Tracking Dengue Virus Intra-host Genetic Diversity during Human-to-Mosquito Transmission

Dengue virus (DENV) infection of an individual human or mosquito host produces a dynamic population of closely-related sequences. This intra-host genetic diversity is thought to offer an advantage for arboviruses to adapt as they cycle between two very different host species, but it remains poorly characterized. To track changes in viral intra-host genetic diversity during horizontal transmission, we infected Aedes aegypti mosquitoes by allowing them to feed on DENV2-infected patients. We then performed whole-genome deep-sequencing of human- and matched mosquito-derived DENV samples on the Illumina platform and used a sensitive variant-caller to detect single nucleotide variants (SNVs) within each sample. >90% of SNVs were lost upon transition from human to mosquito, as well as from mosquito abdomen to salivary glands. Levels of viral diversity were maintained, however, by the regeneration of new SNVs at each stage of transmission. We further show that SNVs maintained across transmission stages were transmitted as a unit of two at maximum, suggesting the presence of numerous variant genomes carrying only one or two SNVs each. We also present evidence for differences in selection pressures between human and mosquito hosts, particularly on the structural and NS1 genes. This analysis provides insights into how population drops during transmission shape RNA virus genetic diversity, has direct implications for virus evolution, and illustrates the value of high-coverage, whole-genome next-generation sequencing for understanding viral intra-host genetic diversity.     

Pristane induced gene activation.

Studies were performed to examine the effects of 2,6,10,14-tetramethyl pentadecane (pristane) versus 12-O-tetradecanoylphorbol 13-acetate (TPA) on the activation of the CAT gene under the regulatory control of viral promoter/enhancer elements transfected into NIH-3T3, CV-1 and COS-7 cells. The results of these studies demonstrated that (1) pristane or TPA induced trans-activation of SV2cat, HIVcat, RSVcat and MMTVcat in cells transfected with each respective plasmid construct, (2) only pristane induced activation of pA10cat and pOSP/11 and (3) neither TPA nor pristane trans-activated pSV0cat. Furthermore, treatment with either pristane or TPA elicited changes in the morphology of each of the cell lines. Collectively these results indicate that pristane is a potent inducer of gene expression and exhibits similar characteristics as the tumor promoter, TPA.     

An Examination of the Association between 5-HTTLPR,Combat Exposure,and PTSD Diagnosis among U.S. Veterans

Objective

To examine the association between the 5-HTTLPR polymorphism of the serotonin transporter (SLC6A4) gene, combat exposure, and posttraumatic stress disorder (PTSD) diagnosis and among two samples of combat-exposed veterans.

Method

The first sample included 550 non-Hispanic Black (NHB) combat-exposed veterans. The second sample included 555 non-Hispanic White (NHW) combat-exposed veterans. Participants were genotyped for the 5-HTTLPR/rs25531 variants of the SLC6A4 gene. A structured clinical interview was used to diagnose PTSD. Combat and civilian trauma exposure were assessed with validated self-report instruments. Logistic regression was used to test for main effects of 5-HTTLPR on PTSD diagnosis as well as gene x environment (GxE) interactions after adjusting for sex, ancestry proportion scores, civilian trauma exposure, and combat exposure.

Results

Within the NHB sample, a significant additive effect was observed for 5-HTTLPR (OR = 1.502, p = .0025), such that the odds of having a current diagnosis of PTSD increased by 1.502 for each additional S’ allele. No evidence for an association between 5-HTTLPR and PTSD was observed in the NHW sample. In addition, no evidence for combat x 5-HTTLPR effects were observed in either sample.

Conclusion

The present study suggests that there may be an association between 5-HTTLPR genotype and PTSD diagnosis among NHB veterans; however, no evidence for the hypothesized 5-HTTLPR x combat interaction was found.     

Cch1 mediates calcium entry in Cryptococcus neoformans and is essential in low-calcium environments

The ability of Cryptococcus neoformans to grow at the mammalian body temperature (37 degrees C to 39 degrees C) is a well-established virulence factor. Growth of C. neoformans at this physiological temperature requires calcineurin, a Ca(2+)/calmodulin-dependent protein phosphatase. When cytosolic calcium concentrations are low ( approximately 50 to 100 nM), calcineurin is inactive and becomes active only when cytosolic calcium concentrations rise ( approximately 1 to 10 microM) through the activation of calcium channels. In this study we analyzed the function of Cch1 in C. neoformans and found that Cch1 is a Ca(2+)-permeable channel that mediates calcium entry in C. neoformans. Analysis of the Cch1 protein sequence revealed differences in the voltage sensor (S4 regions), suggesting that Cch1 may have diminished voltage sensitivity or possibly an alternative gating mechanism. The inability of the cch1 mutant to grow under conditions of limited extracellular calcium concentrations ([Ca(2+)](extracellular), approximately 100 nM) suggested that Cch1 was required for calcium uptake in low-calcium environments. These results are consistent with the role of ScCch1 in mediating high-affinity calcium uptake in Saccharomyces cerevisiae. Although the growth defect of the cch1 mutant under conditions of limited [Ca(2+)](extracellular) ( approximately 100 nM) became more severe with increasing temperature (25 degrees C to 38.5 degrees ), this temperature sensitivity was not observed when the cch1 mutant was grown on rich medium ([Ca(2+)](extracellular), approximately 0.140 mM). Accordingly, the cch1 mutant strain displayed only attenuated virulence when tested in the mouse inhalation model of cryptococcosis, further suggesting that C. neoformans may have a limited requirement for Cch1 and that this requirement appears to include ion stress tolerance.     

Non-autonomous mobile elements in the crenarchaeon Sulfolobus solfataricus

The genome of the archaeon Sulfolobus solfataricus P2 contains at least four types of short sequence elements lacking open reading frames which are similar to eukaryal non-autonomous mobile elements. The most- conserved elements SM1 (79-80 bp) and SM2 (183-186 bp), with 95 % sequence identity, are present in 40 and 25 copies, respectively. The less-conserved elements SM3 (127-139 bp) and SM4 (160-168 bp), with 75-97 % identity, occur in 44 and 34 copies, respectively. In total, the 143 SM elements constitute about 0.6 % of the genome. The wide distribution of each class of conserved element throughout the genome, and their precise locations, indicate that they are mobile. Direct evidence arises from the presence of SM1 and SM2 in only a fraction of genomic copies of a given class of insertion element, and within copies of open reading frames that are conserved in sequence. SM1 to SM4 are likely to be mobilized by transposases encoded by insertion elements ISC1048, ISC1217, ISC1058 and ISC1173, respectively. Furthermore, the occurrence of clusters of interwoven SM and insertion elements, in potentially mobile units, suggests a mechanism for the transfer of SM elements to other organisms.     

Phenotypic variation in adult behavioral response and offspring fitness in Plutella xylostella (Lepidoptera: Plutellidae) in response to permethrin

Phenotypic variation in behavioral response and physiological tolerance to permethrin was measured and compared between two populations of diamondback moth, Plutella xylostella (L.). A field population from Celeryville, OH, and a laboratory population originally collected from Wooster, OH, were compared. In laboratory choice bioassays, females from both populations were less likely to oviposit on cabbage leaf disks and seedlings treated with permethrin. The oviposition-deterrent effect was positively related to permethrin concentration. The laboratory population was significantly more behaviorally responsive to the insecticide and showed a significantly greater avoidance than the field population of the highest concentration of permethrin tested (1.50 g [AI] /liter). The physiological response of each population was measured by feeding bioassays, and the laboratory population was physiologically more susceptible to the permethrin. Larvae from the laboratory population that were fed permethrin-treated leaves had significantly lower growth rate, higher mortality, and lower adult fecundity compared with larvae from the field population. These data suggest that female moths that are more behaviorally responsive to permethrin produce offspring that tend to be more susceptible to the same insecticide, at least for the populations tested. The relationship between adult behavioral response and larval physiological tolerance to permethrin is discussed.     

Prevalence,Awareness, Treatment,and Control of Hypertension in United States Counties, 2001–2009

Hypertension is an important and modifiable risk factor for cardiovascular disease and mortality. Over the last decade, national-levels of controlled hypertension have increased, but little information on hypertension prevalence and trends in hypertension treatment and control exists at the county-level. We estimate trends in prevalence, awareness, treatment, and control of hypertension in US counties using data from the National Health and Nutrition Examination Survey (NHANES) in five two-year waves from 1999–2008 including 26,349 adults aged 30 years and older and from the Behavioral Risk Factor Surveillance System (BRFSS) from 1997–2009 including 1,283,722 adults aged 30 years and older. Hypertension was defined as systolic blood pressure (BP) of at least 140 mm Hg, self-reported use of antihypertensive treatment, or both. Hypertension control was defined as systolic BP less than 140 mm Hg. The median prevalence of total hypertension in 2009 was estimated at 37.6% (range: 26.5 to 54.4%) in men and 40.1% (range: 28.5 to 57.9%) in women. Within-state differences in the county prevalence of uncontrolled hypertension were as high as 7.8 percentage points in 2009. Awareness, treatment, and control was highest in the southeastern US, and increased between 2001 and 2009 on average. The median county-level control in men was 57.7% (range: 43.4 to 65.9%) and in women was 57.1% (range: 43.0 to 65.46%) in 2009, with highest rates in white men and black women. While control of hypertension is on the rise, prevalence of total hypertension continues to increase in the US. Concurrent increases in treatment and control of hypertension are promising, but efforts to decrease the prevalence of hypertension are needed.     

Some spacing relations among the central males of a transplanted troop of Japanese macaques (Arashiyama west)

In February, 1972, a troop of 150 Japanese macaques was tranplanted from Kyoto, Japan, to Laredo, Texas, USA, after 20 years of study in Japan. As part of the general adaptation of the troop to its new environment, spacing behavior was observed in the central adult males [by independent rank, (1)Dai, (2)W, (3)Bus 62, and (4)Kojiwa 59]. Spot checks of locations, vertical space use, mobility patterns, and paths to and from a box of apples suggested that the major influences on spacing were rank, personality and history, social interactions, and several environmental factors (availability of vertical space, water, and shade, extreme heat, daily provisioning, etc).Dai exceeded the other males in use of vertical space, rate and distance of travel, and proximity to the apple box.W confined his high use of vertical space use primarily to one structure. His distance and rate of travel were low, and he maintained the greatest distance from the apple box.Bus 62 ranked second in use of vertical space, distance and rate of travel, and proximity to the apple box.Kojiwa 59 frequently changed sites in his use of vertical space. His distance and rate of travel were low, and he maintained long distances from the apple box.