Dominance (genetics) - Revision history

Ahoussney at 18:26, 15 February 2015

2015-02-15T18:26:21Z

Ahoussney at 18:25, 15 February 2015

2015-02-15T18:25:41Z

Ahoussney at 00:04, 14 February 2015

2015-02-14T00:04:31Z

Ahoussney at 00:04, 14 February 2015

2015-02-14T00:04:06Z

Ahoussney at 00:03, 14 February 2015

2015-02-14T00:03:36Z

Ahoussney: /* Sex-linked dominance */

2015-02-13T23:55:14Z

‎Sex-linked dominance

Ahoussney at 23:53, 13 February 2015

2015-02-13T23:53:16Z

Ahoussney at 23:44, 13 February 2015

2015-02-13T23:44:20Z

Ahoussney at 23:41, 13 February 2015

2015-02-13T23:41:09Z

Ahoussney at 23:38, 13 February 2015

2015-02-13T23:38:09Z

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 (This article should be rewritten and redirected to this general page on [[genetics]] along with summarized in a page on [[Genetics simplified| Genetics for simple folks]] )
-Dominance in genetics describes a type of relationship between an organism's two versions (alleles) of any one gene in which the traits of one allele (the dominant one) are expressed and the traits of the other (the recessive) are repressed. Since most animals are [[Dominance (genetics)#Haploid, diploid and triploid|diploid]], one allele of each gene comes from the dam (mother) and one allele comes from the sire (father). If either parent gives the offspring a completely dominant gene, that trait will be found in all the offspring.
+'''Dominance''' in genetics describes a type of relationship between an organism's two versions (alleles) of any one gene in which the traits of one allele (the dominant one) are expressed and the traits of the other (the recessive) are repressed. Since most animals are [[Dominance (genetics)#Haploid, diploid and triploid|diploid]], one allele of each gene comes from the dam (mother) and one allele comes from the sire (father). If either parent gives the offspring a completely dominant gene, that trait will be found in all the offspring.
 Autosomal dominance simply refers to genes on an autosome, which is any chromosome other than a sex chromosome. Any such genes (more accurately, ''alleles'') and their associated traits are called either autosomal dominant or autosomal recessive.

← Older revision		Revision as of 18:25, 15 February 2015
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	''For Dominance in Animal behavior see'' [[Dominance (animal behavior)]]		''For Dominance in Animal behavior see'' [[Dominance (animal behavior)]]
		+
		+	(This article should be rewritten and redirected to this general page on [[genetics]] along with summarized in a page on [[Genetics simplified\| Genetics for simple folks]] )

	Dominance in genetics describes a type of relationship between an organism's two versions (alleles) of any one gene in which the traits of one allele (the dominant one) are expressed and the traits of the other (the recessive) are repressed. Since most animals are [[Dominance (genetics)#Haploid, diploid and triploid\|diploid]], one allele of each gene comes from the dam (mother) and one allele comes from the sire (father). If either parent gives the offspring a completely dominant gene, that trait will be found in all the offspring.		Dominance in genetics describes a type of relationship between an organism's two versions (alleles) of any one gene in which the traits of one allele (the dominant one) are expressed and the traits of the other (the recessive) are repressed. Since most animals are [[Dominance (genetics)#Haploid, diploid and triploid\|diploid]], one allele of each gene comes from the dam (mother) and one allele comes from the sire (father). If either parent gives the offspring a completely dominant gene, that trait will be found in all the offspring.

← Older revision		Revision as of 00:04, 14 February 2015
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	Black color in [[cattle]], for example, is mainly controlled by an ''autosomal dominant'' allele of the Melanocortin 1 Receptor gene (MC1R) called E<sup>D</sup>. Another version of this gene, called e, is ''autosomal recessive''. Although there are other factors related to color caused by other genes, generally an animal E<sup>D</sup>/E<sup>D</sup>, with two copies of the dominant E<sup>D</sup> alleles, will be black and an animal e/e with two e alleles will be red while an animal E<sup>D</sup>/e with one of each allele, will appear black, but carries the gene for red color.		Black color in [[cattle]], for example, is mainly controlled by an ''autosomal dominant'' allele of the Melanocortin 1 Receptor gene (MC1R) called E<sup>D</sup>. Another version of this gene, called e, is ''autosomal recessive''. Although there are other factors related to color caused by other genes, generally an animal E<sup>D</sup>/E<sup>D</sup>, with two copies of the dominant E<sup>D</sup> alleles, will be black and an animal e/e with two e alleles will be red while an animal E<sup>D</sup>/e with one of each allele, will appear black, but carries the gene for red color.

−	It's important to realize that dominance simply refers to a relationship between alleles; one allele can be dominant over a second allele, recessive to a third allele, and codominant to a fourth. For example, in the black color trait scenario with cattle above, another MC1R allele, E+, exists which is recessive to both the e (red color) allele and E<sup>D . In the E+/e combination the e allele will dominate and the animal will be red and an E<sup>D</sup>/E+ animal will be black (an E+/E+ combination can result in many different colors since other genes seem to get involved.) Dominance differs from epistasis, a relationship in which an allele of one gene affects the expression of another allele at a different gene.[3]	+	It's important to realize that dominance simply refers to a relationship between alleles; one allele can be dominant over a second allele, recessive to a third allele, and codominant to a fourth. For example, in the black color trait scenario with cattle above, another MC1R allele, E+, exists which is recessive to both the e (red color) allele and E<sup>D</sup> . In the E+/e combination the e allele will dominate and the animal will be red and an E<sup>D</sup>/E+ animal will be black (an E+/E+ combination can result in many different colors since other genes seem to get involved.) Dominance differs from epistasis, a relationship in which an allele of one gene affects the expression of another allele at a different gene.[3]

← Older revision		Revision as of 00:04, 14 February 2015
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	Black color in [[cattle]], for example, is mainly controlled by an ''autosomal dominant'' allele of the Melanocortin 1 Receptor gene (MC1R) called E<sup>D</sup>. Another version of this gene, called e, is ''autosomal recessive''. Although there are other factors related to color caused by other genes, generally an animal E<sup>D</sup>/E<sup>D</sup>, with two copies of the dominant E<sup>D</sup> alleles, will be black and an animal e/e with two e alleles will be red while an animal E<sup>D</sup>/e with one of each allele, will appear black, but carries the gene for red color.		Black color in [[cattle]], for example, is mainly controlled by an ''autosomal dominant'' allele of the Melanocortin 1 Receptor gene (MC1R) called E<sup>D</sup>. Another version of this gene, called e, is ''autosomal recessive''. Although there are other factors related to color caused by other genes, generally an animal E<sup>D</sup>/E<sup>D</sup>, with two copies of the dominant E<sup>D</sup> alleles, will be black and an animal e/e with two e alleles will be red while an animal E<sup>D</sup>/e with one of each allele, will appear black, but carries the gene for red color.

−	It's important to realize that dominance simply refers to a relationship between alleles; one allele can be dominant over a second allele, recessive to a third allele, and codominant to a fourth. For example, in the black color trait scenario with cattle above, another MC1R allele, E+, exists which is recessive to both the e (red color) allele and E<sup>D . In the E+/e combination the e allele will dominate and the animal will be red and an E<sup>D/E+ animal will be black (an E+/E+ combination can result in many different colors since other genes seem to get involved.) Dominance differs from epistasis, a relationship in which an allele of one gene affects the expression of another allele at a different gene.[3]	+	It's important to realize that dominance simply refers to a relationship between alleles; one allele can be dominant over a second allele, recessive to a third allele, and codominant to a fourth. For example, in the black color trait scenario with cattle above, another MC1R allele, E+, exists which is recessive to both the e (red color) allele and E<sup>D . In the E+/e combination the e allele will dominate and the animal will be red and an E<sup>D</sup>/E+ animal will be black (an E+/E+ combination can result in many different colors since other genes seem to get involved.) Dominance differs from epistasis, a relationship in which an allele of one gene affects the expression of another allele at a different gene.[3]

← Older revision		Revision as of 00:03, 14 February 2015
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	Black color in [[cattle]], for example, is mainly controlled by an ''autosomal dominant'' allele of the Melanocortin 1 Receptor gene (MC1R) called E<sup>D</sup>. Another version of this gene, called e, is ''autosomal recessive''. Although there are other factors related to color caused by other genes, generally an animal E<sup>D</sup>/E<sup>D</sup>, with two copies of the dominant E<sup>D</sup> alleles, will be black and an animal e/e with two e alleles will be red while an animal E<sup>D</sup>/e with one of each allele, will appear black, but carries the gene for red color.		Black color in [[cattle]], for example, is mainly controlled by an ''autosomal dominant'' allele of the Melanocortin 1 Receptor gene (MC1R) called E<sup>D</sup>. Another version of this gene, called e, is ''autosomal recessive''. Although there are other factors related to color caused by other genes, generally an animal E<sup>D</sup>/E<sup>D</sup>, with two copies of the dominant E<sup>D</sup> alleles, will be black and an animal e/e with two e alleles will be red while an animal E<sup>D</sup>/e with one of each allele, will appear black, but carries the gene for red color.
		+
		+	It's important to realize that dominance simply refers to a relationship between alleles; one allele can be dominant over a second allele, recessive to a third allele, and codominant to a fourth. For example, in the black color trait scenario with cattle above, another MC1R allele, E+, exists which is recessive to both the e (red color) allele and E<sup>D . In the E+/e combination the e allele will dominate and the animal will be red and an E<sup>D/E+ animal will be black (an E+/E+ combination can result in many different colors since other genes seem to get involved.) Dominance differs from epistasis, a relationship in which an allele of one gene affects the expression of another allele at a different gene.[3]

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 ==Sex-linked dominance==
-A classic example of dominance is the inheritance of seed shape (pea shape) in peas. Peas may be round (associated with allele R) or wrinkled (associated with allele r). In this case, three combinations of alleles (genotypes) are possible: RR, Rr, and rr. The RR individuals have round peas and the rr individuals have wrinkled peas. In Rr individuals the R allele masks the presence of the r allele, so these individuals also have round peas. Thus, allele R is dominant to allele r, and allele r is recessive to allele R (this use of upper case for dominant alleles and lower case for recessive alleles is a widely followed convention).
+A classic example of dominance is the inheritance of seed shape (pea shape) in peas. Peas may be round (associated with allele R) or wrinkled (associated with allele r). In this case, three combinations of alleles (genotypes) are possible: RR, Rr, and rr. The RR individuals have round peas and the rr individuals have wrinkled peas. In Rr individuals the R allele masks the presence of the r allele, so these individuals also have round peas. Thus, allele R is dominant to allele r, and allele r is recessive to allele R.
-−
-More generally, where a gene exists in two allelic versions (designated A and a), three combinations of alleles (genotypes) are possible: AA, Aa, and aa. If AA and aa individuals (homozygotes) show different forms of some trait (phenotypes), and Aa individuals (heterozygotes) show the same phenotype as AA individuals, then allele A is said to dominate or be dominant to or show dominance to allele a, and a is said to be recessive to A.
-−
-Dominance is not inherent to an allele. It is a relationship between alleles; one allele can be dominant over a second allele, recessive to a third allele, and codominant to a fourth. Dominance differs from epistasis, a relationship in which an allele of one gene affects the expression of another allele at a different gene.[3]

← Older revision		Revision as of 23:53, 13 February 2015
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	Autosomal dominance simply refers to genes on an autosome, which is any chromosome other than a sex chromosome. Any such genes (more accurately, ''alleles'') and their associated traits are called either autosomal dominant or autosomal recessive.		Autosomal dominance simply refers to genes on an autosome, which is any chromosome other than a sex chromosome. Any such genes (more accurately, ''alleles'') and their associated traits are called either autosomal dominant or autosomal recessive.
		+
		+	Generally, in any autosomal dominant trait a gene exists in at least two versions (designated A and a). Four combinations of these two alleles are possible: AA, Aa, aA, and aa (Aa and aA are functionally the same and are both referred to as Aa). AA and aa individuals will show different forms of some trait ([[Dominance (genetics)#Genotypes and phenotypes\|phenotypes]]), and Aa individuals will show the same phenotype as AA individuals. In that case the allele A is said to be completely dominant to allele a, and a is said to be recessive to A (this use of upper case for dominant alleles and lower case for recessive alleles is a widely followed convention).

	Black color in [[cattle]], for example, is mainly controlled by an ''autosomal dominant'' allele of the Melanocortin 1 Receptor gene (MC1R) called E<sup>D</sup>. Another version of this gene, called e, is ''autosomal recessive''. Although there are other factors related to color caused by other genes, generally an animal E<sup>D</sup>/E<sup>D</sup>, with two copies of the dominant E<sup>D</sup> alleles, will be black and an animal e/e with two e alleles will be red while an animal E<sup>D</sup>/e with one of each allele, will appear black, but carries the gene for red color.		Black color in [[cattle]], for example, is mainly controlled by an ''autosomal dominant'' allele of the Melanocortin 1 Receptor gene (MC1R) called E<sup>D</sup>. Another version of this gene, called e, is ''autosomal recessive''. Although there are other factors related to color caused by other genes, generally an animal E<sup>D</sup>/E<sup>D</sup>, with two copies of the dominant E<sup>D</sup> alleles, will be black and an animal e/e with two e alleles will be red while an animal E<sup>D</sup>/e with one of each allele, will appear black, but carries the gene for red color.

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 ''For Dominance in Animal behavior see'' [[Dominance (animal behavior)]]
-Dominance in genetics describes a type of relationship between an organism's two versions (alleles) of any one gene in which the traits of one allele (the dominant one) are expressed and the traits of the other (the recessive) are repressed. Since most animals are [[diploid]], one allele of each gene comes from the dam (mother) and one allele comes from the sire (father). If either parent gives the offspring a completely dominant gene, that trait will be found in all the offspring.
+Dominance in genetics describes a type of relationship between an organism's two versions (alleles) of any one gene in which the traits of one allele (the dominant one) are expressed and the traits of the other (the recessive) are repressed. Since most animals are [[Dominance (genetics)#Haploid, diploid and triploid|diploid]], one allele of each gene comes from the dam (mother) and one allele comes from the sire (father). If either parent gives the offspring a completely dominant gene, that trait will be found in all the offspring.
 Autosomal dominance simply refers to genes on an autosome, which is any chromosome other than a sex chromosome. Any such genes (more accurately, ''alleles'') and their associated traits are called either autosomal dominant or autosomal recessive.

← Older revision		Revision as of 23:41, 13 February 2015
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	Autosomal dominance simply refers to genes on an autosome, which is any chromosome other than a sex chromosome. Any such genes (more accurately, ''alleles'') and their associated traits are called either autosomal dominant or autosomal recessive.		Autosomal dominance simply refers to genes on an autosome, which is any chromosome other than a sex chromosome. Any such genes (more accurately, ''alleles'') and their associated traits are called either autosomal dominant or autosomal recessive.

−	Black color in [[cattle]], for example, is mainly controlled by an ''autosomal dominant'' allele of the Melanocortin 1 Receptor gene (MC1R) called "E<sup>D</sup>". Another version of this gene, called "e" is ''autosomal recessive''. Although there are other factors related to color caused by other genes, generally an animal "E<sup>D</sup>E<sup>D</sup>" with two copies of the dominant "E<sup>D</sup>~~" gene (more acurately two "E<sup>D</sup>"~~ alleles) will be black and an animal ~~"ee"~~ with two e alleles will be red while an animal "E<sup>D</sup>e" with one of each allele, will appear black, but carries the gene for red color.	+	Black color in [[cattle]], for example, is mainly controlled by an ''autosomal dominant'' allele of the Melanocortin 1 Receptor gene (MC1R) called E<sup>D</sup>. Another version of this gene, called e, is ''autosomal recessive''. Although there are other factors related to color caused by other genes, generally an animal E<sup>D</sup>/E<sup>D</sup>, with two copies of the dominant E<sup>D</sup> alleles, will be black and an animal e/e with two e alleles will be red while an animal E<sup>D</sup>/e with one of each allele, will appear black, but carries the gene for red color.