Ali, R.A., A.W.A. El Ghareeb, and H. Hamdy (2004). Hormonal control in regeneration: IV- thyroxine failed to enhance limb regeneration in metamorphic stages of the Egyptian toad, Bufo regularis Reuss. Journal of Union of Arab Biologists Cairo A Zoology 22: 229-252. ISSN: 1110-5372.
Descriptors: toad, Bufo regularis, limb regeneration, hormonal control, thyroxine, thyroxine, metamorphic stages.
Language of Text: Arabic; English.
Ali, R.A., A.W.A. El Ghareeb, and H. Hamdy (2005). Hormonal control in regeneration: VI - growth hormone enhances limb regeneration in metamorphic stages of the Egyptian toad, Bufo regularis Reuss. Journal of the Egyptian German Society of Zoology 47(B): 29-48. ISSN: 1110-5356.
NAL Call Number: QL1.E49
Descriptors: toad, Bufo regularis, limb regeneration, growth hormone, enhances limb regeneration, effects, metamorphic stages.
Language of Text: Arabic; English.
Araki, M. (2007). Regeneration of the amphibian retina: Role of tissue interaction and related signaling molecules on RPE transdifferentiation. Development Growth and Differentiation. 49(2): 109-120. ISSN: 0012-1592.
Abstract: Regeneration of eye tissue is one of the classic subjects in developmental biology and it is now being vigorously studied to reveal the cellular and molecular mechanisms involved. Although many experimental animal models have been studied, there may be a common basic mechanism that governs retinal regeneration. This can also control ocular development, suggesting the existence of a common principle between the development and regeneration of eye tissues. This notion is now becoming more widely accepted by recent studies on the genetic regulation of ocular development. Retinal regeneration can take place in a variety of vertebrates including fish, amphibians and birds. The newt, however, has been considered to be the sole animal that can regenerate the whole retina after the complete removal of the retina. We recently discovered that the anuran amphibian also retains a similar ability in the mature stage, suggesting the possibility that such a potential could be found in other animal species. In the present review article, retinal regeneration of amphibians (the newt and Xenopus laevis) and avian embryos are described, with a particular focus on transdifferentiation of retinal pigmented epithelium. One of the recent progresses in this field is the availability of tissue culture methods to analyze the initial process of transdifferentiation, and this enables us to compare the proliferation and neural differentiation of retinal pigmented epithelial cells from various animal species under the same conditions. It was revealed that tissue interactions between the retinal pigmented epithelium and underlying connective tissues (the choroid) play a substantial role in transdifferentiation and that this is mediated by a diffusible signal such as fibroblast growth factor 2. We propose that tissue interaction, particularly mesenchyme-neuroepithelial interaction, is considered to play a fundamental role both in retinal development and regeneration.
Descriptors: salamanders and newts, Xenopus laevis, retina-regeneration, transdifferentiation, tissue interaction, signaling molecules.
Araki, M. (2005). Amphibian retinal regeneration - two modes of regeneration process. Zoological Science 22(12): 1375. ISSN: 0289-0003.
NAL Call Number: QL1.Z68
Descriptors: amphibians, retinal regeneration, sense organs, Xenopus metamorphosis, regeneration process, meeting.
Notes: Meeting Information: 76th Annual Meeting of the Zoological Society of Japan, Tsukuba, Japan; October 06 -08, 2005.
Bach, H., V. Arango, D. Feldheim, J.G. Flanagan, and F. Scalia (2004). Fiber order of the normal and regenerated optic tract of the frog (Rana pipiens). Journal of Comparative Neurology 477(1): 43-54. ISSN: 0021-9967.
Descriptors: amphibians, frog, Rana pipiens, optic tract, fiber order, normal, regenerated, retina, axons, regeneration.
Brockes, J.P. (2006). Positional identity of adult limb stem cells during regeneration in salamanders. Journal of Anatomy 209(4): 565-566. ISSN: 0021-8782.
Descriptors: amphibians, salamanders, regeneration, adult limb stem cells, positional identity, meeting.
Notes: Meeting Information: Fall Meeting of the Anatomical Society of Great Britain and Ireland, Oxford, UK; January 04 -06, 2006.
Brockes, J.P. and A. Kumar (2002). Plasticity and reprogramming of differentiated cells in amphibian regeneration. Nature Reviews. Molecular Cell Biology 3(8): 566-574. ISSN: 1471-0072.
Descriptors: amphibians, regeneration, reprogramming, differentiated cells, plasticity.
Carlson, B.M. (2003). Muscle regeneration in amphibians and mammals: passing the torch. Developmental Dynamics 226(2): 167-181. ISSN: 1058-8388.
NAL Call Number: QL801.A4
Descriptors: amphibians, muscle regeneration, mammals.
Chang, W.Y., F. Khosrowshahian, M. Wolanski, R. Marshall, W. McCormick, S. Perry, and M.J. Crawford (2006). Conservation of Pitx1 expression during amphibian limb morphogenesis. Biochemistry and Cell Biology 84(2): 257-262. ISSN: 1208-6002.
Abstract: In contrast to the pattern of limb emergence in mammals, chicks, and the newt N. viridescens, embryos such as Xenopus laevis and Eleutherodactylus coqui initiate pelvic limb buds before they develop pectoral ones. We studied the expression of Pitx1 in X. laevis and E. coqui to determine if this paired-like homeodomain transcription factor directs differentiation specifically of the hindlimb, or if it directs the second pair of limbs to form, namely the forelimbs. We also undertook to determine if embryonic expression patterns were recapitulated during the regeneration of an amputated limb bud. Pitx1 is expressed in hindlimbs in both X. laevis and E. coqui, and expression is similar in both developing and regenerating limb buds. Expression in hindlimbs is restricted to regions of proliferating mesenchyme.
Descriptors: frogs, anuran embryology, anuran genetics, Xenopus laevis proteins, genetics, embryology, anuran growth, development, physiology, gene expression regulation, developmental, genes, hindlimb embryology, growth, development, hindlimb physiology, regeneration, species specificity.
Chevallier, S., M. Landry, F. Nagy, and J.M. Cabelguen (2004). Recovery of bimodal locomotion in the spinal-transected salamander, Pleurodeles waltlii. European Journal of Neuroscience 20(8): 1995-2007. ISSN: print: 0953-816X; online: 1460-9568.
Abstract: Electromyographic (EMG) analysis was used to provide an assessment of the recovery of locomotion in spinal-transected adult salamanders (Pleurodeles waltlii). EMG recordings were performed during swimming and overground stepping in the same animal before and at various times (up to 500 days) after a mid-trunk spinalization. Two-three weeks after spinalization, locomotor EMG activity was limited to the forelimbs and the body rostral to the transection. Thereafter, there was a return of the locomotor EMG activity at progressively more caudal levels below the transection. The animals reached stable locomotor patterns 3-4 months post-transection. Several locomotor parameters (cycle duration, burst duration, burst proportion, intersegmental phase lag, interlimb coupling) measured at various recovery times after spinalization were compared with those in intact animals. These comparisons revealed transient and long-term alterations in the locomotor parameters both above and below the transection site. These alterations were much more pronounced for swimming than for stepping and revealed differences in adaptive plasticity between the two locomotor networks. Recovered locomotor activity was immediately abolished by retransection at the site of the original spinalization, suggesting that the spinal cord caudal to the transection was reinnervated by descending brain and/or propriospinal axons, and that this regeneration contributed to the restoration of locomotor activity. Anatomical studies conducted in parallel further demonstrated that some of the regenerated axons came from glutamatergic and serotoninergic immunoreactive cells within the reticular formation.
Descriptors: salamander, spinal transected, bimodal locomotion, recovery, swimming, stepping, recovery, assessment, anatomical studies.
Da Silva, S.M., P.B. Gates, and J.P. Brockes (2002). The newt ortholog of cd59 is implicated in proximodistal identity during amphibian limb regeneration. Developmental Cell 3(4): 547-555. ISSN: 1534-5807.
Descriptors: amphibians, limb regeneration, newt, cd59, orthlog, proximodistal identity, orthlog, blastema, retinoic acid.
Dunlop, S.A., M. Tennant, and L.D. Beazley (2002). Extent of retinal ganglion cell death in the frog Litoria moorei after optic nerve regeneration induced by lesions of different sizes. Journal of Comparative Neurology 446(3): 276-287. ISSN: 0021-9967.
Descriptors: frog, Litoria moorei, nerves, optic nerve regeneration, eye, retinal ganglion cell death during optic nerve regeneration, development.
El Esawi, M.A. and K.A. Farag (2006). Restoration of the regenerative capacity of the hind limbs after transaction at the middle thigh level during the metamorphosis climactic stage (57) of the toad Bufo regularis Reuss. Journal of the Egyptian German Society of Zoology 51(A): 487-505. ISSN: 1110-5356.
NAL Call Number: QL1.E49
Descriptors: toad, Bufo regularis, regenerative capacity, hind limbs, transaction, middle high level.
Language of Text: Arabic; English.
Endo, T., J. Yoshino, K. Kado, and S. Tochinai (2007). Brain regeneration in anuran amphibians. Development Growth and Differentiation 49(2): 121-129. ISSN: 0012-1592.
Abstract: Urodele amphibians are highly regenerative animals. After partial removal of the brain in urodeles, ependymal cells around the wound surface proliferate, differentiate into neurons and glias and finally regenerate the lost tissue. In contrast to urodeles, this type of brain regeneration is restricted only to the larval stages in anuran amphibians (frogs). In adult frogs, whereas ependymal cells proliferate in response to brain injury, they cannot migrate and close the wound surface, resulting in the failure of regeneration. Therefore frogs, in particular Xenopus, provide us with at least two modes to study brain regeneration. One is to study normal regeneration by using regenerative larvae. In this type of study, the requirement of reconnection between a regenerating brain and sensory neurons was demonstrated. Functional restoration of a regenerated telencephalon was also easily evaluated because Xenopus shows simple responses to the stimulus of a food odor. The other mode is to compare regenerative larvae and non-regenerative adults. By using this mode, it is suggested that there are regeneration-competent cells even in the non-regenerative adult brain, and that immobility of those cells might cause the failure of regeneration. Here we review studies that have led to these conclusions.
Descriptors: amphibians, frog, Xenopus, anuran, Urodele amphibians, brain regeneration, brain injury, ependymal cells.
Fahmy, G.H. and R.E. Sicard (2002). A role for effectors of cellular immunity in epimorphic regeneration of amphibian limbs. In Vivo 16(3): 179-184. ISSN: 0258-851X.
Descriptors: amphibians, epimorphic regeneration of limbs, cellular immunity, effectors, role, suppression, skin allografts.
Gardiner, D.M., T. Endo, and S.V. Bryant (2002). The molecular basis of amphibian limb regeneration: integrating the old with the new. Seminars in Cell and Developmental Biology 13(5): 345-352. ISSN: 1084-9521.
Descriptors: amphibians, limb regeneration, molecular basis, review.
Girvan, J.E., W.M. Olson, and B.K. Hall (2002). Hind-limb regeneration in the dwarf African clawed frog, Hymenochirus boettgeri (Anura: Pipidae). Journal of Herpetology 36(4): 537-543. ISSN: 0022-1511.
NAL Call Number: QL640.J6
Descriptors: dwarf African clawed frog, Hymenochirus boettgeri, hindlimbs regeneration, Anura.
Han, M.J. and W.S. Kim (2002). Effect of retinoic acid on fgf-8 expression in regenerating urodele amphibian limbs. Korean Journal of Biological Sciences 6(4): 301-304. ISSN: 1226-5071.
Descriptors: amphibians, limbs, regenerating, urodele, retinoic acid, fgf-8, effect, mesenchymal tissue, epidermal tissue, salamander.
Ishizuya Oka, A. (2007). Regeneration of the amphibian intestinal epithelium under the control of stem cell niche. Development Growth and Differentiation 49(2): 99-107. ISSN: 0012-1592.
Abstract: The epithelium of the mammalian digestive tract originates from stem cells and undergoes rapid cell-renewal throughout adulthood. It has been proposed that the microenvironment around the stem cells, called 'niche', plays an important role in epithelial cell-renewal through cell-cell and cell-extracellular matrix interactions. The amphibian intestine, which establishes epithelial cell-renewal during metamorphosis, serves as a unique and good model for studying molecular mechanisms of the stem cell niche. By using the organ culture of the Xenopus laevis intestine, we have previously shown that larval-to-adult epithelial remodeling can be organ-autonomously induced by thyroid hormone (TH) and needs interactions with the surrounding connective tissue. Thus, in this animal model, the functional analysis of TH response genes is useful for clarifying the epithelial-connective tissue interactions essential for intestinal remodeling at the molecular level. Recent progress in culture and transgenic technology now enables us to investigate functions of such TH response genes in the X. laevis intestine and sheds light on molecular aspects of the stem cell niche that are common to the mammalian intestine.
Descriptors: amphibian, Xenopus laevis intestine, bone morphogenetic protein 4, intestinal remodeling, sonic hedgehog, stem cell niche, thyroid hormone, regeneration, amphibian.
Karapetian, A.F. and K.A. Dzhivanian (2006). [Liver regenerative potential of the lake frog Rana ridibunda after partial hepatectomy]. Tsitologiia 48(4): 346-354. ISSN: 0041-3771.
Abstract: A histomorphological study of the regenerating liver of Rana ridibunda, within 2 months after partial hepatectomy, shows that regenerative processes on the wound surface are slowly proceeding. Processes of reticular fiber reconstruction occurred in the composition of the basal membrane of liver sinusoids. A cytophotometric study shows that glandular cells in R. ridibunda liver are commonly tetraploid. The post-traumatic regeneration of the liver after partial hepatectomy involves activation of DNA synthesis in hepatocytes, leading to increase in their ploidy. Within the 1st month of regeneration, the mitotic index of hepatocytes substantially increased. Regeneration of glandular parenchyma of the liver is accompanied by a quantitative increase in binucleate hepatocytes, which is most highly expressed within 5-20 days after partial hepatectomy.
Descriptors: lake frog, Rana ridibunda, liver cytology, liver physiology, liver regeneration, physiology, cell nucleus ultrastructure, cytophotometry, hepatectomy, hepatocytes cytology, mitotic index, ploidies, reticulin, time factors.
Language of Text: Russian.
Mescher, A.L. and A.W. Neff (2006). Limb regeneration in amphibians: immunological considerations. The ScientificWorld Journal 6: 1-11. ISSN: 1537-744X.
Descriptors: amphibians, urodele, anuran, limb regeneration, immunological considerations, nerves, regenerative capacity.
Monaghan, J.R., J.A. Walker, R.B. Page, S. Putta, C.K. Beachy, and S.R. Voss (2007). Early gene expression during natural spinal cord regeneration in the salamander Ambystoma mexicanum. Journal of Neurochemistry 101(1): 27-40. ISSN: 0022-3042.
Descriptors: amphibians, salamander, Ambystoma mexicanum, early gene expression, natural spinal cord regeneration, tail amputation.
Morrison, J.I., S. Loof, P. He, and A. Simon (2006). Salamander limb regeneration involves the activation of a multipotent skeletal muscle satellite cell population. Journal of Cell Biology 172(3): 433-440. ISSN: 0021-9525.
NAL Call Number: 442.8 J828
Abstract: In contrast to mammals, salamanders can regenerate complex structures after injury, including entire limbs. A central question is whether the generation of progenitor cells during limb regeneration and mammalian tissue repair occur via separate or overlapping mechanisms. Limb regeneration depends on the formation of a blastema, from which the new appendage develops. Dedifferentiation of stump tissues, such as skeletal muscle, precedes blastema formation, but it was not known whether dedifferentiation involves stem cell activation. We describe a multipotent Pax7 superscript + satellite cell population located within the skeletal muscle of the salamander limb. We demonstrate that skeletal muscle dedifferentiation involves satellite cell activation and that these cells can contribute to new limb tissues. Activation of salamander satellite cells occurs in an analogous manner to how the mammalian myofiber mobilizes stem cells during skeletal muscle tissue repair. Thus, limb regeneration and mammalian tissue repair share common cellular and molecular programs. Our findings also identify satellite cells as potential targets in promoting mammalian blastema formation.
Descriptors: salamander, limb regeneration, satellite cell population, skeletal muscle, blastema formation, tissue repair.
Satoh, A., T. Endo, M. Abe, N. Yakushiji, S. Ohgo, K. Tamura, and H. Ide (2006). Characterization of Xenopus digits and regenerated limbs of the froglet. Developmental Dynamics 235(12): 3316-3326. ISSN: 1058-8388.
NAL Call Number: QL801.A4
Descriptors: amphibians, froglet, Xenopus, regenerated limbs, characterization, digits.
Shimizu Nishikawa, K., J. Takahashi, and A. Nishikawa (2003). Intercalary and supernumerary regeneration in the limbs of the frog, Xenopus laevis. Developmental Dynamics 227(4): 563-572. ISSN: 1058-8388.
NAL Call Number: QL801.A4
Descriptors: amphibians, frog, tadpoles, Xenopus laevis, regeneration, limbs, intercalary, supernumerary, anuran, urodele.
Slack, J.M. (2006). Amphibian muscle regeneration--dedifferentiation or satellite cells? Trends in Cell Biology 16(6): 273-275. ISSN: 0962-8924.
NAL Call Number: QH573.T73
Abstract: Until recently, the cell biology of mammalian muscle repair following damage appeared to be completely different from the formation of new muscles in regenerated appendages of Amphibia. Mammalian muscle repair occurs through the mobilization of muscle satellite cells, whereas the new muscle in amphibian appendage regeneration was believed to arise by dedifferentiation of myofibres to form myoblasts. But recent work shows that muscle satellite cells are also involved in amphibian regeneration and the controversy about the reality of muscle dedifferentiation is heating up again.
Descriptors: amphibia physiology, muscles physiopathology, regeneration physiology, satellite cells, skeletal muscle physiology, cell differentiation, myoblasts physiology, wound healing.
Stocum, D.L. (2004). Amphibian regeneration and stem cells. Current Topics in Microbiology and Immunology 280: 1-70. ISSN: 0070-217X.
Abstract: Larval and adult urodeles and anuran tadpoles readily regenerate their limbs via a process of histolysis and dedifferentiation of mature cells local to the amputation surface that accumulate under the wound epithelium as a blastema of stem cells. These stem cells require growth and trophic factors from the apical epidermal cap (AEC) and the nerves that re-innervate the blastema for their survival and proliferation. Members of the fibroblast growth factor (FGF) family synthesized by both AEC and nerves, and glial growth factor, substance P, and transferrin of nerves are suspected survival and proliferation factors. Stem cells derived from fibroblasts and muscle cells can transdifferentiate into other cell types during regeneration. The regeneration blastema is a self-organizing system based on positional information inherited from parent limb cells. Retinoids, which act through nuclear receptors, have been used in conjunction with assays for cell adhesivity to show that positional identity of blastema cells is encoded in the cell surface. These molecules are involved in the cell-cell signaling network that re-establishes the original structural pattern of the limb. Other systems of interest that regenerate by histolysis and dedifferentiation of pigmented epithelial cells are the neural retina and lens. Members of the FGF family are also important to the regeneration of these structures. The mechanism of amphibian regeneration by dedifferentiation is of importance to the development of a regenerative medicine, since understanding this mechanism may offer insights into how we might chemically induce the regeneration of mammalian tissues.
Descriptors: amphibians, regeneration, stem cells, anurans.
Straube, W.L. and E.M. Tanaka (2006). Reversibility of the differentiated state: regeneration in amphibians. Artificial Organs 30(10): 743-755. ISSN: 0160-564X.
Descriptors: amphibians, regeneration, differentiated state, reversibility, organs, body structures.
Suzuki, M., N. Yakushiji, Y. Nakada, A. Satoh, H. Ide, and K. Tamura (2006). Limb regeneration in Xenopus laevis froglet. The ScientificWorld Journal 6: 26-37. ISSN: 1537-744X.
Descriptors: amphibians, frog, Xenopus laevis, limb regeneration, froglet, epimorphosis, blastema, urodele, anuran, review.