Wide coverage of the tetraploid cotton genome using newly developed microsatellite markers.

Microsatellite [simple-sequence repeat (SSR)] markers were developed and positioned on the genetic map of tetraploid cotton. Three hundred and ninety-two unique microsatellite sequences, all but two containing a (CA/GT) repeat, were isolated, and the deduced primers were used to screen for polymorphism between the Gossypium hirsutum and G. barbadense parents of the mapping population analyzed in our laboratory. The observed rate of polymorphism was 56%. The 204 polymorphic SSRs revealed 261 segregating bands, which ultimately gave rise to 233 mapped loci. The updated status of our genetic map is now of 1,160 loci and 5,519 cM, with an average distance between two loci of 4.8 cM. The presence of a total of 466 microsatellite loci, with an average distance of 12 cM between two SSR loci, now provides wide coverage of the genome of tetraploid cotton and thus represents a powerful means for the production of a consensus map and for the effective tracking of QTLs.

Construction and rapid testing of synthetic and modified toxin gene sequences CryIA (b&c) by expression in maize endosperm culture.

The synthesis of two modified genes, Cry IA(b) and CryIA(c), each consisting of 1845 bp, is described in detail. The genes were synthesized using an improved PCR procedure based on recursive principles. The synthetic CryIA(c) gene was put under the control of a maize ubiquitin promoter. This construct was tested in a maize endosperm-derived suspension culture system. The use of maize endosperm culture as a quick and efficient system to test the activity of synthetic genes is described.

Genomic clones encoding 11S globulins in oats (Avena sativa L.).

We have isolated two complete genomic clones, Glav1 and Glav3, encoding 11S globulins (legumins) in oat. The structure of Glav1 deviates from that of the typical legumin gene. This clone possesses an extra intron and an extra exon that is composed entirely of repeats of sequences found elsewhere in the clone. If this exon is functional, the protein encoded by Glav1 will contain novel octapeptide and hendecapeptide repeats. The two Glav clones show stronger and more extensive homology with one another than with the two previously published genomic clones, OG1-E1 and ASglob5. This result suggests that the oat globulin gene family may be divided into distinct subfamilies or that there may be significant cultivar-specific differences among members of this gene family.

Anoxia induces changes in translatable mRNA populations in turtle organs: a possible adaptive strategy for anaerobiosis.

The effects of anoxic submergence (16 h at 15 degrees C) on cellular mRNA contents were assessed in five organs of anoxia tolerant turtles Trachemys scripta elegans. Poly(A)+ RNA was extracted from liver, red and white skeletal muscle, kidney and heart of control and anoxic turtles, as well as from heart and kidney of turtles allowed 24 h aerobic recovery (at 15 degrees C) after anoxia exposure. Poly(A)+ RNA content increased by 30% in white muscle from anoxic turtles relative to control animals but was unchanged by metabolic state in other organs. Extracted mRNA was translated in vitro in a wheat germ lysate system and the 35S-labelled polypeptides that were produced were separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Overall translational activity of the mRNA pool [cpm 35S-methionine incorporated per microgram poly(A)+ RNA] was altered by anoxia exposure in three organs, increasing by 38 and 18% in liver and kidney and decreasing by 42% in red muscle. Anoxia exposure also led to qualitative changes in the protein products that resulted from in vitro translation. Sodium dodecyl sulphate polyacrylamide gel electrophoresis revealed the presence of a novel 19.5-kDa polypeptide in liver of anoxia-exposed animals as well as increased amounts of two other proteins at 28.6 and 79.9 kDa. In heart a new translation product of 26.8 kDa appeared in anoxia, and in kidney a 32.8-kDa polypeptide was produced during the aerobic recovery period after anoxia exposure. Anoxia stimulated the appearance of a 37.5-kDa protein in red skeletal muscle but anoxic red muscle also lost proteins of 40, 32, and 28.2 kDa that were present in aerobic controls. Anoxia exposure did not change the proteins produced by in vitro translation in white muscle. The results suggest that anoxia exposure triggers rapid cellular responses in T. s. elegans that modify translatable mRNA populations in organs, leading to new protein transcripts.(ABSTRACT TRUNCATED AT 400 WORDS)

The gene III product (P15) of cauliflower mosaic virus is a DNA-binding protein while an immunologically related P11 polypeptide is associated with virions.

Using electron microscopic immunocytochemical staining we demonstrate that the product of gene III of cauliflower mosaic virus (CaMV) is associated with viral particles. Furthermore, a fusion protein, expressed in bacteria, consisting of the N-terminus of beta-galactosidase and the complete gene III protein of CaMV showed DNA-binding activity. From these two results, we discuss the possible function of this viral polypeptide.

Use of the immuno-gold technique for in situ localization of cauliflower mosaic virus (CaMV) particles and the major protein of the inclusion bodies.

We show that the immuno-gold technique adapted to electron microscopy is a sensitive method for in situ localization of viral proteins in plant cells. Using antisera raised against cauliflower mosaic virus and the viroplasm major protein (VmP) we obtained a selective labelling of the viral particles and of the viroplasmic matrix in infected cells.

A second cauliflower mosaic virus gene product influences the structure of the viral inclusion body.

We have used electron microscopy of thin sections and experiments on isolated viroplasms to compare the properties of four strains of cauliflower mosaic virus (CaMV), three of which were partially or completely deleted in open reading frame (ORF) II. Our results confirm that this gene is required for aphid transmissibility and show that the product of ORF II influences the firmness with which virions are held within the viroplasm. Analysis of the proteins in the viroplasms showed that a mutant with a partial deletion in ORF II produced a protein smaller than the normal ORF product. This smaller protein was non-functional with respect both to aphid transmissibility and properties of the viroplasms.