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Full-Text Articles in Life Sciences
Initial Events Associated With Virus Pbcv-1 Infection Of Chlorella Nc64a, Gerhard Thiel, Anna Moroni, David Dunigan, James L. Van Etten
Initial Events Associated With Virus Pbcv-1 Infection Of Chlorella Nc64a, Gerhard Thiel, Anna Moroni, David Dunigan, James L. Van Etten
David D Dunigan Ph. D.
Chlorella viruses (or chloroviruses) are very large, plaque-forming viruses. The viruses are multilayered structures containing a large double-stranded DNA genome, a lipid bilayered membrane, and an outer icosahedral capsid shell. The viruses replicate in certain isolates of the coccal green alga, Chlorella. Sequence analysis of the 330-kbp genome of Paramecium bursaria Chlorella virus 1 (PBCV-1), the prototype of the virus family Phycodnaviridae, reveals <365 protein-encoding genes and 11 tRNA genes. Products of about 40% of these genes resemble proteins of known function, including many that are unexpected for a virus. Among these is a virus-encoded protein, called Kcv, which forms …
Chlorovirus: A Genus Of Phycodnaviridae That Infects Certain Chlorella-Like Green Algae, Ming Kang, David Dunigan, James L. Van Etten
Chlorovirus: A Genus Of Phycodnaviridae That Infects Certain Chlorella-Like Green Algae, Ming Kang, David Dunigan, James L. Van Etten
David D Dunigan Ph. D.
Taxonomy: Chlorella viruses are assigned to the family Phycodnaviridae, genus Chlorovirus, and are divided into three species: Chlorella NC64A viruses, Chlorella Pbi viruses and Hydra viridis Chlorella viruses. Chlorella viruses are large, icosahedral, plaque-forming, dsDNA viruses that infect certain unicellular, chlorella-like green algae. The type member is Paramecium bursaria chlorella virus 1 (PBCV-1).
Physical properties: Chlorella virus particles are large (molecular weight ~1 × 109 Da) and complex. The virion of PBCV-1 contains more than 100 different proteins; the major capsid protein, Vp54, comprises ~40% of the virus protein. Cryoelectron microscopy and three-dimensional image reconstruction of PBCV-1 virions …
Phycodnaviruses: A Peek At Genetic Diversity, David Dunigan, Lisa Fitzgerald, James L. Van Etten
Phycodnaviruses: A Peek At Genetic Diversity, David Dunigan, Lisa Fitzgerald, James L. Van Etten
David D Dunigan Ph. D.
The family Phycodnaviridae encompasses a diverse collection of large icosahedral, dsDNA viruses infecting algae. These viruses have genomes ranging from 160 to 560 kb. The family consists of six genera based initially on host range and supported by sequence comparisons. The family is monophyletic with branches for each genus, but the phycodnaviruses have evolutionary roots that connect with several other families of large DNA viruses, referred to as the nucleocytoplasmic large DNA viruses (NCLDV). The genomes of members in three genera in the Phycodnaviridae have recently been sequenced and the purpose of this manuscript is to summarize these data. The …
Microarray Analysis Of Paramecium Bursaria Chlorella Virus 1 Transcription, Giane M. Yanai-Balser, Garry A. Duncan, James D. Eudy, Dong Wang, Xiao Li, Irina V. Agarkova, David Dunigan, James L. Van Etten
Microarray Analysis Of Paramecium Bursaria Chlorella Virus 1 Transcription, Giane M. Yanai-Balser, Garry A. Duncan, James D. Eudy, Dong Wang, Xiao Li, Irina V. Agarkova, David Dunigan, James L. Van Etten
David D Dunigan Ph. D.
Paramecium bursaria chlorella virus 1 (PBCV-1), a member of the family Phycodnaviridae, is a large double-stranded DNA, plaque-forming virus that infects the unicellular green alga Chlorella sp. strain NC64A. The 330-kb PBCV-1 genome is predicted to encode 365 proteins and 11 tRNAs. To monitor global transcription during PBCV-1 replication, a microarray containing 50-mer probes to the PBCV-1 365 protein-encoding genes (CDSs) was constructed. Competitive hybridization experiments were conducted by using cDNAs from poly(A)- containing RNAs obtained from cells at seven time points after virus infection. The results led to the following conclusions: (i) the PBCV-1 replication cycle is temporally programmed …
Fungal Symbiosis From Mutualism To Parasitism: Who Controls The Outcome, Host Or Invader?, Regina S. Redman, David Dunigan, Rusty J. Rodriguez
Fungal Symbiosis From Mutualism To Parasitism: Who Controls The Outcome, Host Or Invader?, Regina S. Redman, David Dunigan, Rusty J. Rodriguez
David D Dunigan Ph. D.
• Plant symbiotic fungi are generally thought to express a single lifestyle that might increase (mutualism), decrease (parasitism), or have no influence (commensalism) on host fitness. However, data are presented here demonstrating that plant pathogenic Colletotrichum species are able to asymptomatically colonize plants and express nonpathogenic lifestyles. • Experiments were conducted in growth chambers and plant colonization was assessed by emergence of fungi from surface sterilized plant tissues. Expression of symbiotic lifestyles was assessed by monitoring the ability of fungi to confer disease resistance, drought tolerance and growth enhancement. • Several pathogenic Colletotrichum species expressed either mutualistic or commensal lifestyles …
‘Strawberry Festival’ Strawberry, C. K. Chandler, D. E. Legard, David Dunigan, T. E. Crocker, C. A. Sims
‘Strawberry Festival’ Strawberry, C. K. Chandler, D. E. Legard, David Dunigan, T. E. Crocker, C. A. Sims
David D Dunigan Ph. D.
Most of the strawberries (Fragaria xananassa Duchesne) produced in Florida are shipped fresh to locations throughout the eastern United States and Canada (Florida Agricultural Statistics [www.nass.usda.gov/ fl]). Therefore, Florida growers need cultivars that produce fruit that are attractive and flavorful, and maintain these qualities during and after long-distance shipment. 'Strawberry Festival' strawberry has produced commercially acceptable yields of firm, attractive, and flavorful fruit in trials at the Univ. of Florida's Gulf Coast Research and Education Center in Dover (GCREC-Dover) and in two commercial fields in west central Florida. It is recommended for trial in areas where strawberries are grown in …
Chlorovirus-Mediated Membrane Depolarization Of Chlorella Alters Secondary Active Transport Of Solutes, Irina V. Agarkova, David Dunigan, James R. Gurnon, Timo Greiner, Julia Barres, Gerhard Thiel, James L. Van Etten
Chlorovirus-Mediated Membrane Depolarization Of Chlorella Alters Secondary Active Transport Of Solutes, Irina V. Agarkova, David Dunigan, James R. Gurnon, Timo Greiner, Julia Barres, Gerhard Thiel, James L. Van Etten
David D Dunigan Ph. D.
Paramecium bursaria chlorella virus 1 (PBCV-1) is the prototype of a family of large, double-stranded DNA, plaque-forming viruses that infect certain eukaryotic chlorella-like green algae from the genus Chlorovirus. PBCV-1 infection results in rapid host membrane depolarization and potassium ion release. One interesting feature of certain chloroviruses is that they code for functional potassium ion-selective channel proteins (Kcv) that are considered responsible for the host membrane depolarization and, as a consequence, the efflux of potassium ions. This report examines the relationship between cellular depolarization and solute uptake. Annotation of the virus host Chlorella strain NC64A genome revealed 482 putative transporter-encoding …
Capping Of Tobacco Mosaic Virus Rna: Analysis Of Viral-Coded Guanylyltransferase-Like Activity, David Dunigan, Milton Zaitlin
Capping Of Tobacco Mosaic Virus Rna: Analysis Of Viral-Coded Guanylyltransferase-Like Activity, David Dunigan, Milton Zaitlin
David D Dunigan Ph. D.
The 5’ end of tobacco mosaic virus (TMV) genomic RNA is capped with 7- methylguanosine. A virus-coded polypeptide with guanylyltransferase activity has been investigated. This enzyme is responsible for forming the 5’→5’ linkage of guanosine 5’-monophosphate to the 5’- diphosphate of an acceptor RNA, thereby forming the cap. A critical step in the mechanism for cap formation in the eukaryotic nucleus is for guanylyltransferase to bind covalently to guanosine 5’- monophosphate with the hydrolysis of pyrophosphate when guanosine 5’- triphosphate is the substrate. The TMV 126-kilodalton protein, which is most probably a component of the TMV replicase, was found to …
Cloning Of Nt.Cviqii Nicking Endonuclease And Its Cognate Methyltransferase: M.Cviqii Methylates Ag Sequence, Siu-Hong Chan, Zhenyu Zhu, David Dunigan, James L. Van Etten, Shuang-Yong Xu
Cloning Of Nt.Cviqii Nicking Endonuclease And Its Cognate Methyltransferase: M.Cviqii Methylates Ag Sequence, Siu-Hong Chan, Zhenyu Zhu, David Dunigan, James L. Van Etten, Shuang-Yong Xu
David D Dunigan Ph. D.
Chlorella virus NY-2A has a large, highly methylated dsDNA genome (45% of the cytosines are 5-methylcytosine and 37% of the adenines are N6-methyladenine). Here, we report the cloning, expression, and characterization of the NY-2A-encoded CviQII nicking-modification (N-M) system. The nicking endonuclease, Nt.CviQII, recognizes R ↓ AG (R = A or G, ↓ indicating cleavage site) sequences and cleaves the phosphodiester bond 5′ to the adenosine. Because of the difficulty in cloning and expressing the wild-type Nt.CviQII, C-terminal truncation mutants were generated and full-length Nt.CviQII was reconstructed by intein-mediated peptide ligation. The truncation mutants and the reconstructed full-length Nt.CviQII have the …