosses that have worked well in my fish room using my lines. These are pretty well tested crosses so they should work for most lines of these colors. Reds and H/B Reds: I will use the gold bodied red males into the gray bodied h/b red
females to improve the h/b reds. First generation will give 100% h/b reds. These are show stoppers. I then discard all the females from the cross and breed the males back to the pure gray bodied h/b red females. The downside of this cross is losing the deep h/b body color in the males. Always select the females with the darkest body color. (Note: you can create an excellent gray red line by saving some of the F1 females and crossing them back to the pure gold red males. The resultant offspring will be 25% gray reds.) Reds and Albinos: I will cross the gold red males into the albino females to improve the albino line. The F1 is 100% gray reds. I then take these gray red males back to the pure albino females. Theoretically you should get 30% albinos, but I usually end up with 2530%. You can then brother/sister these again for about three generations without much loss in vigor or fertility. Purples and Greens: One of the best kept secrets in the hobby! This cross works both ways and will produce some excellent blues as well. The purple is dominant and will darken the greens considerably. With this in mind, use the lightest green colored male into the purple females to produce bigger and better greens. To improve the purples, cross the purple males into the green females. To select the grown females from the hybrid cross, shine a flashlight on them at night with the lights turned off. The green females will have a green crescent at the base of the peduncle and the purple females will have a purple crescent. Variegated Yellow Snakeskin and H/B AOC (leopard): To improve the pattern in the h/b Aocs, cross the snake males into h/b females. In my lines the h/b is X linked and dominant. This means that the resulting offspring will all be h/b. Take the best male from the cross and breed them back to the pure h/b females. I use this cross about e very 5 or 6 generations in my h/b aoc line. H/B Pastel and Pastels: To improve the size and finnage of the pastels, cross a gold bodied white pastel into a gray bodied h/b pastel female. The offspring from this cross will be washed out gray bodied h/b pastels. Take the best of these males and breed them back to the pure gold bodied pastel females. The offspring will be 50% gold bodied pastels. These will be bigger and more vigorous than the original pastel line. Blue/Green Bicolors and Yellow Variegated Snakeskins: Take the largest blue/green male (don't worry too much about the color pattern) and cross this fish with the snake females. Take the males from this cross and breed them back to the bl/gr females. I have some excellent bl/gr bis coming up from this exact cross.
Basics
Chromosome are found in pairs. Opposite each other on the chromosome pair are two genes which together determine a feature. The gene's position on the chromosome is called it's locus. For example, a guppy's body color, whether it is gold, red or albino is determined by two genes, both of which are located at the same locus (or location) on the chromosome pair. When guppies mate, each parent provides half of the offspring's genes. The mother's and father's chromosomes each split so that there is no longer a pair, only half a pair. One chromosome from the father unites with one chromosome from the mother to form a new chromosome pair. When the genes match up at each locus, a new trait is established. Now, if the genes on both side of a locus are the same as the genes before the chromosome split during mating, then the feature will be identical to the parent. More often than not, this is not the case, so the offspring may have a different feature. Let's take an example of this. It is known in the real world that a gene exists in guppies for wild coloring (full coloring) and albinism. We can create a chart which will show the results of a mating of these two types. We can say that the genetic "code" for the full colored guppy is CC and that the genetic "code" for the albino guppy is cc. Remember that genes exist in pairs, one on each chromosome. Thus we get the codes CC and cc. When mating occurs, the gene splits, so the full colord fish (CC) will supply a "C" gene to the offspring. The albino on the other hand, having a code of "cc" can only supply a "c". Thus, we lay out a simple chart to find out the results of this mating:
The two "C" codes accross the top are the possible genes that the full colored
guppy can supply. The two "c" codes down the left side are the possible genes that the albino guppy can supply. The four boxes show what the offspring will be. In this case, all the offspring is of the code "Cc". In the real world we know that the gene for a full color guppy ("C" in our example) is dominant. A dominant gene only has to be present in a single dose for that feature to exert itself. We also know in the real world that the gene for an albino guppy ("c" in our example) is recessive. Recessive genes have to be present on both sides of the locus for that feature to exert itself. For our example above, this means that an offspring would have to have a genetic code of "cc" in order to be albino. Since all of our offspring have the dominant "C" gene, none will be albino and all will be full color. Now let's move on to a more interesting (and practical) example. What would happen if we mated two of our offspring from the example above? Each parent has a genetic code of "Cc". What would two "Cc" parents yield? Let's draw out a chart:
Again, one parent provides the genetic codes across the top, and the other provides the codes listed down the left side. Each parent is a "Cc", so the a child could inherit either the "C" or the "c". We don't know which, so the chart shows all possibilities. Our chart shows that 25% of our offspring will be "CC", 50% of our offspring wil be "Cc" and 25% of our offspring will be "cc". Since the full color gene "C" is dominant and is present in 75% of our offspring (both the CC and Cc
offspring) we know that 75% of our offspring will be full colored. The 25% that have the "cc" recessive genes will be albino. Dominance
As has been previously mentioned, genes express themselves in several degrees of dominance. Sometimes, something occurs to change the chemical makeup of a gene and creates an alternate to the normal dominant behavior. Genes which have gone through this process are called mutations of the dominant. Each gene, whether it is dominant or a mutation has a certain level of power to affect the expression of a trait. Let's review the three most common "types" or "powers" that genes have. A dominant gene can express itself when present in a single dose no matter what the other gene at the present locus is. In our example on the previous page, the full color "C" gene is a dominant gene. When genetics material is written on paper, the dominant gene is always represented with a c apital letter (like the full color "C" in our example). A recessive gene is one that must be present in a pair (that is, on both sides of the locus) to be expressed in the offspring. In our example on the previous page, the albino "c" gene is a recessive gene. On paper the recessive gene is always written using a lowercase letter (like the albino "c" in our example). When there is a dominant gene on one side of the locus and a recessive gene on the other side, the dominant gene is the trait that is expressed. Hence, the term "dominant". In our example on the previous page, the offspring "Cc" which have one full color gene "C" and one albino gene "c" were, in fact, full color guppies because "C" is dominant and "c" is recessive. It must be remembered that even though a fish which carries the genes "Cc" physically looks full color, the "c" albino gene is still there and will be passed on to offspring. Don't judge the book by it's cover! You have to know what the book says on the inside before you know how it will turn out! There is a third type of gene that we need to talk about that hasn't been
mentioned yet. It is called an incomplete dominant gene. In this case, the dominant gene is not able to fully suppress the effects of the recessive gene. As a result, a fish may express some traits of both genes or as an apparent blending of the two. In reality, genes will never truly blend , so if this appears to be the case, an incomplete dominant gene may be the cause. Another reason for apparent blending is that often a completely different set of genes m ay be affecting the physical trait you are looking at. You have probably noticed that we have used the same letter "C" and "c" when describing the gene pair at the same locus. The letter is arbitrary, we could just as well have used "W" and "w" or any other letter for that matter. It is customary, however, to use the same letter for both dominant and mutational gene. By doing so it is easy to keep track of which gene is the alternative (called an allelomorph in genetic terms) of the other. Two other common genetic terms to be aware of are homozygous and heterozygous: A feature is called homozygous when both genes express the same trait. Examples from the previous page are "CC" and "cc". Both "CC" and "cc" are purebreeding. The gene pair "CC" is homozygous normal and the gene pair "cc" is homozygous recessive. When the pair of genes do not express the same trait, like "Cc" from our examples, the feature they represent is called heterozygous, or nonpurebreeding.
Appearances
Ok. Now we have a basis for calculating our expectations. We have gone over how to create a graph of expectations using the pair of genes from both parents. For a refresher on this, click here. For now, however, we turn our attention to the differences between what is perceived (seen) and what is
reality (genetic). In the real world guppy genetics is very complex and in some strains is still not fully understood, so if you are having problems with a strain take heart! Even the pros don't fully understand guppies! We began our study by looking at albinism. In guppies, as in many fish, albinism is incomplete. This means that not all melanins (pigment, if you will) are suppressed, only those for black and brown are masked. There are two more terms that will be useful now. They are phenotype and genotype. A phenotype describes the physical appearance (e.g. albino or full color), while thegenotype describes the genetic structure (e.g. CC, Cc or cc). It's easy to remember which means what if you remember that "PH" goes with PHenotype and PHysical, and that "GEN" goes with GENotype and GENes. If we mate a homozygous full color guppy (phenotype=full color, genotype=CC) with a homozygous albino (phenotype=albino, genotype=cc), we will come up with all heterozygous full color guppies (phenotype=full color, genotype=Cc). If we mate two of these offspring (CcxCc) we will get offspring with two different phenotypes and three different genotypes. 25% will be CC (phenotype=full color, genotype CC), 50% will be Cc (phenotype=full color, genotype=Cc) and 25% will be cc (phenotype=albino, genotype=cc). The point to be made here is that phenotype and genotype are not the same. You can mate two fish with identical phenotypes and genotypes (appearances and genetic codes) and create fish with very different phenotypes and genotypes. This is what makes genetic breeding possible. We have been making statements similar to "breeding two Cc guppies will result in 25% CC, 50% Cc and 25% cc" throughout this primer, but it cannot be stressed enough that this is just an expectation of an average outcome. Yes, 25% should be CC, but there is no guarantee that this will take place. A gambler rolling a die should get a "6" one out of every six times he rolls, but this almost never takes place in reality. He could also roll a "6" five times in a
row. Genetics are just as random. Rarely will a mating of two Cc guppies ever yield exactly 25% CC, 50% Cc and 25% cc. A mating resulting in 100% CC is quite possible. For that reason, results of one mating should never be trusted. Only over the long run with multiple matings can we begin to tell anything with certainty. One other thing on commonly accepted standards for recording your genetic findings before we move on. If we know exactly what a pair of genes are (e.g. the genotype for an albino guppy is always cc), we can be safe in putting "cc" down on paper. If we are not sure what a gene pair is (e.g. the genotype for a full color guppy could be CC or Cc) it is customary to record the genotype with a dash "-" in place of the uncertain gene. For example, if we were not sure if a full color guppy had a genotype of CC or Cc we would describe it as "C-" instead of CC or Cc.
