Disease relevance of Molting

• The Autographa californica nuclear polyhedrosis virus egt gene encodes an ecdysteroid UDPglucosyltransferase which catalyzes the transfer of glucose from UDPglucose to ecdysteroid insect molting hormones [1].
• Tetracycline treatment and sex-ratio distortion: a role for Wolbachia in the moulting of filarial nematodes [2]?
• Shortly thereafter, ETH targets the tritocerebrum and suboesophageal ganglion to activate the ecdysis neural network in abdominal ganglia through the elevation of cyclic GMP (cGMP) levels [3].
• We concluded that a large dose of T4 (500 micrograms T4/kg, body weight per day) induced an increase in circulating iodothyronine levels, decreased secretion of gonadotropin and sex steroid hormones, and induced molting [4].
• Evaluation of Salmonella enteritidis in molting hens after administration of an experimental chlorate product (for nine days) in the drinking water and feeding an alfalfa molt diet [5].

Psychiatry related information on Molting

• Hemolin is also developmentally regulated as suggested by changes in its concentration during larval and pupal ecdysis (Trenczek, T., 1998. Endogenous defense mechanisms of insects. Zoology 101, 298-315; Lanz-Mendoza, H., Faye, I., 1999. Physiological aspects of the immunoglobulin superfamily in invertebrates. Dev. Comp. Immunol. 23, 359-374) [6].

High impact information on Molting

• Ecdysone in Drosophila has been a paradigm for steroid hormones since its ability to induce gene activity directly was demonstrated by its effects on moulting and polytene chromosome puffing [7].
• Per mRNA levels oscillate with an approximately 24-hour periodicity. lin-42 mRNA levels also oscillate, but with a faster rhythm; the oscillation occurs relative to the approximately 6-hour molting cycles of postembryonic development [8].
• Expression of the egt gene allowed the virus to interfere with normal insect development so that molting was blocked in infected larvae of fall armyworm (Spodoptera frugiperda) [9].
• This enzyme catalyzes the transfer of glucose from UDP-glucose to ecdysteroids, which are insect molting hormones [9].
• Makisterone A is the predominant ecdysone in the 96 +/- 4-hour-old embryo of the large milkweed bug and it is the first molting hormone with a C-24 alkyl substituent of the side chain to be isolated and identified from an insect [10].

Chemical compound and disease context of Molting

• The molting and immunoprotein-inducing hormone, 20-hydroxyecdysone, increased culture growth rate and altered the levels of cell types A and D. Neither 20-hydroxyecdysone nor the larval immunizing agents, apolipophorin-III or Bacillus subtilis, in combination or alone, induced antibacterial activity [11].
• When given to immature insects, glibenclamide clearly caused toxicity, with symptoms indicating molting abnormality comparable to diflubenzuron [12].
• Percent molting in O. volvulus ranged from 0% (F12(K) + 5% CO2: 95% N2) to 33.3% (L-15 + 5% CO2: 95% N2) [13].
• Erythrocytic ecdysis in smears of EDTA venous blood in eight patients with sickle cell anemia [14].

Biological context of Molting

• The steroid hormone ecdysone regulates moulting, cell death, and differentiation during insect development [15].
• The knock-down of Ce-imp-2 leads to embryonic death and an abnormal molting phenotype in Caenorhabditis elegans [16].
• Secondly, by immunoscreening the molting L3 cDNA library with a pool of human sera from putatively immune individuals, we identified six novel immunogenic proteins that otherwise would not have been identified as potential vaccinogens using the gene discovery effort [17].
• Molecular phylogeny analysis suggests the MnSOD gene duplication is as old as the origin of the arthropod phylum. cytMnSOD activity in the hepatopancreas changes during the moulting cycle of the crab [18].
• An ecdysteroid (moulting hormone) agonist, RH-5849, that prevents the occurrence of programmed cell death in two of these muscles also prevents the normally occurring rise in level of MS73 in these muscles [19].

Anatomical context of Molting

• Developmentally regulated expression of a Balbiani ring 1 gene for a 180-kD secretory polypeptide in Chironomus tentans salivary glands before larval/pupal ecdysis [20].
• When l(2)mbn cells were treated with the molting hormone 20-hydroxyecdysone, the cells acquired the ability to phagocytose apoptotic S2 cells, another Drosophila cell line [21].
• Immunoelectron microscopy of L3 demonstrated binding in the region where the cuticle separates during molting, in the channels connecting the esophagus to the cuticle, and in the basal lamina surrounding the esophagus and the body cavity [22].
• Depression of synaptic efficacy at intermolt in crayfish neuromuscular junctions by 20-hydroxyecdysone, a molting hormone [23].
• The steroid molting hormone, 20-hydroxyecdysone (20-HE), appears to act through a rapid, nongenomic mechanism that decreases the probability of synaptic vesicle release and reduces the number of release sites [23].

Associations of Molting with chemical compounds

• Instead, its most probable signalling functions are to control molting and induce a specialized non-feeding larval stage, although no cholesterol-derived signalling molecule has yet been identified for these or any other functions [24].
• It is generally accepted that the prothoracic glands of insects produce ecdysone, which is converted by a 20-monooxygenase in peripheral tissues to the major molting hormone, 20-hydroxyecdysone [25].
• The cultured molting glands (Y-organs) from two species of crabs secrete a product whose behavior in several chromatographic systems and whose mass spectrum are identical with those of authentic alpha-ecdysone [26].
• Cryptocyanin, a crustacean molting protein: evolutionary link with arthropod hemocyanins and insect hexamerins [27].
• When injected 6.3 hr before ecdysis, AcD blocked EH release without altering the response of the nervous system to exogenous peptide [28].

Gene context of Molting

• In D. melanogaster the levels of pburs, burs, and DLGR2 transcripts are increased before ecdysis, consistent with their role in postecdysial cuticle changes [29].
• The molting defect induced by Ce-imp-2 deficiency was mimicked by depleting cholesterol or disrupting Ce-lrp-1 and suppressed, in part, by expression of the Ce-lrp-1 derivate [16].
• The 2B5 early puff locus corresponds to the Broad-Complex BR-C) and encodes a family of transcription factors whose members are induced by the molting hormone ecdysone [30].
• Mutations in daf-9 result in transient dauer-like larval arrest, abnormal reproductive development, molting defects and increased adult longevity [31].
• We propose that the expression of Ance in imaginal cells is co-ordinated by exposure to ecdysteroid (moulting hormone) during the last larval instar moult to increase levels of ACE-like activity during metamorphosis [32].

Analytical, diagnostic and therapeutic context of Molting

• Molecular cloning of lin-29, a heterochronic gene required for the differentiation of hypodermal cells and the cessation of molting in C.elegans [33].
• Western blot analysis indicated that the mucosal tissue of the shell gland of immature, laying, and molting hens contained two forms of immunoreactive VDR, which were approximately 58 and 60 kDa [34].
• Intravenous infusion at the rate of 0.25 mg kg-1 per day for 12 days provided a concentration of EL-979 in the blood of approximately 5 p.p.m. In A. maculatum this blood level prevented feeding in larvae and molting in nymphs, reduced numbers of females successfully feeding and prevented larvae production [35].
• However, when thyroxine levels were restored to 20 ng/ml or more by dietary T4 supplementation, molting was resumed in animals that had undergone either thyroidectomy or thyroidectomy plus castration [36].
• Northern blots revealed that transcripts of CfChitinase appeared prior to each molt and peaked on the day of ecdysis from the second instar to the pupal stage but disappeared immediately after the molt [37].

References