Molecular phylogeny of Heritiera Ait on (Sterculiaceae), a tree mangrove: variations in RAPD markers and nuclear DNA content

Random amplified polymorphic DNA (RAPD) markers are used to estimate interspecific variation among mangrove and non-mangrove Heritiera fomes, H. littoralis and H. macrophylla. All the species have 2n = 38 chromosomes, with minute structural changes distinguishing the karyotype of each species. Significant variation of 4C DNA content occurs at the interspecific level. Interspecific polymorphism ranged from 14.09% between H. fomes and H. littoralis to 52.73% between H. fomes and H. macrophylla. H. macrophylla showed wide polymorphism in the RAPD marker with H. littoralis (51.23%) and H. fomes (52.73%). Two distinct RAPD products obtained from OPA-10 (1000 bp) and OPD-15 (900 bp) found characteristic molecular markers in H. macrophylla , a species from a non-mangrove habitat. H. macrophylla was more distantly related to H. fomes [genetic distance (1-F) = 0.305] than to H. littoralis [genetic distance (1-F) = 0.273]. H. littoralis was of a closer affinity to H. fomes [genetic distance (1-F) = 0.218] than to H. macrophylla.     

Transmission characteristics of Spiroplasma citri and its effect on leafhopper vectors from the Circulifer tenellus complex

Several leafhopper variants of the Circulifer tenellus complex were collected in “citrus stubborn” affected areas in Israel. Two of these variants transmitted the Spiroplasma citri to Matthiola incana after being injected with the disease agent. The variant from Atriplex halimus was designated Circulifer tenellus-A (CTA) and the variant from Portulaca oleracea was designated Circulifer tenellus-? (CTP). Transmission characteristics were determined for both leafhoppers. A high rate of transmission (43.3%) was obtained by single CTA leafhoppers that were injected with the Amiad S. citri isolate from the Upper Galilee, compared with 7% transmission obtained with the CTP leafhoppers. The Gilgal S. citri isolate from the Jordan Valley, was not transmitted by either. Injection was more effective than acquisition access feeding to render the leafhopper infective for both CTA and CTP. The minimum acquisition access period needed for the CTA variant to transmit the Amiad isolate was 1 h. Longer AAPs did not necessarily result in a higher rate of transmission. The minimum incubation period was 6 days and the maximum was 32 days. The LP₅₀ calculated from the logarithmic curve y = 45.74Ln(x)–53.68 was 9.64 days. The minimum inoculation access period (IAP) was lh. The same transmission parameters for the CTP variant could not be determined, as no transmission was obtained even when groups of five-six insects were placed on a single plant.     

The role of ribonucleoproteins in the production of mitotic abnormalities

Summary Immersion of growing roots of onion and lily in aerated solutions of ribonuclease affected their pattern of growth and altered the structure and mitotic distribution of the chromosomes. Action of the enzyme on meristematic cells caused enlargement of nucleoli, excessive contraction, stickiness, adhesion, and clumping of chromosomes, and production of aneuploid and polyploid chromosome complexes, tripolar and multipolar spindles, binucleate and multinucleate cells. Very few cases of chromosome fragmentation were observed.Accumulation of abnormalities accompanied the passage of ribonuclease across the root as determined by alterations in stainability of the cells with pyronin and fast green. There was no visible modification of stainability of the chromosomes with methyl green or the Feulgen reagent.These results, when compared with those produced by control solutions, indicate that ribonuclease enters the living cell and degrades ribonucleoproteins essential for maintenance of structural and functional integrity. The implications of these results, with respect to the production of aberrations by other agents, are discussed.This study was supported by a research grant (RG-149) from the National Institutes of Health, U.S. Public Health Service.     

Leishmania donovani Attachment Stimulates PKC-Mediated Oxidative Events in Bone Marrow-Derived Macrophages

We investigated activation signaling events in bone marrow-derived macrophages after infection with Leishmania donovani, an intracellular parasite of macrophages. Leishmania donovani infection caused a general suppression of activation parameters like O₂^- and NO production. However, conditions which allow parasite attachment and prevent entry resulted in triggering of O₂^- and NO production and stimulation of O₂ consumption. Optimal NO and O₂^- production occurred when bone marrow-derived macrophages and Leishmania ratio was 1:100. The activation signal for O₂^- production was initiated 15 min after parasite attachment, whereas augmentation of NO production started 6 h after attachment. Activation of O₂^- and NO generation by L. donovani attachment was inhibited by staurosporine as well as by prolonged treatment of phorbol myristate acetate suggesting a protein kinase C-dependent mechanism. Translocation studies showed that protein kinase C activity in cell membrane fraction rapidly and transiently increased following parasite attachment. No such protein kinase C translocation event occurred in L. donovani infected bone marrow-derived macrophages. Phorbol myristate acetate was found to stimulate membrane translocation of protein kinase C in parasite attached cells whereas it was impaired in infected cells. However, both attachment and infection induced a similar shift of phorbol receptors from cytosolic to membrane fraction indicating that in infected cells the translocation of protein kinase C protein was not impaired but the activity of the membrane associated enzyme was somehow inhibited. These results suggest that although internalization of intracellular parasites like L. donovani caused inhibition of nitrite and superoxide release, mere attachment on macrophage surface resulted in an activation of protein kinase C-mediated downstream oxidative events.     

SENSORY EVALUATION OF MANGO DRINKS USING FUZZY LOGIC

Three brands of ready to serve mango drinks namely 'Frooti', 'Real'and 'Slice'that are available in the market were used for sensory evaluation along with the vacuum dried reconstituted mango powder drink. Mango powder was produced from mango pulp of 'Totapuri'variety with addition of Maltodextrin, Glycerol monostearate and Tri calcium phosphate at rate of 0.62, 0.015 and 0.015 kg per kg dry mango solid, respectively. These ingredients were added for getting a nonsticky free flowing powder. The pulp along with the ingredients was dried in a vacuum drier at 70 ± 2C and 710–750 mm Hg vacuum. Fuzzy logic analysis was used for finding out the best of the three market mango drinks. BrimA index (a criterion for acceptance of fruit juice) and total solid (kg per kg drink) of the reconstituted mango drink was adjusted based on the BrimA index and total solid values of the best market drink. The reconstituted mango drink satisfied the quality criteria set for 'mouth feel'but not the color, smell and taste.     

Generation and characterization of SCARs by cloning and sequencing of RAPD products: a strategy for species-specific marker development in bamboo

BACKGROUND AND AIMS: The aim of this study was to develop species-specific molecular markers for Bambusa balcooa and B. tulda to allow for their proper identification, in order to avoid unintentional adulteration that affects the quality and quantity of paper pulp production. METHODS: Two putative, species-specific RAPD markers, Bb836 for B. balcooa and Bt609 for B. tulda were generated using a PCR-based RAPD technique. Species-specificity of these two markers was confirmed through Southern hybridization in which RAPD gels were blotted and hybridized with radiolabelled cloned RAPD markers. Southern hybridization analyses were also performed to validate homology of the co-migrating Bb836 and Bt609 marker bands amplified from 16 different populations of B. balcooa and B. tulda, respectively. Sequence-characterized amplified region (SCAR) markers were developed from Bb836 and Bt609 sequences, using 20-mer oligonucleotide primers designed from both the flanking ends of the respective RAPD primers. KEY RESULTS: As anticipated, Bb836 hybridized with an amplified band from B. balcooa and Bt609 hybridized only with an amplified product from B. tulda; the two markers did not hybridize with the amplified products of any of the other 14 bamboo species studied. The two pairs of SCAR primers amplified the target sequences only in the respective species. The species-specific SCAR fragments were named as 'Balco836' for B. balcooa and 'Tuldo609' for B. tulda. The species-specific 'Balco836' was amplified from the genomic DNA of 80 individuals of 16 populations of B. balcooa studied. Similarly, the presence of 'Tuldo609' was noted in all the 80 individuals representing 16 populations of B. tulda assessed. These SCAR fragments contained no obvious repetitive sequence beyond the primers. CONCLUSION: These two molecular markers are potentially useful for regulatory agencies to establish sovereign rights of the germplasms of B. balcooa and B. tulda. In addition, this is the first report of species-specific SCAR marker development in bamboo.