Vertebrate human

L-Ascorbic acid, better known as vitamin C, has the simplest chemical structure of all the vitamins (Figure 18.30). It is widely distributed in the animal and plant kingdoms, and only a few vertebrates—humans and other primates, guinea pigs, fruit-eating bats, certain birds, and some fish (rainbow trout, carp, and Coho salmon, for example)—are unable to synthesize it. In all these organisms, the inability to synthesize ascorbic acid stems from a lack of a liver enzyme, L-gulono-y-lactone oxidase. 

Siegel, J.P. and Shadduck, J.A. 1990. Safety of microbial insecticides to vertebrates-humans. In Safety of Microbial Insecticides (M. Laird, L.A. Lacey, and E.W. Davidson, eds), pp. 101-113. CRC Press, Boca Raton, FL. 

Fig. 5. Phylo-VISTA visualization of the MLAGAN alignment of the stem cell leukemia (SCL) gene in eight vertebrates (human, chimp, mouse, rat, dog, chicken, pufferfish, and zebrafish). The top plot shows the similarity between all the fish sequences and the rest of the organisms, the second one between the chicken and the mammals, and the final one between the rodents and the rest of the mammals. The height of the peak indicates the percent identity in the alignment. As one considers more distant genomes (higher plots) there is less conservation, though the exons are clearly conserved among all vertebrates.

Hemoglobins Vertebrate Human A Invertebrate heme Fe" purple —> red 64,000 4 16,000... 

DDT is slowly converted in vivo by reductive dechlorination to DDD and by further dechlorinations to 4,4 -dichlorodiphenylacetic acid [83-05-6] (DDA), the predominant excretory metaboUte. Anaerobically, it may form 4,4 -dichlorodiphenyiacetonitrile [20968-04-1] (DDCN). However, most DDT that enters the environment is sequestered as DDE, which is ubiquitously present in the body Hpids of invertebrate and vertebrate animals. In humans. 

Vimses contain either RNA or DNA, and this nucleic acid composition forms the basis for thek classification. Although vimses ate known to infect bactetia, insects, plants, animals, and humans, this discussion is restticted to the important vimses of vertebrates. The relevant vimses ate summarized in Table 2, using the nomenclature and taxonomy recommended by the International Committee on Taxonomy of Vimses (4,5). 

Pantothenic acid is found in extracts from nearly all plants, bacteria, and animals, and the name derives from the Greek pantos, meaning everywhere. It is required in the diet of all vertebrates, but some microorganisms produce it in the rumens of animals such as cattle and sheep. This vitamin is widely distributed in foods common to the human diet, and deficiencies are only observed in cases of severe malnutrition. The eminent German-born biochemist Fritz Lipmann was the first to show that a coenzyme was required to facilitate biological acetylation reactions. (The A in... 

MMP genes show a highly conserved modular structure. They were first detected in vertebrates (1962), and human beings, but have since been found in invertebrates and plants as well. The MMP family... 

Bocherens, H., Fizet, M., Mariotti, A., Lange-Badre, B., Vandermeersch, B., Borel, J.P and Bellon, G. 1991a Isotopic biogeochemistry ( C, N) of fossil vertebrate collagen implications for the study of fossil food web including Neandertal Man. Journal of Human Evolution 20 481 92. 

A formidable array of compounds of diverse structure that are toxic to invertebrates or vertebrates or both have been isolated from plants. They are predominately of lipophilic character. Some examples are given in Figure 1.1. Many of the compounds produced by plants known to be toxic to animals are described in Harborne and Baxter (1993) Harborne, Baxter, and Moss (1996) Frohne and Pfander (2006) D Mello, Duffus, and Duffus (1991) and Keeler and Tu (1983). The development of new pesticides using some of these compounds as models has been reviewed by Copping and Menn (2000), and Copping and Duke (2007). Information about the mode of action of some of them are given in Table 1.1, noting cases where human-made pesticides act in a similar way. 

A considerable number of mycotoxins that show high toxicity to vertebrates and/ or invertebrates are produced by organisms associated with crop plants (Flannigan 1991). There are many known cases of human poisoning caused by such compounds. There are three broad categories of mycotoxins represented here, based on the structures of the intermediates from which these secondary metabolites are derived. They are (1) compounds derived from polyketides, (2) terpenes derived from mevalonic acid, and (3) cyclic peptides and derivatives thereof. 

In contrast to the controlled use of these compounds in the neighborhood of farms and human habitation, they have sometimes been used in a less controlled way against rodents and vertebrate predators, which causes problems in conserved areas. In a number of conserved islands in New Zealand, for example, bait containing brodiphacoum has been used for rodent control, both at bait stations and by aerial distribution (Eason et al. 2002). In the latter case, poisoned bait is freely available, and herbivores and omnivores, as well as predators and scavengers are at high risk. This problem will be discussed further in Section 11.6. 

Vertebrates share many functional similarities in their endocrine systems, including their regulatory control and the nature of the hormones and their receptors (Munkittrick et al. 1998). The reproductive abnormalities observed in wildlife populations may therefore potentially be extrapolated to effects in the reproductive health of human populations, if similar exposures to EDCs occur. 

---