New North American Chrysauginae (Pyralidae) described by E.D. Cashatt

A Ph.D. dissertation completed by E.D. Cashatt in 1968 entitled “Revision of the Chrysauginae of North America” does not meet the criteria of publication so the new taxa described therein are not available per the International Code of Zoological Nomenclature. In order to validate the taxa proposed in that document we formally describe and illustrate the following: Arta brevivalvalis Cashatt, sp. n., Heliades lindae Cashatt, sp. n., Paragalasa Cashatt, gen. n., Paragalasa exospinalis Cashatt, sp. n., and Penthesilea sacculalis baboquivariensis Cashatt, subsp. n. We summarize other taxonomic actions proposed in the dissertation and those proposed by subsequent authors. We provide the current nomenclatural status with the literature citation of the paper in which the current status was proposed. A lectotype is designated for Clydonopteran tecomae. Adult holotypes and associated labels, and genitalia of paratypes are newly illustrated.     

The Relative Expression of Mig6 and EGFR Is Associated with Resistance to EGFR Kinase Inhibitors

The sensitivity of only a few tumors to anti-epidermal growth factor receptor EGFR tyrosine kinase inhibitors (TKIs) can be explained by the presence of EGFR tyrosine kinase (TK) domain mutations. In addition, such mutations were rarely found in tumor types other than lung, such as pancreatic and head and neck cancer. In this study we sought to elucidate mechanisms of resistance to EGFR-targeted therapies in tumors that do not harbor TK sensitizing mutations in order to identify markers capable of guiding the decision to incorporate these drugs into chemotherapeutic regimens. Here we show that EGFR activity was markedly decreased during the evolution of resistance to the EGFR tyrosine kinase inhibitor (TKI) erlotinib, with a concomitant increase of mitogen-inducible gene 6 (Mig6), a negative regulator of EGFR through the upregulation of the PI3K-AKT pathway. EGFR activity, which was more accurately predicted by the ratio of Mig6/EGFR, highly correlated with erlotinib sensitivity in panels of cancer cell lines of different tissue origins. Blinded testing and analysis in a prospectively followed cohort of lung cancer patients treated with gefitinib alone demonstrated higher response rates and a marked increased in progression free survival for patients with a low Mig6/EGFR ratio (approximately 100 days, P = 0.01).     

Thermal niche overlap of the corner recluse spider Loxosceles laeta (Araneae; Sicariidae) and its possible predator,the spitting spider Scytodes globula (Scytodidae)

Loxoscelism is a health problem caused by the bite of spiders of the genus Loxosceles. In Chile all cases are attributable to Loxosceles laeta. It has been suggested that the spitting spider Scytodes globula may be a predator of L. laeta and control its population, which is only possible if they share the microhabitat. This study compared the thermal preferences and tolerances of the two species. Later, spiders acclimated to 15 °C and 25 °C were exposed to decreasing and increasing temperatures to determine the lower and upper critical temperatures. The preferred temperatures were lower during the morning, but there were no differences between the species. The thermal niche breadths were similar for the species, with a large overlap. Both species showed tolerance to extreme temperatures, but L. laeta showed greater tolerance to low temperatures. Both species showed acclimation of the lower critical temperatures to changes in acclimation temperatures. The similarity of preferred and tolerated temperatures was partly an expected fact, since the species share the same macrohabitat; these spider species are very common in domestic environments of central Chile. However, the results imply that their microhabitat choices are also very similar, indicating a high probability of meeting and predation, which could have important consequences in loxoscelism epidemiology.     

Isolation and Characterization of Mercury Resistant Bacillus sp. from Soils with an Extensive History as Substrates for Mercury Extraction in Mexico

Metal phytoextraction assisted by bacteria plays an important role in bioremediation systems. In this work, mercury-resistant bacterial strains were isolated from soils with high levels of mercury (San Joaquin, Queretaro State, Mexico) and identified as Bacillus sp. based on the 16S rDNA gene sequence analysis. The bacterial strains were found to exhibit different multiple mercury-resistance and carbon source utilization characteristics. The mercury reduction ability was tested through a volatilization assay. The bacterial isolates were also evaluated for their ability to promote growth and mercury uptake in tomato plants. In a roll towel assay, the maximum vigor index of tomato plants was obtained with the inoculation of Bacillus sp. A2, A12, B11, B15 and C1, while in a pot assay, the maximum vigor index was obtained with the inoculation of Bacillus sp. A6, A7 and B20, compared with un-inoculated controls in the presence of HgCl₂. Maximum Hg accumulation in the roots and shoots of tomato plants was obtained only with Bacillus sp. A7 in the roll towel assay, whereas in the pot assay, maximum accumulation was obtained with Bacillus sp. A12 compared with un-inoculated controls. Our results show that mercury accumulation in tissue is enhanced by these plant growth promoting bacterial strains, which recommends their possible use as microbe-assisted phytoremediation systems in mercury-polluted soils.     

Proliferation of Murine Midbrain Neural Stem Cells Depends upon an Endogenous Sonic Hedgehog (Shh) Source

The Sonic Hedgehog (Shh) pathway is responsible for critical patterning events early in development and for regulating the delicate balance between proliferation and differentiation in the developing and adult vertebrate brain. Currently, our knowledge of the potential role of Shh in regulating neural stem cells (NSC) is largely derived from analyses of the mammalian forebrain, but for dorsal midbrain development it is mostly unknown. For a detailed understanding of the role of Shh pathway for midbrain development in vivo, we took advantage of mouse embryos with cell autonomously activated Hedgehog (Hh) signaling in a conditional Patched 1 (Ptc1) mutant mouse model. This animal model shows an extensive embryonic tectal hypertrophy as a result of Hh pathway activation. In order to reveal the cellular and molecular origin of this in vivo phenotype, we established a novel culture system to evaluate neurospheres (nsps) viability, proliferation and differentiation. By recreating the three-dimensional (3-D) microenvironment we highlight the pivotal role of endogenous Shh in maintaining the stem cell potential of tectal radial glial cells (RGC) and progenitors by modulating their Ptc1 expression. We demonstrate that during late embryogenesis Shh enhances proliferation of NSC, whereas blockage of endogenous Shh signaling using cyclopamine, a potent Hh pathway inhibitor, produces the opposite effect. We propose that canonical Shh signaling plays a central role in the control of NSC behavior in the developing dorsal midbrain by acting as a niche factor by partially mediating the response of NSC to epidermal growth factor (EGF) and fibroblast growth factor (FGF) signaling. We conclude that endogenous Shh signaling is a critical mechanism regulating the proliferation of stem cell lineages in the embryonic dorsal tissue.     

Host‐plant associated genetic divergence of two Diatraea spp. (Lepidoptera: Crambidae) stemborers on novel crop plants

Diatraea lineolata and Diatraea saccharalis (Lepidoptera: Crambidae) are moths with stemboring larvae that feed and develop on economically important grasses. This study investigated whether these moths have diverged from a native host plant, corn, onto introduced crop plants including sorghum, sugarcane, and rice. Diatraea larvae were collected from these four host plants throughout the year in El Salvador and were reared on artificial diet until moths or parasitoids emerged. Adult moths were subsequently identified to species. Amplified fragment length polymorphisms (AFLPs) and mitochondrial DNA cytochrome oxidase I (COI) were used to examine whether or not there was genetic divergence of D. lineolata or D. saccharalis populations on the four host plants. Percent parasitism was also determined for each moth on its host plants. D. lineolata was collected from corn in the rainy season and sorghum in the dry season. D. saccharalis was most abundant on sugarcane in the rainy season and sorghum in the dry season. The AFLP analysis found two genetically divergent populations of both D. lineolata and D. saccharalis. Both moths had high levels of parasitism on their dominant host plant in the rainy season, yet had low levels of parasitism on sorghum in the dry season. The presence of two genotypes of both Diatraea spp. on sorghum suggest that host‐associated differentiation is occurring on this novel introduced crop plant.     

Identification and expression of mutations in the hydroxymethylbilane synthase gene causing acute intermittent porphyria (AIP)

BACKGROUND: Acute intermittent porphyria (AIP), an autosomal dominant inborn error, results from the half-normal activity of the heme biosynthetic enzyme hydroxymethylbilane synthase (EC 4.3.1.8; HMB-synthase). This disease is characterized by acute, life-threatening neurologic attacks that are precipitated by various drugs, hormones, and other factors. The enzymatic and/or biochemical diagnosis of AIP heterozygotes is problematic; therefore, efforts have focused on the identification of HMB-synthase mutations so that heterozygotes can be identified and educated to avoid the precipitating factors. In Spain, the occurrence of AIP has been reported, but the nature of the HMB-synthase mutations causing AIP in Spanish families has not been investigated. Molecular analysis was therefore undertaken in nine unrelated Spanish AIP patients. MATERIALS AND METHODS: Genomic DNA was isolated from affected probands and family members of nine unrelated Spanish families with AIP. The HMB-synthase gene was amplified by long-range PCR and the nucleotide sequence of each exon was determined by cycle sequencing. RESULTS: Three new mutations, a missense, M212V; a single base insertion, g4715insT; and a deletion/insertion, g7902ACT-->G, as well as five previously reported mutations (G111R, R116W, R149X R167W, and R173W) were detected in the Spanish probands. Expression of the novel missense mutation M212V in E. coli revealed that the mutation was causative, having <2% residual activity. CONCLUSIONS: These studies identified the first mutations in the HMB-synthase gene causing AIP in Spanish patients. Three of the mutations were novel, while five previously reported lesions were found in six Spanish families. These findings enable accurate identification and counseling of presymptomatic carriers in these nine unrelated Spanish AIP families and further demonstrate the genetic heterogeneity of mutations causing AIP.