Determination of axial polarity in the urodele limb regeneration blastema

Development ◽  
1982 ◽  
Vol 71 (1) ◽  
pp. 193-214
Author(s):  
David L. Stocum
Keyword(s):  
Limb Regeneration ◽  
Normal Number ◽  
Supernumerary Limbs ◽  
Graft Tissue ◽  
Species Specific ◽  
Host Tissues ◽  
Regeneration Blastema ◽  
Anterior Posterior ◽  
Thin Band

The state of determination of the anterior-posterior, dorsal-ventral and proximal-distal axes of the undifferentiated limb regeneration blastema was evaluated by heterografting and autografting experiments in which these axes were reversed with respect to the limb stump. Species-specific size differences in skeletal elements were used as markers to trace the origin of regenerate tissues in the heterografting experiments, and differences in the skeletal patterns of hindlimbs and forelimbs were used as markers in the autografting experiments. The resulting primary regenerates fell into two categories, those composed wholly or partly of donor tissues, and those composed entirely of host tissues. Regenerate structures formed from donor tissues always maintained the handedness of origin, while regenerates formed from host tissues always displayed host-side handedness. These results demonstrate that the axes of the blastema are determined from the start of regeneration, and that previous claims of axial lability in reversal experiments are based on an illusion created by resorption of graft tissue, accompanied by regeneration from the host. Reversal of the transverse axes resulted in the formation of supernumerary limbs. Analysis of heterograft cases in which the anterior-posterior axis was reversed showed that 50% of the supernumeraries were constructed partly of donor blastema tissue whose axial polarity was reversed with respect to the adjacent primary regenerate. The vast majority of the primary regenerates in these cases possessed the normal number of digits. It is thus likely that the reprogrammed donor blastema cells used to construct the supernumeraries are derived by division of a thin band of cells at the edge of the graft adjacent to the supernumerary.

scholarly journals Evolution of Antennapedia-Class Homeobox Genes

Genetics ◽  
1996 ◽  
Vol 142 (1) ◽  
pp. 295-303 ◽  
Author(s):  
Jianzhi Zhang ◽  
Masatoshi Nei
Keyword(s):  
Gene Expression ◽  
Homeobox Genes ◽  
Amino Acid Sequences ◽  
Gene Arrangement ◽  
Gene Duplications ◽  
Group I ◽  
Group 3 ◽  
Group Ii ◽  
Anterior Posterior

Antennapedia (Antp)-class homeobox genes are involved in the determination of pattern formation along the anterior-posterior axis of the animal embryo. A phylogenetic analysis of Antp-class homeodomains of the nematode, Drosophila, amphioxus, mouse, and human indicates that the 13 cognate group genes of this gene family can be divided into two major groups, i.e., groups I and II. Group I genes can further be divided into subgroups A (cognate groups 1–2), B (cognate group 3), and C (cognate groups 4–8), and group II genes can be divided into subgroups D (cognate groups 9–10) and E (cognate groups 11–13), though this classification is somewhat ambiguous. Evolutionary distances among different amino acid sequences suggest that the divergence between group I and group II genes occurred ∼1000 million years (MY) ago, and the five different subgroups were formed by ∼600 MY ago, probably before the divergence of Pseudocoelomates (e.g., nematodes) and Coelomates (e.g., insects and chordates). Our results show that the genes that are phylogenetically close are also closely located in the chromosome, suggesting that the colinearity between the gene expression and gene arrangement was generated by successive tandem gene duplications and that the gene arrangement has been maintained by some sort of selection.

Molecular determination of the origin of acephalic cysticercus

Parasitology ◽  
2004 ◽  
Vol 130 (2) ◽  
pp. 239-246 ◽  
Author(s):  
J.-Y. CHUNG ◽  
W.-G. KHO ◽  
S.-Y. HWANG ◽  
E.-Y. JE ◽  
Y.-T. CHUNG ◽  
...  
Keyword(s):  
Nadh Dehydrogenase ◽  
Fatal Outcome ◽  
Constitutive Expression ◽  
Molecular Data ◽  
Molecular Characteristics ◽  
Nadh Dehydrogenase Subunit ◽  
Subarachnoidal Space ◽  
Species Specific ◽  
Molecular Determination

Acephalic cysticercus (Ac), a rarely developed multilobulated and nonencysted form of larval Taenia, causes hydrocephalus or adhesive arachnoiditis in the ventricles and subarachnoidal space that often lead to fatal outcome in affected patients. Ac has been proposed to originate from T. solium on the basis of morphological features, while no molecular data supporting the presumption have been available. In the present study, we investigated the immunological properties as well as molecular characteristics of Ac that was obtained surgically from 6 patients. Immunoblotting of the cyst fluid from Ac samples demonstrated the constitutive expression of a T. solium metacestode (TsM) 10 kDa protein. Specific antibodies against the truncated 10 kDa protein, which appears to be species specific for TsM cysticercosis, were detected in both serum and cerebrospinal fluid samples of Ac patients. Nucleotide sequences of mitochondrial cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit 1 (ND1) genes of Ac were almost identical to those of T. solium but differed substantially from those of the other Taenia species. In phylogenetic analysis, Ac clustered with T. solium in a well-supported clade. Our results strongly suggest that Ac may have originated from T. solium.

scholarly journals XVII. On the atomic weight of glucinum (Beryllium)

1883 ◽  
Vol 174 ◽  
pp. 601-613
Keyword(s):  
Specific Heat ◽  
Volatile Compound ◽  
Atomic Weight ◽  
Normal Number ◽  
Vapour Density ◽  
Atomic Heat ◽  
Lothar Meyer ◽  
Free Metal

I. Introductory. Ever since the discovery of glucinum by Vauquelin, in 1798, its atomic weight has been a disputed matter amongst chemists. Its discoverer considered that its oxide was a monoide, an opinion which was however strongly opposed by Berzelius, who wrote the oxide Gl 2 O 3 and the atomic weight 13⋅7 (O=16). The researches of Awdejew and Debrayt again turned the scale in favour of the earlier view, and as an atomic weight of 9⋅2 suited the properties of the metal in the tables of periodicy constructed by MM. Mendeleef and Lothar Meyer, this atomic weight has, up to quite recently, been generally accepted by chemists. As a welcome confirmation to this came a determination of the specific heat of the metal by Professor E. Reynolds, J who found that for its atomic heat to be near the normal number 6⋅0, its atomic weight must be 9⋅2 and not 13⋅8. Almost immediately afterwards a second determination of the specific heat was made by MM. Nilson and Petterson, who, however, obtained a result agreeing not with the lower atomic weight hut with the higher. The reasons for these conflicting opinions are to be found—first, in the anomalous position of glucinum among the elements; secondly, in the difficulties which surround the preparation of even small quantities of the free metal in a tolerably pure condition; and thirdly, in the fact that no volatile compound of glucinum is known of which the vapour density might be easily determined.

Symmetrical vascularization patterns in normal and retinoic acid treated limb regenerates of the axolotl, Ambystoma mexicanum

1998 ◽  
Vol 76 (9) ◽  
pp. 1795-1796 ◽  
Author(s):  
Steven R Scadding ◽  
Andrew Burns
Keyword(s):  
Retinoic Acid ◽  
Pattern Formation ◽  
Vascular System ◽  
Limb Regeneration ◽  
Ambystoma Mexicanum ◽  
Limb Pattern ◽  
Regeneration Blastema

The purpose of this investigation was to determine whether there were any asymmetries in the vascularization of the limb-regeneration blastema in the axolotl, Ambystoma mexicanum, that might be related to pattern formation, and to determine if retinoic acid could modify the vascular patterns of the blastema. We used acrylic casts of the vascular system of the limbs to assess the pattern of vascularization. We observed a very regular symmetrical arrangement of capillaries in the limb-regeneration blastema that did not appear to be modified by doses of retinoic acid sufficient to modify the limb pattern.

A monoclonal antibody stains myogenic cells in regenerating newt muscle

Development ◽  
1987 ◽  
Vol 101 (2) ◽  
pp. 267-277 ◽  
Author(s):  
K.J. Griffin ◽  
D.M. Fekete ◽  
B.M. Carlson
Keyword(s):  
Monoclonal Antibody ◽  
Muscle Regeneration ◽  
Tissue Repair ◽  
Limb Regeneration ◽  
Alternative Interpretation ◽  
Muscle Fibres ◽  
Muscle Repair ◽  
Contralateral Limb ◽  
Minced Muscle ◽  
Regeneration Blastema

Monoclonal antibodies have been used to study minced muscle regeneration in the adult newt, Notophthalmus viridescens. The contralateral limb was amputated and the immunostaining patterns in the regenerating blastema were compared with the minced tissue in sectioned material. Staining with a myofibre-specific antibody, called 12/101 (Kintner & Brockes, 1984), showed that myofibre degeneration was complete by 8–10 days after mincing, with myogenesis commencing 2 days later. Another monoclonal antibody, called 22/18, previously shown to label a subset of cells in the regeneration blastema of the newt (Kintner & Brockes, 1984, 1985), was found also to recognize a population of cells in regenerating minced muscle. At 6 days after mincing, the number of 22/18-positive (22/18+) cells was low but by days 12–16, during the period of myogenesis, their number had increased to become a major population within the minced tissue. A small number of the 22/18+ cells could be double labelled with 12/101 at this time. Prior to this, there was a phase in which 12/101 staining had disappeared from the mince. Cells immunoreactive with both antibodies after this phase confirm that at least some of the 22/18+ cells are myogenic. The number of 22/18+ cells decreased as muscle repair and maturation progressed. These results show that 22/18 is not specifically associated with blastemal cells but is a more general marker for regenerating systems in the newt. They further suggest an alternative interpretation of the double-labelled cells used by Kintner & Brockes (1984) as evidence for myofibre dedifferentiation in limb regeneration. Instead, we propose that such cells represent new myogenesis occurring by tissue repair of locally damaged muscle fibres.

Measurement of progesterone in sheep using a commercial ELISA kit for human plasma

2021 ◽  
pp. 104063872110435
Author(s):  
Valeria Pasciu ◽  
Maria Nieddu ◽  
Elena Baralla ◽  
Cristian Porcu ◽  
Francesca Sotgiu ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Human Plasma ◽  
Method Validation ◽  
Plasma Progesterone ◽  
Freeze Thaw ◽  
Elisa Kit ◽  
Stability Data ◽  
Human Use ◽  
Species Specific

Determination of serum or plasma progesterone (P4) concentrations is important to recognize pregnant and non-pregnant ewes, and also to predict the number of carried lambs. The 2 most common methodologies for the detection of plasma P4 are radioimmunoassay (RIA) and enzyme immunoassay (EIA). RIA is very expensive, and not all laboratories are equipped to perform this test; EIA is commercially available for human use, but only a few companies produce species-specific kits, which are expensive. We verified for ovine plasma a less expensive and easily available ELISA kit (DiaMetra) designed to quantify P4 in humans. Pools of ovine and human plasma were used to compare repeatability, accuracy, sensitivity, and stability of P4 measured by the DiaMetra kit. Repeatability data were within 15%, and accuracy values were ~90% for both plasma matrices. Stability data showed a loss of <20% for freeze–thaw and <30% for 30-d storage. All parameters were acceptable under international guidelines for method validation. The human ELISA kit was used successfully to quantify plasma P4 in 26 ewes during pregnancy until delivery. P4 concentrations were also correlated with the number of carried lambs.

Determination of hexavalent chromium by species specific isotope dilution mass spectrometry and ion chromatography–1,5-diphenylcarbazide spectrophotometry

2003 ◽  
Vol 18 (8) ◽  
pp. 922-932 ◽  
Author(s):  
Kristof Tirez ◽  
Wilfried Brusten ◽  
Annick Cluyts ◽  
Johan Patyn ◽  
Nicole De Brucker
Keyword(s):  
Mass Spectrometry ◽  
Hexavalent Chromium ◽  
Ion Chromatography ◽  
Isotope Dilution ◽  
Isotope Dilution Mass Spectrometry ◽  
Species Specific

Species specific isotope dilution for the accurate and SI traceable determination of arsenobetaine and methylmercury in cuttlefish and prawn

2016 ◽  
Vol 943 ◽  
pp. 41-49 ◽  
Author(s):  
Paramee Kumkrong ◽  
Benjaporn Thiensong ◽  
Phuong Mai Le ◽  
Garnet McRae ◽  
Anthony Windust ◽  
...  
Keyword(s):  
Isotope Dilution ◽  
Species Specific

scholarly journals A comparative evaluation of PCR- based methods for species- specific determination of African animal trypanosomes in Ugandan cattle

2013 ◽  
Vol 6 (1) ◽  
pp. 316 ◽  
Author(s):  
Heba A Ahmed ◽  
Kim Picozzi ◽  
Susan C Welburn ◽  
Ewan T MacLeod
Keyword(s):  
Comparative Evaluation ◽  
Specific Determination ◽  
Species Specific
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