Life Sciences Commons^™

Comparative Transcriptome Profiling Provides Insights Into Plant Salt Tolerance In Seashore Paspalum (Paspalum Vaginatum), Peipei Wu, Steven Cogill, Yijian Qiu, Zhigang Li, Man Zhou, Qian Hu, Zhihui Chang, Hong Luo, Rooksana E. Noorai, Xiaoxia Xia, Christopher Saski, Paul Raymer

Publications

Background

Seashore paspalum (Paspalum vaginatum), a halophytic warm-seasoned perennial grass, is tolerant of many environmental stresses, especially salt stress. To investigate molecular mechanisms underlying salinity tolerance in seashore paspalum, physiological characteristics and global transcription profiles of highly (Supreme) and moderately (Parish) salinity-tolerant cultivars under normal and salt stressed conditions were analyzed.

Results

Physiological characterization comparing highly (Supreme) and moderately (Parish) salinity-tolerant cultivars revealed that Supreme’s higher salinity tolerance is associated with higher Na+ and Ca2+ accumulation under normal conditions and further increase of Na+ under salt-treated conditions (400 mM NaCl), possibly by vacuolar sequestration. Moreover, K+ retention under …

Discovery Of Genomic Variations By Whole-Genome Resequencing Of The North American Araucana Chicken, Rooksana E. Noorai, Vijay Shankar, Nowlan H. Freese, Christopher M. Gregorski, Susan C. Chapman

Publications

Gallus gallus (chicken) is phenotypically diverse, with over 60 recognized breeds, among the myriad species within the Aves lineage. Domestic chickens have been under artificial selection by humans for thousands of years for agricultural purposes. The North American Araucana (NAA) breed arose as a cross between the Chilean “Collonocas” that laid blue eggs and was rumpless and the “Quetros” that had unusual tufts but with tail. NAAs were introduced from South America in the 1940s and have been kept as show birds by enthusiasts since then due to several distinctive traits: laying eggs with blue eggshells, characteristic ear-tufts, a pea …

Non-Enzymatic Roles Of Human Rad51 At Stalled Replication Forks, Jennifer M. Mason, Yuen-Ling Chan, Ralph W. Weichselbaum, Douglas K. Bishop

Publications

The central recombination enzyme RAD51 has been implicated in replication fork processing and restart in response to replication stress. Here, we use a separation-of-function allele of RAD51 that retains DNA binding, but not D-loop activity, to reveal mechanistic aspects of RAD51’s roles in the response to replication stress. Here, we find that cells lacking RAD51’s enzymatic activity protect replication forks from MRE11-dependent degradation, as expected from previous studies. Unexpectedly, we find that RAD51’s strand exchange activity is not required to convert stalled forks to a form that can be degraded by DNA2. Such conversion was shown previously to require replication …

Glucose Signaling Is Important For Nutrient Adaptation During Differentiation Of Pleomorphic African Trypanosomes, Yijian Qiu, Jillian E. Milanes, Jessica A. Jones, Rooksana E. Noorai, Vijay Shankar, James C. Morris

Publications

The African trypanosome has evolved mechanisms to adapt to changes in nutrient availability that occur during its life cycle. During transition from mammalian blood to insect vector gut, parasites experience a rapid reduction in environmental glucose. Here we describe how pleomorphic parasites respond to glucose depletion with a focus on parasite changes in energy metabolism and growth. Long slender bloodstream form parasites were rapidly killed as glucose concentrations fell, while short stumpy bloodstream form parasites persisted to differentiate into the insect-stage procyclic form parasite. The rate of differentiation was lower than that triggered by other cues but reached physiological rates …

Cancer Cell Redirection Biomarker Discovery Using A Mutual Information Approach, Kimberly Roche, F. Alex Feltus, Jang Pyo Park, Marie-May Coissieux, Chenyan Chang, Vera B.S. Chan, Mohamed Bentires-Alj, Brian W. Booth

Publications

Introducing tumor-derived cells into normal mammary stem cell niches at a sufficiently high ratio of normal to tumorous cells causes those tumor cells to undergo a change to normal mammary phenotype and yield normal mammary progeny. This phenomenon has been termed cancer cell redirection. We have developed an in vitro model that mimics in vivo redirection of cancer cells by the normal mammary microenvironment. Using the RNA profiling data from this cellular model, we examined high-level characteristics of the normal, redirected, and tumor transcriptomes and found the global expression profiles clearly distinguish the three expression states. To identify potential redirection …

A Leishmania Secretion System For The Expression Of Major Ampullate Spidroin Mimics, Todd A. Lyda, Elizabeth L. Wagner, Andre X. Bourg, Congyue Peng, Golnaz Najaf Tomaraei, Delphine Dean, Marian S. Kennedy, William R. Marcotte Jr.

Publications

Spider major ampullate silk fibers have been shown to display a unique combination of relatively high fracture strength and toughness compared to other fibers and show potential for tissue engineering scaffolds. While it is not possible to mass produce native spider silks, the potential ability to produce fibers from recombinant spider silk fibers could allow for an increased innovation rate within tissue engineering and regenerative medicine. In this pilot study, we improved upon a prior fabrication route by both changing the expression host and additives to the fiber pulling precursor solution to improve the performance of fibers. The new expression …

Beyond The Mhc: A Canine Model Of Dermatomyositis Shows A Complex Pattern Of Genetic Risk Involving Novel Loci, Jacquelyn M. Evans, Rooksana E. Noorai, Kate L. Tsai, Alison N. Starr-Moss, Cody M. Hill, Kendall J. Anderson, Thomas R. Famula, Leigh Anne Clark

Publications

Juvenile dermatomyositis (JDM) is a chronic inflammatory myopathy and vasculopathy driven by genetic and environmental influences. Here, we investigated the genetic underpinnings of an analogous, spontaneous disease of dogs also termed dermatomyositis (DMS). As in JDM, we observed a significant association with a haplotype of the major histocompatibility complex (MHC) (DLA-DRB1*002:01/-DQA1*009:01/-DQB1*001:01), particularly in homozygosity (P-val = 0.0001). However, the high incidence of the haplotype among healthy dogs indicated that additional genetic risk factors are likely involved in disease progression. We conducted genome-wide association studies in two modern breeds having common …

The Β-Isoform Of Bccip Promotes Adp Release From The Rad51 Presynaptic Filament And Enhances Homologous Dna Pairing, Andrew A. Kelso, Steven D. Goodson, Leah E. Watts, Leanna L. Ledford, Sarah M. Waldvogel, J. Nathaniel Diehl, Shivani B. Shah, Amanda F. Say, Julie D. White, Michael G. Sehorn

Publications

Homologous recombination (HR) is a template-driven repair pathway that mends DNA double-stranded breaks (DSBs), and thus helps to maintain genome stability. The RAD51 recombinase facilitates DNA joint formation during HR, but to accomplish this task, RAD51 must be loaded onto the single-stranded DNA. DSS1, a candidate gene for split hand/split foot syndrome, provides the ability to recognize RPA-coated ssDNA to the tumor suppressor BRCA2, which is complexed with RAD51. Together BRCA2-DSS1 displace RPA and load RAD51 onto the ssDNA. In addition, the BRCA2 interacting protein BCCIP normally colocalizes with chromatin bound BRCA2, and upon DSB induction, RAD51 colocalizes with BRCA2-BCCIP …

Ectopic Expression Of A Cyanobacterial Flavodoxin In Creeping Bentgrass Impacts Plant Development And Confers Broad Abiotic Stress Tolerance, Zhigang Li, Shuangrong Yuan, Haiyan Jia, Fangyuan Gao, Qian Hu, Dongfa Sun, Hong Luo

Publications

Flavodoxin (Fld) plays a pivotal role in photosynthetic microorganisms as an alternative electron carrier flavoprotein under adverse environmental conditions. Cyanobacterial Fld has been demonstrated to be able to substitute ferredoxin (Fd) of higher plants in most electron transfer processes under stressful conditions. We have explored the potential of Fld for use in improving plant stress response in creeping bentgrass (Agrostis stolonifera L.). Overexpression of Fld altered plant growth and development. Most significantly, transgenic (TG) plants exhibited drastically enhanced performance under oxidative, drought and heat stress as well as nitrogen (N) starvation, which was associated with higher water retention and …

Heterologous Expression Of A Rice Mir395 Gene In Nicotiana Tabacum Impairs Sulfate Homeostasis, Ning Yuan, Shuangrong Yuan, Zhigang Li, Dayong Li, Qian Hu, Hong Luo

Publications

Sulfur participates in many important mechanisms and pathways of plant development. The most common source of sulfur in soil –SO₄²⁻– is absorbed into root tissue and distributed into aerial part through vasculature system, where it is reduced into sulfite and finally sulfide within the subcellular organs such as chloroplasts and mitochondria and used for cysteine and methionine biosynthesis. MicroRNAs are involved in many regulation pathways by repressing the expression of their target genes. MiR395 family in Arabidopsis thaliana has been reported to be an important regulator involved in sulfate transport and assimilation, and a high-affinity sulphate transporter …

Heterologous Expression Of A Rice Mir395 Gene In Nicotiana Tabacum Impairs Sulfate Homeostasis, Ning Yuan, Shuangrong Yuan, Zhigang Li, Dayong Li, Hong Luo

Publications

Sulfur participates in many important mechanisms and pathways of plant development. The most common source of sulfur in soil –SO42−– is absorbed into root tissue and distributed into aerial part through vasculature system, where it is reduced into sulfite and finally sulfide within the subcellular organs such as chloroplasts and mitochondria and used for cysteine and methionine biosynthesis. MicroRNAs are involved in many regulation pathways by repressing the expression of their target genes. MiR395 family in Arabidopsis thaliana has been reported to be an important regulator involved in sulfate transport and assimilation, and a high-affinity sulphate transporter and three ATP …

Gene Discovery And Differential Expression Analysis Of Humoral Immune Response Elements In Female Culicoides Sonorensis (Diptera: Ceratopogonidae), Naya Nayduch, Matthew B. Lee, Christopher Saski

Publications

Female Culicoides sonorensis midges (Diptera: Ceratopogonidae) are vectors of pathogens that impact livestock and wildlife in the United States. Little is known about their biology on a molecular-genetic level, including components of their immune system. Because the insect immune response is involved with important processes such as gut microbial homeostasis and vector competence, our aims were to identify components of the midge innate immune system and examine their expression profiles in response to diet across time.

The Reference Transcriptome Of The Adult Female Biting Midge (Culicoides Sonorensis) And Differential Gene Expression Profiling During Teneral, Blood, And Sucrose Feeding Conditions, Dana Nayduch, Matthew B. Lee, Christopher Saski

Publications

Unlike other important vectors such as mosquitoes and sandflies, genetic and genomic tools for Culicoides biting midges are lacking, despite the fact that they vector a large number of arboviruses and other pathogens impacting humans and domestic animals world-wide. In North America, female Culicoides sonorensis midges are important vectors of bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV), orbiviruses that cause significant disease in livestock and wildlife. Libraries of tissue-specific transcripts expressed in response to feeding and oral orbivirus challenge in C. sonorensis have previously been reported, but extensive genome-wide expression profiling in the midge has not. Here, we …

Probing The Effects Of Tbhk2 On Trypanosoma Brucei Growth, Social Growth, And Inhibitor Response, Amber Hackler, William Mcalpine, Yijian Qiu, James Morris

Graduate Research and Discovery Symposium (GRADS)

In sub-Saharan Africa the protozoan parasite, Trypanosoma brucei, continues to be of major concern for the health and economic development of the region. This parasite is known to cause human African trypanosomiasis (HAT or African sleeping sickness) and nagana in livestock such as cattle. Social behaviors, such as colonization and migration, are important in the study of T. brucei because of the way the parasite infects its mammalian host. During the fly bloodmeal, the parasite first passes into the gut but then eventually migrates to the fly salivary glands where it will continue to develop before transmission as a parasitic …

The Genome Sequence Of The Most Widely Cultivated Cacao Type And Its Use To Identify Candidate Genes Regulating Pod Color, Juan C. Motamayor, Keithanne Mockaitis, Jeremy Schmutz, Niina Haiminen, Donald Livingstone Iii, Omar Cornejo, Seth Findley, Ping Zheng, Filippo Utro, Stefan Royaert, Christopher Saski

Publications

Background

Theobroma cacao L. cultivar Matina 1-6 belongs to the most cultivated cacao type. The availability of its genome sequence and methods for identifying genes responsible for important cacao traits will aid cacao researchers and breeders.

Results

We describe the sequencing and assembly of the genome of Theobroma cacao L. cultivar Matina

1-6. The genome of the Matina 1-6 cultivar is 445 Mbp, which is significantly larger than a sequenced Criollo cultivar, and more typical of other cultivars. The chromosome-scale assembly, version 1.1, contains 711 scaffolds covering 346.0 Mbp, with a contig N50 of 84.4 kbp, a scaffold N50 of …

Choline Supplementation And Dna Methylation In The Hippocampus And Prefrontal Cortex Of Rats Exposed To Alcohol During Development, Nicha K H Otero, Jennifer D. Thomas, Christopher Saski, Xiaoxia Xia, Sandra Kelly

Publications

BACKGROUND:

Some of the most frequent deficits seen in children with fetal alcohol spectrum disorders (FASD) and in animal models of FASD are spatial memory impairments and impaired executive functioning, which are likely related to alcohol-induced alterations of the hippocampus and prefrontal cortex (PFC), respectively. Choline, a nutrient supplement, has been shown in a rat model to ameliorate some of alcohol's teratogenic effects, and this effect may be mediated through choline's effects on DNA methylation.

METHODS:

Alcohol was given by intragastric intubation to rat pups during the neonatal period (postnatal days 2 to 10) (ET group), which is equivalent to …

Enhancing Genome Investigations In The Mosquito Culex Quinquefasciatus Via Bac Library Construction And Characterization, Paul V. Hickner, Becky Debruyn, Diane D. Lovin, Akio Mori, Christopher Saski, David W. Severson

Publications

Background

Culex quinquefasciatus (Say) is a major species in the Culex pipiens complex and an important vector for several human pathogens including West Nile virus and parasitic filarial nematodes causing lymphatic filariasis. It is common throughout tropical and subtropical regions and is among the most geographically widespread mosquito species. Although the complete genome sequence is now available, additional genomic tools are needed to improve the sequence assembly.

Findings

We constructed a bacterial artificial chromosome (BAC) library using the pIndigoBAC536 vector and HindIII partially digested DNA isolated from Cx. quinquefasciatus pupae, Johannesburg strain (NDJ). Insert size was estimated by Not …

A Genetically Anchored Physical Framework For Theobroma Cacao Cv. Matina 1-6, Christopher Saski, Frank Feltus, Margaret Staton, Barbara Blackmon, Stephen Ficklin, David Kuhn, Raymond Schnell, Howard Shapiro, Juan Carlos Motamayor

Publications

The fermented dried seeds of Theobroma cacao (cacao tree) are the main ingredient in chocolate. World cocoa production was estimated to be 3 million tons in 2010 with an annual estimated average growth rate of 2.2%. The cacao bean production industry is currently under threat from a rise in fungal diseases including black pod, frosty pod, and witches' broom. In order to address these issues, genome-sequencing efforts have been initiated recently to facilitate identification of genetic markers and genes that could be utilized to accelerate the release of robust T. cacao cultivars. However, problems inherent with assembly and resolution of …

Sequencing Of A Qtl-Rich Region Of The Theobroma Cacao Genome Using Pooled Bacs And The Identification Of Trait Specific Candidate Genes, Frank A. Feltus, Christopher Saski, Keithanne Mockaitis, Niina Haiminen, Laxmi Parida, Zachary Smith, James Ford, Margaret E. Staton, Stephen P. Ficklin, Barbara P. Blackmon, Chun-Huai Cheng, Raymond J. Schnell, David N. Kuhn, Juan-Carlos Motamayor

Publications

BAC-based physical maps provide for sequencing across an entire genome or a selected sub-genomic region of biological interest. Such a region can be approached with next-generation whole-genome sequencing and assembly as if it were an independent small genome. Using the minimum tiling path as a guide, specific BAC clones representing the prioritized genomic interval are selected, pooled, and used to prepare a sequencing library.

New Genomic Resources For Switchgrass: A Bac Library And Comparative Analysis Of Homoeologous Genomic Regions Harboring Bioenergy Traits, Christopher Saski, Zhigang Li, Frank A. Feltus, Hong Luo

Publications

Switchgrass, a C4 species and a warm-season grass native to the prairies of North America, has been targeted for development into an herbaceous biomass fuel crop. Genetic improvement of switchgrass feedstock traits through marker-assisted breeding and biotechnology approaches calls for genomic tools development. Establishment of integrated physical and genetic maps for switchgrass will accelerate mapping of value added traits useful to breeding programs and to isolate important target genes using map based cloning. The reported polyploidy series in switchgrass ranges from diploid (2X = 18) to duodecaploid (12X = 108). Like in other large, repeat-rich plant genomes, this genomic complexity …

Construction Of Papaya Male And Female Bac Libraries And Application In Physical Mapping Of The Sex Chromosomes, Andrea R. Gschwend, Qingyi Yu, Paul Moore, Christopher Saski, Cuixia Chen, Jianping Wang, Jong-Kuk Na, Ray Ming

Publications

Papaya is a major fruit crop in the tropics and has recently evolved sex chromosomes. Towards sequencing the papaya sex chromosomes, two bacterial artificial chromosome (BAC) libraries were constructed from papaya male and female genomic DNA. The female BAC library was constructed using restriction enzyme BstY I and consists of 36,864 clones with an average insert size of 104 kb, providing 10.3x genome equivalents. The male BAC library was constructed using restriction enzyme EcoR I and consists of 55,296 clones with an average insert size of 101 kb, providing 15.0x genome equivalents. The male BAC library was used in constructing …

Adventures In The Enormous: A 1.8 Million Clone Bac Library For The 21.7 Gb Genome Of Loblolly Pine, Zenaida Magbanua, Seval Ozkan, Benjamin Bartlett, Philippe Chouvarine, Christopher Saski, Aaron Siston, Richard Cronn, C Dana Nelson, Daniel Peterson

Publications

Loblolly pine (LP; Pinus taeda L.) is the most economically important tree in the U.S. and a cornerstone species in southeastern forests. However, genomics research on LP and other conifers has lagged behind studies on flowering plants due, in part, to the large size of conifer genomes. As a means to accelerate conifer genome research, we constructed a BAC library for the LP genotype 7-56. The LP BAC library consists of 1,824,768 individually-archived clones making it the largest single BAC library constructed to date, has a mean insert size of 96 kb, and affords 7.6X coverage of the 21.7 Gb …

Genomic Tools Development For Aquilegia: Construction Of A Bac-Based Physical Map, Guang-Chen Fang, Barbara P. Blackmon, David C. Henry, Margaret E. Staton, Christopher Saski, Scott A. Hodges, Jeff P. Tomkins, Hong Luo

Publications

The genus Aquilegia, consisting of approximately 70 taxa, is a member of the basal eudicot lineage, Ranuculales, which is evolutionarily intermediate between monocots and core eudicots, and represents a relatively unstudied clade in the angiosperm phylogenetic tree that bridges the gap between these two major plant groups. Aquilegia species are closely related and their distribution covers highly diverse habitats. These provide rich resources to better understand the genetic basis of adaptation to different pollinators and habitats that in turn leads to rapid speciation. To gain insights into the genome structure and facilitate gene identification, comparative genomics and whole-genome shotgun …

Complete Plastid Genome Sequences Of Three Rosids (Castanea, Prunus, Theobroma): Evidence For At Least Two Independent Transfers Of Rpl22 To The Nucleus, Robert K. Jansen, Christopher Saski, Seung-Bum Lee, Anne K. Hansen, Henry Daniell

Publications

Functional gene transfer from the plastid to the nucleus is rare among land plants despite evidence that DNA transfer to the nucleus is relatively frequent. During the course of sequencing plastid genomes from representative species from three rosid genera (Castanea, Prunus, Theobroma) and ongoing projects focusing on the Fagaceae and Passifloraceae, we identified putative losses of rpl22 in these two angiosperm families. We further characterized rpl22 from three species of Passiflora and one species of Quercus and identified sequences that likely represent pseudogenes. In Castanea and Quercus, both members of the Fagaceae, we identified a …

Complete Chloroplast Genome Sequences Of Hordeum Vulgare, Sorghum Bicolor And Agrostis Stolonifera, And Comparative Analyses With Other Grass Genomes, Susanna Ashton, Seung-Bum Lee, Siri Fjellheim, Chittibabu Guda, Robert K. Jansen, Hong Luo, Jeffrey Tomkins, Odd Arne Rognli, Henry Daniell, Jihong Liu Clarke

Publications

Comparisons of complete chloroplast genome sequences of Hordeum vulgare, Sorghum bicolor and Agrostis stolonifera to six published grass chloroplast genomes reveal that gene content and order are similar but two microstructural changes have occurred. First, the expansion of the IR at the SSC/IRa boundary that duplicates a portion of the 5′ end of ndhH is restricted to the three genera of the subfamily Pooideae (Agrostis, Hordeum and Triticum). Second, a 6 bp deletion in ndhK is shared by Agrostis, Hordeum, Oryza and Triticum, and this event supports the sister relationship between the subfamilies …

Involvement Of Coenzyme M During Aerobic Biodegradation Of Vinyl Chloride And Ethene By Pseudomonas Putida Strain Aj And Ochrobactrum Sp. Strain Td†, Anthony S. Danko, Christopher Saski, Jeffrey P. Tomkins, David L. Freeman

Publications

The involvement of coenzyme M in aerobic biodegradation of vinyl chloride and ethene in Pseudomonas putida strain AJ and Ochrobactrum sp. strain TD was demonstrated using PCR, hybridization, and enzyme assays. The results of this study extend the range of eubacteria known to use epoxyalkane:coenzyme M transferase.

Phylogenetic Analyses Of Vitis (Vitaceae) Based On Complete Chloroplast Genome Sequences: Effects Of Taxon Sampling And Phylogenetic Methods On Resolving Relationships Among Rosids, Robert K. Jansen, Charalambos Kaittanis, Christopher Saski, Seung-Bum Lee, Jeffrey Tomkins, Andrew Alverson, Henry Daniell

Publications

The Vitaceae (grape) is an economically important family of angiosperms whose phylogenetic placement is currently unresolved. Recent phylogenetic analyses based on one to several genes have suggested several alternative placements of this family, including sister to Caryophyllales, asterids, Saxifragales, Dilleniaceae or to rest of rosids, though support for these different results has been weak. There has been a recent interest in using complete chloroplast genome sequences for resolving phylogenetic relationships among angiosperms. These studies have clarified relationships among several major lineages but they have also emphasized the importance of taxon sampling and the effects of different phylogenetic methods for obtaining …