Reptile & Amphibian Forums

If I crossed an Albino Black Ratsnake with a Leucistic Ratsnake?
Thanks.

If you are talking about a leucistic texas ratsnake (the leucistic ratsnake that you most commonly seem to find in the pet trade)...You will get a bunch of black/texas intergrades that don't look anything like the parents, and would look pretty much like what you'd get if you cross a normal black rat with a normal texas rat. I'm guessing a "black" ratsnake that retains part of the pattern into adulthood. You will also probably get alot of heat from some of the readers here (not me!) about breeding "mutts" and "freaks"...etc. Or they will tell you to go ask the question on the hybrid forum where they care.
If you are talking about a leucistic black rat, you will still get normal-looking black rat babies unless your albino is het for leucistic and/or your leucistic is het for albino. Then you might get a mix of normals and whatever somebody was het for.
All of the babies would be het for both, so their future offspring would be a mixed bag of all the above...sort of. Duffy

your Leucistic is already Het. for Albino. If that were the case, you would get half Dbl Hets. & half Albinos (Het. for Leucistic).

There is no simple answer to your question, but your question does show that you lack a basic knowledge of snake coloring genetics. (just like most of us. I had to read up on it myself when I first started looking into corn snakes, and I have a BS degree in biology.) So to help you, I am including a link to a primer on corn snake coloring genetics. (I am not the author) If you can understand those basic concepts that he addresses, you should be able to answer your own question. It works the same way for all snakes.

Good luck.
Link

Actually, Passport's question may have been a little more complicated than a basic "snake coloring genetics" one.
In all liklihood, he's talking about breeding a Texas with a Black rat, bringing up the question of, "What would these intergrades look like?" Also, while the basics of genetics obviously remain the same no matter WHAT animals you are talking about, a knowledge of the genetic peculiarities of a given species are often helpful. For example, there are two kinds of "albino" black rats, and if they are bred together you can wind up with all normal looking babies. Even the experienced breeders can't answer some of the questions which would at first seem to be basic. I asked Brian, of BHB, if the albino "greenish" ratsnake that I got from him would produce albinos if bred to a typical albino black rat. His honest answer was that he was unsure....but if I were to find out, please let him know. The obvious, quick answer would have been, "Sure...You breed an albino with an albino and you get all albinos." But since the gene for albinism is not always carried in the same place when you are talking about different kinds of snakes (or even two different morphs of black rat), the answers can become fairly complex. I took a genetics course in college (and I was a psych major...go figure!), and it seems that the more you know, the less crystal clear some of these things actually are. Fascinating, though. Duffy

I agree that Passport's question is very complex, and with the information given, none of us could give a simple answer to it. I would hope that if Passport took the time to read what was on the link, Passport would have a clue into the complexity of the subject and why there is no simple answer. You need to know about the genetic background of both parents to have a clue. Even knowing that, usually all you can give someone is a set of odds.
Duffy, I enjoy reading your replies. You are a good soul to spend the time to give such full explanations in your answers to the questions that you respond to.

I have been accused of being long-winded, and I can type pretty fast, so it's pretty easy for my to post somewhat... um... lengthy responses. Can be a blessing and a curse. I put both feet in my mouth every so often. I really enjoy these forums and the people on them. It adds a dimension to herping that is both fun and informative. Like your handle, by the way. I also am a big "elaphe" fan. Duffy

I don't type as fast, and I try to keep it short. Now what was your major again, physics or psychology? ;~)

Since we are talking about genetics and crosses, has anyone tried crossing a leucistic black rat with a white sided black rat. Do you get offspring that are mostly in between, or a mix of each. I am wondering if there are multiple alleles for the black pigment in Elaphe obsoleta obsoleta. We are now seeing brindle colored snakes, and brownish coloring is found normally in nature. Has any research been done on this?

Psychology as an undergrad. Counseling Psych in grad school.
Your hypothetical cross may well all turn out to be normal looking, since both are simple recessive traits. Same with the brindle variety, I think, although your idea of multiple alleles in the normal color is a good one. Makes sense, anyway.
I really like the licorice stick (white side) morph. Haven't dished out the $$ for one (yet?) although my normal black is 66%
chance het for it, supposedly. He's 66% chance het for albino, also, which I may explore next year, since I have an albino black rat female. It may be quite some time before I find out if the male has any licorice in him. Duffy

The offspring would be wild-type coloured Ratsnakes - Het. for both mutations, Albino & Leucistic. Wouldn't really matter if they were for Texas or Blacks. The adult colouration (& pattern) would probably vary a bit but they normally do anyways unless you breed specific locality aniamls together. Even then, there is a good chance @ variation. I have bred Leucistics into the Lic. Sticks (aka White-sideds) and have Dbl. Hets. that should produce Leucistics, Licorice Stcks & wild-type coloured animals in the same litter this summer. The Brindle trait is a seperate mutation that does not have anything to do with either of the other two mutaions unless it is bred into them. The Rusty Black Ratsnake is a trait that seems to be linked to the Leucistics. Kinda like a co-dominant trait that signifies an animal ois Het. Leucistic.

We must have different ideas as to what a true albino is. That trait is recessive and is only expressed in homos.

My short time spent in genetics lab tells me that this is not as simple as you seem to think it is. You seem to be very experienced at breeding rat snakes, but what you are saying that you get from these crosses doesn't make sense. If you saw those results, it would indicate that your parents are not what you thought they were.

If you breed an Albino to a Leucistic all the offspring will be Dbl. Hets. or Het. for both mutations. Both are simple recessive traits. It would look like this on a Punnett Square - 7th grade Biology.
A = Albino L = Leucistic
An Albino = aaLL A Leucistic = aaLL

AAll
_______
aaLL/ AaLl = 100% Dbl. Het. offspring

http://www.geneticswizard.com/default.asp

If you breed an Albino to a Leucistic all the offspring will be Dbl. Hets. or Het. for both mutations. Both are simple recessive traits. It would look like this on a Punnett Square - 7th grade Biology.
A = Albino L = Leucistic
An Albino = aaLL A Leucistic = aaLL

AAll

Albino would be aaLL as you suggest, but leucistic would be AAll, not aaLL.

______
aaLL/ AaLl = 100% Dbl. Het. offspring

Actually, aaLL x AaLl would result in Normals and albinos, not 100% double hets. From the cross you suggest (aaLL x AaLl) the following genotypes could potentiall result:

AaLL = Normal, het albino
aaLL = Albino
AaLl = Normal, double het
aaLl = Albino, het leucistic

Maybe what you meant to say was aaLL X AAll would result in AaLl (all double hets)?

kk

That is what I meant

No, we are not on the same page. Both leucistic and albino are phenotypes, not genotypes. You seem to think that one gene accounts for a snake being albino. Sorry, but that is not the case. If these snakes are anything like corns, there are genes that control each color found on them. Since there are white sided black rats (not wild yet not fully leucistic) there must multiple alleles for the black coloring, or incomplete dominance going on. Since some Black Rats are brown, there may still be even more genes involved.

I may not know the answers, but I do know what the questions look like.

Corn Snake Genetics Primer

I understand that there is not one gene that makes a snake an Albino. That is why there at least two - poss. three - different types of Albinism in Black rats. That is also why the T pos. Albinos can range from a Reddish-orange to a Snow-white appearance. So what is your point?? Albino crossed into Leucistic still makes 100% Dbl. Het. for Albino Leucistic!! I've produced Albino Leucistics, Albino White-sideds, & Dbl. Hets for Leuc. & Lic. Stick.

Look, you are a smart person, and you have a good idea of what you get when you cross certain morphs of snakes, but you keep confusing genotype with phenotype. They are related but they are not the same.

Phenotype is what the you see expressed; genotype is the genes themselves. Albinism is a recessive trait that results from an absence of pigment formation. You do not use it directly when doing a cross. Lets take a basic example. In genetics labs, students work with fruit flies. There are as far as color goes two types, wild and albino. The wild type is generally shown as “W” with the albino form shown as “w”. When you do the square for a cross between a homo wild with an albino it is shown as "WW x ww" and the offspring are shown as "Ww".

If Black Rat Snakes had just one gene that controlled color and the snake could be the wild type and the albino type, then you would show the cross as I did above. There would be only one letter used, and the small form of the letter would be used to express the albino form of the gene. An albino would be indicated by having the wild trait expressed as two small letters.

Since a Black Rat Snake has multiple genes for color, you have to show each gene involved as separate when you do your cross. Let us say that a Black Rat has genes for black, brown and white. Let use then say that we are crossing it with an albino form of the snake. The cross would be done something like this: “BB,NN,WW x bb,nn,ww” where "B" stands for black, "N" stands for brown and "W" stands for white. Note that the albino form is shown with all small letters for the genes involved. The resulting offspring would be shown as "Bb,Nn,Ww" and it would tell us that only the wild types were expressed in the offspring. Plese also note that the albino snake could only be one that is "bb,nn,ww". If it were something like "bb,nn,Ww"' it may look a lot like an albino, but it would not be a "true" albino.

At this point, I hope that we all agree that there is more then one gene involved in the albino and leucistic forms of black rat snakes. After all, they are phenotypes and not genotypes. You would also never show a cross of these snakes as "AA,ll x aa,LL" because you would be showing the phenotypes and not the genotypes that produce such snakes.

I have not mentioned the terms phenotype or genotype & therefore, have not confused the terminology. I think it is you that is confusing the terminology. When using a Punnett Square, the phenotype is determined by the traits involved. For example, an animal can have numerous traits represented in the genotype of that animal. A wild type animal can carry the recessive genes to produce Albinos (aa), Leucistics (ll), Brindles (bb), & White-sideds (ww). The genotype of a quadruple Het. would look like this = AaLlBbWw. The lower case letter represents the recessive trait making that animal heterozygous for that particular trait. In recessive mutations, the upper case letter represents the wild-type colouration. The presence of both lower case letters for a particular trait will determine the phenotype of that animal because it is homozygous for that trait. For example, an Albino White-sided black Ratsnake is still an Albino & a White-sided and would be represented by this genotype = aaww. Other traits can and are operational on seperate alleles. An Albino White-sided could be Het. for Leucistic & Brindle & would be represented in this way = aaBbLlww. Therefore, an Albino Leucistic (aall) is still a Leucistic & an Albino in the same specimen.

Ok, try reading this.

Color Anomalies in Snakes

by Myia Sindelar

Why are snakes called albino when they have obvious coloration? How does a pairing of two albino snakes produce normal offspring? What is the difference between leucistic and albino? The answers to these questions involve basic genetics and knowledge about skin pigment cells and the role they play in determining phenotype (outward appearance). While I in no way claim to know all about this subject, I have recently had the opportunity to learn some of the basics behind skin color aberrations in snakes (Actually Eileen forced (ha-ha) me to write a paper for her developmental biology class on the subject). The following paragraphs represent my feeble attempt to explain what I have learned.
Before I get into pigmentation, I thought it might be helpful to do a little background on the skin, where it comes from and what its function is. The simplest definition of skin is that it is a protective barrier between delicate body organs and the environment. The skin also prevents dehydration and protects the snake from toxic substances. Two other functions of the skin rely on the presence of melanin, they are protection from ultraviolet radiation and thermoregulation. The skin of a snake (or any vertebrate for that matter) is composed of two basic layers called the epidermis, the outermost layer, and the dermis, the underlying layer. The origins of these layers can be seen in embryonic development when cells differentiate into ectoderm, mesoderm and endoderm. The ectoderm will give rise to the epidermis along with skin glands and the nervous system. The dermis on the other hand will be formed from mesoderm along with muscles, bones, and the circulatory system. Lastly, endoderm gives rise to several organs and the lining of the respiratory and digestive systems.
Now for the interesting stuff. Skin color is determined by skin pigment cells called chromatophores. Chromatophores arise from the neural crest, a part of the embryonic ectoderm. Early in development these cells migrate to the skin where they may differentiate into one of three chromatophore types. These three types are melanophores, xanthophores and iridophores (this is where I consider reptiles lucky because warm-blooded creatures have only one type of chromatophore, the melanocyte).
Melanophores are cells responsible for synthesizing black and brown pigments. A process called melanosynthesis is essential to the production of melanin. Melanosynthesis involves the conversion of the amino acid tyrosine to melanin which is a somewhat complicated process that has two crucial steps. In step one tyrosine is converted to dihydroxyphenylalinine (dopa); step two converts dopa to dopaquinone. The key to these two steps is that it cannot occur without the enzyme tyrosinase. If tyrosinase is absent, tyrosine cannot be converted to melanin.
Xanthophores are pigment cells responsible for yellow, red, or a mixture of the two colors. The exact color of a xanthophore is determined by the number and combination of the yellow and red pigments in the cell.
Iridophores do not synthesize pigments, they do however produce color based on their physical properties. These cells house organelles called reflecting platelets that reflect and scatter light. The colors that can result from these cells are greens, blues, reds and browns.
These three cell types are situated in the epidermis and it seems that their location is predetermined by genes, although the exact mechanism is not fully understood. The density, distribution, quantity and quality of the pigment cells interact with each other to produce the colors and patterns we see. Pattern is more attributed to the melanophores and xanthophores and color quality is a result of the iridophores.
Variations from normal color and pattern occur for a number of reasons. The most common aberrancies are albinism, axanthism, leucism, piebaldism, and melanism. This is where the terminology can be confusing and misleading. To be perfectly honest, I am still trying to differentiate them in my mind as I write this. The best way to discuss these anomalies is to treat each one separately.
Albino as defined by Bechtel (1995) is a congenital (occurring from or before birth) decrease or absence of melanin in the skin, mucosa, and eyes. This is usually a result from an inherited defect in melanin formation. Mutations at various loci involving pigmentation can cause albinism or in simpler terms, more than one type of defect can result in an albino organism. The two most common forms of albinism are tyrosinase-negative albinism and tyrosinase-positive albinism. In tyrosinase-negative albinism, the organism is unable to synthesize tyrosinase, the enzyme necessary to convert tyrosine to melanin. This is the result when a homozygous recessive pairing of the gene controlling synthesis of tyrosinase occurs. Tyrosinase-positive individuals have the ability to synthesize tyrosinase but are unable to produce melanin for either or both of two reasons. The first reason is that although tyrosinase is present, tyrosine is not transmitted to the melanophore for conversion to melanin. The other reason is that tyrosinase inhibitors could prevent synthesis of melanin. Tyrosinase-negative and tyrosinase-positive albinos look the same, that is they have the same phenotype. Keep in mind that their genotypes are different. This is the reason why a cross between two albino specimens can result in all or some normal offspring. The following examples may be an easy way to understand this concept:

Assume a male with tyrosinase-negative albinism with the genotype (actual gene make-up) nnPP. The lowercase n represents the recessive mutation for tyrosinase-negative albinism. Assume a female with tyrosinase-positive albinism with genotype NNpp. The lowercase p represents the recessive mutation for tyrosinase-positive albinism. Using a simple Punnett square analysis we can expect the genotype of all offspring to be NnPp. All offspring would be heterozygous and their phenotype would therefore be normal.

Assume a male with tyrosinase-negative albinism heterozygous for tyrosinase-positive albinism with genotype nnPp. Assume a female with tyrosinase-positive albinism heterozygous for tyrosinase-negative albinism with genotype Nnpp. A cross between these two snake would result in the following genotypic frequencies: NnPp:nnPp:Nnpp:nnpp. These genotypes would result in the following phenotypic frequency: 1 normal:3 albino.

The last aspect to mention concerning albinism is that it only affects melanin production. Xanthophores in an albino snake are functional and are still capable of producing pigment. This is why some technically albino snakes have yellowish or reddish coloration. Axanthism is a term that was unfamiliar to me until I researched this topic. Axanthism as defined by Bechtel is a hereditary defect of xanthophore pigment metabolism. The result is a decreased amount or absence of red, yellow and the intermediate colors they form. In this defect melanophores and iridophores function normally. The most typical example of an axanthic snake is what is referred to as an anerythristic (the literal translation of this word is "without red" corn snake. Normal cornsnakes are very colorful including reds, oranges, yellow, brown and black. A corn snake with a xanthophore defect is mostly black and grey. Axanthism, similarly to albinism, can also be the result of a number of different mutations. A mating between two axanthic individuals will not always produce axanthic offspring.
Leucism is commonly confused with albinism with good reason. Both defects will produce a so called white snake. The difference is that while I have shown that not all albinos are white, all leucistic animals are pure white. Leucism is a defect that affects all chromatophores including melanophores and xanthophores. They produce no color whatsoever. The defect is caused by a recessive trait in its homozygous state. This is the only known mutation that causes leucism. So, if you have a white snake, how do you know if it is albino or leucistic? The answer to this is surprisingly easy: an albino snake will have red eyes while a leucistic snake will have darkly colored eyes, probably blue or black. Please use caution when using this to identify a snake! While I have received this information from a book by a well respected herper, I imagine there are always exceptions to the rule.
Piebaldism is the defect I find most fascinating. Piebald means spotted or patched, especially in black and white. The example that stands out for me and probably most of you is a piebald ball python. Unfortunately, little is known about the genetics of piebaldism, except that it is most probably hereditary. Vitiligo is a condition similar to piebaldism. Vitiligo is when a normally colored hatchling loses color as it ages resulting in a snake that looks piebald. The cause of this ontogenetic (acquired during life) condition is unknown. I keep hoping that my ball python will undergo this pigment change (I know the chances are slim, but I can dream, right?)
Melanism is a color variation that results in black snakes that are normally characterized by a color pattern. Melanism is the phenotypic opposite of leucism. Like piebaldism, melanism can occur congenitally or ontogenetically.
The various color anomalies I have discussed are commonly found in the herp trade. We find these snakes fascinating and are willing to pay big prices for them. In our hands these snakes will most likely lead a long healthy life. In nature, on the other hand, these snakes have low chances of survival. Imagine that you are an albino snake, what are the chances you will be able to sneak up on prey unnoticed? What are the chances that a hawk flying overhead will notice you before he notices your normally colored sibling? The fact is that albino and leucistic snakes stick out like a sore thumb in most environments, seriously decreasing their chances for survival. Another factor that can affect snakes with little or no melanin is harmful exposure to ultraviolet radiation. The absence of melanin in these snakes magnifies the detrimental affects of the sun.
I have always considered snakes with color defects interesting. The mechanisms that cause these variations, while somewhat complicated and confusing at times, are interesting too! I have received most of the information from a book by Bernard Bechtel entitled "Reptile and Amphibian Variants." I hope that I have managed to relate some of the information that I have gained about this subject to you.

Bechtel, H. Bernard (1995). Reptile and Amphibian Variants: Colors, Pattners, and Scales. Krieger Publishing Co., Malabar, FL. 206 pp.
Toledo Herpetological Society Newsletter

This just backs up everything I have been saying. I think you just like to argue without trying to prove a point. You never answered my question in regards to breeding an Albino into a Leucistic. Why? You have no idea what you are talking about. Anyone can quote passages from a book. You just seem to enjoy typing "big words" that you have "learned from a book". How do you prove an Albino Leucistic is actually a Leucistic?? You don't quote passgaes from a book. You breed an Albino Leucsitic into a Leucistic. You know what you get?? Of course you don't. You get all Leucistics that are Het. for Albino. That is because BOTH animals are homozygous for Leucisism. I don't think you understand that an animal can be homozygous for two traits at the same time. Because an Albino Leucistic has red eyes doesn't mean it is not a Leucistic - it just means that it is an (homozygous) Albino at the same time. If it was a plain Albino it would have pattern and colour. What is your name & the name of your co./business?? I take it you are from OH?? What EXPERIENCE do you have with Dbl. Homozygous mutations?? What is your real job? And what college/tech. school did you attend?Questions for my own amusement....and by the way, Leucism & the White-sided mutations have nothing to do with each other. They are seperate mutations that operate on seperate alleles. You sound like ODNR to me. They were quoted as saying that you get a Leucistic by breeding two White-sideds together. Are you ODNR??

First, I never said you didn't know how to bread snakes to get the results that you wanted. I am quite sure that you can and do.

What I have said is that by definition a snake with pink eyes is not leucistic. Yes, you can have a white snake with pink eyes, but since it has that eye color, it is not leucistic. That term should not be used. Such words have specific meanings and you are using term incorrectly. I have also said that your cross examples were overly simplistic, and were done by phenotype and not by genotype. All of this is still true, but if you read the article, you would also see that you were somewhat correct.

If you read my last post, It is clear that we have both been wrong in parts of what we were saying. If you read it, then you now know that there are two traits that can cause a black rat to be albino. There is also a separate and independent trait that causes a snake to be leucistic. If a snake is homo for the same albino trait (we are talking about for the black/brown coloring only), and is also homo for the leucistic trait, the snake will have pink eyes. If it has pink eyes, again, it is not a true leucistic snake. What I would say if I had such a snake, is that I had a white albino snake that is homozygous for the leucistic trait.

I am not trying to put you down. I have never called you names. The article I posted was a summery of someone else’s work into this very complex subject that we have been posting on. It was on topic. I think the article is worth the time it takes to read and digest. It sheds light on some of what is going on with crosses for color, and why the results come out as they do. On the other hand, it in no way explains everything. Something’s are known from experience before they are understood by science.

Peace