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

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.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007357x ◽

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.

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The structure of the gills of the axolotl, Ambystoma mexicanum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128407 ◽

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).

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Ultrastructure of the basal body apparatus in epidermal cells of a sponge larva (Aplysilla SP: Demospongiae)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010012504x ◽

1992 ◽

Vol 50 (1) ◽

pp. 928-929

Author(s):

R.L. Pinto ◽

R.M. Woollacott

Keyword(s):

Sodium Bicarbonate ◽

Epoxy Resin ◽

Basal Body ◽

Phosphate Buffer ◽

Similar Data ◽

Basal Apparatus ◽

Striated Rootlet ◽

The Common ◽

Basal Foot ◽

Sexually Mature

The basal body and its associated rootlet are the organelles responsible for anchoring the flagellum or cilium in the cytoplasm. Structurally, the common denominators of the basal apparatus are the basal body, a basal foot from which microtubules or microfilaments emanate, and a striated rootlet. A study of the basal apparatus from cells of the epidermis of a sponge larva was initiated to provide a comparison with similar data on adult sponges.Sexually mature colonies of Aplysillasp were collected from Keehi Lagoon Marina, Honolulu, Hawaii. Larvae were fixed in 2.5% glutaraldehyde and 0.14 M NaCl in 0.2 M Millonig’s phosphate buffer (pH 7.4). Specimens were postfixed in 1% OsO4 in 1.25% sodium bicarbonate (pH 7.2) and embedded in epoxy resin. The larva ofAplysilla sp was previously described (as Dendrilla cactus) based on live observations and SEM by Woollacott and Hadfield.

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

Vestnik Zoologii ◽

10.2478/vzoo-2019-0034 ◽

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.

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