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Anonymous, 02.12.2001 21:04
Есть ли у морских свинок такой признок - пестрость? Может ли пестрая особь быть гомозиготной(АА), или она должна быть гетерозиготной(Аа)? Какие признаки у морских свинок доминантные, какие рецессивные?
Anonymous, 03.12.2001 02:06
Zdravstvujtje, Jevgenij!
Nadejusj i Vas njet probljem s anglijskjim, poetomu, pishu po anglijskji:
GUINEA PIG GENETICS
A. Background:
1. 1900-1960's genetic research was concerned with:
a. The genetic analysis of coat colors
b. The texture
c. Studies on the effects of inbreeding.
2. Genetic research today is directed at the analysis
of biochemical, physiological and immunologic
characteristics.
3. Many mutants that have been described are no
longer obtainable.
4. Diploid chromosome number is 2N=64, with one pair
of sex chromosomes and 31 pairs of autosomes.
5. Sex determination is xx (female) and xy (male).

B. Pigmentation:
1. 15 loci are known to influence coat color in
guinea pigs. Most are known to have a single gene
mode of inheritance.
2. Individual loci:
a. Agouti locus (A):
(1) This locus controls amount and
distribution of:
(a) Eumelanin (black or brown pigment)
(B) Phaeomelanin (yellow and reddish
pigment) both in individual hairs
and in the coat. Two alleles
recognized.
(2) Light-bellied agouti allele (A): Agouti
with light belly. This is the wild type
for Cavia porcellus with terminal or
subterminal yellow band (phaeomelanin)
and rest of the hair black or brown
(eumelanin).
(3) Non-agouti allele (a): Eliminates the
phaeomelanin band from individual hairs
and animals are therefore black (or
brown, or variation).
b. Brown locus (B):
(1) Wild type allele (B): Black color
(eumelanin)
(2) Brown allele (B): changes eumelanin in
hair, skin, and eyes brown black to
brown. When combined with agouti wild
type, a cinnamon-agouti color results.
c. Color, or albino locus ©:
(1) A series of mutants at this locus
reduces the amount of pigment. There is
no true albino allele homologous to that
in mice©.
(2) Wild type allele ©: full
pigmentation. Examples include blacks,
reds, golden agoutis. All of these have
black eyes.
(3) Acromelanic albino (ca): Black
(eumelanin reduced to patches on
extremities (nose, feet, ears). Yellow
(Phaeomelanin) eliminated completely.
Eyes are pink due to lack of pigment in
the iris and retina.
(4) The ca allele interacts with the
extension allele (e) at the E locus to
give a synthetic albino (ca/ca e/e) color
in the common laboratory Dunkin-
Hartley"albino" guinea pig.

C. Pelage Variations:
1. Rough ® locus: the dominant gene R is necessary
for any "roughness" rosette patterns.
a. "Roughness" or rosettes: this hair pattern
is characteristic of the Abyssinian breed and
is regulated by four loci.
b. The action of this gene is modified by the
incompletely dominant genes M and Re.

2. Long Hair (l):
a. Autosomal recessive character
b. Hair length up to 8, 12. or 16 cm at 3, 5,
and 7 months
c. Peruvian breed: has long hair (1/1) and
rough ® alleles, resulting in 2 hip
rosettes which throw hair forward over head.
d. Smooth coated long haired type referred to as
"angoras" or "shelties"
Anonymous, 03.12.2001 05:42
Izvinjajusj, zabil pozhelatj Vam vsjego nailuchjshego... Udachji!
Anonymous, 03.12.2001 10:44
Da, kstatji, kak v Latvii - ja bil iz Rigji...? smile.gif))
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