Seiji Takayama

Structure of β-amino acids in antibiotics iturin A

Abstract An antibiotic iturin A was separated into several components (A-1≈8) using HPLC and the structures of the β-amino acids of each component were established based on NMR and mass spectral analysis.

The cDNA sequence of NS1 glycoprotein of Brassica campestris and its homology to S-locus-related glycoproteins of B. oleracea

The self-incompatibility of Brassica species is under the control of multi-alleles at the single locus S [4]. The S glycoproteins have been thought to be products of S genes and to be associated with the recognition system in the selfincompatibility system [ 5 ]. On the other hand, we reported the existence of NS glycoproteins in Brassica campestris which were quite similar to S glycoproteins but not segregated with S genes [ 2]. Nasrallahs group in the USA also reported the presence of a cDNA of a S-locus-related glycoprotein (SLR1) in B. oleracea and determined the cDNA sequence [3]. They further established the wide distribution of the gene homologous to the SLR1 gene in Brassica species and the location of the expressed glycoprotein in the papillar cells of B. oleracea [8]. Two similar genes,

Multilayered dominance hierarchy in plant self-incompatibility

29-1 [7] and

ISOLATION AND CHARACTERIZATION OF NEW ALLOSAMIDINS

63-1 [6], have been isolated from B. oleracea by a group in England. These three genes are highly conserved, the homology being calculated as 99 at the amino acid level. They may play some fundamental roles in their fertilization system, although they are not related to the S genes and hence not to the self-incompatibility system. The amino acid sequence of the NS glycoprotein in B. campestris, which has been partly determined [2], suggests that it should belong to a group of SLR glycoproteins in B. oleracea. Several other NS glycoproteins have been found in the stigma extracts of B. campestris and the analysis of their inheritance in crossing experiments suggests that they are products of a different locus from S (unpublished data). So, a new numbering system is needed for the NS glycoproteins of B. campestris. Therefore, we propose to re-term the NS glycoprotein, which was first isolated from the

Effects of Demethylallosamidin, a Potent Yeast Chitinase Inhibitor, on the Cell Division of Yeast

8and S9-homozygous strains of B. campestris [2], NS1 glycoprotein. In this report, we describe the cDNA sequence of the NS~ glycoprotein of B. campestris and its homology with the SLR1 gene. A cDNA library consisting of 2.2 x 105 recombinant clones was obtained from the poly(A) ÷ RNA fraction of the 6400 stigmas of the S 8 strain ofB. campestris. The DNAs were ligated to 2gtl0 arms. To screen for cDNAs encoding NS~ glycoprotein in the library, 42-mer and 31-mer probes were synthesized on the basis of the determined amino acid sequences. By screening the cDNA with the above two probes, one clone was chosen as a cDNA encoding the NS1 glycoprotein and was subjected to sequencing analysis. The selected cDNA clone was subcloned into the Eco RI site of plasmid vector pUC18 and transformed in Escherichia coli JM 109 competent cells. The resulting recombinant plasmids were

Structure of Carbohydrate Chains of S-Glycoproteins in Brassica campestris Associated with Self-incompatibility

Key messageEpigenetic dominance modifier.AbstractIn polymorphic loci, complex genetic dominance relationships between alleles are often observed. In plants, control of self-incompatibility (SI) expression via allelic interactions in the Brassicaceae is the best-known example of such mechanisms. Here, with emphasis on two recently published papers, we review the progress toward understanding the dominance regulatory mechanism of SI in the Brassicaceae. Multiple small RNA genes linked to the Self-incompatibility (S) locus were found in both Brassica and Arabidopsis genera. Mono-allelic gene expression of the male determinant of SI, SP11/SCR, from a dominant S-allele is under epigenetic control by such small RNA genes. Possible evolutionary trajectories leading to the formation of multilayered dominance hierarchy in Brassicaceae are discussed. We also identify some remaining questions for future studies.