Normal Location Of Thumb/Big Toe may be Related to Programmed Cell Death in the Preaxial Area of Embryonic Limb

Abstract

The forelimbs and hindlimbs of newborn Polydactyly Nagoya (Pdn) mice were examined to analyze the roles of programmed cell death (PCD) in the preaxial region of the limb. Special attention was paid to the relationship between the PCD in the preaxial area and the location and shape of the first digit (thumb/big toe). Although a large, bifurcated or duplicated thumb/big toe appeared in Pdn/þ mice, digit I (thumb/big toe) in Pdn/þ mice, as in þ/þ ones, was located more ventro-proximally than the other four digits. On the other hand, abnormal preaxial digits of the fore/hindlimb in Pdn/Pdn mice lay distally and were aligned at the radial/tibial end of a serial curved plane formed by digits II-V; that is, a thumb and big toe of normal shape and location were not detectable in any preaxial digits of Pdn/Pdn mice. In the limb development of Pdn mouse embryos on Day 11-12, PCD did not occur in the preaxial mesoderm of fore/hindlimb only in one-fourths of all embryos obtained by Pdn/þ x Pdn/þ mating. In addition to digital rays II-V, extra preaxial digital rays appeared in the prominent preaxial expansion of fore/hindlimbs in these embryos on early Day 12. These abnormal limb configurations in embryos were closely similar to those in Pdn/Pdn newborn mice. The present findings suggest that PCD in the preaxial region not only prevents the formation of extra digits but also determines the location of the thumb/big toe for the normal limb morphogenesis. Anat Rec, 294:1352Rec, 294: -1359Rec, 294: , 2011. V V C 2011 Wiley-Liss, Inc.

Prognostic value of age and Wassel classification in the reconstruction of thumb duplication

“…All current publications about this pathology are retrospective [1,[7][8][9], as is Our comprised 99 patients, a number very similar to that in reviews by Wassel [10] and Ogino et al [14]. With the exception of Tada [12], the remaining studies involved significantly smaller groups.…”

“…All current publications about this pathology are retrospective [1,[7][8][9], as is ours. Our group comprised 99 patients, a number very similar to that in reviews by Wassel [10] and Ogino et al [14].…”

“…The classical theory for its etiology is a disruption of the ectoderm and preaxial mesodermal necrosis in the embryologic period, before the eighth week [6]. Recent studies describe the role of both the programmed cell death in the formation of normal preaxial digit formation [7] and the differentiation of the anterior/posterior axis of the limb [8]. To form along this polarity, the zone of polarizing activity (ZPA) is an area of mesenchyme that contains signals which instruct the developing limb bud.…”