Neurotensin is produced by and secreted from classic small cell lung cancer cells

The presence of neurotensin in various human tumor cell lines was investigated by radioimmunoassay. High concentrations (0.06-5.1 pmol/mg protein) were detected in 50% of the classic but not variant small cell lung cancer or other human tumor cell lines examined. Biochemical studies indicated that the main peak of immunoreactivity coeluted with synthetic neurotensin using gel filtration and high pressure liquid chromatography techniques. Also, the rate of neurotensin secretion increased approximately 2-fold when theophylline was added which elevated intracellular levels of cAMP 4-fold. Because neurotensin is present in and secreted from many classic small cell lung cancer cells, it may function as a regulatory peptide in this disease.     

Non‐edible oil seed producing Calophyllum inophyllum ideal for India's future biofuel development

The impending climate change crisis has stimulated enormous interest in the development of biofuel globally. The supporters of biofuel hail that it is naturally carbon‐neutral whereas the critiques argue that the large‐scale plantations and production of biofuel based on Jatropha can not only strain agricultural resources but also threaten future food security. India's subsistence farmers are often faced with challenges and constraints of poverty. Foremost among the challenges are the marginal environmental conditions for agriculture often influenced by erratic rainfall, drought, poor soil quality, and unreliable irrigation water supply. In this article, we have presented a case study on the potential to use nonedible seeds from naturally occurring tree species, Calophyllum inophyllum to meet the increasing demand for biofuel production in India.     

Do scent marks increase predation risk of microtine rodents?

Reproductive activities, including signalling with scents, may increase the risk of predation. Mammalian predators, like small mustelids, find voles by using odour cues of scent marks. Scent marks are also visible in ultraviolet light, and at least some diurnal raptors are attracted to these markings in the field. We performed a field experiment to find out whether manipulation of scent markings affects the density, survival and mobility of free-living voles, and the activity of mammalian and avian predators. A total of 20 plots (each 1 ha) were randomly divided into two treatments: scent manipulation and control plots. Scent manipulation plots were treated with vole scent-liquid and control plots with water. From each plot 1–2 voles were radio-collared and tracked for three weeks. Predators hunted more often on scent manipulation plots than on control plots leading to lower survival time of voles. Although scent manipulation attracted more avian predators, small mustelids were the main predators of voles. The density or the mobility of voles did not differ significantly between manipulation and control plots. Our results suggest that odour of scent marks may be a larger risk to voles than UV visibility of scent marks.     

Exome Sequencing of Uterine Leiomyosarcomas Identifies Frequent Mutations in TP53, ATRX,and MED12

Uterine leiomyosarcomas (ULMSs) are aggressive smooth muscle tumors associated with poor clinical outcome. Despite previous cytogenetic and molecular studies, their molecular background has remained elusive. To examine somatic variation in ULMS, we performed exome sequencing on 19 tumors. Altogether, 43 genes were mutated in at least two ULMSs. Most frequently mutated genes included tumor protein P53 (TP53; 6/19; 33%), alpha thalassemia/mental retardation syndrome X-linked (ATRX; 5/19; 26%), and mediator complex subunit 12 (MED12; 4/19; 21%). Unlike ATRX mutations, both TP53 and MED12 alterations have repeatedly been associated with ULMSs. All the observed ATRX alterations were either nonsense or frameshift mutations. ATRX protein levels were reliably analyzed by immunohistochemistry in altogether 44 ULMSs, and the majority of tumors (23/44; 52%) showed clearly reduced expression. Loss of ATRX expression has been associated with alternative lengthening of telomeres (ALT), and thus the telomere length was analyzed with telomere-specific fluorescence in situ hybridization. The ALT phenotype was confirmed in all ULMSs showing diminished ATRX expression. Exome data also revealed one nonsense mutation in death-domain associated protein (DAXX), another gene previously associated with ALT, and the tumor showed ALT positivity. In conclusion, exome sequencing revealed that TP53, ATRX, and MED12 are frequently mutated in ULMSs. ALT phenotype was commonly seen in tumors, indicating that ATR inhibitors, which were recently suggested as possible new drugs for ATRX-deficient tumors, could provide a potential novel therapeutic option for ULMS.     

The relative and combined effects of herbivore assemblage and soil nitrogen on plant diversity

Science China Life Sciences - Plant diversity can be affected by both herbivore grazing and soil resources. However, it is unclear if the joint effects of herbivores and soil resources might vary...     

Do Egg Carrying and Protracted Copulation Affect Mobility in the Golden Egg Bug?

Golden egg bug Phyllomorpha laciniata (Heteroptera, Coreidae) females oviposit on male and female conspecifics that carry ova until they hatch. Embryos benefit from being carried because of diminished risks of predation. Female carriers are never the parents of carried eggs, and males are only rarely the fathers of any carried eggs. Eggs develop and hatch without being carried in the laboratory. Egg carriers may be viewed as victims, exploited by females that encumber them with eggs. The intensity of selection favouring resistance to egg carrying should be proportional to the costs of this behaviour. One possible cost could be a reduction in mobility caused by carried eggs. We compare movement rates among encumbered and unencumbered golden egg bugs of both sexes. Protracted copulations (often exceeding 20 h) typical of this species and mating may also cause reduction in bugs mobility. Therefore, we also evaluate rates of movement of coupled pairs of bugs. Our results indicate that egg loads do not affect the mobility and speed of either males or females. However, copulating pairs are significantly slowed as compared to single bugs. Thus protracted copulations have a clear cost in rates of movement and possibly risks of predation, but there are no apparent mobility costs for egg carrying.     

Cost efficiency of nutrient acquisition and the advantage of mycorrhizal symbiosis for the host plant

Mycorrhizal symbiosis involves reciprocal transfer of carbon and nutrients between shoots on the one hand and roots colonized by symbiotic fungi on the other. Mycorrhizas may improve the mineral nutrient acquisition rates, but simultaneously increase the belowground demand for carbon. Mycorrhizal plants will have a selective advantage over non-mycorrhizal ones if they are more cost-efficient in terms of carbon cost per unit of acquired mineral nutrient. However, we demonstrate here in a simple model system that this is not a necessary condition. Mycorrhizas may evolve even when they are less cost-efficient, provided that photosynthesis and/or growth are strongly nutrient-limited. This result implies a unique hypothesis for the evolution of mycorrhizal associations which may be inherently cost-inefficient as compared to plant roots. Such symbioses may have evolved when the superior nutrient acquisition rate of fungi combines with the relatively high photosynthetic nutrient use efficiency of the host plant. Consequently, provided that mycorrhizas are really cost-inefficient, the selective advantage of mycorrhizal plants will disappear when an increase in the nutrient acquisition rate is not associated with a sufficiently high nutrient use efficiency of photosynthesis, as at high soil nutrient levels or due to a loss of leaf area, shading or low temperatures.     

Incongruent phylogeographies in spite of similar morphology, ecology, and distribution:Phippsia algida andP. concinna (Poaceae) in the North Atlantic region

Phylogeographic and taxonomic relationships among 54 North Atlantic populations of the snowbed grass genusPhippsia were investigated based on isozymes and genetically based morphological variation. The results support recognition of two distinct species,P. algida andP. concinna, the latter with at least two subspecies. Both of these self-fertilizing arctic pioneer species were genetic allotetraploids almost without intrapopulational variation. The two species showed strikingly different phylogeographies in the North Atlantic region in spite of their similarity in morphology, habitat ecology, mating system, and dispersal ecology, and in spite of their present cooccurrence in many geographic areas, sometimes even in the same snowbeds. The same electrophoretic multilocus phenotype was observed in all populations ofP. algida, and although this species showed considerable morphological variation, the variation was unstructured geographically. Thus,P. algida showed a pattern similar to other arctic species investigated in the North Atlantic region; it has probably dispersed postglacially across the sea barriers among Greenland, Svalbard, Iceland, and Scandinavia. In contrast,P. concinna was virtually fixed for different multilocus phenotypes in the three main geographic areas analyzed (S Norway, Svalbard, Greenland), corresponding to fairly distinct divergence in morphology. This pattern suggests absence of postglacial among-area dispersal ofP. concinna in spite of all of its similarities with its congener; it may have immigrated to the North Atlantic from different source areas and/or survived the last glaciationin situ.