Publications (8)15.84 Total impact
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Article: The localisation of HSP70 and oxidative stress indices in heads of Spodoptera exigua larvae in a cadmium-exposed population.
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ABSTRACT: The effects of cadmium toxicity may vary between animals with different history of metal exposure. The aim of our study was to examine HSP70, protein carbonyl levels, catalase activity and total antioxidant capacity in the heads of Spodoptera exigua (Hübner) larvae originated from undergoing 1- and 44-generational cadmium treatment and in control (those that were not exposed to cadmium). We also measured the cadmium concentration and DNA damage level in the larvae. We observed higher level of heat shock proteins (HSPs) in the heads of larvae derived from multi-generational metal treatment than in the heads of those from one-generational treatment (derived from the control rearing). Analysis of HSP localisation in the larval brain suggests that these changes could be important for protecting the neural function of larval mushroom bodies for animals selected during multigenerational metal exposure. Animals from one-generational treatment had, in turn, higher total antioxidant capacity than animals from multigenerational treatment. Anyway, animals from one- and 44-generational metal treatments did not differ in metal accumulation in the heads and the whole larval bodies, catalase activity or DNA damage level. All these measurements were higher than for control larvae and cadmium accumulation in the heads was much lower than in the whole bodies.Ecotoxicology and Environmental Safety 11/2011; 78:22-7. · 2.29 Impact Factor -
Article: The expression patterns of heat shock genes and proteins and their role during vertebrate's development.
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ABSTRACT: Highly evolutionary conserved heat shock proteins (HSPs) act as molecular chaperones in regulation of cellular homeostasis and promoting survival. Generally they are induced by a variety of stressors whose effect could be disastrous on the organism, but they are also widely constitutively expressed in the absence of stress. Varied HSP expressions seem to be very essential in the critical steps of embryonic and extra-embryonic structures formation and may correspond to cell movements, proliferation, morphogenesis and apoptosis, which occur during embryonic development. While our knowledge of detailed HSP expression patterns is in constant progress, their functions during embryonic development are not yet fully understood. In the paper, we review available data on HSP expression and discuss their role during vertebrate development.Comparative biochemistry and physiology. Part A, Molecular & integrative physiology 08/2011; 159(4):349-66. · 2.20 Impact Factor -
Article: Molecular structure, expression patterns, and localization of the circadian transcription modulator CYCLE in the cricket, Dianemobius nigrofasciatus.
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ABSTRACT: CYCLE (CYC), also known as BMAL1 in vertebrate nomenclature, is a transcription modulator of the circadian genes period and timeless of Drosophila melanogaster. We cloned a cDNA encoding a CYC homologue from the head of the ground cricket, Dianemobius nigrofasciatus (Dncyc), the first CYC from Hemimetabola. The deduced sequence corresponded to a 601 amino-acid polypeptide, with well-defined bHLH, PAS-A, PAS-B, PAC, and BTCR domains. The amino-acid sequence showed 70.7% identity with the CYC protein of Athalia rosae, 63.8% with D. melanogaster, and 52% identity with the human homologue. A cyc transcript of around 3.6kb occurs in the brain, midgut, testis, fatbody, and muscle. An additional band of around 1.1kb gave a hybridization signal in the head. No temporal oscillation in cyc mRNA abundance was observed in the head of the adult cricket when investigated by Northern blot analysis. CYC-like immunohistochemical reactivity (ir) and its dimerization partner CLOCK (CLK)-ir appeared in the pars intercerebralis (PI), tritocerebrum, dorsolateral protocerebrum, and subesophageal ganglion (SOG), but no CYC-ir was observed in the optic lobe (OL) that showed CLK-ir. The deutocerebrum showed a unique CLK-ir but no CYC-ir pattern. Double-labelling experiments showed that both antigens were co-localized in the mandibular and maxillary neuromeres of the SOG. CYC-ir showed no daily oscillation in intensity and the staining pattern was always cytoplasmic. CLK-ir occurred in the nucleus at ZT 16, but was cytoplasmic at other ZT times. A neuronal network equivalent to adult system occurred in the second nymphal stadium.Journal of Insect Physiology 03/2008; 54(2):403-13. · 2.24 Impact Factor -
Article: Evidence for two vitellogenin-related genes in Leucophaea maderae: the protein primary structure and its processing.
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ABSTRACT: We previously reported a cDNA for vitellogenin (Vg) from the cockroach, Leucophaea maderae (Lm). In the present study, we identified another cDNA encoding a second Vg (Vg2) having stretches of amino acid sequences different from the first one, Vg1, reported earlier. The complete nucleotide sequence of Vg2 consisted of 5,915 bp, which encoded a primary protein of 1,911 residues including a 16-residue putative signal peptide. The regions different in both Vg precursors (Pro-Vg1 and pro-Vg2) were four in number, and two, relatively longer, existed at the carboxy terminal. The presence of two Vg-related cDNAs was confirmed by sequencing of RT-PCR products generated using primers designed based on the common sequences flanking the regions different in amino acid sequences. Both forms were transcribed since they could be amplified on mRNA from fat bodies of different individual females. Southern blot analysis of digested genomic DNA revealed the existence of two Vg-related genes in L. maderae indicating that each Vg cDNA originated from a separate gene. Also, the immunoblot analysis using antibodies generated against peptides unique to both Vg1 and Vg2 probed the same antigen in the same individual, suggesting LmVg to be a product coded by two different Vg precursors. Both Vg primary products showed 96% similarity at an amino acid level. Compared to other insect Vgs, Vg2 showed a slightly higher (1-2%) similarity than Vg1. We previously reported, based on amino-terminal sequence analysis, that L. maderae pro-Vg was cleaved into four subunit polypeptides (112-, 100-, 92-, and 55-kD), which were deposited in the egg as four respective vitellin (Vn) polypeptides. We show now based on immunoblot analysis that the 112-kD polypeptide is further cleaved, near the C-terminus, to an 87-kD polypeptide before it is secreted into the hemolymph. Both the L. maderae Vgs were compared with each other and with other insect Vgs and the processing pattern is discussed.Archives of Insect Biochemistry and Physiology 01/2008; 66(4):190-203. · 1.36 Impact Factor -
Article: Molecular characterization and distribution of CYCLE protein from Athalia rosae.
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ABSTRACT: cDNA encoding CYCLE (CYC) from the coleseed sawfly, Athalia rosae (Hymenoptera, Symphyta), was amplified by PCR. This is a first determination of hymenopteran CYC structure. ArCYC had an overall identity of 66% with CYC of Anopheles gambiae and ca. 60% of Drosophila melanogaster. Structural investigation revealed that ArCYC contained characteristic motifs of: bHLH, PAS A, PAS B, PAC and BCTR. Detailed analysis indicated high conservation of these regions among insects. Northern blot analysis showed that the mRNA of ca. 3 kb was transcribed both in the head and in the rest of the body. Southern blot analysis suggested the presence of a single copy of the gene in the genome. Western blot indicates that the quantity of CYC protein does not fluctuate under LD 12:12 in either the head or the rest of the body. Immunocytochemical examination revealed CYC-like antigen in the pars intercerebralis, dorsolateral protocerebrum, dorsal optic tract, tritocerebrum of the brain and the subesophageal ganglion.Journal of Insect Physiology 06/2007; 53(5):418-27. · 2.24 Impact Factor -
Article: Molecular cloning of a cDNA encoding arylalkylamine N-acetyltransferase from the testicular system of Periplaneta americana: primary protein structure and expression analysis.
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ABSTRACT: DNA encoding a fragment of putative arylalkylamine N-acetyltransferase (NAT) of the American cockroach, Periplaneta americana, was amplified by PCR with degenerate primers based on the two peptides previously purified from the testicular system of this species. A full clone was obtained by RACE-PCR. The clone consisted of 89 bp 5'-UTR, 753-bp open reading frame and 712-bp 3'-UTR. The amino acid sequence of 251 residues deduced from this ORF corresponded to the predicted molecular mass of 28.5 kDa. The predicted amino acid sequence had an overall identity of 35% with NAT1 and 27% with NAT2 of Drosophila melanogaster, respectively. Structural analysis revealed that NAT from P. americana contained two motifs characteristic of the NAT superfamily and three conserved regions (C/c-1, D/c-1, D/c-2) distinguishing aaNAT subfamily. Northern blot analysis showed that the mRNA of approximately 1.5 kb was transcribed at a high level in the testicular system, and corresponded to the length of the cDNA, i.e., 1,554 bp. Significant levels of NAT transcript were also detected in the midgut, ovary and the accessory glands and at much lower levels in the fat body and brain. Southern blot analysis suggested the presence of a single copy of the cloned gene in the genome.Archives of Insect Biochemistry and Physiology 09/2005; 59(4):219-29. · 1.36 Impact Factor -
Article: Day/night fluctuations in melatonin content, arylalkylamine N-acetyltransferase activity and NAT mRNA expression in the CNS, peripheral tissues and hemolymph of the cockroach, Periplaneta americana.
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ABSTRACT: Melatonin content measured by a radioenzymatic assay in the brain of the American cockroach (Periplaneta americana) showed a day/night fluctuation with higher levels at night under LD 12:12. The activity of arylalkylamine N-acetyltransferase (NAT) in brain was also higher at night and this pattern continued in constant darkness. The results suggest that the rhythmicity in melatonin content can be caused by NAT. Melatonin content in hemolymph showed an even greater day/night difference, more than 12 times that in brain under LD 12:12. Melatonin levels in retina were also higher at night while NAT activity was not significantly higher at night than at daytime. Using a probe designed from NAT cloned from testes we performed Northern blot analysis of total RNA, which revealed that the level of NAT mRNA was higher in midgut, ovary and female accessory glands than in fat body and brain. The level of transcript in midgut was higher at night, but the levels in ovary and female accessory reproductive gland showed the opposite pattern. We also used the antibody to whole Drosophila melanogaster aaNAT1 protein, seeking a homologous antigen in the cephalic ganglia. NAT-like antigen was detected in several restricted populations of cells in the brain that were partially co-localized with PER-like antigen. The results suggest that NAT exists in multiple forms in various tissues of the cockroach and that its functions and regulations can vary among tissues. The results in the brain led to the conclusion that NAT could be a clock-controlled gene functioning as an output regulator of the circadian clock.Comparative Biochemistry and Physiology Part B Biochemistry and Molecular Biology 02/2005; 140(1):27-36. · 1.92 Impact Factor -
Article: Multiple forms of arylalkylamine N-acetyltransferase (NAT) from cockroach female colleterial glands and activity changes during oocyte maturation.
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ABSTRACT: Arylalkylamine N-acetyltransferase (NAT) from the female colleterial glands of Periplaneta americana showed activity peaks at pH 6.0 and 9.5 and the pH profile changed during oogenesis. The left gland contained higher activity than the right gland but the right gland also contained recognizable activity. The patterns in activity change depended on the substrate used, tryptamine (TN) or serotonin (5-HT). When TN was used as the substrate, the alkaline peak was higher than the acidic peak. In contrast, when 5-HT was used, the acidic peak was much higher than the alkaline peak. This suggests that at least two NATs are present in this species that are specific to pH and substrate species. Of the four combinations of the two pH ranges and two substrate indolamines, the enzyme activity that showed a similar change to the oocyte maturation was obtained in the combination of pH 6.0 and TN. TN was actually detected in the colleterial glands by fluorescent measurements according to Hess and Uderfriend [J. Pharmacol. Exp., 127 (1959) 175-177]. It peaked on the 6th day of emergence, which corresponded to the first rise of oocyte length and yolk accumulation, whereas a small peak appeared in the phase of the second rise. TN, or more likely N-acetyl TN, may therefore be involved in the regulation of oocyte maturation which could be a novel mechanism in oocyte maturation.Comparative Biochemistry and Physiology - Part A Molecular & Integrative Physiology 05/2003; 134(4):795-803. · 2.23 Impact Factor
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Institutions
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2003–2008
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Kobe University
Kōbe-shi, Hyogo-ken, Japan
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