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Evolutionary Genetics Of Canyon Treefrogs (Hyla Arenicolor), Roy A. Murray
Evolutionary Genetics Of Canyon Treefrogs (Hyla Arenicolor), Roy A. Murray
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Population genetics is the study of the mechanisms that cause genetic change in populations over time. Genetic changes may lead to both adaptive evolution and speciation. While the former process is fairly well understood, many questions remain unanswered with regard to the process of speciation. How important is population isolation in the process of speciation? How long must populations be isolated before speciation is complete? Are the genetic changes that take place during speciation caused mainly by natural selection or does genetic drift play a substantial role? Can genetic drift alone lead to reproductive isolation? These types of questions have …
Homology Among The Autosomal Chromosomes Of Boophilus Annulatus (Say) And B. Microplus (Canestrini), Bonnie S. Gunn
Homology Among The Autosomal Chromosomes Of Boophilus Annulatus (Say) And B. Microplus (Canestrini), Bonnie S. Gunn
Theses and Dissertations - UTB/UTPA
Autosomes of Boophilus annulatus and B. microplus were compared using C- and G-bands to establish the degree of homology. Karyotypes of both species consisted of 20 autosomes and an XX:XO sex determination system with the X being the largest chromosome. All chromosomes of B. annulatus were acrocentric with heterochromatin limited to centromeric regions. The B. microplus karyotype was acrocentric with one band of noncentromeric heterochromatin occurring in three chromosome pairs. Interspecific comparisons indicated seven pairs of G-band homologous autosomes and three G-band homologous pairs when added interstitial heterochromatin was considered. The number three chromosome of both species showed variation in …
Production Of Transgenic Channel Catfish., Mark Christian Bates
Production Of Transgenic Channel Catfish., Mark Christian Bates
LSU Historical Dissertations and Theses
The channel catfish industry has experienced tremendous growth over the last several years. This growth has triggered more intensive culture practices resulting in disease outbreaks and devastating mortalities. Medicated feeds and vaccination have been of limited use. This research presents studies on techniques to produce disease resistant channel catfish by gene transfer. The gene used was the cecropin B gene from the giant silkworm moth Hyalophora cecropia, controlled by an acute phase response (APR) promoter also from H. cecropia. The objectives of this study were to: (1) determine if an early maturing population of catfish from Lake Maurepas, Louisiana, could …
The Polysaccharide Capsule Of Vibrio Vulnificus: Virulence, Transposon Mutagenesis, And The Identification Of An Essential Gene., Amy Buscher Zuppardo
The Polysaccharide Capsule Of Vibrio Vulnificus: Virulence, Transposon Mutagenesis, And The Identification Of An Essential Gene., Amy Buscher Zuppardo
LSU Historical Dissertations and Theses
The extracellular capsule polysaccharide (CPS) of Vibrio vulnificus is a primary virulence factor which allows survival of the bacteria in the human host. To study the genes involved in the production of the polysaccharide capsule, 23 mutants were generated that lost their ability to produce CPS due to the insertion of a mini-transposon into the genome of the encapsulated clinical strain V. vulnificus 1003 (O). The mutants were examined by Southern blot analysis to ensure the transposon had inserted only once in the chromosome. Exoenzymes, which are believed to contribute to the virulence of the organism, produced by all 23 …
Intrarow Plant Spacing And Family By Environment Interaction Effects On Sugarcane Cross Evaluation., Orlando De Sousa Vieira
Intrarow Plant Spacing And Family By Environment Interaction Effects On Sugarcane Cross Evaluation., Orlando De Sousa Vieira
LSU Historical Dissertations and Theses
Progeny testing is practiced to select the best crosses (families) prior to individual plant selection and to guide decisions relative to hybridizing and seedling planting in many crops including sugarcane (Saccharum sp. hyb.). Research to optimize the progeny testing methodology examined its effectiveness relative to family, within family, environment, replication, and intrarow plant spacing. Variance-component analysis indicated that family by environment (locations, years) interaction was a minor inhibitor of selection effectiveness. Within-family variance was the largest source of variation for the five traits considered. For stalk weight, stalk length, and stalk diameter, a small majority of this variance was due …