Insect during development

While in anaphylaxis caused by other frequent elicitors like food and drugs, allergen-specific immunotherapy is not established, immimotherapy with Hymenoptera venoms has been shown to be effective in three prospective controlled trials (table 4) [38-40] and also in a number of studies where patients were submitted to a sting challenge with the responsible insect during venom immimotherapy (table 5) [44]. While over 90% of vespid venom-allergic patients are fully protected and do not develop any... 

This suggests that cyclin A2 is not essential for the early embryonic cell cycles. Also D-type cyclins seem to be dispensable for the early mouse embryo cell cycle progression since embryonic stem (ES) cells do not express them at all before differentiation (Savatier et al 1996). We do not know, however, whether the D-type cyclins are also absent in the early embryo. These observations suggest that not only could the first cell cycles of the mouse embryo have specific modifications, but also further embryonic cell cycles are specifically modified as well. Mammalian embryonic cell cycles are probably modified often during development. Such studies could allow us to determine a profile of a minimal cell cycle in mammals which must, however, be much more complex than a simple S M phase embryonic cell cycle of amphibians or insects. 

For birds, insects, and reptiles, which have an egg stage during development, so that water availability is severely restricted, the synthesis of a highly soluble excretory product would have serious osmotic consequences therefore most of the ammonia is converted to the virtually insoluble uric acid (urate). This product can be safely retained in the egg or excreted as a slurry of fine crystals by the adult. In birds that nest colonially this can accumulate in massive amounts on islands off the coast of Peru cormorants have deposited so much that this guano (hence the name guanine) is collected for use as a fertiliser. Uric acid is less effective as an excretory product, since it has a lower nitrogen content than urea (33%) and is more expensive to synthesise (2.25 molecules ATP per atom of nitrogen). Mammals do produce uric acid but as a product of purine catabolism (see above). 

It Is generally conceded that floral nectaries evolved as an attractant to pollinating Insects. The function of extrafloral nectaries Is not so obvious. Some suggest that the secretion of sugars Is associated with a shift from a "sink" to a "source of carbohydrates during development (, . Others propose that... 

Blackburn M. B., Kingan T. G., Raina A. K. and Ma M. C. (1992) Colocalization and differential expression of PBAN- and FMRF-like immunoreactivity in the subesophageal ganglion of Helicoverpa zea (Lepidoptera Noctuidae) during development. Arch. Insect Biochem. Physiol. 21, 225-238. 

The Ametabola do not undergo metamorphosis. This is an evolutionary primitive condition and is exemplified by insects such as the bristletails and springtails. During development, these insects increase in size, but do not undergo distinct changes in form. In general, the Ametabola do not have wings. 

The biosynthesis and, in particular, the origin of insect sex pheromones is unclear. Hendry ei al. (1975) have shown that a number of compounds known as sex pheromones originate from plants serving as a dietary source for the insects. They developed a theory according to which, upon emergence, the male codes the odour complex of the meconium and selects for a mate that conforms to the substances contacted during feeding. 

JH in insects maintains larval and nymphal characteristics during development and suppresses metamorphosis into the adult form similarly, MF in crustaceans retards metamorphosis and larval development [123]. Two types of neuropeptides control the production of JH in the CAs of insects in vitro (a) allatotropins, which stimulate the biosynthesis of JH and have only been found in insects to date, and (b) allatostatins (ASTs) which, inter alia, inhibit the biosynthesis of JH but which also have numerous other effects (mainly myoinhibitory) [137]. Neuropeptides that are structurally similar to the ASTs are also present in crustaceans and, therefore, we will review here what is known from the ASTs of insects and crustaceans. 

S. Characterization of two chitin synthase genes of the red flour beetle, Tribolium castaneum, and alternate exon usage in one of the genes during development. Insect Biochem. Mol. Biol. 2004, 34, 291-304. 

The insect fat body is considered to be the functional analog of the vertebrate liver, and it is of interest, therefore, to note that mitochondrial fractions from the fat body of the cockroach Blaherus discoidalis reveal increases in enzymic activity during development similar to those reported for mammalian liver (Keeley, 1972). Cytochrome oxidase and succinate-cytochrome c reductase activities do not increase in parallel. Immediately after the nymphal-adult ecdysis, succinate-cytochrome c reductase increases in activity and continues to rise for about 10 days when it plateaus at the adult level. Cytochrome oxidase activity remains constant during the first 5 days of this period, but, after the fifth day. 

In vivo, the oxidative polymerisation process shown in Scheme 49 occurs within the cellular matrix during development of the fruit bodies and thus exerts a cross-linking action. These events are analogous to melanisation, e.g. of insect cuticles, and the black Daldinia polymer is a type of fungal melanin 141). 

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