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just info to share with you guys.....i've been reading it and i guess its pretty simple to understand though
"NORMAL PHENOTYPE" (DOMINANT) This refers to the typical leopard gecko coloration of black spots on a variety of base colors. The “normal” phenotype is dominant over all recessive traits (albino, patternless, and blizzard). Therefore, a gecko carrying only one copy of a recessive trait would have at least some degree of black spotting. Normal morph is a term that is often used to describe wild-type leopard geckos. Wild type leopard geckos are usually heavily spotted on a brownish yellow base color. “Normal” phenotype includes the wild type leopard geckos, but also any other morph that is able to produce black spots, including hypo tangerine, high yellow, lavender, pastel, jungle, etc. To avoid confusion, I will use quotation marks around normal when I am referring to the “normal” (dominant) phenotype, but no quotation marks when referring to the normal (wild-type) morph.
RECESSIVE TRAIT This refers to traits that are not expressed when combined with a dominant trait. In order for a recessive trait to be expressed (outwardly visible) the gecko must be carrying two copies of that trait. Recessive traits in leopard geckos include all three strains of albino (Tremper, Rainwater (Las Vegas), and Bell), patternless, and blizzard. Selective breeding cannot create recessive traits. These traits are the result of a mutation of certain genes that control a specific part of the development of the animal. Recessive traits are usually discovered randomly, there is nothing you can do to increase your probability of discovering a new recessive trait, you just need to be lucky!
LINE-BRED TRAIT This refers to traits that were created through selective breeding over many generations. Traits that are line bred include hypo-melanistic (hypo), tangerine, and jungle. In the early stages of the development of these morphs the existed as slight variations from the “normal” phenotype. The tangerine morph is an example of a line bred trait and I will use it in my example of how a line-bred trait is created. The development of this trait began with animals that were observed to have a slight amount of tangerine color in the body. These animals were bred together, and some of the babies were showing more tangerine than their parents. These babies were grown up and bred together, and their offspring showing even more tangerine were selected to breed for the next generation. In this manner the intensity of tangerine was increased with each generation, and this process of selection is continuing today.
These traits are not controlled at a single locus (particular location on the chromosome) and hets cannot be created for line-bred traits. Line-bred traits are controlled by increaser-decreaser alleles, meaning the more intense the traits are in the parents the higher the likelihood of observing these traits in their offspring. For example, if you were to breed the nicest super hypo tangerine in the world (super intense orange-red body color with only a few black spots) with the ugliest wild type normal leopard gecko (heavily spotted with black spots on a brownish yellow base color) you would get babies that were likely somewhere in between in coloration and spotting. Babies could be expected to be brighter tangerine and with less spotting than the normal parent, but more spotting and less intense tangerine coloration than the super hypo tangerine parent. There would likely be a spectrum of orange coloration and spotting between the babies, with not all babies appearing exactly the same. An example of a line bred trait and increaser-decreaser alleles in humans would be height. If a 6-foot tall person were to have children with a 5-foot tall person you would expect the children to fall somewhere in between the parents in terms of their adult height. However, sometimes the children end up taller than their parents as is the case in my family. My father is 5’11” and mother is 5’4”. I am 5’10”, my sister is 5’5”, but my brother is 6’2”. This sort of situation can occur in hypo tangerine leopard geckos as well, where some babies often end up with less spotting and nicer coloration than either of their parents, and is always a welcome surprise!
HET OR HETEROZYGOUS “Het” is a slang term for “heterozygous” (“hetero” means different). Heterozygous animals carry one copy of a specific recessive trait (albino, patternless, blizzard) and one copy of a “normal” trait. We have two copies of each gene (one from each of our parents), and in the case of a heterozygous animal it has inherited one copy of a recessive gene and one copy of a dominant gene. Example: If you were to breed an albino leopard gecko with a non-albino (“normal”) animal, all babies would be heterozygous for albinism, carrying one copy of the albino gene and one copy of the non-albino (“normal”) gene. Remember that because the “normal” phenotype is dominant over the albino gene, the appearance of the animal is “normal”. The term heterozygous only applies to recessive traits, and is often used improperly, as in the case of line-bred traits (hypo-melanistic (hypo), tangerine, and jungle).
HOMOZYGOUS This is the opposite of heterozygous. Homozygous means carrying two copies of the same trait (“homo” means same). A homozygous gecko is carrying two copies of the same trait, one copy inherited from each of its parents. Animals that are homozygous for a specific trait would express it in their phenotype. Example: A blizzard is homozygous for the blizzard trait, and carrying two copies of the blizzard trait. A patternless albino is homozygous for both albino and patternless, and carrying two copies of the albino trait and two copies of the patternless trait.
This post has been edited by luc: Nov 26 2009, 10:41 AM
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