Daniel Larry Smith

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Eukaryotes produce functionally diverse classes of small RNAs (20-25 nt). These include microRNAs (miRNAs), which act as regulatory factors during growth and development, and short-interfering RNAs (siRNAs), which function in several epigenetic and post-transcriptional silencing systems. The Arabidopsis Small RNA Project (ASRP) seeks to characterize and(More)
Model organisms have played an important role in the elucidation of multiple genes and cellular processes that regulate aging. In this study we utilized the budding yeast, Saccharomyces cerevisiae, in a large-scale screen for genes that function in the regulation of chronological lifespan, which is defined by the number of days that non-dividing cells(More)
The chronological lifespan of eukaryotic organisms is extended by the mutational inactivation of conserved growth-signaling pathways that regulate progression into and through the cell cycle. Here we show that in the budding yeast S. cerevisiae, these and other lifespan-extending conditions, including caloric restriction and osmotic stress, increase the(More)
Four agents--acarbose (ACA), 17-α-estradiol (EST), nordihydroguaiaretic acid (NDGA), and methylene blue (MB)--were evaluated for lifespan effects in genetically heterogeneous mice tested at three sites. Acarbose increased male median lifespan by 22% (P < 0.0001), but increased female median lifespan by only 5% (P = 0.01). This sexual dimorphism in ACA(More)
BACKGROUND Divergence within cis-regulatory sequences may contribute to the adaptive evolution of gene expression, but functional alleles in these regions are difficult to identify without abundant genomic resources. Among African cichlid fishes, the differential expression of seven opsin genes has produced adaptive differences in visual sensitivity.(More)
We describe a gene that is expressed in lateral and adventitious root primordia of Arabidopsis. The gene was identified by expression of a transposon-borne promoterless beta-glucuronidase gene in lateral root primordia. The gene, designated LRP1 for lateral root primordium 1, and its corresponding cDNA were cloned and sequenced. The expression pattern of(More)
OBJECTIVE To investigate the effect of risperidone on energy expenditure and weight gain in female C57BL/6J mice. DESIGN AND METHODS Body weight and composition, food intake, energy expenditure, and activity were determined weekly. mRNA expression of uncoupling protein 1 in brown adipose tissue, orexin, and brain-derived neurotrophic factor in the(More)
OBJECTIVE To investigate the variations in body weight, food intake, and body composition of both male and female C57BL/6J mice during a diet-induced obesity model with high-fat diet (HFD) feeding. METHODS Mice were individually housed and fed ad libitum either a low-fat diet (LFD, 10% calories from fat; n = 15 male, n = 15 female) or HFD (45% calories(More)
The occurrence of polygynous marriage in hunter-gatherer societies, which do not accumulate wealth, remains largely unexplored since resource availability is dependent on male hunting capacity and limited by the lack of storage. Hunter-gatherer societies offer the greatest insight in to human evolution since they represent the majority of our species'(More)
The social organization of mobile hunter-gatherers has several derived features, including low within-camp relatedness and fluid meta-groups. Although these features have been proposed to have provided the selective context for the evolution of human hypercooperation and cumulative culture, how such a distinctive social system may have emerged remains(More)