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Genetics and Genomics

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Doctoral Dissertations

Evolution

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Tetrameric Photosystem I: From Initial Discovery And Characterization In Chroococcidiopsis Sp. Ts-821 To Exploration Of Its Distribution And Understanding Of Its Significance In Cyanobacteria, Meng Li Dec 2016

Tetrameric Photosystem I: From Initial Discovery And Characterization In Chroococcidiopsis Sp. Ts-821 To Exploration Of Its Distribution And Understanding Of Its Significance In Cyanobacteria, Meng Li

Doctoral Dissertations

Photosystem I (PSI) forms trimeric complexes in most characterized cyanobacteria. We had reported the tetrameric form of PSI in the unicellular cyanobacterium, Chroococcidiopsis sp. TS-821 (TS-821). Using Cryo-EM, a 3D model of the PSI tetramer structure at 11.5 [Angstrom] resolution was obtained and a 2D map within the membrane plane of at 6.1 [Angstrom]. In contrast to the three-fold symmetry in trimeric PSI crystal structure from T. elongatus, two different inter-monomer interactions involving PsaLs are found in the PSI tetramer. Phylogenetic analysis based on PsaL protein sequences shows that TS-821 is closely related to heterocyst-forming cyanobacteria. Additionally, this tetrameric …


Computational Identification Of Terpene Synthase Genes And Their Evolutionary Analysis, Qidong Jia May 2016

Computational Identification Of Terpene Synthase Genes And Their Evolutionary Analysis, Qidong Jia

Doctoral Dissertations

Terpenoids, the largest and most structurally and functionally diverse class of natural compounds on earth, are mostly synthesized by plants to be involved in various plant environment interactions. Some terpenoids are classified as primary metabolites essential for plant growth and development. Terpene synthases (TPSs), the key enzymes for terpenoid biosynthesis, are the major determinant of the tremendous diversity of terpenoid carbon skeletons. The TPS genes represent a mid-size family of about 30-100 functional genes in almost all major sequenced plant genomes. TPSs are also found in fungi and bacteria, but microbial TPS genes share low levels of sequence similarity and …


Functional Analysis Of Corazonin And Its Receptor In Drosophila Melanogaster, Kai Sha Aug 2013

Functional Analysis Of Corazonin And Its Receptor In Drosophila Melanogaster, Kai Sha

Doctoral Dissertations

Corazonin (Crz) is an amidated undecapeptide originally isolated from the American cockroach. It has been shown to affect diverse physiological functions in a species-specific manner. However, the functionality of Crz in Drosophila melanogaster has not yet been determined. To gain insight into the role of Crz signaling in vivo, Crz and CrzR null alleles were obtained by transposable element mobilization. Flies carrying a deficiency uncovering Crz and pr-set7 loci were generated via P-element excision, and the latter was rescued by wild-type pr-set7 transgene. A mutation of Crz receptor (CrzR) was generated by Minos-element mobilization from …