Reducing Meloidogyne incognita Injury to Cucumber in a Tomato-Cucumber Double-Cropping System

The effects of a root-knot nematode-resistant tomato cultivar and application of the nematicide ethoprop on root-knot nematode injury to cucumber were compared in a tomato-cucumber double-cropping system. A root-knot nematode-resistant tomato cultivar, Celebrity, and a susceptible cultivar, Heatwave, were grown in rotation with cucumber in 1995 and 1996. Celebrity suppressed populations of Meloidogyne incognita in the soil and resulted in a low root-gall rating on the subsequent cucumber crop. Nematode population densities were significantly lower at the termination of the cucumber crop in plots following Celebrity than in plots following Heatwave. Premium and marketable yields of cucumbers were higher in plots following Celebrity than in plots following Heatwave. Application of ethoprop through drip irrigation at 4.6 kg a.i./ha reduced root galling on the cucumber crop but had no effect on the nematode population density in the soil at crop termination. Ethoprop did not affect cucumber yield. These results indicate that planting a resistant tomato cultivar in a tomato-cucumber double-cropping system is more effective than applying ethoprop for managing M. incognita.     

The Development of A-ring Modified Analogues of Oestrone-3-O-sulphamate as Potent Steroid Sulphatase Inhibitors with Reduced Oestrogenicity

Steroid sulphatases regulate the formation of oestrogenic steroids which can support the growth of endocrine-dependent breast tumours. The development of potent steroid sulphatase inhibitors could therefore have considerable therapeutic potential. Several such inhibitors have now been developed of which the most potent to date is oestrone-3-O-sulphamate (EMATE). Unexpectedly, this inhibitor proved to be a potent oestrogen. In an attempt to reduce the oestrogenicity, whilst retaining the potent sulphatase inhibitory properties associated with this type of molecule, a number of A-ring modified derivatives were designed and synthesized. A-ring modified compounds included the 2-methoxy, 2/4-nitro, 2/4-n-propyl and 2/4-allyl EMATE analogues. The ability of these derivatives to inhibit oestrone sulphatase activity was examined using placental microsomes. The allyl-substituted EMATE derivatives were more potent inhibitors than the propyl analogues but were all considerably less potent than EMATE. In contrast, the 2-methoxy and 2/4-nitro analogues were potent sulphatase inhibitors with 4-nitro EMATE being 5 times more active than EMATE. The 4-nitro, 2-methoxy, 4-n-propyl and 4-allyl derivatives were also tested in vivo for their oestrogenicity and ability to inhibit sulphatase activity. While both 4-nitro and 2-methoxy EMATE were potent inhibitors in vivo, 2-methoxy EMATE had no stimulatory effect on uterine growth in ovariectomized rats. The identification of a potent steroid sulphatase inhibitor lacking any oestrogenicity, such as 2-methoxy EMATE, should be of considerable value in evaluating the potential of steroid sulphatase inhibition for breast cancer therapy.     

Sociality, Mate Choice, and Timing of Mating in American Bison (Bison bison): Effects of Large Males

We studied group size, composition, and mating activities in American bison (Bison bison) during rut on the Delta Junction Bison Range in interior Alaska, USA, in 1996 and 1997. Our purpose was to determine the effects of large males (≥5 yr old) on mating and associated activities. Groups with large males were larger than those containing smaller males. Most groups of bison were mixed‐sex (90%), but large males occurred in only one‐half of all groups. Moreover, females in groups with large males were more likely to copulate than those in groups with smaller males, indicating a female preference for large males. Nevertheless, our results are consistent with large males seeking out adult females for mating rather than vice versa. Mating peaked in mid‐August during both the study years and was highly synchronous. Scent marking was coincident with mating, an outcome consistent with a hypothesis of such behavior triggering ovulation. Scent marking by large male bison occurred in both male–male and male–female contexts, but was associated most often with sexual activities. No differences in group size occurred with changes in weather or among vegetation types occupied by bison. Group size of bison, however, was larger with increasing distance from the forest edge, which likely was a response to predation risk in this predator‐rich environment.     

Characterisation of the Small RNAs in the Biomedically Important Green-Bottle Blowfly Lucilia sericata

Background

The green bottle fly maggot, Lucilia sericata, is a species with importance in medicine, agriculture and forensics. Improved understanding of this species’ biology is of great potential benefit to many research communities. MicroRNAs (miRNA) are a short non-protein coding regulatory RNA, which directly regulate a host of protein coding genes at the translational level. They have been shown to have developmental and tissue specific distributions where they impact directly on gene regulation. In order to improve understanding of the biology of L. sericata maggots we have performed small RNA-sequencing of their secretions and tissue at different developmental stages.

Results

We have successfully isolated RNA from the secretions of L. sericata maggots. Illumina small RNA-sequencing of these secretions and the three tissues (crop, salivary gland, gut) revealed that the most common small RNA fragments were derived from ribosomal RNA and transfer RNAs of both insect and bacterial origins. These RNA fragments were highly specific, with the most common tRNAs, such as GlyGCC, predominantly represented by reads derived from the 5’ end of the mature maggot tRNA. Each library also had a unique profile of miRNAs with a high abundance of miR-10-5p in the maggot secretions and gut and miR-8 in the food storage organ the crop and salivary glands. The pattern of small RNAs in the bioactive maggot secretions suggests they originate from a combination of saliva, foregut and hindgut tissues. Droplet digital RT-PCR validation of the RNA-sequencing data shows that not only are there differences in the tissue profiles for miRNAs and small RNA fragments but that these are also modulated through developmental stages of the insect.

Conclusions

We have identified the small-RNAome of the medicinal maggots L. sericata and shown that there are distinct subsets of miRNAs expressed in specific tissues that also alter during the development of the insect. Furthermore there are very specific RNA fragments derived from other non-coding RNAs present in tissues and in the secretions. This new knowledge has applicability in diverse research fields including wound healing, agriculture and forensics.     

Clinicopathologic Predictors of Survival in Patients with Desmoplastic Melanoma

Background and Objectives

Desmoplastic melanoma is a unique subtype of melanoma which typically affects older patients who often have comorbidities that can adversely affect survival. We sought to identify melanoma-specific factors influencing survival in patients with desmoplastic melanoma.

Methods

Retrospective review from 1993 to 2011 identified 316 patients with primary desmoplastic melanoma. Clinicopathologic characteristics were correlated with nodal status and outcome.

Results

Fifty-five patients (17.4%) had nodal disease: 33 had a positive sentinel lymph node biopsy and 22 developed nodal recurrences (no sentinel lymph node biopsy or false-negative sentinel lymph node biopsy). Nodal disease occurred more often in younger patients and in cases with mixed compared with pure histology (26.7% vs. 14.6%); both of these variables significantly predicted nodal status on multivariable analysis (p<0.05). After a median follow-up of 5.3 years, recurrence developed in 87 patients (27.5%), and 111 deaths occurred. The cause of death was known in 79 cases, with 47 deaths (59.5%) being melanoma-related. On multivariable analysis, Breslow thickness, mitotic rate ≥1/mm² and nodal status significantly predicted melanoma-specific survival (p<0.05).

Conclusions

Nodal status predicts melanoma-specific survival in patients with desmoplastic melanoma. However, since patients with desmoplastic melanoma represent an older population, and a considerable proportion of deaths are not melanoma-related (40.5%), comorbidities should be carefully considered in making staging and treatment decisions in this population.     

A global approach to crop wild relative conservation: securing the gene pool for food and agriculture

In light of the growing concern over the potentially devastating impacts on biodiversity and food security of climate change and the massively growing world population, taking action to conserve crop wild relatives (CWR), is no longer an option — it is a priority. Crop wild relatives are species closely related to crops, including their progenitors, many of which have the potential to contribute beneficial traits to crops, such as pest or disease resistance, yield improvement or stability. They are a critical component of plant genetic resources for food and agriculture (PGRFA), have already made major contributions to crop production and are vital for future food security; their systematic conservation in ways that ensure their continuing availability for use is therefore imperative. This is a complex, interdisciplinary, global issue that has been addressed by various national and international initiatives. Drawing on the lessons learnt from these initiatives we can now propose a global approach to CWR conservation, the key elements of which are: (1) estimating global CWR numbers, (2) assessment of the global importance of CWR diversity, (3) current conservation status, (4) threats to CWR diversity, (5) systematic approaches to CWR conservation, (6) CWR informatics, and (7) enhancing the use of CWR diversity.     

Dispersal mood revealed by shifts from routine to direct flights in the meadow brown butterfly Maniola jurtina

A comprehensive mechanistic approach to dispersal requires the translation of the whole mobility register of the target organism into movement rules that could subsequently be used to model its displacements. According to the optimality paradigm, this procedure implies a cost–benefit analysis of mobility patterns taking into account not only movements, but also their external context and the internal state of the moving individuals. Using this framework, we detected a ‘dispersal mood’ in some individuals of the meadow brown butterfly Maniola jurtina. These adopted a direct flight strategy, which was topologically different from the previously documented foray search strategy. Those individuals that used the direct flight strategy moved straighter as soon as they left the habitat and avoided heading back to their patch of origin, which is the best inter‐patch search strategy when dispersal risks and costs are high. The direct flight strategy was conditional to sex: females used it twice as much as males. We suggest that this sex bias was due to female investment in offspring, which is maximized by male avoidance and spatial bet hedging. Inter‐patch dispersal of gravid females is crucial for the persistence of M. jurtina populations in spatially and temporally unpredictable environments.     

Influence of Lipopolysaccharide on the Surface Proton-Binding Behavior of <Emphasis Type="Italic">Shewanella</Emphasis> spp.

This study investigates the potentiometric properties of several strains of Shewanella spp. and determines whether these properties can be correlated with lipopolysaccharide (LPS) type. The LPS of eight Shewanella strains was characterized using silver-stained sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) and their potentiometric properties determined using high-resolution acid–base titrations. Titrations showed that total ligand concentrations (L _T ) ranged from 0.903 ± 0.007 μmol/mg (S. baltica 63) to 1.387 ± 0.007 μmol/mg (S. amazonensis SB2B). Smooth strains (possessing O-side chains) exhibited higher mean L _T values than rough strains (no O-side chain). A Tukey’s honestly significantly different (HSD) test revealed, smooth strains exhibited significantly higher L _T values than rough strains in 69% of comparisons. Comparison of individual pK _a concentrations revealed that smooth LPS strains of Shewanella were relatively enriched in reactive groups at pK _a 5, suggesting their LPS O-side chains contained detectable carboxyl groups. Combined pKa spectra from all eight Shewanella strains produced a common trend indicating that the way in which the surface proton-buffering capacity changes with pH is similar for the species studied here.     

beta-Alkylthio indolyl carbinols: potent nonsteroidal antiandrogens with oral efficacy in a prostate cancer model

Through an in vivo screening model, we developed the in vivo SAR of beta-alkylthio indolyl carbinols. Through these efforts we identified a compound with potent oral in vivo efficacy in both immature and mature rat prostate weight reduction models and in a murine xenograft prostate cancer model.