Comparative studies of glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1: evidence for a eutherian mammalian origin for the GPIHBP1 gene from an LY6-like gene

Glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) functions as a platform and transport agent for lipoprotein lipase (LPL) which functions in the hydrolysis of chylomicrons, principally in heart, skeletal muscle and adipose tissue capillary endothelial cells. Previous reports of genetic deficiency for this protein have described severe chylomicronemia. Comparative GPIHBP1 amino acid sequences and structures and GPIHBP1 gene locations were examined using data from several mammalian genome projects. Mammalian GPIHBP1 genes usually contain four coding exons on the positive strand. Mammalian GPIHBP1 sequences shared 41–96% identities as compared with 9–32% sequence identities with other LY6-domain-containing human proteins (LY6-like). The human N-glycosylation site was predominantly conserved among other mammalian GPIHBP1 proteins except cow, dog and pig. Sequence alignments, key amino acid residues and conserved predicted secondary structures were also examined, including the N-terminal signal peptide, the acidic amino acid sequence region which binds LPL, the glycosylphosphatidylinositol linkage group, the Ly6 domain and the C-terminal α-helix. Comparative and phylogenetic studies of mammalian GPIHBP1 suggested that it originated in eutherian mammals from a gene duplication event of an ancestral LY6-like gene and subsequent integration of exon 2, which may have been derived from BCL11A (B-cell CLL/lymphoma 11A gene) encoding an extended acidic amino acid sequence

Spatial ecology and site occupancy of the Northern red-legged frog (Rana aurora) in a coastal dune environment

Study conducted on the Northern red-legged frog in permanent and seasonal wetland habitats. Occupancy modeling incorporating detection was used for predicting egg mass distribution in seasonal wetlands. Habitat selection modeling was used to explore adult and juvenile distribution in the post-breeding season.Thesis (M.A.)--Humboldt State University, Biology,\ud 2008The southern distribution of the northern red-legged frog (Rana aurora) extends only into the three most northern coastal counties of California and seems to be restricted to the coastal belt. Because of recent declines in the population and destruction of its habitat, the California Department of Fish and Game has declared it a Species of Special Concern in California and it is also federally listed as a Sensitive Species by the US Forest Service. This study investigated the spatial distribution and habitat selection of the species on the North Spit of Humboldt Bay, CA in a locally isolated dune environment. The first part of this study concentrated on natural history facets of the species such as differences in relative abundance, movement, and breeding phenology between and among permanent and seasonal pond-breeding habitats in the study area. The second part of this study described the spatial distribution of the northern red-legged frog within seasonal wetlands of the dune swales using site occupancy models. It also gleaned knowledge on the species??? habitat preferences during the breeding and post-breeding seasons and serves as a baseline experiment for future monitoring of this species distribution. Detection probability was also examined in the egg mass site occupancy models. Frog abundance was greater in the smaller, permanent pond habitat. Movement towards the ponds was greatest during the breeding season in both habitats. Juveniles were most active prior to and during the breeding season, whereas adults were more active during and after the breeding season. Prior rainfall increased movements in both juveniles and adults, although adults were not as affected except prior to the breeding season. No differences in breeding chronology and physical characteristics were found between the habitats. The egg mass occupancy models showed that gravid females preferred oviposition sites with deeper water and less than 50% emergent vegetation. Egg mass detection probabilities were affected by fluctuating water levels throughout the survey period. Egg mass occupancy rates were underestimated when detection was not incorporated into the models. Adult and juveniles in the post-breeding season selected sites with longer hydroperiods that were farther from sites which had contained egg masses. Occupancy results indicate that water depth and hydroperiod length are important factors in determining the spatial distribution of R. aurora in palustrine wetlands, detection probability is an important parameter to include when surveying the species, and the adult and juveniles use more than just the breeding ponds in the wetland habitat. This is the first study to research R. aurora egg mass site occupancy incorporating detection probability. The top model can be used as a foundation to predict egg mass occurrence in palustrine wetlands and as a baseline for development of a larger monitoring program to research spatial dynamics and population fluctuations of the species