The tail of the Xenopus tadpole contains major axial structures, including a spinal cord, notochord and myotomes, and regenerates within 2 weeks following amputation. The tail regeneration in Xenopus can provide insights into the molecular basis of the regeneration mechanism. The regenerated tail has some differences from the normal tail, including an immature spinal cord and incomplete segment...

Understanding rhythmic behavior at the developmental and genetic levels has important implications for neurobiology, medicine, evolution, and robotics. We studied rhythmic behavior--larval crawling--in the genetically and developmentally tractable organism, Drosophila melanogaster. We used narrow-diameter channels to constrain behavior to simple, rhythmic crawling. We quantified crawling at the...

This paper reports the histopathological responses of the gill, liver and tail muscle tissues in tadpoles of the Asian Common Toad Duttaphrynus melanostictus (Schneider, 1799) exposed to chlorpyrifos a common organophosphorus pesticide. Tadpoles of Gosner stages 24-26 were continuously exposed to low, mid and high (500, 1000 and 1500 μgl –1 ) concentrations of chlorpyrifos for two weeks. Histol...

Paralyzed skeletal muscle sometimes becomes faster and more fatigable after spinal cord injury (SCI) because of reduced activity. However, in some cases, pronounced muscle activity in the form of spasticity (hyperreflexia and hypertonus) occurs after long-term SCI. We hypothesized that this spastic activity may be associated with a reversal back to a slower, less fatigable muscle. In adult rats...

Bradykinin-related peptides (BRPs) are one of the most extensively studied frog secretions-derived peptide families identified from many amphibian species. The diverse primary structures of BRPs have been proven essential for providing valuable information in understanding basic mechanisms associated with drug modification. Here, we isolated, identified and characterized a dodeca-BRP (RAP-L1, T...

Amputation of the larval tail of Xenopus injures the notochord, spinal cord, muscle masses, mesenchyme, and epidermis, induces the growth and differentiation of cells in those tissues, and results in tail regeneration. A dorsal incision in the larval tail injures the same tissues and induces cell growth and differentiation, but never results in the formation of any extra appendages. The first s...

It is important to determine the enabling mechanisms that underlie locomotor performance to explain the evolutionary patterns and ecological success of animals. Our aim was to determine the extent to which calcium (Ca(2+)) handling dynamics modulate the contractile properties of isolated skeletal muscle, and whether the effects of changing Ca(2+) handling dynamics in skeletal muscle are paralle...

The aim of this study was to compare physiological effects of hindlimb suspension (HLS) in tail- and pelvic-HLS rat models to determine if severe stretch in the tail-HLS rats lumbosacral skeleton may contribute to the changes traditionally attributed to simulated microgravity and musculoskeletal disuse in the tail-HLS model. Adult male Sprague-Dawley rats divided into suspended and control-nons...

The tail of the Xenopus tadpole will regenerate completely after transection. Much of the mass of the regenerate is composed of skeletal muscle, but there has been some uncertainty about the source of the new myofibres. Here, we show that the growing tail contains many muscle satellite cells. They are active in DNA replication, whereas the myonuclei are not. As in mammals, the satellite cells e...