Figure 1. A dozen Krispy Kreme doughnuts. Now imagine an entire box yourself.

Although I do not intake a meal’s worth of doughnuts every other weekend anymore, I still do occasionally enjoy a doughnut or two… or more.  Last year, when I was in New York City, my boyfriend introduced me to the Doughnut Plant.  I was literally expecting a large building at which they produced copious amounts of doughnuts, but to my surprise, it was just a little shop that produced a limited number of doughnuts every day.  We went late afternoon, and luckily, they still had some left.  At first, we only bought four, but we demolished the Valhrona Chocolate, Vanilla Bean, Jelly Filled Square and Glazed Cake right there on the spot!  Thus, we had to purchase another six to take back.  Best of all, they were “healthy”: all natural ingredients!

Don’t worry Chicagoans, there is a place just like Doughnut Plant (except better) right here in our 175 year old city.  I had heard raving rumors about the Doughnut Vault from numerous food sources, but I did not have the chance to go to their little shop right next to Merchandise Mart to wait in line—until recently.  I cannot stress the importance of getting there early because they sell till they run out, and they run out of the best flavors first.

Figure 2. The line outside Doughnut Vault

My friend and I arrived a little before 9 A.M. (it opens at 9:30 on Saturdays) to wait in line, which was thankfully still short (Figure 2).  As we stood outside with bits of snow drifting onto us, we watched the line quickly grow to what Doughnut Vault tweeted as “70 people in line.”  As the vault opened its doors, the line inched forward.  I was jealous and worried as the first people started exiting with 2, 3, or even 4 boxes of doughnuts—what if they start running out of flavors before I get there?!?!  As we stepped inside the door (Figure 3a), what looked like Dippin-Dots began dropping from the sky, but people were determined to hold their spots in line.

Figure 3. Doughnut Vault. (a) The entrance and (b) the inside of Doughnut Vault.

The Doughnut Vault was a tiny space, enough for perhaps 10 people to squeeze snuggly inside (Figure 3b).  The decorations transported us back in time to an era when a crystal light fixture would hang in a brick vault, but the smell was of enchanting, freshly-made doughnuts.  My eyes truly lit up when we got to the front of the line as a warm, fat doughnut of every flavor was placed into two large boxes.  Each flavor was delicious (Figure 4); biting into every doughnut was a unique experience with a different flavor fulfilling my taste buds.  Although they were all amazing, the gingerbread stack did not live up to the others.  It may just be the lack of a glaze, though.  The best was definitely one of their specials of the day: Drizzled chocolate glaze topped with bits of pistachio that brought together a blend of flavors (Figure 4b).  Overall, these doughnuts were definitely worth waiting 50 minutes in the snow for.

Figure 4. The DOUGHNUTS!!!! (a) From the left: Vanilla, Chestnut and Gingerbread; (b) From the top: Pineapple Old-Fashioned, Old-fashioned, Chocolate and Chocolate Glaze with Pistachio bits.

This post covered A TON of sugar up to here, and too much perpetual sugar could lead to diabetes later in life (type 2 diabetes) unless one is already predisposed to it (type 1 diabetes).  Type 2 diabetes arises when the body becomes insensitive to insulin due to consistently high intake of glucose.  The story of type 1 diabetes, however, has a curious evolutionary twist.  The majority of type 1 diabetes cases, which cause a potentially lethal destruction of beta cells that produce insulin in the pancreas, are diagnosed in children.  Because children have not yet reached reproductive age, natural selection should select against people with type 1 diabetes (decrease in prevalence over generations).  But it was found that 58 of the 80 known mutations associated with type 1 diabetes are actually positively selected for (Corona et al. 2010)!  How could this be?!

Here, I must deviate to a popularly used example to explain the evolutionary basis of those seemingly strange 58 mutations.  Sickle cell anemia is a recessive disease that causes red blood cells to become sickle shaped, rendering the cells almost useless in carrying oxygen in the blood.  However, in Africa there are large populations of people who are heterozygous for the sickle cell trait, meaning they have a dominant and recessive copy of the gene (instead of two recessive copies as in full sickle cell patients).  It turns out that being heterozygous for sickle cell anemia is like a natural malaria vaccination.  In a place where malaria is rampant, this heterozygous sickle cell trait is particularly useful.

This may just be the case with type 1 diabetes.  Although any of those 58 mutations result in a chronic disease, they may also have a hidden agenda, some of which are already known.  For example, a mutation that increases the risk of diabetes actually decreases the risk of enterovirus infections, which  could cause terrible, and even fatal, abdominal pain.  Scientists still need to search the genome for more trade-offs because unlike sickle cell anemia, type 1 diabetes can be caused by any one of hundreds of gene variations.

Enjoy the sugary goodness!

-Lu

References.

Corona E, Dudley JT & Butte AJ. (2010). Extreme evolutionary disparities seen in positive selection across seven complex diseases. PLos One 5(8): e12236.

http://www.mthfr.net and http://www.detox puzzle.com

I continue to learn more and hopefully will improve over time.

It’s been a long great while since I made a science post, what greater day to do so than now?

If you all haven’t at least hovered over your special Google image today, perhaps you’d be enlightened to hear that today is Gregor Mendel’s 189th birthday!

Dubbed the father of genetics for his ground breaking work with happy pea plants, he followed patterns of pea characteristic inheritance by crossbreeding them under controlled conditions. He’s responsible for the terms recessive, dominant, homozygous, heterozygous, and so forth in biology textbooks.

I won’t go through the whole biography of this great friar, but he is one of the many reasons I found myself interested in science. When first mentioned in my middle school, his chapter in the life sciences textbook dealt with the ever so delicate and difficult art of Punnett squares, which were used to predict the percentage/chances of offspring to inherit traits from their parents.

Like many great scientists, Mendel’s work was not fully appreciate until much later when the study of genetics came into full bloom. I hope one day I can contribute to the science world like Mendel did (even if my contribution be small).  Also, I hope to go on some type of academic pilgrimage to visit the areas where other great scientists of the past used to dwell and came about their amazing discovers. Just like Mendel’s monastary, where he cared lovingly for his pea plants that expelled knowledge of independent assortment and segregation of traits.

Thank you to the father of modern genetics. Because of you, we are able to understand how traits, especially pathological ones, are passed on (or at least have the basis on learning how to solve them). Thus helping us to understand and improve our lives.

One time for AP Biology, I had to write a play with my lab partners that invited a variety of historical science figures to discuss their theories: Darwin, Cuvier, Lamarck to name a few. I had written Gregor Mendel as a simple monk, eloquently sipping split pea soup, and rocking out to Gregorian chants on his Ipod. Happy Birthday good Gregor Mendel.

Because of this, a “strong” coat has nothing to do with the actual gene. A black andalusian gene has an equal chance of passing (and showing) to another generation as a brown bay gene.

Have you ever noticed that one horse has a tendency to “throw” it’s coat, or it’s long mane to its offspring? For example, I have a male, Darius, that has passed his long mane and long tail in 4 out of 6 bundles that he’s produced. His half brother, Panda, is the opposite, passing these long long traits in only 2 out of 6 bundles. Both horses are long longs. However, Darius has a stronger genotype than Panda. Remember that phenotype is what they look like – the physical set of traits that you see when you click on a horse’s stats. (If you’re wondering what the heck I’m talking about, check out my post here on horse genetics.) In this case, Panda and Darius’s phenotype are the same: Long mane, long tail. The genotype of a horse however, should and is far more valuable to a breeder than phenotype, and it refers to the two genes that a horse carries for every trait!

Homozygous long x homozygous normal

Heterozygous long x homozygous normal cross

So now think about this. If you have a homozygous horse, you double your chances of getting the trait to the baby! 100% of your bundles carry the gene and 50% have a chance of showing the trait, as opposed to 50% carrying the gene from a heterozygous horse with a 25% chance of showing the trait.

So how do we find these homozygous horses and breed for them in our herd? I will write more about that in my next post! ^.^

Also, I have gotten this question a lot from new breeders as well as it is a topic that shows up in group chat:

If there’s no dominance or recessive genes, why are there more of one coat (like palominos) than another (like andalusians)?
The reason why we see more “starter” coats (Painteds, Palominos, Bays and Buckskins) isn’t because they are dominant genes, but it’s because there are MORE of these genes in the population. As breeders, we place a selection preference (also called selection pressure) against the horses that have the traits we want, however, if Amaretto releases starter horses with a lot of these genes out, we have to “select” for other coats in order to increase the number of those genes in the overall horse population. Like for instance, have you noticed how many walkers are out there? Even though Amaretto has discontinued this coat, meaning they will no longer release these genes in their starter bundles, everyone breeds for them. Therefore, walkers have a very, very slim chance of becoming extinct and (I think) are even more common on the market than palominos!

Do you have more questions for me? Please feel free to send me a notecard or an IM.

Happy Trails!
Blue Myanamotu aka Akemi

By crossing two of those offspring, he received 3 dominant for every 1 recessive plant.  Random chance indicates that if you run that test a thousand times you’ll get a ratio of 3:1.  The more times you run the cross, the closer to 3:1 you’ll get.  Genetics is partially a lesson in simple probability.

In order to perform crosses by hand, we set up a Punnett square, which will allow us to work out the cross on paper.  Because showing your work is actually advantageous outside of homework and tests, we’ll do some samples.

In the below image, which I’ve beautifully created just for you, you’ll find the Punnett square, with one parent’s genotype on the top and the other on the side.  Which parent goes where, doesn’t matter; just make sure there’s always one allele for each of the 4 boxes (2 on top, 2 on the side).

The first square crosses a purebred dominant tall pea plant with a purebred recessive short pea plant.  Just as Mendel showed, when you cross, you get all tall plants.  The genotype for all 4 is hybrid (heterozygous) tall.

The second square cross two of the offspring from the first square.  2 hybrid tall pea plants result in 4 offspring: 1 purebred (homozygous) tall, 2 hybrid (heterozygous) tall, and 1 purebred (homozygous) short.  So the ratio for phenotype can be described as 3:1 (3 tall : 1 short) and the genotypic ratio can be described as 1:3:1 (1 homozygous dominant : 2 heterozygous : 1 homozygous recessive).

Full size for download

Any questions? Let me know!

Think you got it down? Try a few more:

Cross and determine the 1. phenotypic ratio and 2. genotypic ratio of:

1) Ss x Ss
2) Ww x WW
3) PP x Pp
4) A hybrid rough and a homozygous recessive for smooth seeds.

On Wednesday, September 20, 2006, in his poignant address to the United Nations, Venezuelan President Hugo Chavez likened former President George Bush to the devil: “the devil came here yesterday,” referring to Bush, who addressed the world body during his Tuesday address, Chavez said, “and it smells of sulfur still today.”

“The devil came here yesterday,” referring to Bush, who addressed the world body during his Tuesday address, Chavez said, “and it smells of sulfur still today.”

Racist John Bolton, the former U.S. ambassador to the United Nations under the Bush regime, dismissed Chavez’s comments saying, “I think that [Chavez's] rhetoric today shows exactly what kind of man he is.”

While many in the West derided Chavez’s comments as such, biologically, there is a reason The Devil smells like sulfur. In the documentation of his graft of the white man, the original Yakub not only noted this but predicted it would happen.

Homocysteine, a Sulfur amino acid, is, in Western science, noted as being (only) “mildly” more present in heterozygous persons (mankind). Heterozygous refers to having two different alleles for a single trait. Organisms have two alleles for each trait. When the alleles of a pair are heterozygous, one is dominant and the other is recessive. (Link)

Using static testing methods to measure non static and non stable  properties in mankind, the modern West estimates the percent of “whites” that are heterozygous is 10%. Their (“whites’”) well documented “recessive gene,” however, demonstrates the racial manipulation in their findings.

What they note as Hyperhomo-cysteinemia, a blood disorder marked by an excess amount of  Sulfur amino acid(s) shows a prevalence near 15% in European, Middle Eastern and Japanese populations, compared with a range at or below 1.4% in African Americans. Among them, the condition can and will  fluctuate seemingly sporadically and spontaneously as a result of constantly changing dynamics such as temperature and even emotion(s). Thus, the rate of Hyperhomocysteinemia or the presence of excessive amounts of Sulfuric amino acids in Caucasian persons cannot be measured by tools that render static results.

Grafted in gene separation, from various beasts and lowly compounds like sulfur – & chiefly noticeable when they sweat, there is a reason the Caucasian population smells the way it do.

Because it is the path they chose and, hence, now given over to the reprobate minds and psychologies their forefathers designed for them, there is a reason they’re called the devil: they fulfilled the prophesy of continued treachery, deceit and evil the ancients foretold of them.

What will be the color of your eyes?

Blue or Brown which colors  more dominant?

Like the color of your eyes now that’s more prominant.

Or you can get genes that are recessive

And really are…less excessive

It’s the chromosomes that give you your traits.

But, first they’re all together like tiny crates.

They go through a process called meiosis.

This could be furocious!

Homozygous alleles are the same

Heterozgous you’ll see you’ll get a change.

We come out in  our own way.

And then we meet each other every single day.

No, skin without eumelanin is not skin.

While the new science is not yet publishing publicly what the layer covering the so-called fairskinned is, the conclusion that it is not skin, as defined by classic definitions is now widely accepted. For, skin does not burn in the sun light.

Heightening the problem, however, is that ultra- violet light does not only adversely affect what white people call their skin, it also adversely affects what they call their minds. Yes, ultraviolet light burns their brains further corrupting their thoughts.

“The more UV light coming through the Ozone layer, the crazier, more dangerous, more psychotic and more perverse white people will become,” says black sun worship leader and scientist Yacub 12 X. “As more UV light comes through the Ozone Layer and burns their skin, it also burns and destroys their brains. It is making it increasing difficult for them to choose between their normal evil and the increased levels of perversion in them we are seeing.”

Unlike blacks, whose pineal glands contain eumelanin, the pineal glands in whites are calcified. The calcification is tantamount rocks. The increases in ultraviolet light cause these rocks to rub against each other. The result, again, are the increased levels of perversion and evil we are seeing in them.”

Article continues below:

Of The Biggest Differences Between The Properties Of God & Satan: EUMELANIN VS PHEOMELANIN & Why The Devil Smells Like Sulfur…….

The level of UV light now is generally speaking higher that it was 50 years ago. This is due to a reduction of ozone in the earth’s atmosphere. Ozone serves as a filter to screen out and reduce the amount of UV light that we are exposed to. With less atmospheric ozone, a higher level of UV light reaches the earth’s surface.

Contrary to Western Science, mankind’s pollution and toxins are not responsible for the increases in ultraviolet light passing through the Ozone layer.

God opened the Ozone layer up to burn His reproach and begin the Fires of His prophesied 2nd Rapture.

Because white people chose perversion, greed and hate over love, God turned them over to their reprobate minds. But moreso, so that the entire world can see the fufillment of evil, the increased levels of ultraviolet light magnify the evil nature they chose.

FOR NOVICE PET BIRD BREEDERS

A handy reference of practical applications for cage-bird breeders who want to produce certain colors in their stock or guarantee the sex of the offspring.

The subject of genetics can be either an all-consuming lifetime study for a professor in research, or for us more average people, an effective tool to get a job done. Hobbyist-breeders of high quality stock will find themselves concerned with attaining specific goals for their birds. By applying the basic principles of heredity and selectively pairing the different types of mutations together one can know beforehand what to expect in the nestbox.

Propagation of different colors, the ability to sex chicks, and breeding to conform to a show standard are all high priority items for serious breeders. Our primary focus here will be utilizing different color mutations to obtain desired results and, hopefully, answer common questions. Along the way some of the common errors should also be cleared up.

One nice thing about working with parrot-type birds is the similarities in their colors and how these traits are passed on from one generation to the next. Dominant, recessive, and sex-linked mutations find parallels in cockatiels, budgies, lovebirds, ringnecks, amazons, lineolateds, etc. For this reason it is logical that future aviculturists can expect to see many of the same colors showing up in the less established species as we now see in the lovebird and budgerigar. In many of the less domesticated species of parrot a new color showing up in a clutch is cause for much excitement and celebration. Among aviculturists these are very valuable birds!

Sometimes a mutation showing much the same genetic and visual properties will be called by different names on different species. The opaline budgie and pearl cockatiel exhibit much the same melanin deficiency pattern in the feathers and both are also genetically sex-linked. Conversely, the mutation called “Fallow” is said to be recessive in cockatiels but sex-linked in Green Cheeked conures – how confusing!

I believe the easiest way to illustrate the concepts involved is simply to answer a few of the practical questions asked by fellow breeders. For those who wish to find their own answers to other questions there is a listing of possible matings and outcomes shown in a way the average person can follow. All you have to do is pick a single mutation you wish to know about and “plug it” into the following lists of matings.

As will be made clear, the results of these crosses apply equally well to any mutation with similar genetic properties found in many different species of parrot. By the way, all the answers and solutions to the questions and crosses involve only a single mutation. In real life other colors could pop up from unknown carriers of other traits.

Just in case you didn’t know: “NORMAL” refers to the wild form of any trait. This wild form is usually dominant but not always so.

A “VISUAL” bird shows the mutation but a “CARRIER”or “SPLIT”does not.

“FACTOR” is a layman’s term for a gene or allele carrying the desired trait. Therefore the terms SINGLE FACTOR, CARRIER or SPLIT all describe the “HETEROZYGOUS”condition of having one mutant gene paired with a normal gene.

“DOUBLE FACTOR” refers to a pair of two identical or “HOMOZYGOUS”genes carrying the same trait.

“PHENOTYPE” is simply what the bird visually looks like.

“GENOTYPE” describes the genetic composition.

“SEX-LINKED” traits seem to be fairly common in birds so let’s start with the pairing of any one sex-linked color. (All mutations showing these results are found on the sex chromosome which determines the sex in higher forms of life, hence the name sex-linked.) In birds, males have a double set of complete sex chromosomes where hens have only one complete set. (The reverse is true in mammals.)

SEX-LINKED QUESTIONS:

1. Question: I have a pearl hen paired with a normal cock. Will I get any visual pearl babies?

1. Answer: Maybe, it all depends on if the cock is carrying the pearl. If he is you can get 50% pearls and 50% normals of either sex but if he is not “split” to pearl all of your chicks will be normal.

2. Question: How can you guarantee the sex of a baby cockatiel while it is in the nest?

2. Answer: Normal gray chicks are very difficult to sex but with knowledge of how sex-linked traits work it becomes a 100% guarantee for the seller. Simply pair a cock showing any sex-linked color with a hen not showing that same color, then all the daughters will show it but the sons won’t. All the normal birds must be cocks carrying the trait from the mother but they will still look completely normal.

3. Question: I have a pair of normal Peach Faced lovebirds and I found a lutino baby in the nest. How did this happen?

3. Answer: Simple, The father must be carrying the gene for lutino which he passed on. Statistically 50% of his babies will carry this gene. Among those that do, only hens can show the color from a pairing of normal looking birds. Therefore, 50% of the cock siblings will be “split” for lutino and another 50% will not receive the mutation at all. None of the cocks will show the trait. Only by breeding these cocks can you tell if they are indeed “split” to lutino.

4. Question: It sounds simple to produce hens displaying a sex-linked color. How do you produce males showing it?

4. Answer: You’re right, there are more ways to get hens than cocks showing sex-linked colors. The trick for producing cocks is to pair a hen showing the desired trait to a cock either showing it or carrying it. In order for a baby cock to show any sex-linked trait he must have gotten the allele (the mutation site on the gene) from both his parents. If the father is only “split” 50% of the babies will show it and be of either sex. Of the chicks looking normal, all the cocks must be “split”, as they would inherit the trait from the mother.

Here are a few rules to follow when dealing with sex-linked properties.

SEX-LINKED RULES:

I. NO HEN CAN BE “SPLIT” TO OR CARRY A SEX-LINKED TRAIT: If she doesn’t show it she doesn’t have it.

II. ALL HENS GET SEX-LINKED TRAITS FROM THEIR FATHER: A visual cock has two alleles whereas a hen can only carry one. Therefore, a daughter must have received her one allele on her single sex chromosome from her father. (If she had gotten two, one from each parent, the bird would be male.)

From this it follows that a double factor visual cock paired with a normal hen will result in all daughters showing the sex-linked trait, but no sons. These sons will all carry the allele but not show it. Conversely, a visual hen paired with a normal cock will only produce normal colored “split” sons and normal daughters, but no visuals. Once again this is the key for sexing babies. Pair a sex-linked visual cock with a non-visual hen.

III. COCKS CAN BE VISUAL OR “SPLIT”: To show a visual trait a cock must receive it from both parents (much like a non-sex-linked recessive trait requires). Remember in sex-linked genetics this only applies to cocks – not hens. (Of course, this assumes the trait we’re dealing with is sex-linked recessive, not all of them are!)

Once you understand sex-linked rules and regulations, recessive and dominance is easy. Next we’re going to deal with AUTOSOMAL or “body forming” chromosomes in which both sexes have the same double pairing. There is no need to worry about cocks and hens as different examples because hens carry the double dose too.

Here are some questions illustrating the mechanics of simple dominant-recessive inheritance.

DOMINANT-RECESSIVE QUESTIONS:

1. Question: A pair of green budgies produced a blue chick. How come?

1. Answer: Even though both parents look pure green, genetically they are not. To produce any recessive trait such as blue a chick must receive a blue allele from each parent. This means the parents must both be “split” to blue.

Your chance of getting more blue chicks is 25%. The remaining green chicks have a 66.6% chance of carrying the blue gene (heterozygous) but will look identical to the 33.3% green chicks not “split” but having a set of two green genes or alleles (homozygous). Only by breeding these green chicks with mates having one or two blue alleles will you know which is which. If there ever is a blue (recessive) chick from a green (dominant) parent, that parent bird is carrying the recessive trait from one of it’s own parents.

2. Question: I have a blue Indian ringneck paired with a normal green and am not getting any blue chicks. Why?

2. Answer: Green is dominant over blue so a visual blue chick must have a set of two blue genes, one from each parent, to show blue. If the green parent is not heterozygous to blue it has no blue allele to pass to the offspring. I can guarantee all of the chicks are “split” to blue so when paired to blue carrying mates they will have either a 25% or 50% chance of producing blue chicks. (These odds reflect the pairing of either a split or visual blue to a split to blue mate.)

DOMINANT / RECESSIVE RULES:

I. DOMINANT TRAITS HIDE RECESSIVE TRAITS. If an animal or plant has a dominant gene paired with a recessive gene (heterozygous or “split”) only the dominant feature will show up.

II. A RECESSIVE TRAIT MUST BE GENETICALLY PRESENT IN BOTH PARENTS BEFORE OFFSPRING CAN SHOW IT. A fertilized egg (zygote) receives a single set of chromosomes from each parent. To show a visual recessive mutation the zygote must have two recessive alleles. If it only receives one recessive its 2nd gene or allele will mask it, which by default is dominant.

Here is a quick reference guide to help you pair your stock correctly. To get the desired results all you need to know is which traits are dominant, sex-linked, or recessive. Of course all theoretical outcomes reflect statistical probabilities. Some clutches will probably not show these expected ratios but it will all work out over the long run.

1. Use any dominant or recessive trait.

2. Select the pairing of your choice from the dominant and recessive pairing combinations below.

3. “Plug in” your particular dominant or recessive trait to see how it works out.

DOMINANT TRAITS: (autosomal non-sex-linked) include MOST WILD COLORS, DOMINANT PIED in budgies, AUSTRALIAN GREY in budgies, DOMINANT SILVER in cockatiels etc.

RECESSIVE TRAITS: (autosomal) include PIED or HARLEQUIN, BLUE – WHITEFACE, in budgies and tiels; WHITEBREAST, BLUE and YELLOW HEADED in Gouldians etc.

DOMINANT & RECESSIVE

TRAIT PAIRING COMBINATIONS AND RESULTS:

1. Dominant double factor (homozygous) mated to a dominant double factor or dominant single factor “split” to a recessive.

RESULT = 100% dominant looking chicks.

2. Dominant double factor (homozygous) mated to a recessive double factor (homozygous).

RESULT = 100% dominant single factor (heterozygous) babies carrying the recessive but showing the dominant color.

3. Recessive single factor ” split” to dominant mated to a recessive single factor “split” to dominant (both heterozygous birds carrying one dominant and one recessive allele).

RESULT = 75% dominant and 25% visual recessive (homozygous) chicks in the nest.

4. Recessive single factor / dominant (heterozygous) mated to a recessive double factor (homozygous)

RESULT = 50 % dominant single factor “splits” and 50 % recessive visuals.

5. Recessive double factor visual mated to a recessive double factor visual.

RESULT = 100% visual homozygous recessive chicks.

SEX – LINKED RECESSIVE

TRAIT COMBINATION PAIRINGS AND RESULTS:

SEX-LINKED RECESSIVE TRAITS inc. LUTINO, PEARL, OPALINE, CINAMIN, in tiels and budgies, ROSY in Bourkes etc.

Pick any Sex-Linked trait,”plug it” into the pairing of your choice and check out the outcome.

1. Sex-linked visual double factor cock mated to a normal hen.

RESULT = 50% normal cocks carrying the sex-linked color and 50% hens all showing the sex-linked color. All babies are sexable as soon as you see the color on the feathers.

2. Sex-linked visual double factor cock mated to a sex-linked visual (must be single factor) hen.

RESULT = 100% sex-linked visual chicks of either sex.

3. Sex-linked single factor (non-visual) cock mated to a normal hen.

RESULT = 25% normal homozygous cocks, 25% normal cocks “split” to the Sex-Linked color, 25% visual hens showing the sex-linked color, 25% normal hens. This translates to 75% normal birds and 25% sex-linked colored birds. All the colored sex-linked babies are hens but the normals are not sexable by sight. Also 50% of the normal colored males will be split for the sex-linked trait and 50% will not carry it at all.

4. Sex-linked single factor (non-visual) cock mated to a sex-linked single factor (visual) hen.

RESULT = 50% sex-linked visual birds of either sex and 50% normal colored babies. All of the normal colored cocks will be “split” for the sex-linked color.

5. Normal cock mated to a sex-linked visual hen.

RESULT = 100% normal offspring. The sons will all be carrying the sex-linked gene but will all look normal.

Now that we have run through the possible different pairing combinations and statistical outcomes of single mutation matings let’s apply this to a real situation.

A breeder-friend excitedly showed me what appeared to be a lutino Sun conure chick that came out of normal looking parents. Various “expert” breeders advised her to breed this chick to a sibling to produce more lutinos. There are two good reasons why this practice should not be followed.

First: if your goal is to breed the strongest chicks possible you should avoid inbreeding as much as possible. Contrary to the beliefs of many, brother-sister matings are less desirable than breeding back to the parent.

Look at it this way. Common sense should tell us that birds having two different parents or even one different parent should be more distantly related than siblings sharing both parents. Although breeding back to a parent is still considered close inbreeding, you are still bringing in more genetic diversity from a previous generation. This is certainly better than breeding together two individuals sharing both parents and thus the same genetic source from both sides!

Second: If your goal is to pair your birds to provide the greatest chance of producing a desired trait, it is much better to mate the desirable chick to a parent proven to carry the color (he produced the chick) rather than to a sibling who might be carrying it.

Let’s look at this chick that might be a lutino Sun conure. There are a couple of basic questions that must be asked.

1. Question: Is this mutation dominant, recessive, or sex-linked?

1. Answer: Since this chick came from a set of normal looking parents from different bloodlines and mutations at this time are relatively rare in Sun conures the easiest way for a mutation to pop up would be for a sex-linked single factor cock to pass it on to a daughter. (See sex-linked trait pairings

Since both parents look normal we can rule out a dominant allele and since a recessive trait requires it’s presence in both parents to produce a visual chick (see Dominant / Recessive Rules) it is unlikely to be recessive. Also, the chick looks like a lutino and lutino has a consistent history of being sex-linked in other species of parrots. I would suspect this mutation is sex-linked.

2. Question: How should this chick be bred to gain the greatest chance of producing more lutinos?

2. Answer: Assuming we are dealing with a sex-linked trait we must also assume the lutino chick is a hen. The best option is to breed her back to the father who we know is carrying the mutation.

As you can see, a little common sense paired with a basic understanding of genetics can help you work out some of the many everyday problems confronted by the average breeder. It is hoped that as you work with applying the above pairings and results to your own birds that, with practice, you will begin to understand and appreciate a small part of the wonder to be seen in the natural world. How fortunate we are to have this opportunity to serve and respect the natural order around us!

Yet, we are not done – not even close. I cannot think of a subject more befitting to the belief “The more we know, the more we know we don’t know”, than genetics. The basic premise is beautifully simple but the applications of this simplicity becomes challengingly complicated in a hurry, especially when in the real world of multiple traits and multiple properties.

ALBINO: A TWO-FACTOR TRAIT

“Found in cockatiels, budgies, ringnecks etc.”

Let us begin with a combination of two traits and properties called the albino. What it is and how it is produced.

The albino form is not a single mutation at all. It is a combination of two very different traits, lutino which is sex-linked and blue or whiteface, which is recessive. The lutino factor takes away the dark melanin resulting in a yellow bird with pink eyes.

The whiteface factor in cockatiels removes the yellow pigment in much the same way as we see in the blue budgie. Since a normal cockatiel is not green the result, when yellow pigment is removed, is a gray and white bird. Both mutations working together in budgies and cockatiels produces a beautiful snow white bird with no yellow or dark markings.

Obviously if one wishes to breed this type of albino it is essential to keep track of both sets of alleles and their different properties in both parents. The easiest way to do this is to look at an albino cockatiel, budgie, ringneck, etc. as the result of seeing two separate traits working independently of each other on the same bird; one is sex-linked, the other is recessive.

Plug in the blue-whiteface into the recessive matings and lutino into the sex-linked matings and then combine the two outcomes.

As an example let’s pair a visual lutino “split” to whiteface cock with a whiteface hen. The cock must be a double factor lutino to show the trait while the hen cannot carry a sex-linked trait at all unless she shows it (see Ex. #1 Sex-Linked Pairings). Due to the “lutino” factor all the chicks will be sexable. The recessive whiteface must also be present in both parents to produce whiteface or albino.

In our example we have paired a visual lutino/”split” whiteface cock with a double factor whiteface hen (see Ex. #4 Dominant/Recessive Trait Pairings). 50% of the offspring of either sex will show whiteface and 50% will be heterozygous non-whiteface normals. Combining the results of these two traits gives us the answer to the number of albinos expected in the nest.

Since we know 50% of the clutch will be daughters who in turn must be lutino and 50% of all chicks statistically will show whiteface, that leaves us with 25% of the clutch showing up as albino daughters.

CINNAMIN PEARL:

Don’t let this combination fool you.

A common misconception among cockatiel breeders is the idea that two separate mutations, namely pearl and cinnamon, combine to form one indivisible single cinnamon-pearl trait. In other words, a bird with both cinnamon and pearl can produce only cinnamon-pearls with no single trait cinnamons or pearls in the nest.

Two separate traits combining to form one is extremely rare and does not happen in this case. It is true that a double factor cinnamon-pearl cock will only produce cinnamon-pearl daughters but these traits are passed on independently of each other. A simple test is to mate a cock “split” to both cinnamon and pearl with any hen. You will indeed over time see cinnamon only, pearl only, cinnamon-pearl and normal gray chicks.

VIOLET: A THREE-FACTOR TRAIT.

Now let’s look at a color requiring a set of three different traits to be present in the right proportions for it to show up. The violet allele is in itself a dominant autosomal mutation that is also lethal (if a baby receives two violet alleles it dies). Also, for the true violet color to show, the trait must be present on a cobalt blue bird. If violet is present on a homozygous sky blue bird lacking one dark-factor allele then the bird will look much like cobalt but will actually be a sky blue violet.

Here is an example of how to simplify what appears to be a complex question.

Question: I have a pair of green budgies and I found a violet chick in the nest. How did this happen?

Answer:

1. First, in order for a pair of green birds to have a blue chick, both parents must be “split” to blue.

2. Second, visual violet requires just one dark-factor for it to show up.

This can come from either parent.

3. Third, violet is dominant so this single gene on cobalt will automatically give violet. Violet can also be passed on from either parent.

Now let’s move on and look at a few examples of mutations that do not neatly categorize themselves as dominant or recessive. These PARTIAL DOMINANTS can be found on either the autosomal or sex determining chromosomes.

PARTIAL DOMINANT AUTOSOMAL

“DARK FACTORS”

Found commonly in budgies and appearing now in many other species of parrot, is an autosomal non-sex-linked trait that is neither dominant nor recessive. It is instead classified as a “PARTIAL DOMINANT” exhibiting characteristics in between the two.

Unlike what is seen in the familiar dominant / recessive scheme of things a SINGLE FACTOR HETEROZYGOUS CARRIER LOOKS DIFFERENT THAN A DOUBLE FACTOR HOMOZYGOUS BIRD. In other words, on a blue budgie, we see a non-dark-factor bird referred to as “sky blue”.

A single-dark-factor bird, showing an intermediate darker shade of blue is called a “cobalt”; and the bird having the double-dark-factor set of genes is described as “mauve”. A pair of “cobalts” will produce 25% “sky blue”, 50% “cobalt”, and 25% “mauve” chicks.

“SPANGLED BUDGIES”

Here is another impressive mutation found in the ever-popular budgie. A single factor of this partially dominant autosomal allele is all that is needed to show a beautiful “spangle” pattern on the back and wings of either sex. A double dose of this mutation hides most of the coloring of the bird, some might mistake it for a “black eyed clear” or even a “lutino”, but the single “split” dose only partly reduces the darker colors creating the sought after “spangle” effect.

SEX-LINKED DOMINANT: “in Red Headed Gouldian finches”

As alluded to earlier, there exists a relatively unusual form of sex-linked expression, which is dominant. Many writers fail to differentiate between recessive and dominant sex-linked traits, assuming all are recessive, but I believe that is a mistake. Red head genetic properties in Gouldian finches are an example why.

In accordance with sex-linked rules cock birds can either carry one or two factors for a given trait on each of their two sex chromosomes. Heterozygous birds (cocks having one mutation allele paired with a normal allele) will show red headed color instead of it being masked by the non-mutation gene. Hens, of course, cannot be hidden carriers so must express the red head if they have it. With this difference in mind, red head can be added to the list of sex-linked traits.

A note of interest; both red headed and black headed Gouldians are found in wild populations yet both colors respectively exhibit dominant or recessive sex-linked genetic traits. Some authorities classify them as separate color forms within the same species. With red head being dominant but only seen in 25% of wild Gouldians we may be witnessing a new development in the “normal” wild Gouldian finch.

SEX-LINKED PARTIAL DOMINANT:

“IN YELLOW BODIED GOULDIAN FINCHES”

This is a SEX-LINKED INCOMPLETE or PARTIALLY DOMINANT trait. A single factor cock will exhibit a partial dilute form of yellow-body while a hen (being only a single factor) cannot be dilute but must express fully the yellow-body coloration on her single sex chromosome; a double factor cock displays a full yellow -body.

It follows then that a double factor cock mated to a normal hen will produce all dilute sons and yellow-body daughters. A note of interest; the recessive white-breast allele mutation in Gouldians enhances the yellow-body factor. A genetic single factor dilute male showing white-breast looks like its double factor yellow-body brother!

Congratulations!

You have completed “Genetics For Novice Pet Bird Breeders” #101. Now please feel free to “plug, in, and play” as needed to work out your own challenges.

For more on picking the right bird as a family pet see http://birdpets.onenessbecomesus.com