In JoVE (1)
Articles by Lauren A. Ostrowski in JoVE
Investigating Teliospore Germination Using Microrespiration Analysis and Microdissection Lauren A. Ostrowski*1, Amanda M. Seto*1, Barry Saville1,2 1Environmental and Life Sciences Graduate Department, Trent University, 2Forensic Science Department, Trent University Smut fungi cause many devastating agricultural diseases. They are dispersed as dormant teliospores that germinate in response to environmental cues. We outline two methods to investigate molecular changes during germination: measuring respiration increase to detect metabolic activation and assessing changing molecular events by isolating teliospores at distinct morphological stages.
Other articles by Lauren A. Ostrowski on PubMed
Natural Antisense Transcripts Are Linked to the Modulation of Mitochondrial Function and Teliospore Dormancy in Ustilago Maydis Molecular Microbiology. Mar, 2017 | Pubmed ID: 27888605 The basidiomycete smut fungus Ustilago maydis causes common smut of corn. This disease is spread through the production of teliospores, which are thick-walled dormant structures characterized by low rates of respiration and metabolism. Teliospores are formed when the fungus grows within the plant, and the morphological steps involved in their formation have been described, but the molecular events leading to dormancy are not known. In U. maydis, natural antisense transcripts (NATs) can function to alter gene expression and many NATs have increased levels in the teliospore. One such NAT is as-ssm1 which is complementary to the gene for the mitochondrial seryl-tRNA synthetase (ssm1), an enzyme important to mitochondrial function. The disruption of ssm1 leads to cell lysis, indicating it is also essential for cellular viability. To assess the function of as-ssm1, it was ectopically expressed in haploid cells, where it is not normally present. This expression led to reductions in growth rate, virulence, mitochondrial membrane potential and oxygen consumption. It also resulted in the formation of as-ssm1/ssm1 double-stranded RNA and increased ssm1 transcript levels, but no change in Ssm1 protein levels was detected. Together, these findings suggest a role for as-ssm1 in facilitating teliospore dormancy through dsRNA formation and reduction of mitochondrial function.
Transcriptome Analysis of Smut Fungi Reveals Widespread Intergenic Transcription and Conserved Antisense Transcript Expression BMC Genomics. 05, 2017 | Pubmed ID: 28464849 Biotrophic fungal plant pathogens cause billions of dollars in losses to North American crops annually. The model for functional investigation of these fungi is Ustilago maydis. Its 20.5 Mb annotated genome sequence has been an excellent resource for investigating biotrophic plant pathogenesis. Expressed-sequence tag libraries and microarray hybridizations have provided insight regarding the type of transcripts produced by U. maydis but these analyses were not comprehensive and there were insufficient data for transcriptome comparison to other smut fungi. To improve transcriptome annotation and enable comparative analyses, comprehensive strand-specific RNA-seq was performed on cell-types of three related smut species: U. maydis (common smut of corn), Ustilago hordei (covered smut of barley), and Sporisorium reilianum (head smut of corn).
Ataxin-2: From RNA Control to Human Health and Disease Genes. Jun, 2017 | Pubmed ID: 28587229 RNA-binding proteins play fundamental roles in the regulation of molecular processes critical to cellular and organismal homeostasis. Recent studies have identified the RNA-binding protein Ataxin-2 as a genetic determinant or risk factor for various diseases including spinocerebellar ataxia type II (SCA2) and amyotrophic lateral sclerosis (ALS), amongst others. Here, we first discuss the increasingly wide-ranging molecular functions of Ataxin-2, from the regulation of RNA stability and translation to the repression of deleterious accumulation of the RNA-DNA hybrid-harbouring R-loop structures. We also highlight the broader physiological roles of Ataxin-2 such as in the regulation of cellular metabolism and circadian rhythms. Finally, we discuss insight from clinically focused studies to shed light on the impact of molecular and physiological roles of Ataxin-2 in various human diseases. We anticipate that deciphering the fundamental functions of Ataxin-2 will uncover unique approaches to help cure or control debilitating and lethal human diseases.