Induction of Metamorphosis in Axolotls (Ambystoma mexicanum)

2009 ◽  
Vol 2009 (8) ◽  
pp. pdb.prot5268-pdb.prot5268 ◽  
Author(s):  
R. B. Page ◽  
S. R. Voss
Keyword(s):  
Ambystoma Mexicanum ◽  
Induction Of Metamorphosis

The Ultrastructure of Myocardial Cells in Normal and Cardiac Lethal Mutant Mexican Axolotls, (Ambystoma Mexicanum)

1970 ◽  
Vol 28 ◽  
pp. 62-63
Author(s):  
Larry F. Lemanski ◽  
Eldridge M. Bertke ◽  
J. T. Justus
Keyword(s):  
Fine Structure ◽  
Heart Development ◽  
Osmium Tetroxide ◽  
Picric Acid ◽  
Ambystoma Mexicanum ◽  
Recessive Mutation ◽  
Acid Mixture ◽  
Myocardial Cells ◽  
Lethal Mutant ◽  
Mexican Axolotl

A recessive mutation has been recently described in the Mexican Axolotl, Ambystoma mexicanum; in which the heart forms structurally, but does not contract (Humphrey, 1968. Anat. Rec. 160:475). In this study, the fine structure of myocardial cells from normal (+/+; +/c) and cardiac lethal mutant (c/c) embryos at Harrison's stage 40 was compared. The hearts were fixed in a 0.1 M phosphate buffered formaldehyde-glutaraldehyde-picric acid-styphnic acid mixture and were post fixed in 0.1 M s-collidine buffered 1% osmium tetroxide. A detailed study of heart development in normal and mutant embryos from stages 25-46 will be described elsewhere.

Arrangement of Mitochondria in Spermatozoa of the Mexican Axolotl, Ambystoma Mexicanum

1973 ◽  
Vol 31 ◽  
pp. 626-627
Author(s):  
Ezzatollah Keyhani ◽  
Larry F. Lemanski ◽  
Sharon L. Lemanski
Keyword(s):  
Plasma Membrane ◽  
Sperm Motility ◽  
Substrate Oxidation ◽  
Ambystoma Mexicanum ◽  
Axial Filament ◽  
Mexican Axolotl ◽  
Middle Piece

Energy for sperm motility is provided by both glycolytic and respiratory pathways. Mitochondria are involved in the latter pathway and conserve energy of substrate oxidation by coupling to phosphorylation. During spermatogenesis, the mitochondria undergo extensive transformation which in many species leads to the formation of a nebemkem. The nebemkem subsequently forms into a helix around the axial filament complex in the middle piece of spermatozoa.Immature spermatozoa of axolotls contain numerous small spherical mitochondria which are randomly distributed throughout the cytoplasm (Fig. 1). As maturation progresses, the mitochondria appear to migrate to the middle piece region where they become tightly packed to form a crystalline-like sheath. The cytoplasm in this region is no longer abundant (Fig. 2) and the plasma membrane is now closely apposed to the outside of the mitochondrial layer.

The structure of the gills of the axolotl, Ambystoma mexicanum

1987 ◽  
Vol 45 ◽  
pp. 824-825
Author(s):  
Mohinder S. Jarial
Keyword(s):  
Leydig Cells ◽  
Secretory Granules ◽  
Light And Electron Microscopy ◽  
Cell Types ◽  
Ambystoma Mexicanum ◽  
Basal Cells ◽  
Granular Cells ◽  
Gill Filaments ◽  
Mitotic Figures ◽  
Apical Membranes

The axolotl is a strictly aquatic salamander in which the larval external gills are retained throughout life. The external gills of the adult axolotl have been studied by light and electron microscopy for ultrastructural evidence of ionic transport. The thin epidermis of the gill filaments and gill stems is composed of 3 cell types: granular cells, the basal cells and a sparce population of intervening Leydig cells. The gill epidermis is devoid of muscles, and no mitotic figures were observed in any of its cells.The granular cells cover the gill surface as a continuous layer (Fig. 1, G) and contain secretory granules of different forms, located apically (Figs.1, 2, SG). Some granules are found intimately associated with the apical membrane while others fuse with it and release their contents onto the external surface (Fig. 3). The apical membranes of the granular cells exhibit microvilli which are covered by a PAS+ fuzzy coat, termed “glycocalyx” (Fig. 2, MV).

Application of DNA Barcoding in Taxonomy and Phylogeny: An Individual Case of COI Partial Gene Sequencing from Seven Animal Species

2019 ◽  
Vol 53 (5) ◽  
pp. 375-384
Author(s):  
M. Drohvalenko ◽  
A. Mykhailenko ◽  
M. Rekrotchuk ◽  
L. Shpak ◽  
V. Shuba ◽  
...  
Keyword(s):  
Phylogenetic Trees ◽  
Far East ◽  
Individual Case ◽  
Ambystoma Mexicanum ◽  
Leaf Miner ◽  
Horse Chestnut ◽  
Natural Reserve ◽  
Rock Lizard ◽  
Sand Lizard ◽  
Lacerta Agilis

Abstract A part of the COI mitochondrial barcoding gene was sequenced from seven species of different taxonomical groups: Ambystoma mexicanum (Amphibia, Ambystomatidae), Darevskia lindholmi, Lacerta agilis exigua (Reptilia, Lacertidae), Erinaceus roumanicus (Mammalia, Erinaceidae), Macrobiotus sp. 1 and 2 (Eutardigrada, Macrobiotidae) and Cameraria ohridella (Insecta, Gracillariidae). The sequences were compared with available sequences from databases and positioned on phylogenetic trees when the taxa had not yet been sequenced. The presence of Mexican axolotls in herpetoculture in Ukraine was confirmed. The partial COI genes of the Crimean rock lizard and an eastern sub-species of the sand lizard were sequenced. We demonstrated the presence of two tardigrade mitochondrial lineages of the Macrobiotus hufelandi group in the same sample from the Zeya Natural Reserve in the Far East: one was nearly identical to the Italian M. macrocalix, and the other one is similar to M. persimilis and M. vladimiri. We also confirmed the presence of the invasive haplotype “A” of the horse chestnut leaf miner in Ukraine, in line with the hypothesized route of invasion from Central Europe.

Proteolytic cleavage of ACTH in corticotropes of sexually mature axolotls (Ambystoma mexicanum)

Peptides ◽  
1993 ◽  
Vol 14 (5) ◽  
pp. 1029-1035 ◽  
Author(s):  
Robert M. Dores ◽  
Frances L. Sandoval ◽  
Lorraine K. McDonald
Keyword(s):  
Proteolytic Cleavage ◽  
Ambystoma Mexicanum ◽  
Sexually Mature

Distribution of sulfhydryloxidase (SOx) immunoreactivity in the testis of the axolotl (Ambystoma mexicanum) (amphibia, urodela)

1991 ◽  
Vol 23 (3) ◽  
pp. 377-384 ◽  
Author(s):  
F. Oehmen ◽  
G. Aumüller ◽  
M. Bergmann ◽  
J. Seitz
Keyword(s):  
Ambystoma Mexicanum

scholarly journals Dual embryonic origin and patterning of the pharyngeal skeleton in the axolotl ( Ambystoma mexicanum )

2015 ◽  
Vol 17 (3) ◽  
pp. 175-184 ◽  
Author(s):  
Elizabeth M. Sefton ◽  
Nadine Piekarski ◽  
James Hanken
Keyword(s):  
Ambystoma Mexicanum ◽  
Embryonic Origin

scholarly journals Equilibrium properties of a voltage-dependent junctional conductance.

1981 ◽  
Vol 77 (1) ◽  
pp. 77-93 ◽  
Author(s):  
D C Spray ◽  
A L Harris ◽  
M V Bennett
Keyword(s):  
Steady State ◽  
Rana Pipiens ◽  
Energy Difference ◽  
Ambystoma Mexicanum ◽  
Voltage Sensitivity ◽  
Junctional Conductance ◽  
Voltage Dependent ◽  
Accumulation Mechanism ◽  
Conductance Changes ◽  
A Current

The conductance of junctions between amphibian blastomeres is strongly voltage dependent. Isolated pairs of blastomeres from embryos of Ambystoma mexicanum, Xenopus laevis, and Rana pipiens were voltage clamped, and junctional current was measured during transjunctional voltage steps. The steady-state junctional conductance decreases as a steep function of transjunctional voltage of either polarity. A voltage-insensitive conductance less than 5% of the maximum remains at large transjunctional voltages. Equal transjunctional voltages of opposite polarities produce equal conductance changes. The conductance is half maximal at a transjunctional voltage of approximately 15 mV. The junctional conductance is insensitive to the potential between the inside and outside of the cells. The changes in steady-state junctional conductance may be accurately modeled for voltages of each polarity as arising from a reversible two-state system in which voltage linearly affects the energy difference between states. The voltage sensitivity can be accounted for by the movement of about six electron charges through the transjunctional voltage. The changes in junctional conductance are not consistent with a current-controlled or ionic accumulation mechanism. We propose that the intramembrane particles that comprise gap junctions in early amphibian embryos are voltage-sensitive channels.

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