Identification, Evolution and Expression of Three Olfactory Gene Families in Atlantic Salmon (Salmo Salar)

Identification, Evolution and Expression of Three Olfactory Gene Families in Atlantic Salmon (Salmo Salar)
Author: Kimberley Anne Johnstone
Publisher:
Total Pages: 0
Release: 2011
Genre: Atlantic salmon
ISBN:

It has been hypothesized that salmonids use olfactory cues to return to their natal rivers and streams. However, the key components of the molecular pathway involved in imprinting and homing are still unknown. If odorants are involved in salmon homing migration then olfactory receptors should play a critical role in the dissipation of information from the environment to the fish. To understand the molecular basis for imprinting and homing in Atlantic salmon (Salmo salar), it is important to identify and characterize the olfactory receptors in the Atlantic salmon genome. Aquatic chemical cues are received through the salmon nares and into the nasal cavity that contains a single olfactory organ, olfactory rosette. The olfactory rosette contains sensory neurons, which are thought to express only one olfactory receptor. In this study, three major superfamilies of fish olfactory receptors (MOR, ora and OlfC) were examined. To identify the olfactory genes in Atlantic salmon several genomic and bioinformatic techniques were used. First, an Atlantic salmon bacterial artificial chromosome (BAC) library was screened with probes designed from previously identified fish olfactory receptor sequences. Then a selected number of hybridization positive BACs containing olfactory receptors were shotgun cloned and sequenced. From these BAC sequences, two ora genes and 55 OlfC genes were identified in Atlantic salmon. The second technique used to identify olfactory receptors in Atlantic salmon was a bioinformatic approach that involved screening a 3-fold Atlantic salmon genome sequence for olfactory receptors. Using this approach, 24 MOR and the remaining five ora genes were identified, as well as another 24 partial genes or pseudogenes. As a first step to understand how olfactory receptors are involved in imprinting and homing, a suite of olfactory receptors were selected to examine the expression profiles of these genes across different life stages and life histories of wild Atlantic salmon from Newfoundland, Canada. Seven differentially expressed OlfC genes were identified in juvenile anadromous salmon compared to returning adult salmon. From this research, I hypothesize that OlfC genes may play an important role in the imprinting of home stream water olfactory cues in anadromous Atlantic salmon.

Identification, Evolution, and Expression of the Trace Amine-Associated Receptor (TAAR) Gene Family in Atlantic Salmon (Salmo Salar)

Identification, Evolution, and Expression of the Trace Amine-Associated Receptor (TAAR) Gene Family in Atlantic Salmon (Salmo Salar)
Author: Jordan Anthony Tessarolo
Publisher:
Total Pages: 95
Release: 2014
Genre:
ISBN:

It is widely hypothesized that Atlantic salmon are imprinted at a young age with olfactory cues, which they use as a guide in order to return to their natal streams to spawn. However, the molecular mechanism(s) behind this biological phenomenon remain unknown. Therefore, in order to better understand imprinting and homing in Atlantic salmon, it is important to characterize the repertoire of olfactory receptors in thisspecies. A search of the first assembly of the Atlantic salmon genome revealed 27 putatively functional trace amine-associated receptor (TAAR) genes and 25 putative TAAR pseudo-genes. Genetic mapping, phylogenetic analysis, binding-site prediction, and quantitative PCR were performed using the Atlantic salmon TAAR genes. The identification of this gene family in Atlantic salmon will facilitate additional studiesinvolving olfaction and homing such as determining the range of allelic variation in olfactory receptors genes of different salmon populations.

Identification and Annotation of Full-length Genes in Atlantic Salmon (Salmo Salar)

Identification and Annotation of Full-length Genes in Atlantic Salmon (Salmo Salar)
Author: Jong S. Leong
Publisher:
Total Pages: 0
Release: 2010
Genre: Atlantic salmon
ISBN:

Large-scale expressed sequence tags (ESTs) in Atlantic salmon (Salmo salar) are examined to answer questions regarding salmonid transcriptomes. ESTs represent raw and incomplete gene sequences that need to be read, assembled and analyzed with computer software. The goal of this thesis was to develop an automatically curated and publicly accessible set of annotated full-length genes, representing a near-complete transcript set for Salmo salar. In turn, these genes provide the framework for studies in gene expression, conservation, and molecular evolution. The work presented here also touches on the results of a molecular evolution study, as an example of how full-length gene identification can be used to answer biological questions. Previous to this study, a limited number of Atlantic salmon cDNA libraries and ESTs were known. To further the goal of determining complete gene sequences, highly enriched full-length cDNA libraries and full-length libraries were created and sequenced, resulting in the ability to identify a large number of full-length reference genes. Together, all libraries represent a diverse pool of transcriptome sequences for Salmo salar. The goal of producing an accurate large-scale full-length gene set on a duplicated genome is not trivial. Complete systems for this objective do not readily exist. EST sequencing, EST assembly, and data storage, are just a few of the initial computational issues that are addressed. Once these issues are resolved, the multi-step workflow of full-length gene determination is described. The final challenge involving the development of a concise and universally accessible system for visualization is discussed. The resulting computational framework that has been developed is shown to be able to handle the intricacies and the size of a duplicated salmonid genome. It has been largely accepted that Atlantic salmon have undergone a recent genome duplication. Gene paralogs provide one source of evidence for this event. Analysis of paralogs revealed signatures of asymmetric evolution possibly due to relaxation of selective pressure. This thesis provides a complete Bioinformatics analysis pipeline to analyze and to visualize a set of full-length reference genes for Atlantic salmon. Using full-length genes as a framework, the topic of molecular evolution was addressed to show evidence of asymmetrical evolution among gene duplicates. The full-length reference genes, along with ESTs and all putative transcripts, have been made publicly available. These results serve as a valuable genomic resource for next-generation sequencing and for all other salmonid research endeavours.

Identification and Annotation of Full-length Genes in Atlantic Salmon (Salmo Salar)

Identification and Annotation of Full-length Genes in Atlantic Salmon (Salmo Salar)
Author: Jong S. Leong
Publisher:
Total Pages: 248
Release: 2010
Genre: Atlantic salmon
ISBN:

Large-scale expressed sequence tags (ESTs) in Atlantic salmon (Salmo salar) are examined to answer questions regarding salmonid transcriptomes. ESTs represent raw and incomplete gene sequences that need to be read, assembled and analyzed with computer software. The goal of this thesis was to develop an automatically curated and publicly accessible set of annotated full-length genes, representing a near-complete transcript set for Salmo salar. In turn, these genes provide the framework for studies in gene expression, conservation, and molecular evolution. The work presented here also touches on the results of a molecular evolution study, as an example of how full-length gene identification can be used to answer biological questions. Previous to this study, a limited number of Atlantic salmon cDNA libraries and ESTs were known. To further the goal of determining complete gene sequences, highly enriched full-length cDNA libraries and full-length libraries were created and sequenced, resulting in the ability to identify a large number of full-length reference genes. Together, all libraries represent a diverse pool of transcriptome sequences for Salmo salar. The goal of producing an accurate large-scale full-length gene set on a duplicated genome is not trivial. Complete systems for this objective do not readily exist. EST sequencing, EST assembly, and data storage, are just a few of the initial computational issues that are addressed. Once these issues are resolved, the multi-step workflow of full-length gene determination is described. The final challenge involving the development of a concise and universally accessible system for visualization is discussed. The resulting computational framework that has been developed is shown to be able to handle the intricacies and the size of a duplicated salmonid genome. It has been largely accepted that Atlantic salmon have undergone a recent genome duplication. Gene paralogs provide one source of evidence for this event. Analysis of paralogs revealed signatures of asymmetric evolution possibly due to relaxation of selective pressure. This thesis provides a complete Bioinformatics analysis pipeline to analyze and to visualize a set of full-length reference genes for Atlantic salmon. Using full-length genes as a framework, the topic of molecular evolution was addressed to show evidence of asymmetrical evolution among gene duplicates. The full-length reference genes, along with ESTs and all putative transcripts, have been made publicly available. These results serve as a valuable genomic resource for next-generation sequencing and for all other salmonid research endeavours.

Chemosensory Transduction

Chemosensory Transduction
Author: Frank Zufall
Publisher: Academic Press
Total Pages: 432
Release: 2016-02-18
Genre: Science
ISBN: 0128017864

Written by leaders in the field of chemosensation, Chemosensory Transduction provides a comprehensive resource for understanding the molecular mechanisms that allow animals to detect their chemical world. The text focuses on mammals, but also includes several chapters on chemosensory transduction mechanisms in lower vertebrates and insects. This book examines transduction mechanisms in the olfactory, taste, and somatosensory (chemesthetic) systems as well as in a variety of internal sensors that are responsible for homeostatic regulation of the body. Chapters cover such topics as social odors in mammals, vertebrate and invertebrate olfactory receptors, peptide signaling in taste and gut nutrient sensing. Includes a foreword by preeminent olfactory scientist Stuart Firestein, Chair of Columbia University’s Department of Biological Sciences in New York, NY. Chemosensory Transduction describes state-of-the-art approaches and key findings related to the study of the chemical senses. Thus, it serves as the go-to reference for this subject for practicing scientists and students with backgrounds in sensory biology and/or neurobiology. The volume will also be valuable for industry researchers engaged in the design or testing of flavors, fragrances, foods and/or pharmaceuticals. Provides a comprehensive overview for all chemosensory transduction mechanisms Valuable for academics focused on sensory biology, neurobiology, and chemosensory transduction, as well as industry researchers in new flavor, fragrance, and food testing Edited by leading experts in the field of olfactory transduction Focuses on mammals, but lower vertebrates and invertebrate model systems are also included

Olfactory subsystems in mammals: morphology, genetic and evolution

Olfactory subsystems in mammals: morphology, genetic and evolution
Author: Ignacio Salazar,
Publisher: Frontiers Media SA
Total Pages: 78
Release: 2015-06-17
Genre: Mammals
ISBN: 2889195546

The nasal cavity and the elements it comprises are lined by mucosa. This mucosa contains olfactory sensory neurons, which are organized into four different territories: main olfactory epithelium, septal organ, vomeronasal epithelium and ganglion of Grünemberg. From a morphological point of view, these territories could initially be considered as isolated olfactory subsystems, which - as a whole or independently - have been addressed in the contributions enclosed in this Topic.

Evolution and Characterization of the Fatty Acid-binding Proteins (fabps) in Atlantic Salmon (Salmo Salar)

Evolution and Characterization of the Fatty Acid-binding Proteins (fabps) in Atlantic Salmon (Salmo Salar)
Author: Yuk Yin Lai
Publisher:
Total Pages: 0
Release: 2012
Genre: Atlantic salmon
ISBN:

It is suggested that gene or genome duplication is the driving force in evolution that leads to speciation. Two models, the classical model and the duplication- degeneration-complementation (DDC) model, have been proposed on the fates of gene duplicates resulting from either a gene or a genome duplication event. The classical model suggests that one of the gene duplicates might result in loss of function (non- functionalization) or gain of a new function (neo-functionalization) depending on whether the accumulated mutations over the years are deleterious or beneficial to the organism. In the DDC model, it is proposed that each of the gene duplicates might accumulate different deleterious mutations in the regulatory region of the gene, such that these genes partition the ancestral gene function (sub-functionalization). Combinations of the phylogenetic analysis of many gene families support that salmonids have undergone two additional whole genome duplications compared to the mammals, one occurred in the common ancestors of teleosts and another happened in the common ancestor of salmonids approximately 25-120 million years ago. In this thesis, the evolution of the fatty acid-binding protein (fabp) family in fish and salmonids was examined. I have characterized eighteen unique fabp genes in Atlantic salmon. These include the seven fabp sub-families described previously in fish. Phylogenetic analyses and conservation of synteny support the two whole genome duplication events in the common ancestors of teleosts and salmonids and indicate when gene losses occurred. Genetic mapping of fabp gene duplicates to homeologous chromosomes in Atlantic salmon also support that they arose by the 4R genome duplication. I also searched for the signatures of neo-functionalization and sub-functionalization by calculating dN/dS ratios, examining the nature of amino acid substitutions and expression patterns, and suggested the fates of fabp gene duplicates in Atlantic salmon. Overall, the findings of this project provide insight into the evolutionary processes at play in salmonid genomes.

The Physiology of Fishes

The Physiology of Fishes
Author: Suzanne Currie
Publisher: CRC Press
Total Pages: 285
Release: 2020-09-07
Genre: Nature
ISBN: 1000174654

The fifth edition of The Physiology of Fishes represents a compendium of knowledge across fish physiology, collecting up-to-date research into an easy-to-access single textbook. Written by the leaders in the field, it provides a comprehensive, accessible review of the core topics, integrating physiology with environmental science, ecology, evolution, and molecular cell biology. New chapters address Epigenetics, Biomechanics and Locomotion, and Behaviour and Learning. Each chapter contains an extensive bibliography, providing readers with the best sources from the primary literature. Almost three decades after the publication of the first edition, this book remains the only published single-volume work on fish physiology. The fifth edition provides an important reference for new students of fish biology, marine and freshwater biologists, ichthyologists, fisheries scientists, and comparative physiologists.

The Fate of Duplicated Regions of the Atlantic Salmon (Salmo Salar) Genome [microform]

The Fate of Duplicated Regions of the Atlantic Salmon (Salmo Salar) Genome [microform]
Author: Leslie Mitchell
Publisher: Library and Archives Canada = Bibliothèque et Archives Canada
Total Pages: 264
Release: 2004
Genre: Atlantic salmon
ISBN: 9780494035382

Gene and genome duplications have played a major role in vertebrate evolution. Salmonids provide a useful resource for studying the consequences of these events as their common ancestor underwent a genome duplication between 25 and 120 miliion years ago. To understand how a genome reorganizes itself to cope with duplicated chromosomes and the importance of gene duplications for evolution and adaptation, homeologous regions of the Atlantic salmon genome were identified and studied within a large insert, genomic BAC library; these BACs contain the metallothionen event. A BAC from each region was subsequently shotgun subcloned and sequenced. Sequence analysis revealed the presence of 10 genes, retaining their collinearity between the BAcs, although pseudogenization events have occurred in one of the duplicate loci in two instances. Comparative genomic analysis revealed the existence of extraordinary conservation of syntney over time.