In this paper, the mimetic biomineralization of CaC2O4 in lecithin water(PC H2O) ordered systems has been discussed. First, the effect of the aggregation state of PC aqueous solutions on the crystal structure of CaC2O4 has been studied. In all experiments, the only precipitated crystal forms obtained are calcium oxalate monohydrate(COM) and calcium oxalate dihydrate(COD). It have been shown that the relative amount of COD in PC H2O systems is much higher than that of in H2O system, and furthermore the aggregation state of PC influences the composition of coprecipitations to some extent. When PC distributing in aqueous solution as single molecules, it acts as inhibitor of COM , and then favors the formation of COD. While PC in micelle existence, the relative amount of COM increases , but is still lower than that of in H2O system . And when PC aggregates as vesicles, COD forms predominantly. Second, the morphology of CaC2O4 obtained in different reaction systems under different conditions has been also investigated. In H2O system, we observed thin, plate like crystals with serrated edges underISL(low ionic strength) condition and oriented clusters under ISH(high ionic strength) condition. Crystals with two layers arrangement were obtained in micelleordered PC H2O system under ISL condition. And in vesicle ordered PC H2O system, clusters with butterfly like shape were observed. The results obtained revealed a complex dependence of calcium oxalate formation,crystal growth, structure and morphology on the aggregation state of PC H2O systems.
Comparative genetic studies have shown that there are widespread synteny and colinearity of the genes among different species within grass family. Rice ( Oryza sativa L.) is a model plant, and analysis of its genome allows us to reveal the common features and the evolutionary rules of the gramineous genomes and accumulate the data for establishment of a common genetic system in the Poaceae. In this study, a rice gene Pib ( 10.3 kb), a map-based cloned gene, and RFLP markers linked with it are used as the tested probes to investigate their homology and physical location among the tested species. Southern blotting analysis showed that there were sequences homologous to Pib in maize genome. Further, Pib was localized onto the chromosomes of O. sativa ssp. indica cv. Guangluai 4, O. officinalis Wall ex Watt and the inbred line of Zea mays cv. Huangzao 4. The results of fluorescence in situ hybridization (FISH) and double-color FISH indicated that a synteny of Pib and RFLP markers linked with Pib existed among the genomes of the three tested species.
