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You searched for +publisher:"Cornell University" +contributor:("Cilia, Michelle"). Showing records 1 – 3 of 3 total matches.

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1. Pinheiro, Patricia Valle. EVOLUTIONARY AND MECHANISTIC INTERACTIONS IN VIRUS TRANSMISSION BY APHIDS.

Degree: PhD, Entomology, 2017, Cornell University

Virus transmission by aphids involves a combination of biological players that have co-evolved over years of interaction: plant hosts, aphid vectors, plant viruses and the aphid’s bacterial endosymbiont. In this interaction, plant hosts activate their immune defenses against plant viruses and aphids and the latter two use a myriad of strategies to overcome, counteract or skip the host plant defense, which sometimes is done in collaboration. Bacterial endosymbionts of insect vectors might also play a role in virus transmission, either directly or indirectly, as I discussed in a critical literature review. I used proteomics and aphid genetics to show that the “biotype” phenotype of aphids is generated by genetic recombination in sexual reproduction and that aphid virulence and virus transmission are independent traits. I also showed that the host plant where aphids are reared on affects the aphid ability to transmit a circulative virus, the Luteovirid Potato leafroll virus (PLRV). Using organismal, biochemical, molecular, and imaging approaches, I show that the differential expression and activity of gut cysteine proteases at the cell membrane of aphids reared on a PLRV non-host plant is responsible for the change in virus transmission phenotype. Finally, using small RNA sequencing, I showed that aphids do not activate their small interference RNA (siRNA) antiviral defense against PLRV, which provides additional evidence for the lack of replication of Luteovirids in their aphid vectors. However, aphids produce 22 nt long siRNA as an immune defense against an aphid virus, Myzus persicae Densovirus (MpDNV), which infects and replicates in the aphid. Strikingly, an abundance of unusually large sRNA, from 33 to 38 nt that aligned to MpDNV were produced only in aphids fed on PLRV-infected plants, suggesting that feeding on a plant infected with a circulative virus modulates the aphid antiviral immune defenses. The function of these large sRNAs is not yet known. Advisors/Committee Members: Cilia, Michelle (chair), Fei, Zhangjun (committee member), Reeve, Hudson Kern (committee member), Gray, Stewart (committee member), Blissard, Gary (committee member).

Subjects/Keywords: Hemipteran; Insect immunology; Insect-plant interaction; Mutualism; Plant virus; Vector biology; Plant pathology; Biochemistry; Entomology

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Pinheiro, P. V. (2017). EVOLUTIONARY AND MECHANISTIC INTERACTIONS IN VIRUS TRANSMISSION BY APHIDS. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/47727

Chicago Manual of Style (16th Edition):

Pinheiro, Patricia Valle. “EVOLUTIONARY AND MECHANISTIC INTERACTIONS IN VIRUS TRANSMISSION BY APHIDS.” 2017. Doctoral Dissertation, Cornell University. Accessed November 28, 2020. http://hdl.handle.net/1813/47727.

MLA Handbook (7th Edition):

Pinheiro, Patricia Valle. “EVOLUTIONARY AND MECHANISTIC INTERACTIONS IN VIRUS TRANSMISSION BY APHIDS.” 2017. Web. 28 Nov 2020.

Vancouver:

Pinheiro PV. EVOLUTIONARY AND MECHANISTIC INTERACTIONS IN VIRUS TRANSMISSION BY APHIDS. [Internet] [Doctoral dissertation]. Cornell University; 2017. [cited 2020 Nov 28]. Available from: http://hdl.handle.net/1813/47727.

Council of Science Editors:

Pinheiro PV. EVOLUTIONARY AND MECHANISTIC INTERACTIONS IN VIRUS TRANSMISSION BY APHIDS. [Doctoral Dissertation]. Cornell University; 2017. Available from: http://hdl.handle.net/1813/47727


Cornell University

2. da Silva, Washington. USING HIGH-THROUGHPUT TECHNOLOGIES TO ADVANCE OUR UNDERSTANDING ON POTATO VIRUS Y INFECTIONS.

Degree: PhD, Plant Pathology and Plant-Microbe Biology, 2018, Cornell University

Potato virus Y (PVY) is a major virus pathogen of potato worldwide. Surveys indicate that re-combinant strains of PVY have emerged in recent years to predominate in the U.S. potato crop and that the genetic diversity among and within PVY strains is prodigious. Vegetative propaga-tion of potato via tubers allows PVY to survive year to year and to be transported over long dis-tances. Whereas, aphids are primarily responsible for spread of PVY within the crop and over regional distances. Furthermore, the tuber necrotic strain (PVYNTN) is associated with potato tuber necrotic ringspot disease (PTNRD), a tuber deformity that negatively impacts tuber quali-ty, marketability, and poses a serious threat to seed and commercial potato production world-wide. To map loci that influence tuber and foliar symptoms in potatoes infected with PVYNTN and the length of tuber dormancy, two potato populations were genotyped with a potato SNP chip. QTL analyses revealed major-effect QTLs in a Waneta x Pike cross for mosaic on chromosomes 4 and 5, and for PTNRD and for foliar-necrosis symptoms on chromosomes 4 and 5, respective-ly. QTLs for dormancy were detected on chromosomes 2, 3, 5, 6, and 8, in a Waneta x Superior cross. Locating QTLs associated with PVY-related symptoms and tuber dormancy provides a framework for breeders to develop varieties with resistance to multiple PVY-symptoms and to manipulate tuber dormancy length. Illumina high-throughput sequencing was used to study the quasispecies diversity of 15 isolates representing seven different PVY strains and to investigate how transmission modes (insect and mechanical) are contributing to the evolution and diversification of PVY. Eight were PVYN isolates and six of those came from the same geographic region in two different years. A con-sensus sequence, without indels or insertions, was successfully extracted from the sequenced reads of each isolate after being mapped to the strain reference genome. PVYN had a higher population genetic diversity than any other strain evaluated and the population genetic diversi-ty of the PVYN isolates, differed between collection years and sites. We found that the popula-tion diversity of PVY varies by the virus strain but doesn’t differ among transmission modes. Our data suggest that each transmission mode exerts unique selection pressures on the virus population and allows different mutations to accumulate and become fixed. Knowledge of how rapidly PVY can evolve and of the factors driving PVY quasispecies diversity could be used to enhance the efficiency of PVY management practices in potato fields. Advisors/Committee Members: Gray, Stewart (chair), De Jong, Walter S. (committee member), Cilia, Michelle (committee member), Fei, Zhangjun (committee member).

Subjects/Keywords: HIGH-THROUGHPUT TECHNOLOGIES; Potato; PVY; Plant pathology; Molecular biology; Plant Breeding; Bioinformatics; Virology

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

da Silva, W. (2018). USING HIGH-THROUGHPUT TECHNOLOGIES TO ADVANCE OUR UNDERSTANDING ON POTATO VIRUS Y INFECTIONS. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/59364

Chicago Manual of Style (16th Edition):

da Silva, Washington. “USING HIGH-THROUGHPUT TECHNOLOGIES TO ADVANCE OUR UNDERSTANDING ON POTATO VIRUS Y INFECTIONS.” 2018. Doctoral Dissertation, Cornell University. Accessed November 28, 2020. http://hdl.handle.net/1813/59364.

MLA Handbook (7th Edition):

da Silva, Washington. “USING HIGH-THROUGHPUT TECHNOLOGIES TO ADVANCE OUR UNDERSTANDING ON POTATO VIRUS Y INFECTIONS.” 2018. Web. 28 Nov 2020.

Vancouver:

da Silva W. USING HIGH-THROUGHPUT TECHNOLOGIES TO ADVANCE OUR UNDERSTANDING ON POTATO VIRUS Y INFECTIONS. [Internet] [Doctoral dissertation]. Cornell University; 2018. [cited 2020 Nov 28]. Available from: http://hdl.handle.net/1813/59364.

Council of Science Editors:

da Silva W. USING HIGH-THROUGHPUT TECHNOLOGIES TO ADVANCE OUR UNDERSTANDING ON POTATO VIRUS Y INFECTIONS. [Doctoral Dissertation]. Cornell University; 2018. Available from: http://hdl.handle.net/1813/59364


Cornell University

3. Rowland, Elden Ernest. PROTEOLYTIC MATURATION AND PROTEIN DEGRADATION IN ARABIDOPSIS THALIANA CHLOROPLASTS.

Degree: PhD, Plant Biology, 2017, Cornell University

Proteolysis is crucial for the maturation, regulation and recycling of the chloroplast proteome. Although several dozen chloroplast proteases are known, information concerning their substrates and functions is limited. In particular, little is known about the structural features of substrates that trigger their proteolysis. Most chloroplast proteins are nuclear encoded and are targeted through an N-terminal chloroplast transit peptide (cTP) that is removed by stromal processing peptidase (SPP). To better understand proteolytic maturation, the soluble N-terminal proteome of the Arabidopsis thaliana chloroplast was characterized. A cTP cleavage motif was observed that suggests other peptidases, in addition to SPP, are involved in chloroplast protein maturation. There was a clear preference for small uncharged amino acids at the processed protein N-terminus suggesting the existence of a chloroplast specific ‘N-end rule’. The soluble chloroplast peptidases PREP and OOP have been shown to degrade small polypeptides in vitro and are thought to be responsible for removal of cTP fragments and other degradation products. The CLP protease system can degrade intact protein substrates with the aid of ATP dependent (AAA+) CLPC chaperones that unfold and feed substrates into the CLP proteolytic core. An array of proteomic tools were used to compare Arabidopsis mutants deficient in the above peptidases with wild type. Degradation products, including cTPs, were found to accumulate in peptidase mutants indicative, of rate-limited or blocked degradation pathways. Incomplete or altered N-terminal maturation for chloroplast proteins was dependent on the type and severity of the peptidase deficiency. These results provide molecular details to help explain dwarf, chlorotic mutant phenotypes and demonstrate the interplay between protein import, proteolytic processing and the downstream degradation of damaged or unwanted proteins in the chloroplast. Substrate and sequence cleavage specificity was determined for soluble chloroplast glutamyl-endopeptidase (CGEP) and the plastoglobule localized metallopeptidase PGM48. Structural models were used to predict peptidase substrate binding mechanisms. Advisors/Committee Members: Van Wijk, Klaas (chair), Hanson, Maureen R. (committee member), Owens, Thomas G. (committee member), Cilia, Michelle (committee member).

Subjects/Keywords: Plant sciences; Biochemistry; Arabidopsis; chloroplast; N-terminal proteome; protease; proteolytic degradation; proteolytic maturation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Rowland, E. E. (2017). PROTEOLYTIC MATURATION AND PROTEIN DEGRADATION IN ARABIDOPSIS THALIANA CHLOROPLASTS. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/58987

Chicago Manual of Style (16th Edition):

Rowland, Elden Ernest. “PROTEOLYTIC MATURATION AND PROTEIN DEGRADATION IN ARABIDOPSIS THALIANA CHLOROPLASTS.” 2017. Doctoral Dissertation, Cornell University. Accessed November 28, 2020. http://hdl.handle.net/1813/58987.

MLA Handbook (7th Edition):

Rowland, Elden Ernest. “PROTEOLYTIC MATURATION AND PROTEIN DEGRADATION IN ARABIDOPSIS THALIANA CHLOROPLASTS.” 2017. Web. 28 Nov 2020.

Vancouver:

Rowland EE. PROTEOLYTIC MATURATION AND PROTEIN DEGRADATION IN ARABIDOPSIS THALIANA CHLOROPLASTS. [Internet] [Doctoral dissertation]. Cornell University; 2017. [cited 2020 Nov 28]. Available from: http://hdl.handle.net/1813/58987.

Council of Science Editors:

Rowland EE. PROTEOLYTIC MATURATION AND PROTEIN DEGRADATION IN ARABIDOPSIS THALIANA CHLOROPLASTS. [Doctoral Dissertation]. Cornell University; 2017. Available from: http://hdl.handle.net/1813/58987

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