Factors associated with cancer disclosure in adolescent and young adult cancer survivors: An integrative review from the social-ecological model perspective.

PURPOSE: Young cancer survivors ("young survivors") may need to disclose their cancer experiences to reintegrate into society. In such cases, the recognition of social support through the disclosure of cancer experiences may prevent potential social disadvantages． This review aimed to describe the motivations, strategies and outcomes, and benefits and disadvantages of disclosure in young survivors based on the social-ecological model (SEM) to identify the support survivors need when disclosing their cancer experiences. METHODS: Using the integrated review methodology, we systematically searched six databases in English and Japanese as well as searched the reference lists of the selected studies. The themes identified via thematic analysis were categorized within the SEM levels. RESULTS: This review analyzed 14 studies and identified four themes, including "Motivation for Cancer Disclosure," "Barriers to Cancer Disclosure," "Consequences of Cancer Disclosure: Benefits," and "Consequences of Cancer Disclosure: Disadvantages." Motivations for young survivors to disclose their cancer involved post-cancer differences, perceptions, relationships, and social context. In navigating barriers, including self-stigma, peer exclusion, and discrimination, they employed strategies such as reassurance and information limitation. Tailored disclosure strategies at each SEM level offered social and psychological benefits, however, disadvantages, including stress, vulnerability, employment issues, and limited insurance coverage, were experienced by young survivors due to cancer disclosure. CONCLUSIONS: To optimize the benefits of cancer disclosure for young survivors, addressing psychological burdens, enhancing disclosure skills, offering familial psychological support, and fostering public awareness of cancer are essential.

Endogenous oxytocin levels in extracted saliva elevates during breastfeeding correlated with lower postpartum anxiety in primiparous mothers.

BACKGROUND: Breastfeeding in the early postpartum period is expected to have mental benefits for mothers; however, the underlying psychobiological mechanisms remain unclear. Previously, we hypothesized that the release of oxytocin in response to the suckling stimuli during breastfeeding would mediate a calming effect on primiparous mothers, and we examined salivary oxytocin measurements in primiparous mothers at postpartum day 4 using saliva samples without extraction, which was erroneous. Thus, further confirmation of this hypothesis with a precise methodology was needed. METHODS: We collected saliva samples at three time points (baseline, feeding, and post-feeding) to measure oxytocin in 24 primiparous mothers on postpartum day 2 (PD2) and 4 (PD4) across the breastfeeding cycle. Salivary oxytocin levels using both extracted and unextracted methods were measured and compared to determine the qualitative differences. State and trait anxiety and clinical demographics were evaluated to determine their association with oxytocin changes. RESULTS: Breastfeeding elevated salivary oxytocin levels; however, it was not detected to a significant increase in the extraction method at PD4. We found a weak but significant positive correlation between changes in extracted and unextracted oxytocin levels during breastfeeding (feeding minus baseline); there were no other significant positive correlations. Therefore, we used the extracted measurement index for subsequent analysis. We showed that the greater the increase in oxytocin during breastfeeding, the lower the state anxiety, but not trait anxiety. Mothers who exclusively breastfed at the 1-month follow-up tended to be associated with slightly higher oxytocin change at PD2 than those who did not. CONCLUSIONS: Breastfeeding in early postpartum days could be accompanied by the frequent release of oxytocin and lower state anxiety, potentially contributing to exclusive breastfeeding.

Comparison of the Concentration of Suspended Particles and Their Chemical Composition near the Ground Surface and Dust Extinction Coefficient by LIDAR.

In many epidemiological studies, the dust extinction coefficient measured by light detection and ranging (LIDAR) is used as an indicator of exposure to Asian dust. However, few reports on the relationship between the distribution of total suspended particles (TSPs) near the ground surface and the dust extinction coefficient exist. In this study, we examined the relationship between the concentrations of TSPs near the ground surface, substances indicative of mineral content, and air pollutants that may be transported with Asian dust and dust extinction coefficients in two regions: Imizu and Yurihama-Matsue, from March to May in 2011 and 2013. In both years, large dust extinction coefficients were observed in Imizu and Matsue on days when the concentrations of TSPs and mineral content indicators were high near the ground surface in Imizu and Yurihama, and Asian dust was expected to be highly suspended. In both regions, the concentrations of TSPs and mineral content indicators were significantly positively correlated with the dust extinction coefficient. The concentrations of all air pollutants analyzed were significantly positively correlated with the dust extinction coefficient in each region in 2013, but not in 2011. These results suggest that the dust extinction coefficient is a useful indicator of Asian dust near the ground surface; however, as harmful air pollutants occasionally move with Asian dust, it is necessary to monitor these pollutants near the ground surface when conducting an epidemiological study on the health effect of airborne particles.

Seasonal Fluctuation of Endotoxin and Protein Concentrations in Outdoor Air in Sasebo, Japan.

To determine the levels of endotoxin, which is a major component of outer membrane of Gram-negative bacteria, and protein in the atmosphere in Sasebo, Japan, we measured these biological materials in fine (aerodynamic diameter ≤2.5 µm) and coarse (≥2.5 µm) particles collected for 81 weeks (September 2014 to May 2016). The monthly concentrations (i.e., the mean value of weekly concentrations for each month) of endotoxin were higher in coarse particles than in fine particles. Fluctuations in monthly endotoxin concentrations were large in both fine (0.0005-0.0208 EU/m3) and coarse (0.0032-0.1164 EU/m3) particles. Furthermore, the endotoxin concentrations in coarse particles were highest in October 2014 and 2015 as well as September 2014 (0.0407-0.1164 EU/m3). However, the monthly protein concentrations were higher in fine particles than in coarse particles. Compared to the endotoxin concentrations, the fluctuations in the monthly protein concentrations were smaller in both coarse and fine particles. To our knowledge, this study is the first to report long-term atmospheric concentrations of endotoxin and protein in Japan. Since the endotoxin concentrations in coarse particles were positively associated with the concentrations of Na+ and Cl-, it suggests the involvement of Gram-negative bacteria from seawater to the endotoxin levels in the atmosphere. For fine particles, the protein concentrations were positively associated with the concentrations of particles, NO3- and SO42-. These results suggest that combustion of organic materials, such as biomass burning, may be a contributor to atmospheric protein during this study period.

Dual Therapeutic Effects of an Albumin-Based Nitric Oxide Donor on 2 Experimental Models of Chronic Kidney Disease.

Chronic kidney disease (CKD) is accompanied by a variety of complications, typically renal anemia and kidney fibrosis. Accordingly, it is desirable to develop the novel therapeutics that can treat these CKD conditions. Since nitric oxide (NO) has multiple functions including hypoxia inducible factor stabilizing, anti-inflammatory, anti-oxidative, and anti-apoptoic activities, the use of NO for the CKD therapy has attracted considerable interest. Here, we evaluate the therapeutic impacts of S-nitrosated human serum albumin (SNO-HSA), a long-lasting NO donor, on 2 animal models of CKD. SNO-HSA increased the expression of erythropoietin (EPO), VEGF, and eNOS by stabilizing hypoxia inducible factor-1α in HepG2 and HK-2 cells. SNO-HSA increased hematopoiesis in both healthy and renal anemia rats, suggesting the promotion of EPO production. In unilateral ureteral obstruction-treated mice, SNO-HSA ameliorated kidney fibrosis by suppressing the accumulation of renal extracellular matrix. SNO-HSA also inhibited unilateral ureteral obstruction-induced α-smooth muscle actin increase and E-cadherin decrease, suggesting that SNO-HSA might suppress the accumulation of myofibroblasts, an important factor of fibrosis. SNO-HSA also inhibited the elevations of fibrosis factors, such as transforming growth factor-ß, interleukin-6, and oxidative stress, while it increased EPO production, an anti-fibrosis factor. In conclusion, SNO-HSA has the potential to function as a dual therapeutics for renal anemia and kidney fibrosis.

Enzymatic activity necessary to restore the lethality due to Escherichia coli RNase E deficiency is distributed among bacteria lacking RNase E homologues.

Escherichia coli RNase E (Eco-RNase E), encoded by rne (Eco-rne), is considered the global RNA decay initiator. Although Eco-RNase E is an essential gene product in E. coli, some bacterial species, such as Bacillus subtilis, do not possess Eco-RNase E sequence homologues. B. subtilis instead possesses RNase J1/J2 (Bsu-RNase J1/J2) and RNase Y (Bsu-RNase Y) to execute RNA decay. Here we found that E. coli lacking the Eco-rne gene (Δrne E. coli) was viable conditional on M9 minimal media by introducing Bsu-RNase J1/J2 or Bsu-RNase Y. We also cloned an extremely short Eco-RNase E homologue (Wpi-RNase E) and a canonical sized Bsu-RNase J1/J2 homologue (Wpi-RNase J) from Wolbachia pipientis, an α-proteobacterial endosymbiont of arthropods. We found that Wpi-RNase J restored the colony-forming ability (CFA) of Δrne E. coli, whereas Wpi-RNase E did not. Unexpectedly, Wpi-RNase E restored defective CFA due to lack of Eco-RNase G, a paralogue of Eco-RNase E. Our results indicate that bacterial species that lack Eco-RNase E homologues or bacterial species that possess Eco-RNase E homologues which lack Eco-RNase E-like activities have a modest Eco-RNase E-like function using RNase J and/or RNase Y. These results suggest that Eco-RNase E-like activities might distribute among a wide array of bacteria and that functions of RNases may have changed dynamically during evolutionary divergence of bacterial lineages.

Comparison of Air Pollution in Metropolises in China (Beijing) and Japan (Osaka and Nagoya) on the Basis of the Levels of Contaminants and Mutagenicity.

Public concern regarding the transport of air pollutants from mainland East Asia to the leeward area by the prevailing westerlies in spring and winter monsoon has been growing in recent years. We collected total suspended particle (TSP) in Beijing, a metropolis of China located windward of Japan, in spring (late February 2011-May 2011) and in winter (November 2012-early February 2013), then analyzed metals, ions, and organic compounds and mutagenicity, and compared the pollution levels with samples collected at two Japanese metropolises (Osaka and Nagoya) during the same periods. The medians of concentration of TSP and other factors in Beijing were much larger than those in the Japanese metropolises. Especially, the concentrations of polycyclic aromatic hydrocarbons (PAHs) were remarkably high in Beijing in winter, and the median of total PAHs concentration in Beijing was 62-63 times larger than that in the Japanese sites. The mutagenicity of TSP from Beijing toward Salmonella typhimurium YG1024, with and without a mammalian metabolic system (S9 mix), was 13-25 times higher than that from the Japanese sites in winter. These results suggest that air pollution levels in Beijing are very high compared with those at the two Japanese metropolises we evaluated. The diagnostic ratios of PAHs and nitrated polycyclic aromatic hydrocarbons (NPAHs) suggest that the major sources of PAHs and NPAHs in Beijing are different from those at the two Japanese sites in winter, and that the major source in Beijing is coal/biomass combustion.

PpsA-mediated alternative pathway to complement RNase E essentiality in Escherichia coli.

Escherichia coli cells require RNase E, encoded by the essential gene rne, to propagate. The growth properties on different carbon sources of E. coli cells undergoing suppression of RNase E production suggested that reduction in RNase E is associated with decreased expression of phosphoenolpyruvate synthetase (PpsA), which converts pyruvate to phosphoenolpyruvate during gluconeogenesis. Western blotting and genetic complementation confirmed the role of RNase E in PpsA expression. Adventitious ppsA overexpression from a multicopy plasmid was sufficient to restore colony formation of ∆rne E. coli on minimal media containing glycerol or succinate as the sole carbon source. Complementation of ∆rne by ppsA overproduction was observed during growth on solid media but was only partial, and bacteria showed slowed cell division and grew as filamentous chains. We found that restoration of colony-forming ability by ppsA complementation occurred independent of the presence of endogenous RNase G or second-site suppressors of RNase E essentiality. Our investigations demonstrate the role of phosphoryl transfer catalyzable by PpsA as a determinant of RNase E essentiality in E. coli.

Seasonal Fluctuations in Air Pollution in Dazaifu, Japan, and Effect of Long-Range Transport from Mainland East Asia.

To clarify the seasonal fluctuations in air pollution and the effect of long-range transport, we collected airborne particles (n=118) at Dazaifu in Fukuoka, Japan, from June 2012 to May 2013 and measured Pb and SO4(2-), which are indicators of the long-range transport of anthropogenic air pollutants, as well as their mutagenicity, and other factors. The levels of airborne particles, Pb, and SO4(2-) were very high on March 4, 8, 9, and 19, and May 13, 21, and 22, 2013. The backward trajectories indicated that air masses had arrived from the Gobi Desert and northern China on those days. The mutagenicity of airborne particles was examined using the Ames test on Salmonella typhimurium YG1024. Highly mutagenic airborne particles were mostly collected in winter, and most of them showed high activity both with and without S9 mix. High levels of polycyclic aromatic hydrocarbons (PAHs) were found in many samples that showed high mutagenicity. For the samples collected on January 30, February 21, and March 4, the levels of Pb, SO4(2-), PAHs, and mutagenicity were high, and the backward trajectories indicated that air masses present on those days had passed through northern or central China. The Japan Meteorological Agency registered Asian dust events at Fukuoka on March 8, 9, and 19, 2013. The results of the present study suggest that high levels of anthropogenic air pollutants were transported with Asian dust. Similarly, long-range transport of air pollutants including mutagens occurred on days when Asian dust events were not registered.

Purification and functional characterization of diadenosine 5',5‴-P(1),P(4)-tetraphosphate phosphorylases from Mycobacterium smegmatis and Mycobacterium avium.

We recently demonstrated that the Rv2613c protein from Mycobacterium tuberculosis H37Rv is a novel diadenosine 5',5‴-P(1),P(4)-tetraphosphate (Ap4A) phosphorylase (MtAPA) that forms a tetramer. Mycobacterium avium and Mycobacterium smegmatis express proteins named MAV_3489 and MSMEG_2932, respectively, that are homologous to MtAPA. Here we showed that the MAV_3489 and MSMEG_2932 proteins possess Ap4A phosphorylase activity and enzymatic properties similar to those of MtAPA. Furthermore, gel-filtration column chromatography revealed that MAV_3489 and MSMEG_2932 assembled into homotetramers in solution, indicating that they may also form unique Ap4A-binding sites composed of tetramers.

Long-range transport of mutagens and other air pollutants from mainland East Asia to western Japan.

INTRODUCTION: Asian dust events, transport of dust particles from arid and semi-arid areas in China and Mongolia to the east by prevailing westerlies, are often observed in Japan in spring. In recent decades, consumption of fossil fuels has markedly increased in mainland East Asia with rapid economic growth, and severe air pollution has occurred. A part of air pollutants including mutagens, such as polycyclic aromatic hydrocarbons (PAHs), generated in mainland East Asia are thought to be transported to Japan by the prevailing westerlies, like Asian dust, and winter monsoon. The objective of this study was to clarify the long-range transport of mutagens and other air pollutants in East Asia. Thus, we collected total suspended particles (TSP) at a rural town in western Japan, namely, Yurihama in Tottori Prefecture, for 1 year (June 2012-May 2013), and investigated their chemical constituents and mutagenicity. RESULTS: Many TSP collected from January to March showed high mutagenicity toward Salmonella typhimurium YG1024 with and without S9 mix, and high levels of lead (Pb) and sulfate ions (SO4 (2-)), which are indicators of transboundary air pollutions from mainland East Asia, were detected in those TSP. A large amount of iron, which is an indicator of sand, was found in highly mutagenic TSP collected in March, but not in TSP collected in January and February. High levels of PAHs were detected in highly mutagenic TSP collected from January to March. The ratios of the concentration of fluoranthene to those of fluoranthene and pyrene suggested that the main source of PAHs in TSP collected in winter and spring was coal and biomass combustion. Backward trajectories of air masses on days when high levels of mutagenicity were found indicated that these air masses had traveled from eastern or northern China to Yurihama. CONCLUSIONS: These results suggest that high levels of mutagens were transported from mainland East Asia to western Japan, and this transportation accompanied Asian dust in March, but not in January and February.

Lipid transfer particle from the silkworm, Bombyx mori, is a novel member of the apoB/large lipid transfer protein family.

Lipid transfer particle (LTP) is a high-molecular-weight, very high-density lipoprotein known to catalyze the transfer of lipids between a variety of lipoproteins, including both insects and vertebrates. Studying the biosynthesis and regulation pathways of LTP in detail has not been possible due to a lack of information regarding the apoproteins. Here, we sequenced the cDNA and deduced amino acid sequences for three apoproteins of LTP from the silkworm (Bombyx mori). The three subunit proteins of the LTP are coded by two genes, apoLTP-II/I and apoLTP-III. ApoLTP-I and apoLTP-II are predicted to be generated by posttranslational cleavage of the precursor protein, apoLTP-II/I. Clusters of amphipathic secondary structure within apoLTP-II/I are similar to Homo sapiens apolipoprotein B (apoB) and insect lipophorins. The apoLTP-II/I gene is a novel member of the apoB/large lipid transfer protein gene family. ApoLTP-III has a putative conserved juvenile hormone-binding protein superfamily domain. Expression of apoLTP-II/I and apoLTP-III genes was synchronized and both genes were primarily expressed in the fat body at the stage corresponding to increased lipid transport needs. We are now in a position to study in detail the physiological role of LTP and its biosynthesis and assembly.

Identification and functional analysis of a splice variant of mouse sodium-dependent phosphate transporter Npt2c.

Mutations in the SLC34A3 gene, a sodium-dependent inorganic phosphate (Pi) cotransporter, also referred to as NaPi IIc, causes hereditary hypophosphatemic rickets with hypercalciuria (HHRH), an autosomal recessive disorder. In human and rodent, NaPi IIc is mainly localized in the apical membrane of renal proximal tubular cells. In this study, we identified mouse NaPi IIc variant (Npt2c-v1) that lacks the part of the exon 3 sequence that includes the assumed translation initiation site of Npt2c. Microinjection of mouse Npt2c-v1 cRNA into Xenopus oocytes demonstrated that Npt2c-v1 showed sodium-dependent Pi cotransport activity. The characterization of pH dependency showed activation at extracellular alkaline-pH. Furthermore, Npt2c-v1 mediated Pi transport activity was significantly higher at any pH value than those of Npt2c. In an in vitro study, the localization of the Npt2c-v1 protein was detected in the apical membrane in opossum kidney cells. The expression of Npt2c-v1 mRNA was detected in the heart, spleen, testis, uterus, placenta, femur, cerebellum, hippocampus, diencephalon and brain stem of mouse. Using mouse bone primary cultured cells, we showed the expression of Npt2c-v1 mRNA. In addition, the Npt2c protein was detected in the spermatozoa head. Thus, Npt2c-v1 was expressed in extra-renal tissues such as epididymal spermatozoa and may function as a sodium-dependent phosphate transporter.

A possible overestimation of the effect of acetylation on lysine residues in KQ mutant analysis.

Acetylation of lysine residues, one of the most common protein post-transcriptional modifications, is thought to regulate protein affinity with other proteins or nucleotides. Experimentally, the effects of acetylation have been studied using recombinant mutants in which lysine residues (K) are substituted with glutamine (Q) as a mimic of acetyl lysine (KQ mutant), or with arginine (R) as a mimic of nonacetylated lysine (KR mutant). These substitutions, however, have not been properly validated. The effects lysine acetylation on Ku, a multifunctional protein that has been primarily implicated in DNA repair and cell survival, are characterized herein using a series of computer simulations. The binding free energy was reduced in the KQ mutant, while the KR mutant had no effect, which is consistent with previous experimental results. Unexpectedly, the binding energy between Ku and DNA was maintained at almost the same level as in the wild type protein despite full acetylation of the lysine residues. These results suggest that the effects of acetylation may be overestimated when the KQ mutant is used as a mimic of the acetylated protein.

Coordinate control of the locus of enterocyte effacement and enterohemolysin genes by multiple common virulence regulators in enterohemorrhagic Escherichia coli.

The locus of enterocyte effacement (LEE) pathogenicity island is required for the intimate adhesion of enterohemorrhagic Escherichia coli (EHEC) to the intestinal epithelial cells. GrlR and GrlA are LEE-encoded negative and positive regulators, respectively. The interaction of these two regulators is important for controlling the transcription of LEE genes through Ler, a LEE-encoded central activator for the LEE. The GrlR-GrlA regulatory system controls not only LEE but also the expression of the flagellar and enterohemolysin (Ehx) genes in EHEC. Since Ehx levels were markedly induced in a grlR mutant but not in a grlR grlA double mutant and significantly increased by overexpression of GrlA in a ler mutant, GrlA is responsible for this regulation (T. Saitoh et al., J. Bacteriol. 190:4822-4830, 2008). In this study, additional investigations of the regulation of ehx gene expression determined that Ler also acts as an activator for Ehx expression without requiring GrlA function. We recently reported that the LysR-type regulator LrhA positively controls LEE expression (N. Honda et al., Mol. Microbiol. 74:1393-1411, 2009). The hemolytic activity of the lrhA mutant strain of EHEC was lower than that of the wild-type strain, and LrhA markedly induced ehx transcription in an E. coli K-12 strain, suggesting that LrhA also activates the transcription of ehx without GrlA and Ler. Gel mobility shift assays demonstrated that Ler and LrhA directly bind to the regulatory region of ehxC. Together, these results indicate that transcription of ehx is positively regulated by Ler, GrlA, and LrhA, which all act as positive regulators for LEE expression.

Multilocus sequence typing implicates rodents as the main reservoir host of human-pathogenic Borrelia garinii in Japan.

Multilocus sequence typing of Borrelia garinii isolates from humans and comparison with rodent and tick isolates were performed. Fifty-nine isolates were divided into two phylogenetic groups, and an association was detected between clinical and rodent isolates, suggesting that, in Japan, human-pathogenic B. garinii comes from rodents via ticks.

Diversity in copy number and structure of a silkworm morphogenetic gene as a result of domestication.

The carotenoid-binding protein (CBP) of the domesticated silkworm, Bombyx mori, a major determinant of cocoon color, is likely to have been substantially influenced by domestication of this species. We analyzed the structure of the CBP gene in multiple strains of B. mori, in multiple individuals of the wild silkworm, B. mandarina (the putative wild ancestor of B. mori), and in a number of other lepidopterans. We found the CBP gene copy number in genomic DNA to vary widely among B. mori strains, ranging from 1 to 20. The copies of CBP are of several types, based on the presence of a retrotransposon or partial deletion of the coding sequence. In contrast to B. mori, B. mandarina was found to possess a single copy of CBP without the retrotransposon insertion, regardless of habitat. Several other lepidopterans were found to contain sequences homologous to CBP, revealing that this gene is evolutionarily conserved in the lepidopteran lineage. Thus, domestication can generate significant diversity of gene copy number and structure over a relatively short evolutionary time.

LrhA positively controls the expression of the locus of enterocyte effacement genes in enterohemorrhagic Escherichia coli by differential regulation of their master regulators PchA and PchB.

Summary Genes essential for eliciting pathogenicity of enterohemorrhagic Escherichia coli are located within the locus of enterocyte effacement (LEE). Expression of LEE genes is positively regulated by paralogues PchA, PchB and PchC, which are encoded by separate loci of the chromosome. To elucidate the underlying regulatory mechanism, we screened transposon mutants exhibiting reduced expression of pchA, transcription level of which is highest among the pch genes. Here, we report that the LysR-homologue A (LrhA) positively regulated the transcription of pchA and pchB. A deletion in lrhA reduced the transcription levels of pchA and pchB to different degrees, and also reduced the expression of LEE-coded type 3-secreted protein, EspB. Expression of LrhA from a plasmid restored and markedly increased the transcription levels of pchA and pchB respectively, and highly induced EspB expression. Deletion analysis of the regulatory region showed that both promoter-proximal (-195 to +88) and promoter-distal (-418 to -392 for pchA and -391 to -375 for pchB) sequences were required for the LrhA-mediated upregulation of pchA and pchB genes. Purified His(6)-LrhA protein differentially bound to the regulatory regions of pchA/B, suggesting that direct regulation of pchA and pchB genes by LrhA in turn controls the expression of LEE genes.

Juvenile hormone acid O-methyltransferase in Drosophila melanogaster.

Juvenile hormone (JH) acid O-methyltransferase (JHAMT) is the enzyme that transfers a methyl group from S-adenosyl-l-methionine (SAM) to the carboxyl group of JH acids to produce active JHs in the corpora allata. While the JHAMT gene was originally identified and characterized in the silkworm Bombyx mori, no orthologs from other insects have been studied until now. Here we report on the functional characterization of the CG17330/DmJHAMT gene in the fruit fly Drosophila melanogaster. Recombinant DmJHAMT protein expressed in Escherichia coli catalyzes the conversion of farnesoic acid and JH III acid to their cognate methyl esters in the presence of SAM. DmJHAMT is predominantly expressed in corpora allata, and its developmental expression profile correlates with changes in the JH titer. While a transgenic RNA interference against DmJHAMT has no visible effect, overexpression of DmJHAMT results in a pharate adult lethal phenotype, similar to that obtained with application of JH analogs, suggesting that the temporal regulation of DmJHAMT is critical for Drosophila development.

Differential regulation of ecdysteroidogenic P450 gene expression in the silkworm, Bombyx mori.

The regulatory mechanisms of ecdysteroidogenic P450 gene expression were investigated in the silkworm, Bombyx mori. Bommo-FMRFamide (BRFa), a neural suppressor of prothoracic gland (PG) activity, was found to suppress the expression of several P450 genes induced by prothoracicotropic hormone (PTTH) in the PG. A transcription inhibitor suppressed PTTH-induced expression of the P450 genes and the opposing effects of BRFa, while their short-term effects on ecdysteroidogenesis remained unchanged. This result suggests that the effects of these factors on the P450 gene transcripts become obvious on a longer time scale. Moreover, spontaneous expression of a P450 gene was observed in long-term PG culture, and was repressed by juvenile hormone. These results explain well the developmental fluctuation patterns of the P450 gene transcripts in the PG, indicating that multiple factors coordinate to regulate basal PG activity during insect development.