Faculty Members

Dr. Joel Dacks

Associate Professor
Department of Medicine
    Contact details are for academic matters only.

About Me

Awards

  • Canada Research Chair (Tier II) in Evolutionary Cell Biology, 2011-2021
  • 2016 Hutner Award (presented by the International Society of Protistologists)

Research Description

The membrane-trafficking system is a key characteristic of eukaryotes (humans, plants, yeast, etc.) and one of the defining features that separates us from bacteria at a cellular level. It is responsible for the proper movement and final location of most of the material in our cells. It underlies not only brain activity, and hormone secretion in humans, but healthy plant growth, as well as normal cellular activity in a diverse array of single-celled organisms important for our economy, our environment and our health. The pathogenic mechanisms of many parasites, such as the organisms causing malaria, primary amoebic meningoencephalitis and African sleeping sickness, are all underpinned by action of the membrane-trafficking system.

Evidence suggests that the membrane-trafficking system arose early on in eukaryotic evolution, with the major protein families involved likely having been already present in our ancestors over one billion years ago. The innovation of an endomembrane system would have been crucial for early eukaryotes, allowing predation, surface remodelling and increased cell size.

The long-term goal of my research program is to understand the evolution and diversity of the eukaryotic membrane-trafficking system. 

Although evolutionary in nature, my research also provides insight into basic cell biology, parasitism and pathogenesis. By comparative genomics and evolutionary cell biology addressing organisms from across the taxonomic breadth of eukaryotes (beyond yeast to man), core components of eukaryotic cellular systems are identified. This allows the development of models of cell biological mechanism that are valid for all eukaryotic cells. It is also possible to place in context some aspects that are unique to a particular model system. Features that are unique, when found in parasitic protistan pathogens, may represent potential therapeutic targets.

We use genomics and molecular evolutionary tools such as phylogenetics and homology searching to address our questions. Some of our analyses involve searching publicly available genome data. Additionally, the lab participates in international sequencing projects of protist genomes to examine their membrane trafficking machinery. This has included important microbial parasites (eg. Trichomonas vaginalisBlastocystis hominis, and on-going work for Naegleria fowleri), as well as important free-living relatives of parasites (eg. Bodo saltansEuglena gracilisNaegleria gruberiand Chromera velia/Vitrella brassicaformis). We are also interested in protists of ecological and evolutionary importance (eg.  Emiliania huxleyiGuillardia thetaBigelowiella natansMonocercomonoides exilis).  




Research

Several interconnected lines of research are currently on-going in my lab relating ancient origins of the endomembrane system and the subsequent evolution in modern eukaryotes:

Origin and evolution of the membrane trafficking system Detailed evolutionary studies of individual protein families (eg. SNAREs, vesicle coats) can reveal important information about the specific history of that membrane-trafficking machinery and about the membrane-trafficking system in general. Such studies have thus far demonstrated ancient complexity in the trafficking system and the proposal of an evolutionary mechanism for non-endosymbiotic organelle evolution. As a by-product of these investigations, we have uncovered new protein complexes and trafficking pathways, even in human cells and revealed the cryptic origin of others relevant to neurodegenerative diseases. We continue to investigate the evolution of protein families involved in membrane-trafficking, with the goal of understanding the emergence of specificity and organelle identity in the eukaryotic cell. 

While some membrane trafficking organelles are conserved across eukaryotes, poorly understood organelles are present outside the well -known model systems that are ripe for exploration. The Contractile Vacuole (CV) is an osmoregulatory organelle found in ecologically important freshwater and soil­-dwelling organisms. However, it is often not reported as present in parasites or marine organisms, raising questions of whether organelles identified as contractile vacuoles are truly orthologous between diverse eukaryotes. We have an NSERC-funded research program to use molecular evolutionary and transcriptomic analysis to examine the evolution and function of the CV across the breadth of protist lineages. 

Evolutionary parasitology and Global Health Some of the world’s most significant infectious diseases are caused by microbial eukaryotes. Our work investigates the ways in which the cell biology of membrane-trafficking, as we understand it primarily from studies in animal and yeast models, applies to that of organisms that cause significant mortality and poverty across the world. We often collaboratively pair our in silico work with molecular cell biology to test hypotheses. Current work includes the evolution of invasion organelles in Apicomplexa (malaria, toxoplasmosis) and of non-canonical organelles (eg. Peripheral Vacuoles) in the Fornicata (eg. Giardia, the organism causing Beaver Fever). We are also among research groups leading the genome sequencing project of Naegleria fowleri (the brain-eating amoeba). 

Furthermore, I am the co-founder and co-director of the (UAlberta) Biomedical Global Health Research Network. The goal of the network is to facilitate interaction between UAlberta researchers doing biomedical work with relevance to, and in aid of, Global Health.

Additional research lines include microbial eukaryotes in oilsands-associated environmentsand genomics of microbial eukaryotesto better understand the diversity of membrane-trafficking machinery and the evolutionary processes that shape the endomembrane system in lineages post-LECA



Research Keywords

amoeba, Bio-diversity, endocytosis, Environmental monitoring, Evolution, organelle, membrane-trafficking, genome, meningitis, Microbial eukaryotes, Naegleria, Next-Generation Sequencing, Systems Biology