The xylanase introns from Cryptococcus albidus are accurately spliced in transgenic tobacco plants

The xylanase gene from Cryptococcus albidus contains seven introns. Genomic and cDNA clones under the control of the CaMV 35S promoter were transferred into tobacco plants using Agrobacterium-mediated cell transformation. The genes were transcribed and the mRNAs were amplified by the polymerase chain reaction using primers on each side of the intron region. About 90% of the amplification products from plants transformed with the genomic clone corresponded to the size of the pre-mRNA (1.2 kb) and 10% represented the spliced product (0.85 kb). The 0.85 kb fragment was cloned and sequenced and the result indicated that the introns from the xylanase gene were accurately spliced by the plant cells.     

Using 137Cs technique to quantify soil conservation capacities of different ecosystems in Wolong Natural Reserve, southwestern China

Reliable information about soil conservation capacities of different natural ecosystems is an important reference for the design of targeted erosion and sediment control strategies. The objective of this paper is to quantify the soil conservation capacities of different natural ecosystems that can represent different climatic zones. The 137Cs technique has been used to estimate soil redistribution rates in different natural ecosystems over the past 40 years in Wolong Nature Reserve. The reserve, transiting from the Chengdu plain to the Qinghai-Tibet plateau, maintains rich ecosystems from subtropical to frigid.The net soil erosion rates of 5 selected ecosystems that represent a warm coniferous-broadleaf-mixed forest, a cold-resistant deciduous taiga forest, a cold-resistant shrub, an evergreen cold-resistant taiga servation capacities are reversed in order. The reference inventories for 137Cs in different ecosystems velop effective erosion and sediment strategies in areas with similar climates should consider natural ecosystem types.     

Primary structure of apolipophorin-III from the greater wax moth,Galleria mellonella

The complete amino acid sequence of apolipophorin-III (apoLp-III), a lipid-binding hemolymph protein from the greater wax moth,Galleria mellonella, was determined by protein sequencing. The mature protein consists of 163 amino acid residues forming a protein of 18,075.5 Da. Its sequence is similar to apoLp-III from other Lepidopteran species, but remarkably different from the apoLp-IIIs of insects from other orders. As shown by mass spectrometric analysis, the protein carries no modifications. Thus, all of its known physiological functions, including its recently discovered immune response-stimulating activity, must reside in the protein itself.     

Mannose-binding lectin from<Emphasis Type="Italic">Curcuma zedoaria</Emphasis> Rosc

A mannose-binding lectin was isolated from rhizomes of the medicinal plantCurcuma zedoaria. We used extraction with 20 mM phosphate buffer, ammonium sulfate precipitation, ion exchange chromatography on Q-Sepharose, gel filtration chromatography on Superdex 75, and reverse-phase HPLC. The purified lectin yielded a single band on SDS-PAGE that corresponded to a molecular mass of 13 kDa. This lectin exhibited hemagglutinating activity toward rabbit erythrocytes, which could be inhibited by mannose only. The lectin was digested with trypsin and its digests were analyzed using MALDI-TOF/TOF. Partial amino acid sequences were obtained from tandem mass spectra via automatedde novo sequencing, and were then identified by MS-BLAST homology searches to enable recognition of related proteins in other species. Inferred peptide sequences exhibited similarity to a mannose-binding lectin fromEpipactis helleborine, a member of the Orchidaceae.     

Isolation and characterization of a cDNA clone encoding the anti-viral protein from Phytolacca americana

Phytolacca anti-viral protein (PAP) was purified from Phytolacca leaves and the N-terminal was sequenced. A cDNA library was made from mRNAs isolated from Phytolacca leaves and cDNA clones for PAP were identified using oligonucleotide probes derived from the N-terminal amino acid sequence. The PAP-cDNA clone was sequenced from both directions. The predicted amino acid sequence of PAP was compared with the amino acid sequences of other ribosome-inactivating proteins. The identities of these proteins to PAP ranged from 29 to 38%, and a region was found in each with a sequence similar to the PAP sequence (AIQMVSEAARFKYI). Southern blot analysis indicates that PAP is encoded by a multi-gene family.Abbreviations MAP Mirabilis jalapa anti-viral protein - PAP Phytolacca anti-viral protein - SO6 30 kDa ribosome-inactivating protein from the seeds of Saponaria officinalis     

A direct approach to the measurement of genetic variation in fish populations: applications of the polymerase chain reaction to studies of Atlantic cod, Gadus morhua L.

We used the polymerase chain reaction (PCR) and direct DNA sequencing to study genetic variation within and among populations of Atlantic cod, Gadus morhua , in the western North Atlantic. In a 307 bp region of the mitochondrial cytochrome b gene, 24 variable nucleotide positions define 24 genotypes, which differ by from one to six nucleotide substitutions. Greenland cod ( G. ogac ) differs from the most similar G. morhua genotype by an additional 12 nucleotide substitutions. Silent transitions dominate both intra- and interspecific comparisons, however four nucleotide substitutions within morhua result in amino acid replacements. Direct sequencing of DNA reveals substantially more of the genetic variation that exists within and between species than do previous indirect methods based on restriction fragment length polymorphisms, and thus has far greater potential to quantify such differences as may exist among fish stocks. Preliminary experiments also indicate that automation of DNA sequencing provides an efficient, rapid, and accurate means for detection of genetic variation in natural populations offish.     

Three types of polymorphisms in exon 14 in porcine Mx1 gene

Much is known about the antiviral activity of Mx proteins in species such as mouse and human. In the mouse, loss of resistibility to influenza virus has been shown to be due to specific polymorphisms in the Mx gene. This gene is therefore an interesting candidate gene for disease resistance in farm animals. The porcine Mx1 gene has already been identified and characterized based on its homology with mouse Mx1; however, until now no evidence of polymorphisms in the porcine gene has been reported. In this study, we have found two new polymorphisms in exon 14 of porcine Mx1 by DNA sequencing and confirmed their presence in different breeds, using polymerase chain reaction (PCR)–restriction fragment length polymorphisms (RFLP) with NarI and NaeI restriction enzymes. On the basis of the deduced amino acid sequence, one allele contains a deletion that may result in a frameshift to yield several amino acid substitutions and extension of the carboxyl terminal region of Mx1 protein. The deletion allele, Mx1 ^c, was found to be segregating in Landrace, Berkshire, Duroc, Hampshire, and Yucatan miniature pig. A second point mutation, Mx1 ^b, was detected in Meishan and two Vietnamese native pig breeds. All other breeds tested were fixed for the Mx1 ^a allele that is identical to the sequence reported previously. It will be interesting to determine if the Mx1 ^c deletion is associated with variation in resistance to the myxovirus family in the pig.     

Coexistence of two mitochondrial DNA haplotypes in Japanese populations of Hypera postica (Col., Curculionidae)

Abstract:  In Japan, the alfalfa weevil, Hypera postica , was first recorded in 1982 from Fukuoka and Okinawa Prefectures and has been spreading to many other prefectures. The weevil seriously infests the Chinese milk vetch, Astragalus sinicus , one of the most important honey resources for honeybees in Japan. Direct sequencing of partial mitochondrial DNA and PCR-RFLP data for alfalfa weevil individuals indicated the coexistence of two haplotypes at various localities in Japan. Molecular phylogenetic analysis for H. postica haplotypes and strains indicated that the two Japanese haplotypes had not derived from a single genetic origin. Based on the results, special comments are made on biological control measures using introduced parasitic waSPS.     

The genus Lactobacillus--a genomic basis for understanding its diversity

The genus Lactobacillus is a diverse group that includes many species used in food production and preservation. Some lactobacilli are considered probiotic, conferring health benefits upon the host. The heterogeneity of this genus poses challenges and opportunities when characterizing or exploiting individual strains. To date, 10 Lactobacillus genome sequences have been published, and at least 11 more sequencing projects are ongoing. These studies will dramatically improve one's understanding of metabolic processes, bioprocessing capabilities and potential roles in health and well-being of the Lactobacilli. This review describes the current status of Lactobacillus genome sequence projects, highlights the major findings and summarizes functional genomics or comparative genomics studies. The genomic basis for the unusual diversity of this genus is discussed, and the potential for comparative genomics to rigorously extend phylogenetic analysis of the Lactobacilli is described.