Replacement of irradiated epidermis by migration of non-irradiated epidermis in the newt limb: the necessity of healthy epidermis for regeneration

Development ◽  
1983 ◽  
Vol 76 (1) ◽  
pp. 217-234
Author(s):  
Emile Lheureux
Keyword(s):  
Skin Graft ◽  
Dna Content ◽  
Limb Regeneration ◽  
Epidermal Cells ◽  
Cell Nuclei ◽  
Complete Replacement ◽  
Muscle Graft ◽  
Epidermis Cell ◽  
Newt Limb

An X-irradiated newt limb is able to regenerate if non-irradiated skin as well as non-irradiated muscle is transplanted to the stump. Non-irradiated epidermis is brought to the stump with a skin graft but not with a muscle graft. In order to know whether limb regeneration required healthy epidermis or not, a triploid skin cuff was set at the most proximal level of an irradiated limb and muscle was transplanted to the level of the midforearm. The forearm was then amputated through the muscle graft. A cytophotometrical analysis of DNA content of the epidermis cell nuclei sampled from the skin of the regenerate was undertaken to detect a migration of triploid epidermal cells. The result was a complete replacement of diploid irradiated epidermis by triploid epidermis, during the six weeks necessary for regeneration. Another investigation consisted of detecting a possible migration of non-irradiated triploid epidermis along an irradiated limb which had not been amputated. Healthy epidermis was found to migrate distally and replace irradiated epidermis in three weeks. Previous experiments involving transplantation of a non-irradiated skin cuff or muscle to an irradiated limb stump were carried out again but on animals which had been entirely irradiated to prevent any extra healthy epidermis cells from contaminating the regenerating limb epidermis. A regenerate developed from the skin graft but not from muscle graft. It is concluded that healthy epidermis must be present on the limb stump to permit the blastema to develop.

scholarly journals Normal newt limb regeneration requires matrix metalloproteinase function

2005 ◽  
Vol 279 (1) ◽  
pp. 86-98 ◽  
Author(s):  
Vladimir Vinarsky ◽  
Donald L. Atkinson ◽  
Tamara J. Stevenson ◽  
Mark T. Keating ◽  
Shannon J. Odelberg
Keyword(s):  
Matrix Metalloproteinase ◽  
Limb Regeneration ◽  
Newt Limb

scholarly journals The Role of the Prod1 Membrane Anchor in Newt Limb Regeneration

2016 ◽  
Vol 129 (1) ◽  
pp. 276-280
Author(s):  
Kaoru Nomura ◽  
Yasushi Tanimoto ◽  
Fumio Hayashi ◽  
Erisa Harada ◽  
Xiao-Yuan Shan ◽  
...  
Keyword(s):  
Limb Regeneration ◽  
Membrane Anchor ◽  
Newt Limb

Analysis of Hox-4.5 and Hox-3.6 expression during newt limb regeneration: differential regulation of paralogous Hox genes suggest different roles for members of different Hox clusters

Development ◽  
1993 ◽  
Vol 117 (4) ◽  
pp. 1397-1407 ◽  
Author(s):  
H.G. Simon ◽  
C.J. Tabin
Keyword(s):  
Hox Genes ◽  
Limb Regeneration ◽  
Differential Regulation ◽  
Epithelial Tissue ◽  
Cdna Clones ◽  
Rnase Protection ◽  
Adult Kidney ◽  
Early Expression ◽  
Hox Clusters ◽  
Newt Limb

Adult urodele amphibians can regenerate their limbs and tail. Based on their roles in other developing systems, Hox genes are strong candidates for genes that play a role in regulating pattern formation during regeneration. There are four homologous clusters of Hox genes in vertebrate genomes. We isolated cDNA clones of two newt homeobox genes from homologous positions within two Hox clusters; Hox-4.5 and Hox-3.6. We used RNase protection on nonamputated (normal) and regenerating newt appendages and tissue to compare their transcriptional patterns. Both genes show increased expression upon amputation with similar kinetics. Hox-4.5 and Hox-3.6 transcription is limited to the mesenchymal cells in the regenerates and is not found in the epithelial tissue. In addition to regenerating appendages, both genes are transcriptionally active in adult kidney of the newt. Striking differences were found in the regulation of Hox-4.5 and Hox-3.6 when they were compared in unamputated limbs and in regenerating forelimbs versus regenerating hindlimbs. Hox-4.5 is expressed in the blastema of regenerating fore- and hindlimbs, but Hox-4.5 transcripts are not detectable in normal limbs. In contrast, Hox-3.6 transcripts are found exclusively in posterior appendages, but are present in normal as well as regenerating hindlimbs and tails. Hox-4.5 is also expressed at a higher level in proximal (mid-humerus) regenerates than in distal ones (mid-radius). When we proximalized the positional memory of a distal blastema with retinoic acid, we find that the early expression level of Hox-4.5 is also proximalized. When the expression of these genes is compared to the expression of two previously reported newt Hox genes, a consistent pattern emerges, which can be interpreted in terms of differential roles for the different Hox clusters in determining regenerative limb morphology.

Characterization of a newt tenascin cDNA and localization of tenascin mRNA during newt limb regeneration by in situ hybridization

1991 ◽  
Vol 148 (1) ◽  
pp. 219-232 ◽  
Author(s):  
Hiroaki Onda ◽  
Matthew L. Poulin ◽  
Roy A. Tassava ◽  
Ing-Ming Chiu
Keyword(s):  
In Situ Hybridization ◽  
Limb Regeneration ◽  
Newt Limb

DNA–Feulgen cytophotometric determination of genome size for the freshwater-invading copepod Eurytemora affinis

Genome ◽  
2004 ◽  
Vol 47 (3) ◽  
pp. 559-564 ◽  
Author(s):  
Ellen M Rasch ◽  
Carol Eunmi Lee ◽  
Grace A Wyngaard
Keyword(s):  
Somatic Cell ◽  
Genome Size ◽  
Dna Content ◽  
Nuclear Dna ◽  
Growth Characteristic ◽  
Nuclear Dna Content ◽  
Cell Nuclei ◽  
Chromatin Diminution ◽  
Eurytemora Affinis ◽  
Genomic Studies

Variation in nuclear DNA content within some eukaryotic species is well documented, but causes and consequences of such variation remain unclear. Here we report genome size of an estuarine and salt-marsh calanoid copepod, Eurytemora affinis, which has recently invaded inland freshwater habitats independently and repeatedly in North America, Europe, and Asia. Adults and embryos of E. affinis from the St. Lawrence River drainage were examined for somatic cell DNA content and the presence or absence of embryonic chromatin diminution, using Feulgen–DNA cytophotometry to determine a diploid or 2C genome size of 0.6–0.7 pg DNA/cell. The majority of somatic cell nuclei, however, have twice this DNA content (1.3 pg/nucleus) in all of the adults examined and possibly represent a population of cells arrested at the G2 stage of the cell cycle or associated with some degree of endopolyploidy. Both suggestions contradict assumptions that DNA replication does not occur in adult tissues during the determinate growth characteristic of copepods. Absence of germ cell nuclei with markedly elevated DNA values, commonly found for species of cyclopoid copepods that show chromatin diminution, indicates that E. affinis lacks this trait. The small genome size and presumed absence of chromatin diminution increase the potential utility of E. affinis as a model for genomic studies on mechanisms of adaptation during freshwater invasions.Key words: copepod, genome size, DNA–Feulgen, calanoid, Eurytemora.

A comparative study of mycorrhizas in several genera of Pyroleae (Ericaceae) from western Canada

Botany ◽  
2008 ◽  
Vol 86 (6) ◽  
pp. 610-622 ◽  
Author(s):  
H. B. Massicotte ◽  
L. H. Melville ◽  
L. E. Tackaberry ◽  
R. L. Peterson
Keyword(s):  
Laser Scanning ◽  
Cortical Cell ◽  
Fungal Species ◽  
Epidermal Cells ◽  
Cell Nuclei ◽  
Symbiotic Associations ◽  
Tangential Wall ◽  
Confocal Scanning ◽  
Light Fluorescence ◽  
Chimaphila Umbellata

Genera in the tribe Pyroleae (subfamily Monotropoideae, family Ericaceae) occur as understory plants in northern temperate zones where some form major components of ecosystems. Most have been poorly studied in terms of their association with symbiotic fungi. In this study, colonization patterns of mycorrhizal roots of five members of the Pyroleae ( Pyrola asarifolia Michx., Pyrola chlorantha Sw., Orthilia secunda (L.) House, Chimaphila umbellata (L.) W. Bart., Moneses uniflora (L.) Gray) were explored. Root samples were processed for light, fluorescence, and laser scanning confocal, scanning electron, and transmission electron microscopy, as well as for immunocytochemistry. Roots of all species had enlarged epidermal cells containing hyphal complexes, Hartig nets confined to the epidermis, and mantles. Epidermal cells were penetrated by hyphae originating from the Hartig net at more than one site either along the inner tangential wall or radial walls. The outer tangential wall of epidermal cells of all species, except M. uniflora, was thicker than radial and inner tangential walls and consisted of two layers, the outer containing nonesterified pectins that were labeled with JIM 5 antibodies. Radial walls and inner tangential walls did not label, but cortical cell walls did. Intracellular hyphal complexes developed initially around centrally positioned, enlarged epidermal cell nuclei and, through branching, occupied most of the cell volume. Senescence and degradation of the complexes followed. The fungal species in these symbiotic associations may be important functionally in nutrient exchange, as well as in contributing to broader linkages with other hosts in these plant communities.

scholarly journals Plasticity of Retrovirus-Labelled Myotubes in the Newt Limb Regeneration Blastema

2000 ◽  
Vol 218 (2) ◽  
pp. 125-136 ◽  
Author(s):  
Anoop Kumar ◽  
Cristiana P. Velloso ◽  
Yutaka Imokawa ◽  
Jeremy P. Brockes
Keyword(s):  
Limb Regeneration ◽  
Regeneration Blastema ◽  
Newt Limb

scholarly journals MICROCHEMICAL DEOXYRIBONUCLEIC ACID DETERMINATION IN INDIVIDUAL CELLS

1961 ◽  
Vol 9 (3) ◽  
pp. 619-626 ◽  
Author(s):  
Jan-Erik Edström ◽  
Jerzy Kawiak
Keyword(s):  
Dna Content ◽  
Mitotic Cycle ◽  
Deoxyribonucleic Acid ◽  
Test Material ◽  
Cell Nuclei ◽  
Fixed Tissue ◽  
Dna Contents ◽  
Two Factors ◽  
Good Agreement

A method for the quantitative determination of DNA in the 50 to 500 µµg. range is presented. Cells or cell nuclei are isolated individually from fixed tissue by means of micromanipulation. The tissue units in question are extracted in an oil chamber with deoxyribonuclease solution. The extracts are evaporated to dryness and redissolved to lens-shaped drops, the DNA contents of which are determined by a photographic-photometric procedure in ultraviolet light. Determinations on calf thymocytes and rat spermatids show a relatively good agreement with biochemical data. The present method tends, however, to give some. what higher values than those reported earlier. The coefficient of variation for analytical values from test material is about ± 10 per cent. The method has been applied to cells from the axolotl, adults as well as tadpoles. Germ cells (spermatids and spermatocytes) do not show any evidence of a biological variation in DNA content. Cells from proliferating tissues give an increased spread of the DNA values. It could be shown, for epithelial cells, that there are at least two factors determining the DNA content of these cells. One is the fact that the cells are investigated at different phases of the mitotic cycle; the other is the fact that the DNA synthesis cycle occupies different ranges for different cells.

Sign in / Sign up

Export Citation Format

Share Document