The amphibian limb regeneration blastema is used here to examine whether irradiated, non-dividing tissue can participate in the development of new pattern of morphogenesis. Irradiated blastemas were rotated 180 degrees on normal stumps and normal blastemas rotated on irradiated stumps. In both cases supernumerary elements developed from the unirradiated tissue. The supernumeraries were defectiv...

Phantom limbs are usually observed after amputation of extremities. In patients after a stroke, a similar but rarely occurring phenomenon consisting of the patient experiencing the presence of an additional limb has been described. This phenomenon, generally called supernumerary phantom limb (SPL), may be caused by lesions in the right or left cerebral hemisphere, but has been predominantly rep...

The occasional occurrence of high frequencies of limb abnormalities, including extra limbs, in natural populations of amphibians has long been a puzzle. In this paper we report the discovery of a population in which such limb abnormalities appear to be caused by a parasitic flatworm (trematode) that uses amphibians as intermediate hosts. The cercarial larval stage of the trematode attacks amphi...

Complete dipygus is a very rare congenital malformation involving complete lumbosacral duplication with two pelves and four lower limbs [1]. Several incomplete forms have been reported. Pygomelia is an incomplete form in which two of the lower limbs fusion (symmelia) form a single supernumerary middle limb inserting into the pelvis [2—5]. Pygomelia has often been described as caudal or lumbosac...

Some investigators of the rubber hand illusion (RHI) have suggested that when standard RHI induction procedures are employed, if the rubber hand is experienced by participants as owned, their corresponding biological hands are experienced as disowned. Others have demurred: drawing upon a variety of experimental data and conceptual considerations, they infer that experience of the RHI might incl...

to our knowledge, bilateral supernumerary kidney is a very rare renal abnormality and there are five cases presented in the literature. it is difficult to diagnose supernumerary kidney and clinicians have not detected most cases preoperatively. laboratory and imaging studies were acquired and carefully examined. the normal laboratory tests were found. emergency ultrasonography was performed and...

A major function of the limb bud apical ectodermal ridge (AER) is to produce fibroblast growth factors (FGFs) that signal to the underlying mesenchyme. Previous studies have suggested that of the four FGF genes specifically expressed in the mouse AER, Fgf8 is unique not only in its expression pattern, but also because it is the only such FGF gene that causes limb skeletal abnormalities when ind...

Twist1 encodes a transcription factor that plays a vital role in limb development. We have used a tamoxifen-inducible Cre transgene, Ubc-CreERT2, to generate time-specific deletions of Twist1 by inducing Cre activity in mouse embryos at different ages from embryonic (E) day 9.5 onwards. A novel forelimb phenotype of supernumerary pre-axial digits and enlargement or partial duplication of the di...