Life Sciences Commons^™

Retention And Loss Of Rna Interference Pathways In Trypanosomatid Protozoans, Lon-Fye Lye, Katherine Owens, Huafang Shi, Silvane M. F. Murta, Ana Carolina Vieira, Salvatore J. Turco, Christian Tschudi, Elisabetta Ullu, Stephen M. Beverley

Molecular and Cellular Biochemistry Faculty Publications

RNA interference (RNAi) pathways are widespread in metaozoans but the genes required show variable occurrence or activity in eukaryotic microbes, including many pathogens. While some Leishmania lack RNAi activity and Argonaute or Dicer genes, we show that Leishmania braziliensis and other species within the Leishmania subgenus Viannia elaborate active RNAi machinery. Strong attenuation of expression from a variety of reporter and endogenous genes was seen. As expected, RNAi knockdowns of the sole Argonaute gene implicated this protein in RNAi. The potential for functional genetics was established by testing RNAi knockdown lines lacking the paraflagellar rod, a key component of the …

The Combined Effect Of Environmental And Host Factors On The Emergence Of Viral Rna Recombinants, Hannah M. Jaag, Peter D. Nagy

Plant Pathology Faculty Publications

Viruses are masters of evolution due to high frequency mutations and genetic recombination. In spite of the significance of viral RNA recombination that promotes the emergence of drug-resistant virus strains, the role of host and environmental factors in RNA recombination is poorly understood. Here we report that the host Met22p/Hal2p bisphosphate-3'-nucleotidase regulates the frequency of viral RNA recombination and the efficiency of viral replication. Based on Tomato bushy stunt virus (TBSV) and yeast as a model host, we demonstrate that deletion of MET22 in yeast or knockdown of AHL, SAL1 and FRY1 nucleotidases/phosphatases in plants leads to increased TBSV recombination …

The Mir-15/107 Group Of Microrna Genes: Evolutionary Biology, Cellular Functions, And Roles In Human Diseases, John R. Finnerty, Wang-Xia Wang, Sébastien S. Hébert, Bernard R. Wilfred, Guogen Mao, Peter T. Nelson

Pathology and Laboratory Medicine Faculty Publications

The miR-15/107 group of microRNA (miRNA) gene is increasingly appreciated to serve key functions in humans. These miRNAs regulate gene expression involved in cell division, metabolism, stress response, and angiogenesis in vertebrate species. The miR-15/107 group has also been implicated in human cancers, cardiovascular disease and neurodegenerative disease, including Alzheimer's disease. Here we provide an overview of the following: (1) the evolution of miR-15/107 group member genes; (2) the expression levels of miRNAs in mammalian tissues; (3) evidence for overlapping gene-regulatory functions by different miRNAs; (4) the normal biochemical pathways regulated by miR-15/107 group miRNAs; and (5) the roles played …

New Views On Strand Asymmetry In Insect Mitochondrial Genomes, Shu-Jun Wei, Min Shi, Xue-Xin Chen, Michael J. Sharkey, Cornelis Van Achterberg, Gong-Yin Ye, Jun-Hua He

Entomology Faculty Publications

Strand asymmetry in nucleotide composition is a remarkable feature of animal mitochondrial genomes. Understanding the mutation processes that shape strand asymmetry is essential for comprehensive knowledge of genome evolution, demographical population history and accurate phylogenetic inference. Previous studies found that the relative contributions of different substitution types to strand asymmetry are associated with replication alone or both replication and transcription. However, the relative contributions of replication and transcription to strand asymmetry remain unclear. Here we conducted a broad survey of strand asymmetry across 120 insect mitochondrial genomes, with special reference to the correlation between the signs of skew values and …

Comparative Mitogenomics Of Braconidae (Insecta: Hymenoptera) And The Phylogenetic Utility Of Mitochondrial Genomes With Special Reference To Holometabolous Insects, Shu-Jun Wei, Min Shi, Michael J. Sharkey, Cornelis Van Achterberg, Xue-Xin Chen

Entomology Faculty Publications

BACKGROUND: Animal mitochondrial genomes are potential models for molecular evolution and markers for phylogenetic and population studies. Previous research has shown interesting features in hymenopteran mitochondrial genomes. Here, we conducted a comparative study of mitochondrial genomes of the family Braconidae, one of the largest families of Hymenoptera, and assessed the utility of mitochondrial genomic data for phylogenetic inference at three different hierarchical levels, i.e., Braconidae, Hymenoptera, and Holometabola.

RESULTS: Seven mitochondrial genomes from seven subfamilies of Braconidae were sequenced. Three of the four sequenced A+T-rich regions are shown to be inverted. Furthermore, all species showed reversal of strand asymmetry, suggesting …

Distinct Evolutionary Histories Of The Dna-A And Dna-B Components Of Bipartite Begomoviruses, Rob W. Briddon, Basavaprabhu L. Patil, Basavaraj Bagewadi, Muhammad Shah Nawaz-Ul-Rehman, Claude M. Fauquet

Plant Pathology Faculty Publications

BACKGROUND: Viruses of the genus Begomovirus (family Geminiviridae) have genomes consisting of either one or two genomic components. The component of bipartite begomoviruses known as DNA-A is homologous to the genomes of all geminiviruses and encodes proteins required for replication, control of gene expression, overcoming host defenses, encapsidation and insect transmission. The second component, referred to as DNA-B, encodes two proteins with functions in intra- and intercellular movement in host plants. The origin of the DNA-B component remains unclear. The study described here was initiated to investigate the relationship between the DNA-A and DNA-B components of bipartite begomoviruses with a …

Copy Number Variation Shapes Genome Diversity In Arabidopsis Over Immediate Family Generational Scales, Seth Debolt

Horticulture Faculty Publications

Arabidopsis thaliana is the model plant and is grown worldwide by plant biologists seeking to dissect the molecular underpinning of plant growth and development. Gene copy number variation (CNV) is a common form of genome natural diversity that is currently poorly studied in plants and may have broad implications for model organism research, evolutionary biology, and crop science. Herein, comparative genomic hybridization (CGH) was used to identify and interrogate regions of gene CNV across the A. thaliana genome. A common temperature condition used for growth of A. thaliana in our laboratory and many around the globe is 22 degrees C. …