Mammals comparisons

Kelt, D.A., Brown, J.H., Heske, E.J., Marquet, P.A., Morton, S.R., Reid, J.R., Rogouin, K.A., and Shenbrot, G. (1996) Community structure of desert small mammals Comparisons across four continents. Ecology, 11 746-761. 

Figure 6.3. 5 "0 in surface water (data from Gat 1980) compared with that in biogenic phosphates of various mammals from many world regions (data shown in squares are from conventional phosphate analyses Longinelli 1984 Luz et al. 1984 Ayliffe and Chivas 1990 D Angela and Longinelli 1990 Yoshida and Miyazaki 1991 Huertas et al. 1995). For comparison, plotted as filled circles, are 8 0 values for tooth enamel analyzed by laser fluorination (six humans, one shark, and one wolf Kohn et al. 1996). 

In comparison to the situation in birds, there is far less evidence of dieldrin having had harmful effects in the field in mammals. It has been suggested that this is a reflection of the fact that mammals tend to be more reclusive and therefore more difficult to observe, catch, or count (Shore and Rattner 2001). That said, at the time when cyclodienes were widely used in Western Europe and North America, there were a fair number of reports of mammals being poisoned by them on agricultural land. Such animals included predators such as the fox (Vulpes vulpes) and badger (Meles meles), which had evidently acquired lethal doses from their prey. 

In rabbits, the as yet unidentified maternal signal during lactation has analogous properties in guiding the reliable orientation of suckling, mainly via MOS input (Hudson and Distel, 1986 Schaal et al., unpubl.). Minor fractions may still function as flag contributors, exemplified by the attractiveness of proestrous elephant urine. Male responses show that intact urine is conspicuously more attractive in comparison with the pure insect mammal pheromone (9.) presented in water (Rasmussen et al., 1996). 

The vertebrates show many morpho-functional variants on a basic theme (Chap. 2). Some of these, such as the pattern of distribution of the genetically distinct chemosensory neurones within die VN epithelium, will be related to the level of complexity of the animal. In some groups, the VNO can be equally complex, whilst the accessory areas of the brain will differ in complexity, as in the advanced reptiles and mammals. Eventually, detailed comparisons of the genomic repertoire of the various accessory systems should reveal the extent of the operational distinctions amongst them. Of particular interest would be the events which account for the suppression of AOS morphogenesis, and those which compensate for its absence. 

Figure 4.4 Comparison of oxidase-dependent iron transport in mammals and yeast. In mammals, the plasma glycoprotein cerulpolasmin mediates iron oxidation, facilitating iron export from the cells and delivery to other tissues throughout the body. In yeast, Fet3p, an integral membrane protein mediates iron oxidation, resulting in plasma membrane iron transport through the permease Ftrlp. Reprinted from Askwith and Kaplan, 1998. Copyright (1998), with permission from Elsevier Science.

Recent work in our laboratories has confirmed the existence of a similar pathway in the oxidation of vindoline in mammals (777). The availability of compounds such as 59 as analytical standards, along with published mass spectral and NMR spectral properties of this compound, served to facilitate identification of metabolites formed in mammalian liver microsome incubations. Two compounds are produced during incubations with mouse liver microsome preparations 17-deacetylvindoline, and the dihydrovindoline ether dimer 59. Both compounds were isolated and completely characterized by spectral comparison to authentic standards. This work emphasizes the prospective value of microbial and enzymatic transformation studies in predicting pathways of metabolism in mammalian systems. This work would also suggest the involvement of cytochrome P-450 enzyme system(s) in the oxidation process. Whether the first steps involve direct introduction of molecular oxygen at position 3 of vindoline or an initial abstraction of electrons, as in Scheme 15, remains unknown. The establishment of a metabolic pathway in mammals, identical to those found in Strep-tomycetes, with copper oxidases and peroxidases again confirms the prospective value of the microbial models of mammalian metabolism concept. 

Furthermore, all 2,3,7,8-substituted compounds persist in the environment and have been found to strongly bioaccumulate in fish and mammals. Measurement and calculation of TEQ is considered to be sufficient for estimation of PCDD/Fs hazard to the humans and environment. In 1999 European Community, after intensive studies and WHO recommendations introduced new, revised TEFs, so comparison of recent results with previously published in literature needs special attention ... 

Currently, only the Hydra system incorporates a measurement of toxicity to the adult to provide a comparison of the sensitivity of the embryo with that of the adult (Johnson et al., 1988). However, the Hydra screen has not been fully validated as being predictive of results in mammals, and has fallen from favor. Thus, a major goal of research directed toward developing an in vitro teratogen screen should be to find a simple yet appropriate measure of toxicity unrelated to development. This would allow the comparison of the dose for a 50% effect (ED50) on developmental toxicity as measured in vitro to an ED50 for adult toxicity in vitro. The validation... 

Comparison of the action of organo-phosphorus compounds on mammals and insects 183... 

Comparison of the Action of Organo-phosphorus Compounds on Mammals and Insects... 

The MSAL-type alkaloids are potent neuromuscular poisons in mammals, acting at the post-synaptie neuromuseular junction. Variations in structural features of eaeh norditerpenoid alkaloid ean exaeerbate or reduee toxieity. While the mechanism of action of the norditerpenoid alkaloids involves blocking of neuromuscular transmission at the al nicotinic acetylcholine receptors, relative toxicity of individual alkaloids is observed to change with variations in the structural characteristics of the alkaloids (Dobelis et al., 1999). In comparison with the lyeoetonine and MDL-type alkaloids, the high toxicity... 

The above general scheme based on comparisons of the most evolutionarily conserved GHl domain does not reveal the rich microheterogeneity of linker histones which stems from differences between the less well conserved basic tails. Such variants, often referred to as somatic subtypes, occur in plants (for review see Ref. [80]) and animals, both invertebrates and vertebrates (for review see Refs. [81-83]). For example in mammals five somatic subtypes represent the major form of HI HF-1, HF-2, HF-3, HF-4, and HI a, according to the nomenclature proposed in Ref. [82]. The N- and C-terminal tails of the subtypes differ in length, the amino acid composition and the frequency and distribution of phosphorylation sites. The testis specific Hit can be considered the most diverged subtype of the major form. 

Signaling pheromones are animal-produced, interindividual chemicals that modulate behavior in conspecifics. Like visual and auditory signals, they have comparatively rapid effects exchange of signals takes seconds or minutes. (Priming pheromones [Ch. 8], hy comparison, trigger slower endocrine or developmental processes.) The pheromone concept, originally based on insects (Karlson and Luscher, 1959), has been debated for vertebrates, notably mammals (e.g. Beauchamp etal., 1976 Johnston, 2001). Often it is better to use the term body odors to avoid particular assumptions. Now the term pheromones is widely used for vertebrates, without any particularly narrow definition implied. 

---