Regeneration

Alibardi, L. and M. Toni (2005). Wound keratins in the regenerating epidermis of lizard suggest that the wound reaction is similar in the tail and limb. Journal of Experimental Zoology. Part A, Comparative Experimental Biology 303(10): 845-860. ISSN: 1548-8969.
NAL Call Number: QL1.J854
Descriptors: epidermis, extremities, keratins, lizard physiology, tail physiology, wound healing, amputation stumps, immunohistochemistry, keratinocytes.

Avallone, B., M. Porritiello, D. Esposito, R. Mutone, G. Balsamo, and F. Marmo (2003). Evidence for hair cell regeneration in the crista ampullaris of the lizard Podarcis sicula. Hearing Research 178(1-2): 79-88. ISSN: 0378-5955.
Abstract: We studied hair cell regeneration in the crista ampullaris of the lizard Podarcis sicula both in untreated animals and at early and late time intervals following a single high dose of gentamicin. The study was carried out using the S-phase marker 5-bromo-2'-deoxyuridine. Our ultrastructural and immunofluorescence studies showed that both apoptosis and hair cell regeneration happen in the lizard crista ampullaris in untreated animals, and that regenerative processes are greatly accelerated after treatment with the aminoglycoside antibiotic gentamicin. Our observations indicate that hair cell regeneration is strongly implicated in the repair of damaged sensory epithelium, and that new hair cells appear likely to arise from supporting cells.
Descriptors: reptiles, lizard, hair cell regeneration, crista ampullaris, gentamicin, apoptosis, repair, damaged sensory epithelium.

Blacker, H.A., C. Tsopelas, S. Orgeig, C.B. Daniels, and B.E. Chattertonz (2007). How regenerating lymphatics function: lessons from lizard tails. Anatomical Record 290(1): 108-114. ISSN: 0003-276X.
Descriptors: reptiles, lizard, tails, regenerating lymphatics, function, nonlymphoedematous tails, lymphangiogenesis, gecko.

Daniels, C.B., B.C. Lewis, C. Tsopelas, S.L. Munns, S. Orgeig, M.E. Baldwin, S.A. Stacker, M.G. Achen, B.E. Chatterton, and R.D. Cooter (2003). Regenerating lizard tails: a new model for investigating lymphangiogenesis. FASEB Journal 17(3): 479-481. ISSN: print: 0892-6638; online: 1530-6860.
NAL Call Number: QH301.F3
Abstract: Impaired lymphatic drainage in human limbs causes the debilitating swelling termed lymphoedema. In mammals, known growth factors involved in the control of lymphangiogenesis (growth of new lymph vessels) are vascular endothelial growth factors-C and -D (VEGF-C/D). Here we characterize a model of lymphangiogenesis in which the tail of lizards is regenerated without becoming oedematous. Three weeks after the tail is shed (autotomy), there are a small number of large diameter lymphatic vessels in the regenerated tail. Thereafter, the number increases and the diameter decreases. A functional lymphatic network, as determined by lymphoscintigraphy, is established 6 wk after autotomy. The new network differs morphologically and functionally from that in original tails. This lymphatic regeneration is associated with an up-regulation of a reptilian homologue of the VEGF-C/D protein family (rVEGF-C/D), as determined by Western blot analysis using a human reactive VEGF-C polyclonal antibody. Regenerating lizard tails are potentially useful models for studying the molecular basis of lymphangiogenesis with a view to developing possible treatments for human lymphoedema.
Descriptors: reptiles, lizard tails, regenerating, new model, investigating, lymphangiogenesis.

Fitch, H.S. (2003). A comparative study of loss and regeneration of lizard tails. Journal of Herpetology 37(2): 395-399. ISSN: 0022-1511.
NAL Call Number: QL640.J6
Descriptors: reptiles, lizard tails, loss, regeneration, comparative study.

Galis, F., G.P. Wagner, and E.L. Jockusch (2003). Why is limb regeneration possible in amphibians but not in reptiles, birds, and mammals? Evolution and Development 5(2): 208-220. ISSN: 1520-541X.
Abstract: The capacity to regenerate limbs is very high in amphibians and practically absent in other tetrapods despite the similarities in developmental pathways and ultimate morphology of tetrapod limbs. We propose that limb regeneration is only possible when the limb develops as a semiautonomous module and is not involved in interactions with transient structures. This hypothesis is based on the following two assumptions: To an important extent, limb development uses the same developmental mechanisms as normal limb development and developmental mechanisms that require interactions with transient structures cannot be recapitulated later. In amniotes limb development is early, shortly after neurulation, and requires inductive interactions with transient structures such as somites. In amphibians limb development is delayed relative to amniotes and has become decoupled from interactions with somites and other transient structures that are no longer present at this stage. The limb develops as a semi-independent module. A comparison of the autonomy and timing of limb development in different vertebrate taxa supports our hypothesis and its assumptions. The data suggest a good correlation between self-organizing and regenerative capacity. Furthermore, they suggest that whatever barriers amphibians overcame in the evolution of metamorphosis, they are the same barriers that need to be overcome to make limb regeneration possible in other taxa.
Descriptors: reptiles, amphibians, regeneration, limbs, capacity, tetrapod limb morphology, developmental patyhways, metamorphosis.

Harman, A.M., J. Rodger, A. Ahmat, C. Thomas, C. Bartlett, P. Chen, S.A. Dunlop, and L.D. Beazley (2003). PSA-NCAM is up-regulated during optic nerve regeneration in lizard but not in goldfish. Experimental Neurology 182(1): 180-185. ISSN: 0014-4886.
Abstract: The addition of polysialic acid (PSA) to neural cell adhesion molecule (NCAM) facilitates axon growth. Here we use Western blots and immunohistochemistry to examine expression of PSA-NCAM during optic nerve regeneration. In lizard, retinal ganglion cell axons become transiently PSA-NCAM positive. By contrast, goldfish RGC axons are PSA-NCAM negative both in normal animals and throughout regeneration with the exception of a PSA-NCAM-positive fascicle arising from newly generated RGCs. Transient sialylation of NCAM in lizard may assist regeneration in the nonpermissive reptilian visual pathway and facilitate the reestablishment of a crude topographic map; down-regulation in the long term may contribute to the breakdown in topography. The lack of sialylation in goldfish presumably reflects the permissive nature of the substrate allowing axon regeneration and the successful reestablishment of a topographic map.
Descriptors: reptiles, optic nerve, regeneration, lizard, PSA-NCAM up-regulated, retinal ganglion cell axons.

Kuchling, G. (2005). Bifid tail regeneration in a turtle, Emydura sp. (Testudines: Chelidae). Chelonian Conservation and Biology 4(4): 935-937. ISSN: 1071-8443.
Descriptors: reptiles, regeneration, bifid tail, turtle, Emydura.

Lang, D.M., M. del Mar Romero Aleman, J.F. Arbelo Galvan, C.A. Stuermer, and M. Monzon Mayor (2002). Regeneration of retinal axons in the lizard Gallotia galloti is not linked to generation of new retinal ganglion cells. Journal of Neurobiology 52(4): 322-335. ISSN: 0022-3034.
NAL Call Number: QP351.J55
Descriptors: reptiles, lizard, Gallotia galloti, retinal axons, regeneration, new retinal ganglion cells.

Lin, Z.H. and X. Ji (2005). Partial tail loss has no severe effects on energy stores and locomotor performance in a lacertid lizard, Takydromus septentrionalis. Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology 175(8): 567-573. ISSN: print: 0174-1578; online: 1432-136X.
NAL Call Number: QP33.J681
Abstract: Many species of lizards use caudal autotomy as a defense strategy to avoid predation, but tail loss entails costs. These topics were studied experimentally in the northern grass lizard, Takydromus septentrionalis. We measured lipids in the three-tail segments removed from each of the 20 experimental lizards (adult females) initially having intact tails to evaluate the effect of tail loss on energy stores; we obtained data on locomotor performance (sprint speed, the maximal length traveled without stopping and the number of stops in the racetrack) for these lizards before and after the tail-removing treatments to evaluate the effect of tail loss on locomotor performance. An independent sample of 20 adult females that retained intact tails was measured for locomotor performance to serve as controls for successive measurements taken for the experimental lizards. The lipids stored in the removed tail was positively correlated with tailbase width when holding the tail length constant, indicating that thicker tails contained more lipids than did thinner tails of the same overall length. Most of the lipids stored in the tail were concentrated in the proximal portion of the tail. Locomotor performance was almost unaffected by tail loss until at least more than 71% of the tail (in length) was lost. Our data show that partial tail loss due to predatory encounters or other factors may not severely affect energy stores and locomotor performance in T. septentrionalis.
Descriptors: reptiles, lacertid lizard, Takydromus septentrionalis, partial tail loss, energy stores, effects, locomotor performance, defense strategy, predation.

Meyer, V., M.R. Preest, and S.M. Lochetto (2002). Physiology of original and regenerated lizard tails. Herpetologica 58(1): 75-86. ISSN: 0018-0831.
NAL Call Number: QL640.H4
Descriptors: reptiles, lizard tails, regenerated, physiology, original.

Turgut, M., S. Kaplan, K. Metin, Y.B. Koca, E. Soylu, B. Sahin, Z.B. Ateslier, and H.K. Basaloglu (2006). Effects of constant lightness, darkness and parachlorophenylalanine treatment on tail regeneration in the lizard Ophisops elegans macrodactylus: macroscopic, biochemical and histological changes. Anatomia, Histologia, Embryologia 35(3): 155-161. ISSN: 0340-2096.
Abstract: A better understanding of regenerative growth is very important for the development of new potential strategies. Recently, the pineal secretory product melatonin was shown to stimulate the regeneration process. In this study, we carried out an experimental investigation of tail regeneration in young adult lizards, Ophisops elegans macrodactylus Berthold, 1842, addressing the role of melatonin on the regeneration process. Lizards were divided into three groups: constant light-exposed control group (n = 13), constant dark-exposed group (n = 15) and parachlorophenylalanine (p-CPA) treatment group exposed to constant light (n = 15). Using a tail autotomy procedure, the effects of p-CPA treatment on connective tissue together with neural tissue and vascular tissue in regenerating tail in lizards were investigated. p-CPA (400 microg/kg body mass) was injected from day 0 to 30 days after autotomy. p-CPA treatment produced a significant increase in the length of the regenerated tail compared with light-exposed control and dark-exposed lizards. Total collagen content was found to be higher in p-CPA-treated animals in comparison with other groups. Histologically, a higher percentage of connective tissue and vascular tissue and a lower percentage of neural tissue were found in the regenerated tails of the p-CPA-treated lizards. Importantly, the percentage of neural tissue in lizards in the dark-exposed animals was higher than that in animals of both light-exposed and p-CPA treatment groups. Thus, it is clear that p-CPA has a stimulatory influence on fibroblast collagen production and vascularization of the regenerated tail in the lizards. Furthermore, it seems that the neural regeneration process was markedly enhanced in lizards exposed to continuous darkness. Based on the results of our study, it is suggested that melatonin may be an active factor that speeds up the rate of tail regeneration in lacertilians.
Descriptors: reptiles, Ophisops elegans macrodactylus, lizards physiology, melatonin physiology, pineal gland physiology, regeneration physiology, tail physiology, fenclonine pharmacology, light, random allocation, regeneration drug effects.

Turgut, M., Y.B. Koca, S. Kaplan, K. Metin, N. Uzum, E. Soylu, A. Avc, M.C. Ragbetli, E.P. Beytas, and K. Olgun (2007). Effects of Ca2+channel blocker verapamil on tissue regeneration in a lizard tail autotomy model: a biochemical and histological study. Amphibia Reptilia 28(1): 7-15. ISSN: 0173-5373.
Descriptors: reptiles, lizard, tail, autotomy model, tissue regeneration, Ca2+ channel blocker verapamil, effects.