Salamanders forms

The production of a female-influencing secretion from the chin gland of male Plethodontid salamander (P. jordani) points to a similar extension of function by the acquisition of female olfactory sensitivity to an intercellular signal protein. Female receptivity is enhanced by a male cytokine-like compound of the interleukin-6 family, in its released form. Rollman et al. (1999) note that pheromonal activity is a previously unrecognised function for cytokines. 

Significant concentrations of cyanotoxins have been found to accumulate in the tissues of macroinvertebrates such as mollusks and crustaceans, presenting an indirect route of exposure for invertebrates, fish, and aquatic mammals at higher trophic levels (Negri and Jones 1995). In natural systems, mortality among benthic invertebrate herbivores is probably low because most bloom-forming bacteria are planktonic and only periodically come into contact with the benthos. Nevertheless, Kotak et al. (1996) determined that enhanced mortality of snails at the end of a bloom cycle in Canadian lakes was due to consumption of Microcystis cells that had formed a scum on the surface of macrophytes. Oberemm et al. (1999) found that aqueous microcystins, saxitoxins, and anatoxin-a all resulted in developmental delays in fish and salamander embryos. Interestingly, more severe malformations and enhanced mortality were observed when larvae were exposed to crude cyanobacterial extracts than to pure toxins applied at natural concentrations (Oberemm et al. 1999). 

The long-toed salamander, macrodactylum, a terrestrial form, avoids... 

A non-toxic species of salamander may derive protection from predators by visually resembling a toxic form so closely that predators cannot distinguish between them Batesian mimicry). Free-ranging birds avoid both the toxic red eft Notophthalmus viridescens) and the similar-looking non-toxic red morph of the red-backed salamander Plethodon cinereus). The red-striped morph of P. cinereus, which does not resemble the red eft, is eaten (Brodie and Brodie, 1980). 

It is difficult to reconcile the unique chemical structure of tetrodotoxin with that of an animal product. Its structure is not related to that of other animal products by any readily recognized biosynthetic scheme. It is not a terpenoid, not obviously formed from amino acid or carbohydrate units, and apparently not constructed from acetate or propionate units. Nor does it resemble any of the various plant alkaloid patterns. It thus appears to be a very unlikely animal product to result from known biogenetic pathways. In this connection the metabolic incorporation of radioactive precursors using torosa and ]C. granulosa salamanders was studied by Shimizu et al. (47). They observed significant isotopic incorporation into amino acids and steroid metabolites, but they found no such incorporation associated with tetrodotoxin. 

Figure 5.1.1-1 Predicted secondaiy structure of salamander red rod rhodopsin as reported by Crouch Ma. Based on their identification of the source of this material as a red rod, it is likely that this material forms the substrate of the disks of a M-channel photoreceptor. See Crouch Ma, 2000 for details.

Metamorphosis has also been extensively studied in amphibians, a class of vertebrates which includes frogs, toads, and salamanders. Amphibian means dual (amphi ) life form (-bian) and refers to the typical life history of these animals, in which an aquatic larva metamorphoses into a terrestrial adult. The reptiles, such as turtles, lizards, and snakes, is another class of vertebrates whose species superficially resemble adult amphibians, but do not undergo metamorphosis. 

The biosynthesis of salamander alkaloids starts from cholesterol. Insertion of nitrogen between the carbon atoms 2 and 3 of the steroid skeleton, and hydroxylation of carbon atom 16 is followed by stepwise degradation of the side chain to form alkaloids like samandinin or samandaridin. 

Others have also demonstrated fast separations that could be useful for neurochemical monitoring. Shear s laboratory has detected cyclization reactions of catecholamines to form trihydroxyindoles that allowed them to be detected with two photon fluorescence. Their method allowed separation of norepinephrine and epinephrine within 80 s and cofactors such as FADH and NADH within 4 min. Bowser and coworkers have developed rapid chiral CE separations for D-serine in salamander retinas and rat brain samples. Fast separations of nitrate and nitrite in rat brain perfusates have been... 

Occurrence Since most A. are nerve poisons they cannot form in larger amounts in the animal world, except in skin glands where they are excreted for specific purposes as neurotoxins (e.g. the amphibian venoms samandarine and other salamander alkaloids, tetrod-otoxin, batrachotoxins, bufotenine and other toad poisons, glomerine, serotonine, histamine, tyra-mine and other biogenic amines). Most A. occur in plants as by-products of amino acid metabolism where they are mostly stored in peripheral parts of the plant (leaves, roots, barks, fruits) and much less frequently in the wood. A. occur only rarely as free bases in plants and are mostly found as salts with oxalic, acetic, lactic, and citric acids, etc. Some higher plant families are... 

To collect odor samples for the second comparison, the methods were similar except for the following odors were collected over 72 h from four snakes on four 20 cm-diame-ter coffee filters flattened out on the bottom of an 18.9-L aquarium, a 200 mL rinse of the combined filters formed the source sample, and the test semi-circles with snake odor were created by inoculating them with 1.7 mL of the wash (near saturation of semi-circle). Semi-circles from unfamiliar salamanders were prepared as before and placed opposite the snake samples. 

The boundary between the Terra-Nova-Bay area and the main part of the Wilson terrane is not defined because the Ross Orogen continues from southern Victoria Land through the Terra-Nova-Bay area into the Wilson Terrane of northern Victoria Land without discernible interruption. The Wilson Terrane extends from the Terra-Nova-Bay area north to the Oates Coast of Antarctica and is separated from the Bowers Terrane by the Lanterman fault zone in Fig. 4.2. The Wilson Terrane extends east across the Renifick Glacier and includes the Lanterman and Salamander ranges which form its eastern province. ... 

Certain groups of secondary products protect animals against predation and microbial attack (Table 67). These substances may be either synthesized de novo in the animal body or are taken up with the food and are used directly or in a modified form. Some compounds are built, stored and secreted in special glands, e.g., the defense glands of insects and the skin glands of salamanders and toads. Others are constituents of blood or gut. Most of the toxins have a broad spectrum of activity against different kinds of predators or microorganisms. 

In 1955, Ris [120], working with sectioned meiotic and mitotic chromosomes of rat, salamander, lily, and onion, was the first to observe that long fibers about 200 A in diameter were fundamental units of structure in both plant and animal chromosomes. During mitosis and meiosis, these 200-A fibers are apparently coiled around each other, forming large bundles. From his studies on honey bee embryonic cells, DuPraw [121] demonstrated that 230-A fundamental fibers can be found in vivo and that such fibers are firmly attached to the nuclear envelope at the edges of the annuli. 

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