cell culture for in vitro teratogen screening: validation of an improved assessment method using 51 compounds.
We prepared stage E11.5 mouse limb bud
mesenchymal stem cells (MSCs) by enzymatic digestion of limb bud
tissue as previously described (Zhang et al.
At day 12 of pregnancy, control embryo appeared normal with closed visceral arches and cervical sinuses; tongue and limb buds
formed, head folds were particularly prominent and neural closure occurred normally (Figs.
Autotomy of one or more of the primary (1[degrees]) limb regenerates (limb bud
autotomy, or LBA) before a critical period interrupts proecdysis until secondary (2[degrees]) limb buds
differentiate and grow to the approximate size of those lost (Holland and Skinner, 1976).
By implanting microscopic beads coated with retinoic acid into the limb buds
of unhatched chicks, two independent groups of researchers -- one from the University of California, Irvine, and another from three Japanese universities -- have shown that retinoic acid, a metabolite of vitamin A, does not directly dictate the pattern of limb formation in developing embryos.
The link between retinoic acid levelsand limb differentiation was first recognized in 1982, when researchers showed that they could induce the same type of mirror-image pattern by implanting retinoic-acid-soaked bits of paper into the front part of a limb bud
. But it remained to be proved that limb buds
contained a natural supply of retinoic acid and, if so, that it was present in a naturally occurring gradient.
Regenerate limb bud
sufficient for claw reversal in adult snapping shrimps.
Variations in branching pattern of axillary artery are due to defects in embryonic development of the vascular plexus of upper limb bud
. This may be due to an arrest at any stage of development of vessels followed by regression, retention or reappearance, thus leading to variations in the arterial origin and course of major upper limb vessels.
It enters the limb bud
during stage 12 when limb bud
begins its outgrowth.
However, tendons develop independently and are derived from limb bud
mesoderm rather than from somites.
Variations in the contributions to the plexus may be correlated with the position of the limb bud
in embryo and the nerves first grow into.
DISCUSSION: Sciatic artery is a branch of umbilical artery and during early stages of embryonic development (6mm stage) and is the principal vascular supply of the developing lower limb bud
. The external iliac artery also arises from umbilical artery proximal to the origin of sciatic artery.