dp-5/dp-5 dp-5 limb normal limb
Origin & History: Olympio, OS et al. 1983 J Hered 74:341-343;
received from Crawford in late 1980's.
Breed: Brown Leghorn background
Symbol: dp-5
Characteristics: Autosomal recessive, embryonic lethal.
Description: Homozygotes display moderate preaxial polydactyly,
dwarfing, shortened upper beak and ectopic viscera.
In the limbs the tibia is shorter and thicker than normal; the fibula
is curved and longer (relative to the tibia) than normal.
dp-5/dp-5
dp-5 limb
normal limb
Additional Information: In normal limb buds, GHox-4.6
is
expressed solely in the posterior mesoderm, from which the digits and most
of the other skeletal elements arise. GHox-8 is expressed
in the anterior mesoderm which will not give
rise to skeletal elements. In diplopodia-5 supression of GHox-8 in
the anterior mesoderm and ectopic expression of GHox-4.6 precede
formation of extra digits in the preaxial tissue. Expression of GHox-8
in the apical ectodermal ridge (AER) is not affected by dp-5 (or ta-2).
(Development 115:629-637, 1992)
Consistent with the hypothesis that GHox-7 expression is involved
in the outgrowth promoting effect of the AER, and may be required for limb
outgrowth to occur, dp-5 wing buds show GHox-7 expression throughout
the expanded subridge mesoderm. (Differentiation 52:129-137, 1993)