A Bioinformatic Analysis Of The Biosynthesis Of Carotenoids In The Copepod Tigriopus Californicus, Anchalya Balasubramaniam

Theses and Dissertations (Comprehensive)

Abstract

Biological pigments, also called biochromes, are coloured compounds which are displayed by a variety of life forms, including animals, due to selective colour absorption. The combination of light absorption and reflection enables each pigment to portray a distinct colour which results in the broad spectrum of colours we observe in our surroundings. Carotenoids are a large group of yellow, orange, and red biological pigments found in living organisms. Our current biomolecular knowledge of carotenoids is heavily derived from studying the pathway in photosynthetic prokaryotes, bacteria, fungi, and plants. Carotenoid pigments are exceptionally multifunctional as they act as photo-protectors against …

Composition And Homology In The Taxonomic Classification Of Escherichia Coli, Tanya Irani

Theses and Dissertations (Comprehensive)

As new techniques have been introduced, specifically the possibility of complete genome sequencing, better methods of defining bacterial species have also been proposed. One of the most recently proposed methods, using bioinformatic techniques, is to calculate the average nucleotide identity (ANI) between the homologous genome segments of different isolates. Another method for species discrimination that has been tested successfully is the similarity of DNA compositional signatures. However, in a recent update, DNA signatures split the available Escherichia coli complete genomes into three groups. To check if this result was consistent with such genomes belonging to different species, we tested methods …

Sparse Forward-Backward Alignment For Sensitive Database Search With Small Memory And Time Requirements, David H. Rich

Graduate Student Theses, Dissertations, & Professional Papers

Sequence annotation is typically performed by aligning an unlabeled sequence to a collection of known sequences, with the aim of identifying non-random similarities. Given the broad diversity of new sequences and the considerable scale of modern sequence databases, there is significant tension between the competing needs for sensitivity and speed, with multiple tools displacing the venerable BLAST software suite on one axis or another. In recent years, alignment based on profile hidden Markov models (pHMMs) and associated probabilistic inference methods have demonstrated increased sensitivity due in part to consideration of the ensemble of all possible alignments between a query and …

Polya: A Tool For Adjudicating Competing Annotations Of Biological Sequences, Kaitlin Carey

Graduate Student Theses, Dissertations, & Professional Papers

Annotation of a biological sequence is usually performed by aligning that sequence to a database of known sequence elements. When that database contains elements that are highly similar to each other, the proper annotation may be ambiguous, because several entries in the database produce high-scoring alignments. Typical annotation methods work by assigning a label based on the candidate annotation with the highest alignment score; this can overstate annotation certainty, mislabel boundaries, and fails to identify large scale rearrangements or insertions within the annotated sequence. Here, I present a new software tool, PolyA, that adjudicates between competing alignment-based annotations by computing …