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Full-Text Articles in Biology

Hcnabc Gene Expression In The Soil Bacterium Pseudomonas Putida Ath2-Iri/9 Under Various Culture And Rhizosphere Conditions, Myrna May Biswas Jan 2010

Hcnabc Gene Expression In The Soil Bacterium Pseudomonas Putida Ath2-Iri/9 Under Various Culture And Rhizosphere Conditions, Myrna May Biswas

Master's Theses

Pseudomonas putida ATH2-1RI/9, a bacterium that colonizes plant roots, can suppress weed seedling growth of velvetleaf by producing hydrogen cyanide in the rhizosphere. The operon hcnABC constitutively expresses HCN synthase, an enzyme which catalyzes glycine to form carbon dioxide and hydrogen cyanide, a secondary metabolite. Cyanogenesis is influenced by several environmental factors including iron, phosphate, and oxygen-limiting conditions. This study used a hcnABC::luxAB gene fusion in Pseudomonas putida ATH2-1RI/9 involving the insertion of a promoterless luxAB gene into the hcnABC operon, which results in bacterial luciferase expression instead of HCN synthase. Bioluminescence by this reporter strain was compared to cyanide …


Courtship And Copulation In Glaucous-Winged Gulls, Larus Glaucescens, Kelly M. Mcwilliams Jan 2010

Courtship And Copulation In Glaucous-Winged Gulls, Larus Glaucescens, Kelly M. Mcwilliams

Master's Theses

Using video recordings and scan counts, I examined the occurrence, sequences, and durations of behavior and environmental factors associated with courtship and copulation in glaucous-winged gulls, Larus glaucescens. Males and females in a pair had equivalent pre- and post-Mount behavior occurrences and durations. The main courtship sequence was Head Toss -- Courtship Beg/Respond -- Mounted/Mount, and felames appeared to initiate transitions between these pre-Mount behaviors. More Mounts occurred during the egg-laying stage of the breeding season, but copulation duration, wing-flag duration, and cloacal contacts per copulation showed no significant differences across sampling periods. Poisson analysis showed no significant grouping …