Analysis Of Gene Expression Of The Deinagkistrodon Acutus Venomous Gland And Porcine Brain Based On ESTs And A Complete Genome Sequence Of Marine Vibriophage EH3-23P1

In this report, we analyzed the expressed sequence tags involved in cellular function from the venomous gland of Deinagkistrodon acutus and the evolution of toxin related genes and gene expression of porcine brain and a complete genome sequence of vibriophage EH3-23P1.EST represents a segmental DNA sequence from cDNA 5'/3' end sequencing and has been an important tool for studying the gene expression, difference expression and function. The snake venomous gland is a specialized organ, which synthesizes and secretes the complex and abundant toxin proteins. Though gene expression in the snake venomous glands has been extensively studied, the focus has been on the components of the venom. As far as the molecular mechanism of toxin secretion and metabolism is concerned, we still knew a little. Therefore, a fundamental question being arisen is what genes are expressed in the snake venom glands besides many toxin components? To examine extensively the transcripts expressed in the venom gland of Deinagkistrodon acutus and unveil the potential of its products on cellular structure and functional aspects, we generated 8,696 expressed sequence tags (ESTs) from a non-normalized cDNA library. All ESTs were clustered into 3,416 clusters, of which 40.16% of total ESTs belong to recognized toxin-coding sequences; 39.85% are similar to cellular transcripts; and 20.00% have no significant similarity to any known sequences. By analyzing cellular functional transcripts, we found high expression of some venom related genes and gland-specific genes, such as calglandulin EF-hand protein gene and protein disulfide Isomerase gene. The transcripts of creatine kinase and NADH dehydrogenase were also identified at high level. Moreover, abundant cellular structural proteins similar to mammalian muscle tissues were also identified. The comparative analysis with gene expression of other snake venomous glands, the toxin protein of never growth factor is absent of the venom of Deinagkistrodon acutus. The phylogenetic analysis of two snake venom toxin families of group III metalloproteinase and serine protease in suborder Colubroidea showed an early single recruitment event in the viperids evolutionary process. Gene cataloguing and profiling of the venom gland of Deinagkistrodon acutus is an essential requisite to provide molecular reagents for functional genomic studies needed for elucidating mechanisms of action of toxins and surveying physiological events taking place in the very specialized secretory tissue. So this study provides a first global view of the genetic programs for the venom gland of Deinagkistrodon acutus described so far and an insight into molecular mechanism of toxin secreting.To understand gene expression variation of porcine brain among several developmental stages, seven cDNA libraries from Landrace brain were constructed. We obtained 43,122 high quality expressed sequence tags from 5' end cDNA clone sequencing. After clustering, 16,101 clusters were produced. Of these clusters, 30.6% showed similarity with known functional sequences; 75.1% had homology with nucleic acid database; 73.3% matched porcine ESTs from database; 21.5% represented novel genes. Comparison of gene expression indicated that the level of many genes expression showed significant difference between prenatal and postnatal porcine brain, which implied the development of porcine and functional differentiation.Based on complete genome sequences, we can identify bacteriophages and understand their evolution and biological character. We isolated a vibrio strain named EH3-23 in estuarine seawater of Southern China Pearl River and a lytic EH3-23P1. The electron micrograph showed that EH3-23P1 belong to Caudovirales. The 113,861 bp closed circular genome of EH3-23P1 was determined by whole genome shotgun sequencing, which has 40.4% of an average G+C content. EH3-23P1 encodes 195 putative protein-encoding open reading frames (CDSs), 3 tRNAs, 12 rho-independent transcription terminators. Of putative 195 CDSs, 30 match known function genes, 30 match known hypothetic genes, 135 are unique to phage EH3-23P1. We identified a phosphate starvation gene phoH in EH3-23P1. No terminal redundant repeat sequences were identified in EH3-23P1 genome, implying non-permute DNA replication mode.