Ferritin Gene Research Articles

Molecular and functional characterization of ferritin in abalone Haliotis diversicolor supertexta

Ferritin is an iron storage protein that plays a key role in the processes of physiology and pathology. In the present study, the authors reported the ferritin gene from abalone Haliotis diversicolor supertexta, which we named hds-ferritin. The full-length of hds-ferritin cDNA consisted of 879 bp with an ORF encoding a 171 amino acids. Amino acid sequence analysis revealed that hds-ferritin shared highly homology with other species. Real time PCR and western blot analysis showed that hds-ferritin was distributed ubiquitously in abalone tissues and had the highest expression level in digestive glands, but its transcripts are not modified remarkably by the stimulation with LPS. The recombinant protein was successfully expressed in Escherichia coli BL21 (DE3), and the titre of anti-ferritin antibody was about 1:14 000. The effects of ROS and RNS on ferritin were analyzed in the present study. The results showed that H2O2 played an important role in decreasing hds-ferritin, however NO cation appeared to have a protecting effect on H2O2-medied reduction of hds-ferritin.

RNAi assay in primary cells: a new method for gene function analysis in marine bivalve

RNA interference (RNAi) is an effective approach for gene function analysis, which is well developed in mammal cell lines. However, RNAi has rarely been reported in marine bivalve species. To provide support on functional analysis of bivalve genes, for the first time to our knowledge, we conducted RNAi assay on primary cell of clam Meretrix meretrix in this study. Firstly we explored the method of culturing primary cells of M. meretrix to ensure the cells to live at high activity for at least 2 weeks. Ferritin gene was chosen as the target gene and RNAi assay was conducted through soaking the primary cells of M. meretrix digestive gland in medium containing dsRNA of ferritin gene. Realtime PCR, western blot and immunocytochemistry analysis were used to analyze the inhibition of gene expression after RNAi. Results showed the ferritin mRNA was significantly down-regulated by 66.11% after RNAi. Western blot result showed that the expression level of ferritin protein was also depressed post RNAi. The method developed in this study proved to be reliable and effective for RNAi assay on marine bivalve cells. It would be an efficient tool for gene function analysis in marine bivalves and more studies based on primary cells of marine bivalves can be expected.

Antioxidative responses of cell suspension cultures of two Coffea arabica varieties to low aluminum levels at pH 5.8

The effects of aluminum (Al) on the activities of antioxidant enzymes and ferritin expression were studied in cell suspension cultures of two varieties of Coffea arabica, Mundo Novo and Icatu, in medium with pH at 5.8. The cells were incubated with 300 µM Al3+, and the Al speciation as Al3+ was 1.45% of the mole fraction. The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) were increased in Mundo Novo, whereas glutathione reductase (GR) and guaiacol peroxidase (GPOX) activities remained unchanged. SOD, GR, and GST activities were increased in Icatu, while CAT activity was not changed, and GPOX activity decreased. The expression of two ferritin genes (CaFer1 and CaFer2) were analyzed by Real-Time PCR. Al caused a downregulation of CaFER1 expression and no changes of CaFER2 expression in both varieties. The Western blot showed no alteration in ferritin protein levels in Mundo Novo and a decrease in Icatu. The differential enzymes responses indicate that the response to Al is variety-dependent.

GSH threshold requirement for NO-mediated expression of the Arabidopsis AtFer1 ferritin gene in response to iron

Iron treatment of Arabidopsis cultured cells promotes a rapid NO burst within chloroplasts, necessary for up-regulation of the AtFer1 ferritin gene expression. The same occurs in Arabidopsis leaf chloroplasts, and is dependent upon the GSH content of plants. A leaf GSH concentration threshold between 10 and 50nmol GSHg−1 FW is required for full induction of AtFer1 gene expression in response to iron.

Differential Expression and Gene Cloning of Ferritin from Nostoc flagelliforme Subjected to Desiccation

Nostoc flagelliforme is a terrestrial nitrogen-fixing cyanobacterium with strong drought adaptability.We performed 2-DE analysis,gel image analysis and MALDI-TOF-TOF/MS to compare and identify differential proteins from N.flagelliforme subjected to desiccation.The results indicated that Ferritin,Dps family protein expression quantum gradually declined under desiccation stress.The Ferritin gene was cloned by designed degeneracy primer based on identified amino acid sequences.A full length of 540 bp DNA was obtained(GenBank access number: HM854287).Homology analysis showed that the N.flagelliforme Ferritin gene had high consensus regions.The secondary structures of Ferritin were made up of α helix and random coil.The RT-PCR showed that mRNA of Ferritin gradually declined under drought stress.The Ferritin gene was expressed in Escherichia coli,and a 22.4 kD heterologous protein was observed.The results laid a foundation for understanding the drought-resistant molecular mechanisms and protection mechanisms of N.flagelliforme in extreme arid environments.

In vitroMRI and Characterization of Rat Mesenchymal Stem Cells Transduced with Ferritin as MR Reporter Gene

Purpose : This study was performed to evaluate the characteristics of rat mesenchymal stem cells (RMSCs) transduced with human ferritin gene and investigate MRI detectability of ferritin-transduced RMSCs. Materials and Methods: The RMSCs expressing both myc-tagged human ferritin heavy chain subunit (myc-FTH) and green fluorescence protein (GFP) were transduced with lentiviurs. Transduced cells were sorted by GFP expression using a fluorescence-activated cell sorter. Myc-FTH and GFP expression in transduced cells were detected by immunofluorescence staining. The cell proliferative ability and viability were assessed by MTT assay. The RMSC surface markers (CD29+/CD45-) were analyzed by flow cytometry. The intracellular iron amount was measured spectrophotometically and the presence of ferritin-iron accumulation was detected by Prussian blue staining. magnetic resonance imaging (MRI) study of cell phantoms was done on 9.4 T MR scanner to evaluate the feasibility of imaging the ferritin-transduced RMSCs. Results: The myc-FTH and GFP genes were stably transduced into RMSCs. No significant differences were observed in terms of biologic properties in transduced RMSCs compared with non-transduced RMSCs. Ferritin-transduced RMSCs exhibited increased iron accumulation ability and showed significantly lower relaxation time than non-transduced RMSCs. Conclusion: Ferritin gene as MR reporter gene could be used for non-invasive tracking and visualization of therapeutic mesenchymal stem cells by MRI.

Demonstration of genes encoding virulence and virulence life-style factors in Brachyspira spp. isolates from pigs

The distribution of many genes encoding virulence and virulence life-style (VL-S) factors in Brachyspira (B.) hyodysenteriae and other Brachyspira species are largely unknown. Their knowledge is essential e.g. for the improvement of diagnostic methods targeting the detection and differentiation of the species.Thus 121 German Brachyspira field isolates from diarrhoeic pigs were characterized down to the species level by restriction fragment length polymorphism analysis of the nox gene and subsequently subjected to polymerase chain reaction detecting VL-S genes for inner (clpX) and outer membrane proteins (OMPs: bhlp16, bhlp17.6, bhlp29.7, bhmp39f, bhmp39h), hemolysins (hlyA/ACP, tlyA), iron metabolism (ftnA, bitC), and aerotolerance (nox). For comparison, B. hyodysenteriae reference strains from the USA (n=7) and Australia (2) were used.Of all genes tested only nox was detected in all isolates. The simultaneous presence of both the tlyA and hlyA/ACP was restricted to the species B. hyodysenteriae. The hlyA infrequently occurred also in weakly hemolytic Brachyspira. Similarly to tlyA and hlyA all B. hyodysenteriae strains contained the ferritin gene ftnA which was also found in two Brachyspira intermedia isolates. OMP encoding genes were present in B. hyodysenteriae field isolates in rates of 0% (bhlp17.6, bhmp39h), 58.1% (bhlp29.7), and 97.3% (bhmp39f).Since the study revealed a high genetic heterogeneity among German B. hyodysenteriae field isolates differentiating them from USA as well as Australian strains, targets for diagnostic PCR were limited to the nox gene (genus specific PCR) as well as to the species specific noxhyo gene and the combination of hlyA and tlyA which allow to specifically detect B. hyodysenteriae.

Constitutive overexpression of the OsNAS gene family reveals single-gene strategies for effective iron- and zinc-biofortification of rice endosperm.

BackgroundRice is the primary source of food for billions of people in developing countries, yet the commonly consumed polished grain contains insufficient levels of the key micronutrients iron (Fe), zinc (Zn) and Vitamin A to meet daily dietary requirements. Experts estimate that a rice-based diet should contain 14.5 µg g−1 Fe in endosperm, the main constituent of polished grain, but breeding programs have failed to achieve even half of that value. Transgenic efforts to increase the Fe concentration of rice endosperm include expression of ferritin genes, nicotianamine synthase genes (NAS) or ferritin in conjunction with NAS genes, with results ranging from two-fold increases via single-gene approaches to six-fold increases via multi-gene approaches, yet no approach has reported 14.5 µg g−1 Fe in endosperm.Methodology/Principal FindingsThree populations of rice were generated to constitutively overexpress OsNAS1, OsNAS2 or OsNAS3, respectively. Nicotianamine, Fe and Zn concentrations were significantly increased in unpolished grain of all three of the overexpression populations, relative to controls, with the highest concentrations in the OsNAS2 and OsNAS3 overexpression populations. Selected lines from each population had at least 10 µg g−1 Fe in polished grain and two OsNAS2 overexpression lines had 14 and 19 µg g−1 Fe in polished grain, representing up to four-fold increases in Fe concentration. Two-fold increases of Zn concentration were also observed in the OsNAS2 population. Synchrotron X-ray fluorescence spectroscopy demonstrated that OsNAS2 overexpression leads to significant enrichment of Fe and Zn in phosphorus-free regions of rice endosperm.ConclusionsThe OsNAS genes, particularly OsNAS2, show enormous potential for Fe and Zn biofortification of rice endosperm. The results demonstrate that rice cultivars overexpressing single rice OsNAS genes could provide a sustainable and genetically simple solution to Fe and Zn deficiency disorders affecting billions of people throughout the world.

Expression of ferritin gene in Mesembryanthemum crystallinum plants under different supply with iron and different intensity of oxidative stress

In plants of the facultative halophyte Mesembryanthemum crystallinum L. cultivated under climate-controlled conditions, expression of one of ferritin genes, McFer, the ortholog of arabidopsis AtFer1 gene was studied for the first time. The level of this gene expression occurring in response to oxidative stress and changes in the iron status was similar to that of AtFer1 gene. A dependence of McFer gene expression and ferritin content on the regime of plant supplying with Fe-EDTA on the background of medium salinity (300 mM NaCl), oxidative stress modeling by leaf treatment with paraquat (PQ, 100 μM), or in the presence of antioxidant spermidine (Spd, 1 mM) was analyzed. The level of gene expression was assessed by RT-PCR, whereas the content of ferritin by Western blotting, using the primary polyclonal antibody against pea ferritin. An enhanced production of superoxide radical and hydrogen peroxide at leaf treatment with PQ activated gene expression and ferritin content, whereas ROS scavenging with the antioxidant Spd suppressed gene expression. It is concluded that ferritin deposits in the halophyte M. crystallinum, which we have observed earlier in the chloroplasts of the mesophyll and parenchyma of the vascular system, fulfill not only storage but also protective role by binding the excessive Fe2+, a catalyzer of OH·− production.

Molecular Cloning and Copy Number Variation of a Ferritin Subunit (Fth1) and Its Association with Growth in Freshwater Pearl Mussel Hyriopsis cumingii

Iron is one of the most important minor elements in the shells of bivalves. This study was designed to investigate the involvement of ferritin, the principal protein for iron storage, in shell growth. A novel ferritin subunit (Fth1) cDNA from the freshwater pearl mussel (Hyriopsis cumingii) was isolated and characterized. The complete cDNA contained 822 bp, with an open reading frame (ORF) of 525 bp, a 153 bp 5′ untranslated region (UTR) and a 144 bp 3′ UTR. The complete genomic DNA was 4125 bp, containing four exons and three introns. The ORF encoded a protein of 174 amino acids without a signal sequence. The deduced ferritin contained a highly conserved motif for the ferroxidase center comprising seven residues of a typical vertebrate heavy-chain ferritin. It contained one conserved iron associated residue (Try27) and iron-binding region signature 1 residues. The mRNA contained a 27 bp iron-responsive element with a typical stem-loop structure in the 5′-UTR position. Copy number variants (CNVs) of Fth1 in two populations (PY and JH) were detected using quantitative real-time PCR. Associations between CNVs and growth were also analyzed. The results showed that the copy number of the ferritin gene of in the diploid genome ranged from two to 12 in PY, and from two to six in JH. The copy number variation in PY was higher than that in JH. In terms of shell length, mussels with four copies of the ferritin gene grew faster than those with three copies (P<0.05), suggesting that CNVs in the ferritin gene are associated with growth in shell length and might be a useful molecular marker in selective breeding of H. cumingii.

Regulating action of iron regulatory protein-2 in iron metabolism of lung cancer

To discuss the regulating mechanism of iron regulatory protein-2 (IRP2) in the iron metabolism of lung cancer. The cultured A549 cells were divided into 3 groups: liposome group (including liposomes 20 mg/L), random oligonucleotide group (SCODN group) and antisense oligonucleotide group (ASODN group). And the liposome-mediated transfection was employed with the liposome and SCODN groups as controls. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to examine the mRNA and protein expressions of iron metabolism-related transferring (Tf), transferrin receptor (TfR) and ferritin (Fn) genes, etc. After a 48-hour transfection, the mRNA expression of Tf had no statistically significant difference among three groups (F = 2.18, P = 0.078); the mRNA expression of TfR in the ASODN group was significantly lower than that in the liposome and SCODN groups (P < 0.05). The expression of Fn mRNA in the ASODN group (0.56 ± 0.06) was higher than that in the liposome (0.36 ± 0.05) and SCODN groups (0.39 ± 0.03) (P < 0.05). After a 48-hour transfection, the IRP2 protein expression of the ASODN group was significantly lower than those of the liposome and SCODN groups (P < 0.05). The Tf protein expression was not statistically different in three groups (F = 2.67, P = 0.088). The TfR protein expression of the ASODN group was lower than those of the liposome and SCODN groups (P < 0.05). And the Fn protein expression of the ASODN group was higher than those of the liposome and SCODN groups (P < 0.05). IRP2 may affect the expressions of TfR and Fn in lung adenocarcinoma A549 cells by changing the amount of protein and regulating the iron metabolism.

Enhanced Iron and Zinc Accumulation in Genetically Engineered Pineapple Plants Using Soybean Ferritin Gene

Pineapple (Ananas comosus L. Merr., cv. "Queen") leaf bases were transformed with Agrobacterium tumefaciens strain EHA 105 harboring the pSF and pEFESF plasmids with soybean ferritin cDNA. Four to eight percent of the co-cultivated leaf bases produced multiple shoots 6weeks after transfer to Murashige and Skoog's medium supplemented with α-naphthalene acetic acid 1.8mg/l, indole-3-butyric acid 2.0mg/l, kinetin 2.0mg/l, cefotaxime 400mg/l, and kanamycin 50mg/l. Putatively transformed shoots (1-2cm) were selected and multiplied on medium of the same composition and elongated shoots (5cm) were rooted on liquid rooting medium supplemented with cefotaxime 400mg/l and kanamycin 100mg/l. The rooted plants were analyzed through PCR, genomic Southern analysis, and reverse transcription PCR. The results clearly confirmed the integration and expression of soybean ferritin gene in the transformed plants. Atomic absorption spectroscopic analysis carried out with six independently transformed lines of pSF and pEFE-SF revealed a maximum of 5.03-fold increase in iron and 2.44-fold increase in zinc accumulation in the leaves of pSF-transformed plants. In pEFE-SF-transformed plants, a 3.65-fold increase in iron and 2.05-fold increase in zinc levels was observed. Few of the transgenic plants were hardened in the greenhouse and are being grown to maturity to determine the enhanced iron and zinc accumulation in the fruits. To the best of our knowledge this is the first report on the transformation of pineapple with soybean ferritin for enhanced accumulation of iron and zinc content in the transgenic plants.

Isolation and Characterization of a Ferritin cDNA from the Mud Crab Scylla paramamosain

Ferritin is an important protein for iron storage in cells. A hepatopancreas cDNA library from the mud crab Scylla paramamosain was constructed using the SMART technique. A complete cDNA sequence that showed high identity with the conserved sequence of the ferritin gene was cloned from the cDNA library and subjected to further investigation. The full-length ferritin gene of Scylla paramamosain (SpFer) consists of 767 bp and contains a complete open reading frame of 513 bp and a 26-bp iron-respective element in the 59'-untranslated region. The gene encodes a polypeptide of 170 amino acids, constituting a predicted molecular weight of 19.44 kDa and a theoretical isoelectric point of 5.24. The deduced protein shares 84% identity with the ferritin protein of the crab Eriocheir sinensis. Quantitative real-time PCR analyses revealed that the expression of ferritin was ubiquitous in different organs of S. paramamosain, including muscle, heart, ovary, testis, and hepatopancreas. The highest expression level was found in the heart, while testis tissue showed the lowest level. Ferritin mRNA expression in continuous developmental stages in zoeal phases, including Z1, Z2, Z3, Z4, and Z5, as well as megalopa and juvenile crab I stages, were also examined by quantitative real-time PCR. The expression level of ferritin was highest in the Z1 stage and lowest in the megalopa stage. This study provides useful information regarding the structure and function of ferritin and will play an important role in immunity and resistance research in S. paramamosain.

Abstract 5410: Down regulating heavy chain ferritin gene increasesthe radiation therapeutic efficacy for treatment of glioma

Abstract Gliomas, especially glioblastoma multiforme are resistant to radiation and chemotherapy. Therefore, efforts to develop new course of therapy to enhance efficacy of treatment strategies are obviously critical. We hypothesized that disrupting iron homeostasis in malignant tumor cells could prove effective at negatively affecting tumor growth because cancer cells have a robust iron requirement consistent with their rapid growth and high metabolic rates. The high levels of iron uptake require a mechanism to limit iron induced oxidative damage. This function is the responsibility of ferritin; an iron storage protein with 24 subunits of two types of chains light and heave chains. Heavy chain ferritin (H-ferritin) has been found in the nucleus of tumor cells where it appears to protect DNA from oxidative damage and promote transcription. We hypothesized that silencing the H-ferritin gene could increase the sensitivity of tumors cells to radiation. On the other hand, our previous data already demonstrated that silencing the H-ferritin gene increased chemotherapeutic efficacy for treating gliomas. To test our present hypothesis, the H-ferritin gene will be silenced via a cationic liposome carrying siRNA. We have chosen glioma cell lines (U251, U87 and MNSF) as our in vitro model. Subcutaneous glioma tumor in mouse model (athymic nude mice) was chosen as our in vivo model. Our preliminary in vitro data demonstrated silencing the H-ferritin gene in U251 cells leads to a 50% increase in cell death at 20 Gy for 24, 48 and 72 hours post radiation. Intratumoral injections of cationic liposomes containing H-ferritin siRNA reduced the effective in vivo dose of radiation for tumor suppression by more than 90% at 7 weeks. A supercoil relaxation assay demonstrated that H-ferritin, but not L-ferritin directly protects DNA from radiation by maintaining DNA in a relaxed from. We will further test our hypothesis in glioma-U87, neurofibroma-sNF96.2 and breast cancer-MCF-7 cells. As of now our data shows that silencing the H-ferritin gene appears to be an effective way to increase the sensitivity of the glioma tumors to radiation, which sheds light on increasing the radiation therapeutic efficacy for treatment of malignant tumors. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5410. doi:10.1158/1538-7445.AM2011-5410

Hereditary hyperferritinemia-cataract syndrome (HHCS) presenting with iron deficiency anemia associated with a new mutation in the iron responsive element of the L ferritin gene in a swiss family

Hereditary hyperferritinemia-cataract syndrome (HHCS) is one of the differential diagnoses of hyperferritinemia (HF) with low or normal transferrin saturation but is usually not associated with anemia. Here, we report a case of a microcytic, hypochromic anemia with hyperferritinemia as the initial presentation of a combination of iron deficiency anemia and HHCS. The latter is an autosomal dominant disorder characterized by distinctive cataracts and HF in the absence of iron overload. Sequencing studies were carried out to look for mutations in the iron responsive element (IRE) of the L ferritin gene. A heterozygous single point mutation for a +24T to C substitution in the IRE of the L ferritin gene (=HGVS c.-176T>C) was detected which has not been described before. To evaluate the pathogenetic relevance of this new mutation, we performed family studies of parents and siblings. We could identify the father and one brother with HF, cataract, and the heterozygous +24T>C mutation. Neither the mother nor the five other siblings had HF, cataract or that mutation. We therefore conclude that this newly described heterozygous +24T>C mutation in the IRE of the L ferritin gene causes HHCS.

Heavy Chain Ferritin siRNA Delivered by Cationic Liposomes Increases Sensitivity of Cancer Cells to Chemotherapeutic Agents

Approximately half of all gliomas are resistant to chemotherapy, and new therapeutic strategies are urgently needed to treat this cancer. We hypothesized that disrupting iron homeostasis in glioma cells could block tumor growth, based on an acute requirement for high levels of iron to meet energy requirements associated with their rapid growth. Ferritin is best known as an intracellular iron storage protein, but it also localizes to tumor cell nuclei where it seems to protect DNA from oxidative damage and to promote transcription. In this study, we hypothesize that silencing the H-ferritin (heavy chain ferritin) gene could increase tumor sensitivity to chemotoxins. To test this hypothesis, H-ferritin siRNA was delivered to several human cancer cell lines by using cationic liposomes (C-liposome). H-ferritin siRNA decreased protein expression by 80% within 48 hours, and this decrease was associated with more than 50% decrease in the LD(50) for DNA-alkylating agent carmustine (BCNU), which is commonly used to treat glioma in clinic. In a subcutaneous mouse model of human glioma, intratumoral injections of liposomes containing H-ferritin siRNA reduced the effective dose of BCNU needed for tumor suppression by more than 50%. A plasmid supercoil relaxation assay showed that H-ferritin specifically and directly protected DNA from BCNU treatment. H-ferritin siRNA additionally seemed to increase apoptosis in glioma cells in vitro upon H-ferritin knockdown. Overall, our results illustrate how silencing H-ferritin can effectively sensitize tumors to chemotherapy and also show the ability of C-liposomes to serve as a novel in vivo delivery tool for siRNAs.

Identification and characterization of a clam ferritin from Sinonovacula constricta

Ferritin, a major iron storage protein of most living organisms, plays a crucial role in iron metabolism. Here we reported the isolation and characterization of a cDNA of ferritin gene from Sinonovacula constricta (denoted as ScFER). The full-length cDNA of ScFER was of 996 bp, consisting of a 5′-UTR of 120 bp, a 3′-UTR of 360 bp, and a complete open reading frame of 516 bp encoding a polypeptide with 171 amino acid residues. The predicted molecular mass of deduced amnio acid of ScFER was 19.76 kDa and the theoretical pI was 5.07. Quantitative real-time PCR was employed to analyze the expression profiles of ScFER mRNA in muscle, mantle and visceral mass after iron exposure. The peak expression level of ScFER in the three tissues was 1.79-fold, 1.31-fold and 3.51-fold increases in muscle, mantle and visceral mass, respectively. The ployclonal antibodies generated from the recombinant product of ScFER could be specifically identified not only the recombinant product, but also the native protein from muscle. All these results strongly suggested that ScFER was involved in the iron metabolism regulation in S. constricta.

Identification and characterization of a Tegillarca granosa ferritin regulated by iron ion exposure and thermal stress

Ferritin, a conserved iron storage protein of most living organisms, plays a crucial role in iron metabolism. In this study, the ferritin gene from Tegillarca granosa (denoted as TgFER) was identified by expressed sequence tag (EST) and PCR approaches. The full-length cDNA of TgFER was of 895 bp, consisting of a 5′-UTR of 163 bp with a putative iron regulatory element (IRE), a 3′-UTR of 213 bp, and a complete open reading frame of 519 bp encoding a polypeptide with 172 amino acid residues. The predicted molecular mass of deduced amino acid of TgFER was 20.00 kDa and the theoretical pI was 4.89. The deduced amino acid of TgFER shared high identities to ferritin from abalone, oyster, clam and human. The tissue distribution of TgFER in the tissues of mantle, foot, gill, haemocytes and hepatopancreas was examined by quantitative real-time PCR (q-PCR) and mRNA transcripts of TgFER were found to be dominately expressed in haemocytes, hepatopancreas and gill and weakly in foot and mantle. The temporal expression of TgFER in haemocytes or hepatopancreases after challenged by metals ion (FeCl 2 and FeCl 3) exposure and thermal stress were also analyzed with q-PCR. The diverse expression patterns of TgFER were detected depending upon the types of stimulators and tissues. The ployconal antibodies generated from the recombinant product of TgFER could be specifically identified not only the recombinant product, but also the native protein from haemocytes. All these results strongly suggested that TgFER was involved in the iron metabolism and thermal stress regulation in T. granosa.

Iron homeostasis and fire blight susceptibility in transgenic pear plants overexpressing a pea ferritin gene

The bacterial pathogen Erwinia amylovora causes the devastating disease known as fire blight in some rosaceous plants including apple and pear. One of the pathogenicity factors affecting fire blight development is the production of a siderophore, desferrioxamine, which overcomes the limiting conditions in plant tissues and also protects bacteria against active oxygen species. In this paper we examine the effect of an iron chelator protein encoded by the pea ferritin gene on the fire blight susceptibility of pear ( Pyrus communis). Transgenic pear clones expressing this gene controlled either by the constitutive promoter CaMV 35S or by the inducible promoter sgd24 promoter were produced. The transgenic clones produced were analysed by Q-RT-PCR to determine the level of expression of the pea transgene. A pathogen-inducible pattern of expression of the pea transgene was observed in sgd24-promoter transformants. Adaptation to iron deficiency in vitro was tested in some transgenic clones and different iron metabolism parameters were measured. No strong effect on iron and chlorophyll content, root reductase activity and fire blight susceptibility was detected in the transgenic lines tested. No transformants showed a significant reduction in susceptibility to fire blight in greenhouse conditions when inoculated with E. amylovora.

Nanoparticles for cell labeling.

Cell based therapeutics are emerging as powerful regimens. To better understand the migration and proliferation mechanisms of implanted cells, a means to track cells in living subjects is essential, and to achieve that, a number of cell labeling techniques have been developed. Nanoparticles, with their superior physical properties, have become the materials of choice in many investigations along this line. Owing to inherent magnetic, optical or acoustic attributes, these nanoparticles can be detected by corresponding imaging modalities in living subjects at a high spatial and temporal resolution. These features allow implanted cells to be separated from host cells; and have advantages over traditional histological methods, as they permit non-invasive, real-time tracking in vivo. This review attempts to give a summary of progress in using nanotechnology to monitor cell trafficking. We will focus on direct cell labeling techniques, in which cells ingest nanoparticles that bear traceable signals, such as iron oxide or quantum dots. Ferritin and MagA reporter genes that can package endogenous iron or iron supplement into iron oxide nanoparticles will also be discussed.