Wednesday 25 September 2013 at 11:00am

Title: “The extraordinary biology of shipworms and their endosymbionts: a reservoir of cellulases and antimicrobials”

Speaker: Roberta O'Connor, Ph.D.
Research Scientist, Ocean Genome Legacy

Abstract:
Shipworms are marine bivalves that burrow into and eat wood. Like most xylophagous animals, this lifestyle is enabled by a community of cellulolytic symbiotic bacteria. In the shipworm, however, the symbiont community is found cloistered within the cells of gill, sequestered away from the digestive tract. In contrast, the caecum, the primary site of wood digestion, is nearly free of bacteria. Using a combination of metagenomics, genomics, proteomics, bioinformatics and old fashioned protein chemistry, we have shown that the gill endosymbionts, despite their location, provide the enzymes for the wood digestion in the gut. Thus the shipworm caecum is a natural “bioreactor” that may provide valuable information to improve commercial biofuel production. In addition to celluolytic enzymes, the genomes of shipworm symbionts also display a significant investment in secondary metabolite synthesis. This capacity, combined with the ability of shipworm symbionts to produce compounds that move through multiple cellular compartments and influence processes distant from their living quarters, suggested a reservoir of unusual anti-microbial compounds worthy of investigation. We tested this hypothesis by screening symbionts for activity against the apicomplexan parasites Toxoplasma and Cryptosporidium, and discovered a symbiont that secretes a compound inhibitory to intracellular growth of both these pathogens. These results suggest that mining shipworms symbionts for bioactive compounds could open up a new area of anti-parasitic drug discovery and potentially identify new molecular targets for drug development.

Host: Russell Hill, Ph.D.

International Aquafeed: Veggie diets for cobia
September/October 2013

Title: “Merging ecology and genomics to understand evolutionary responses to environmental change”

Speaker: Stephen Keller, Ph.D.
AL-UMCES

An emerging challenge for environmental scientists and natural resource managers is determining how species respond to environmental change, including changes in climate that affect growing season length and ecosystem productivity. In forested ecosystems, growing season length is determined by phenology -- the period between the onset of tree growth in spring (bud flush) and the cessation of growth in late summer (bud set). The period between these key phenological events dictates the active period of biomass accrual and height growth in trees, and is thus under considerable selective constraint within populations, and strong divergent selection between populations inhabiting different environments. Trees in the genus Populus (poplars and aspens) are ecologically and economically important components of North American forests, and are also a model system in tree genomics. Ecological genetic studies of poplar trees sampled from natural stands across North America suggest a strong impact of historical climate change on past population movements, as well as on evolutionary shifts in phenology and other ecophysiological traits that adapt populations to their local climate environments. However, with this evolutionary history of past climate responses comes the susceptibility of forests to becoming maladapted in the future, as modern climate change may offset populations from their optimal environments more rapidly than dispersal or selection can reconnect them. This question is currently being explored by integrating genomic data on climate adaptation with spatial models of growing season length and climate variability to predict where populations are likely to become the most and least adapted to future climates.

Host: J. Sook Chung, Ph.D.

Location: IMET's Multi-Purpose Room

Dan Rodricks discusses Maryland Fish Farming on his September 17, 2013 broadcast.
Listen online.

Title: “Large scale ocean variability and regional ecosystem response in the Northern California Current system”

Speaker: Hongsheng Bi, Ph.D.
CBL-UMCES

Host: J. Sook Chung, Ph.D.

Location: IMET's Multi-Purpose Room

Sir Richard J. Roberts, Nobel Laureate and Chief Scientific Officer at New England Biolabs, visited the Institute of Marine and Environmental Technology on the September 4, 2013 and delivered the first IMET Distinguished Seminar to a packed auditorium at the Columbus Center. In the talk, entitled “Bacterial methylomes”, Dr. Roberts reported on a novel approach to characterizing restriction-modification systems and DNA methylation patterns on a genome-wide basis using single molecule real time (SMRT) sequencing. The implications of his talk were far reaching in the field of biotechnology. Dr. Roberts is well-known for his discovery and characterization of over 100 restriction enzymes. He also discovered introns and mRNA splicing for which he received the Nobel Prize in Physiology or Medicine in 1993. The seminar was hosted by Professor Shiladitya DasSarma and co-sponsored by the University of Maryland School of Medicine’s Department of Microbiology and Immunology.

Relevant articles by Dr. Roberts:
1. The methylomes of six bacteria
2. Characterization of DNA methyltransferase specificities using single-molecule, real-time DNA Sequencing
3. Genome-wide mapping of methylated adenine residues in pathogenic Escherichia coli using single-molecule real-time sequencing

Title: “Bacterial methylomes”

Speaker: Sir Richard J. Roberts
The Nobel Prize in Physiology or Medicine 1993

Host: Shil DasSarma, Ph.D.

Relevant articles by Dr. Roberts:

• 1. The methylomes of six bacteria


• 2. Characterization of DNA methyltransferase specificities using single-molecule, real-time DNA Sequencing


• 3. Genome-wide mapping of methylated adenine residues in pathogenic Escherichia coli using single-molecule real-time sequencing

Sir Richard Roberts will visit IMET on 4th September 2013 to present a seminar. Dr. Roberts is the Chief Scientific Officer at New England Biolabs, Ipswich, Massachusetts. He was educated in England, attending the University of Sheffield where he obtained a B.Sc. in Chemistry in 1965 and a Ph.D. in Organic Chemistry in 1968. His postdoctoral research was carried out in Professor J.L. Strominger's laboratory at Harvard, where he studied the tRNAs that are involved in the biosynthesis of bacterial cell walls. From 1972 to 1992, he worked at Cold Spring Harbor Laboratory, reaching the position of Assistant Director for Research under Dr. J.D. Watson. He began work on the newly discovered Type II restriction enzymes in 1972 and in the next few years more than 100 such enzymes were discovered and characterized in Dr. Roberts' laboratory. Dr. Roberts has also been involved in studies of Adenovirus-2 and discovered split genes and mRNA splicing in 1977 for which he received the Nobel Prize in Physiology or Medicine in1993. His laboratory sequenced the 35,937 nucleotide Adenovirus-2 genome, and wrote some of the first programs for sequence assembly and analysis. DNA methyltransferases are an area of active research interest and, in collaboration with Dr. X. Cheng, DNA base flipping was discovered in 1993. Current interests focus on the identification of restriction enzyme and methylase genes within the GenBank database and the development of rapid methods to assay their function.

Dr. Roberts' visit will be hosted by Dr. Shil DasSarma.

Relevant articles by Dr. Roberts:

• The methylomes of six bacteria


• Characterization of DNA methyltransferase specificities using single-molecule, real-time DNA Sequencing


• Genome-wide mapping of methylated adenine residues in pathogenic Escherichia coli using single-molecule real-time sequencing