Diel vertical migration and seasonal diapause are critical life history events for the copepod Calanus finmarchicus. While much is known about these behaviors phenomenologically, little is known about their molecular underpinnings. Recent studies in insects suggest that some circadian genes/proteins also contribute to the establishment of seasonal diapause. Thus, it is possible that in Calanus these distinct timing regimes share some genetic components. To begin to address this possibility, we used the well-established Drosophila melanogaster circadian system as a reference for mining clock transcripts from a 200,000+ sequence Calanus transcriptome; the proteins encoded by the identified transcripts were also deduced and characterized. Sequences encoding homologs of the Drosophila core clock proteins CLOCK, CYCLE, PERIOD and TIMELESS were identified, as was one encoding CRYPTOCHROME 2, a core clock protein in ancestral insect systems, but absent in Drosophila. Calanus transcripts encoding proteins known to modulate the Drosophila core clock were also identified and characterized, e.g. CLOCKWORK ORANGE, DOUBLETIME, SHAGGY and VRILLE. Alignment and structural analyses of the deduced Calanus proteins with their Drosophila counterparts revealed extensive sequence conservation, particularly in functional domains. Interestingly, reverse BLAST analyses of these sequences against all arthropod proteins typically revealed non-Drosophila isoforms to be most similar to the Calanus queries. This, in combination with the presence of both CRYPTOCHROME 1 (a clock input pathway protein) and CRYPTOCHROME 2 in Calanus, suggests that the organization of the copepod circadian system is an ancestral one, more similar to that of insects like Danaus plexippus than to that of Drosophila.
Neurochemicals are likely to play key roles in physiological/behavioral control in the copepod crustacean Calanus finmarchicus, the biomass dominant zooplankton for much of the North Atlantic Ocean. Previously, a de novo assembled transcriptome consisting of 206,041 unique sequences was used to characterize the peptidergic signaling systems of Calanus. Here, this assembly was mined for transcripts encoding enzymes involved in amine biosynthesis. Using known Drosophila melanogaster proteins as templates, transcripts encoding putative Calanus homologs of tryptophan-phenylalanine hydroxylase (dopamine, octopamine and serotonin biosynthesis), tyrosine hydroxylase (dopamine biosynthesis), DOPA decarboxylase (dopamine and serotonin biosynthesis), histidine decarboxylase (histamine biosynthesis), tyrosine decarboxylase (octopamine biosynthesis), tyramine β-hydroxylase (octopamine biosynthesis) and tryptophan hydroxylase (serotonin biosynthesis) were identified. Reverse BLAST and domain analyses show that the proteins deduced from these transcripts possess sequence homology to and the structural hallmarks of their respective enzyme families. Developmental profiling revealed a remarkably consistent pattern of expression for all transcripts, with the highest levels of expression typically seen in the early nauplius and early copepodite. These expression patterns suggest roles for amines during development, particularly in the metamorphic transitions from embryo to nauplius and from nauplius to copepodite. Taken collectively, the data presented here lay a strong foundation for future gene-based studies of aminergic signaling in this and other copepod species, in particular assessment of the roles they may play in developmental control.
Objectives: To systematically review the literature on economic evaluations of dental sealants and examine the costs and effectiveness of caries prevention using sealants.Methods: Of 21 full-text articles examined, a total of 13 were included in this study. These studies are grouped by the type of intervention as follows: (i) sealants compared with no sealants; (ii) sealants compared with other forms of caries prevention; (iii) resin-based sealants compared with glass-ionomer sealants; (iv) different sealing strategies in primary teeth; (v) different sealing strategies in permanent teeth; and (vi) sealants based on school-or clinic-based setting of delivery. All currency is reported in constant 2010 US$.Results: Cost-effectiveness analyses differed due to varying study designs, assumptions, sealant delivery settings, outcomes, caries risk assessment and study durations.Findings varied on the cost-effectiveness of sealants compared with other caries-preventive strategies. Under the assumption of equal caries risk, always sealing primary molars appeared to be the most effective strategy, whereas risk-based sealing was the optimal strategy with differing caries risk. Studies that assessed sealing strategies in permanent teeth reported that risk-based sealing was more cost-effective than not sealing, but they differed on the cost-effectiveness of risk-based seal compared with non-risk-based seal. Sealants delivered in school settings had mixed results on costs but were as equally effective as sealants delivered in private practices.
Conclusions:The cost-effectiveness of sealants is dependent on the conditions of delivery. The list of cost-effectiveness ratios for each intervention can support policy makers to estimate expected returns on their investments in dental sealants. States in 2014. 5 Interventions involving the delivery of dental sealants on a large scale have been limited due to uncertainty on their cost-effectiveness, as there are concerns that treating dental decay is cheaper than using sealants. economic evaluations in dentistry means that there has been a growing number of reviews which examine the scientific literature on the cost and effectiveness of dental caries prevention programmes more generally.12,13The current study builds on this scientific literature by focusing specifically on economic evaluation of dental sealants for caries prevention. The primary objective of this study was to review the literature on costs and benefits of using dental sealants to prevent caries. 2 | ME TH ODS 2.1 | Search strategy and data collectionTo identify articles published on the economic evaluation of dental sealants, we searched PubMed, MEDLINE (via EBSCOhost) and CINAHL (via EBSCOhost) databases using search terms such as "dental sealants," "pit and fissure sealants," "cost," "cost analysis,""cost-benefit analysis," "cost allocation," "direct service costs" and "economics" (see Table 1 for complete search terms). Only English language articles published in peer-reviewed journals from 1996 through Octob...
Neurochemical signaling is a major component of physiological/behavioral control throughout the animal kingdom. Gas transmitters are perhaps the most ancient class of molecules used by nervous systems for chemical communication. Three gases are generally recognized as being produced by neurons: nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S). As part of an ongoing effort to identify and characterize the neurochemical signaling systems of the copepod Calanus finmarchicus, the biomass dominant zooplankton in much of the North Atlantic Ocean, we have mined a de novo assembled transcriptome for sequences encoding the neuronal biosynthetic enzymes of these gases, i.e. nitric oxide synthase (NOS), heme oxygenase (HO) and cystathionine β-synthase (CBS), respectively. Using Drosophila proteins as queries, two NOS-, one HO-, and one CBS-encoding transcripts were identified. Reverse BLAST and structural analyses of the deduced proteins suggest that each is a true member of its respective enzyme family. RNA-Seq data collected from embryos, early nauplii, late nauplii, early copepodites, late copepodites and adults revealed the expression of each transcript to be stage specific: one NOS restricted primarily to the embryo and the other was absent in the embryo but expressed in all other stages, no CBS expression in the embryo, but present in all other stages, and HO expressed across all developmental stages. Given the importance of gas transmitters in the regulatory control of a number of physiological processes, these data open opportunities for investigating the roles these proteins play under different life-stage and environmental conditions in this ecologically important species.
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