We have isolated several α-amylase genomic clones from an Eco RI library of barley DNA in λ-Charon 32. Five of these clones exhibit unique restriction maps and differences in their abilities to hybridize with two previously characterized α-amylase cDNA probes representing two different loci, α-Amy 1 (high pI) and α-Amy 2 (low pI) on barley chromosomes 6 and 1, respectively. Stringent hybridizations indicate that four of the five genomic clones contain α-Amy 1 sequences and one contains α-Amy 2 sequences. The regions containing α-amylase genes from one representative genomic clone of each group have been sub-cloned, mapped and sequenced. S1-nuclease protection experiments indicate that the two α-amylase genes contained in these clones are functional in aleurone tissue. Transcription start sites in these genes were determined by primer extension using specific synthetic oligonucleotide primers.The DNA sequences of the two α-amylase genes, including promoter regions, are divergent, as are the predicted amino acid sequences of the mature proteins and the N-terminal "leader" peptides. The α-Amy 1 gene contains two introns while the α-Amy 2 gene has three introns. In the coding region, each gene shows 7-10% sequence divergence with respect to the previously characterized cDNA clones of the same gene type. Therefore, differences in nucleotide sequences can account for some of the isozyme variations seen between the sub-families of α-amylases and among members of the same subfamily. Although the nucleotide sequences of the promoter regions of α-Amy 1 and α-Amy 2 genes show little homology, both contain pairs of inverted repeat elements which could constitute regulatory sites.

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ABSTRACTVibrio harveyisiphophage 1 (VHS1) is a tailed phage with an icosahedral head of approximately 66 nm in diameter and an unornamented, flexible tail of approximately 153 nm in length. WhenVibrio harveyi1114GL is lysogenized with VHS1, its virulence for the black tiger shrimp (Penaeus monodon) increases by more than 100 times, and this coincides with production of a toxin(s) associated with shrimp hemocyte agglutination. Curiously, the lysogen does not show increased virulence for the whiteleg shrimp (Penaeus[Litopenaeus]vannamei). Here we present and annotate the complete, circular genome of VHS1 (81,509 kbp; GenBank accession numberJF713456). By software analysis, the genome contains 125 putative open reading frames (ORFs), all of which appear to be located on the same DNA strand, similar to the case for many other bacteriophages. Most of the putative ORFs show no significant homology to known sequences in GenBank. Notable exceptions are ORFs for a putative DNA polymerase and putative phage structural proteins, including a portal protein, a phage tail tape measure protein, and a phage head protein. The last protein was identified as a component of the species-specific toxin mixture described above as being associated with agglutination of hemocytes fromP. monodon.