Psychrophilic Extremophiles from Antarctica: Biodiversity and Biotechnological Potential

Bowman John P.,Abell Gyu C.J.,Nichols Carol A. Mancuso Korea Institute of Ocean ScienceTechnology 2005 Ocean and Polar Research Vol.27 No.2

Recently there has been a rapid accumulation of knowledge of microbial life in cold and frozen ecosystems. This understanding has revealed the extensive diversity of psychrophilic prokaryotes. Cultivation-based and molecular-based surveys have been performed in Antarctic habitats ranging from glacial ice to continental shelf sediments. Results indicate that psychrophilic taxa permeate throughout the Bacteria while they represent a more mysterious element of diversity in the Archaea owing to a notable lack of cultured strains. In certain cold climate ecosystems the diversity of psychrophilic populations reach levels comparable to the richest temperate equivalents. Within these communities must exist tremendous genetic diversify that is potentially of fundamental and of practical value. So far this genetic pool has been hardly explored. Only recently have genomic data become available for various psychrophilic prokaryotes and more is required. This owes to the fact that psychrophilic microbes possess manifold mechanisms for cold adaptations, which not only Provide enhanced survival and Persistence but Probably also contributes to niche specialisation. These mechanisms, including cold-active and ice-active proteins, polyunsaturated lipids and exopolysaccharides also have a great interest to biotechnologists.

Psychrophilic Extremophiles from Antarctica: Biodiversity and Biotechnological Potential

John P. Bowman,Guy C.J. Abell,Carol A. Mancuso Nichols 한국해양과학기술원 2005 Ocean and Polar Research Vol.27 No.2

Recently there has been a rapid accumulation of knowledge of microbial life in cold and frozen ecosystems. This understanding has revealed the extensive diversity of psychrophilic prokaryotes. Cultivation-based and molecular-based surveys have been performed in Antarctic habitats ranging from glacial ice to continental shelf sediments. Results indicate that psychrophilic taxa permeate throughout the Bacteria while they represent a more mysterious element of diversity in the Archaea owing to a notable lack of cultured strains. In certain cold climate ecosystems the diversity of psychrophilic populations reach levels comparable to the richest temperate equivalents. Within these communities must exist tremendous genetic diversity that is potentially of fundamental and of practical value. So far this genetic pool has been hardly explored. Only recently have genomic data become available for various psychrophilic prokaryotes and more is required. This owes to the fact that psychrophilic microbes possess manifold mechanisms for cold adaptations, which not only provide enhanced survival and persistence but probably also contributes to niche specialisation. These mechanisms, including cold-active and ice-active proteins, polyunsaturated lipids and exopolysaccharides also have a great interest to biotechnologists.

Comparative Analysis of the Conserved Functions of Arabidopsis DRL1 and Yeast KTI12

전상은,김경태,조규형,황지영,Wael Abdel-Fattah,Alexander Hammermeister,Raffael Schaffrath,John L. Bowman 한국분자세포생물학회 2015 Molecules and cells Vol.38 No.3

Patterning of the polar axis during the early leaf developmental stage is established by cell-to-cell communication between the shoot apical meristem (SAM) and the leaf primordia. In a previous study, we showed that the DRL1 gene, which encodes a homolog of the Elongator-associated protein KTI12 of yeast, acts as a positive regulator of adaxial leaf patterning and shoot meristem activity. To determine the evolutionally conserved functions of DRL1, we performed a comparison of the deduced amino acid sequence of DRL1 and its yeast homolog, KTI12, and found that while overall homology was low, well-conserved domains were presented. DRL1 contained two conserved plant-specific domains. Expression of the DRL1 gene in a yeast KTI12-deficient yeast mutant suppressed the growth retardation phenotype, but did not rescue the caffeine sensitivity, indicating that the role of Arabidopsis Elongatorassociated protein is partially conserved with yeast KTI12, but may have changed between yeast and plants in response to caffeine during the course of evolution. In addition, elevated expression of DRL1 gene triggered zymocin sensitivity, while overexpression of KTI12 maintained zymocin resistance, indicating that the function of Arabidopsis DRL1 may not overlap with yeast KTI12 with regards to toxin sensitivity. In this study, expression analysis showed that class-I KNOX genes were downregulated in the shoot apex, and that YAB and KAN were upregulated in leaves of the Arabidopsis drl1- 101 mutant. Our results provide insight into the communication network between the SAM and leaf primordia required for the establishment of leaf polarity by mediating histone acetylation or through other mechanisms.

THE RELATION OF DIETARY FORMULATION AND DIGESTA PROPERTIES ON THE ATLANTIC SALMON (Salmo salar L.) GASTROINTESTINAL MICROBIAL COMMUNITY

Kamarul Zaman Zarkasi,Richard S. Taylor,Guy C.J. Abell,Mark L. Tamplin,Brett Glencross,John P. Bowman 한국수산과학회 양식분과 2015 한국수산과학회 양식분과 학술대회 Vol.2015 No.5

Comparative Genomic Analysis Reveals That the 20K and 38K Prophages in Listeria monocytogenes Serovar 4a Strains Lm850658 and M7 Contribute to Genetic Diversity but Not to Virulence

( Chun Fang ),( Tong Cao ),( Ying Shan ),( Ye Xia ),( Yong Ping Xin ),( Chang Yong Cheng ),( Houhui Song ),( John Bowman ),( Xiao Liang Li ),( Xiang Yang Zhou ),( Wei Huan Fang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.1

Listeria monocytogenes is a foodborne pathogen of considerable genetic diversity with varying pathogenicity. Initially, we found that the strain M7 was far less pathogenic than the strain Lm850658 though both are serovar 4a strains belonging to the lineage III. Comparative genomic approaches were then attempted to decipher the genetic basis that might govern the strain-dependent pathotypes. There are 2,761 coding sequences of 100% nucleotide identity between the two strains, accounting for 95.7% of the total genes in Lm850658 and 92.7% in M7. Lm850658 contains 33 specific genes, including a novel 20K prophage whereas strain M7 has 130 specific genes, including two large prophages (38K and 44K). To examine the roles of these specific prophages in pathogenicity, the 20K and 38K prophages were deleted from their respective strains. There were virtually no differences of pathogenicity between the deletion mutants and their parent strains, although some putative virulent factors like VirB4 are present in the 20K region or holin-lysin in the 38K region. In silico PCR analysis of 29 listeria genomes show that only strain SLCC2540 has the same 18 bp integration hotspot as Lm850658, whereas the sequence identity of their 20K prophages is very low (21.3%). The 38K and 44K prophages are located in two other different hotspots and are conserved in low virulent strains M7, HCC23, and L99. In conclusion, the 20K and 38K prophages of L. monocytogenes serovar 4a strains Lm850658 and M7 are not related to virulence but contribute to genetic diversity.

Novel Mechanism of Massive Photoreceptor Degeneration Caused by Mutation in the trp Gene of Drosophila

Yoon, Jaeseung,Ben-Ami, Hagit Cohen,Hong, Young Seok,Park, Soyeon,Strong, Lydia L.R.,Bowman, John,Geng, Chaoxian,Baek, Kwanghee,Minke, Baruch,Pak, William L. 경희대학교 생명자원과학연구원 2000 硏究論文集 Vol.21 No.-

The Drosophila trp gene encodes a light-activated Ca^(2+) channel subunit, which is a prototypical member of a novel class of channel proteins. Previously identified trp mutants are all recessive, loss-of-function mutants characterized by a transient receptor potential and the total or near-total loss of functional TRP protein. Although retinal degeneration does occur in these mutants, it is relatively mild and slow in onset. We report herein a new mutant, Trp^(p365), that does not display the transient receptor potential phenotype and is characterized by a substantial level of the TAP protein and rapid, semi-dominant degeneration of photoreceptors. We show that, in spite of its unusual phenotypes, Trp^(p365) is a trp allele because a Trp^(p365) transgene induces the mutant phenotype in a wild-type back-ground, and a wild-type trp transgene in a Trp^(p365) background suppresses the mutant phenotype. Moreover, amino acid alterations that could cause the Trp^(p365) phenotype are found in the transmembrane segment region of the mutant channel protein. Whole-cell recordings clarified the mechanism underlying the retinal degeneration by showing that the TRP channels of Trp^(p365) are constitutively active. Although several genes, when mutated, have been shown to cause retinal degeneration in Drosophila, the underlying mechanism has not been identified for any of them. The present studies provide evidence for a specific mechanism for massive degeneration of photoreceptors in Drosophila. Insofar as some human homologs of TRP are highly expressed in the brain, a similar mechanism could be a major contributor to degenerative disorders of the brain.

Comparative Analysis of the Conserved Functions of Arabidopsis DRL1 and Yeast KTI12

Jun, Sang Eun,Cho, Kiu-Hyung,Hwang, Ji-Young,Abdel-Fattah, Wael,Hammermeister, Alexander,Schaffrath, Raffael,Bowman, John L.,Kim, Gyung-Tae Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.3

Patterning of the polar axis during the early leaf developmental stage is established by cell-to-cell communication between the shoot apical meristem (SAM) and the leaf primordia. In a previous study, we showed that the DRL1 gene, which encodes a homolog of the Elongator-associated protein KTI12 of yeast, acts as a positive regulator of adaxial leaf patterning and shoot meristem activity. To determine the evolutionally conserved functions of DRL1, we performed a comparison of the deduced amino acid sequence of DRL1 and its yeast homolog, KTI12, and found that while overall homology was low, well-conserved domains were presented. DRL1 contained two conserved plant-specific domains. Expression of the DRL1 gene in a yeast KTI12-deficient yeast mutant suppressed the growth retardation phenotype, but did not rescue the caffeine sensitivity, indicating that the role of Arabidopsis Elongator-associated protein is partially conserved with yeast KTI12, but may have changed between yeast and plants in response to caffeine during the course of evolution. In addition, elevated expression of DRL1 gene triggered zymocin sensitivity, while overexpression of KTI12 maintained zymocin resistance, indicating that the function of Arabidopsis DRL1 may not overlap with yeast KTI12 with regards to toxin sensitivity. In this study, expression analysis showed that class-I KNOX genes were downregulated in the shoot apex, and that YAB and KAN were upregulated in leaves of the Arabidopsis drl1- 101 mutant. Our results provide insight into the communication network between the SAM and leaf primordia required for the establishment of leaf polarity by mediating histone acetylation or through other mechanisms.