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[
Cell,
2009]
The serine/threonine kinase Akt is a focal point in signaling pathways that control cell tumorigenesis and insulin resistance. In this issue, Padmanabhan et al. (2009) identify a phosphatase regulatory subunit PPTR-1 that regulates the insulin/insulin-like growth factor 1 pathway by counteracting Akt activity in worms and mammalian cells.
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Aging (Albany NY),
2014]
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[
Physiol Genomics,
2003]
Life developed in a stressful environment. Stressors at the cellular level include heat, hypoxia, oxidative or reductive substances, mechanical or osmotic pressure, and toxic compounds like heavy metals. Various molecular pathways, more or less specific for the different stressors, developed during evolution to combat the molecular consequences of cell stress. Thermal stress induces the induction of a highly conserved protein family, the heat shock proteins (HSP).
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[
Elife,
2021]
Experiments in <i>C. elegans</i> reveal new insights into how the ANC-1 protein helps to anchor the nucleus and other organelles in place.
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[
BMC Biol,
2012]
Most if not all animals sense temperature using specialized thermosensory neurons. Genetic studies in simple organisms have been used to identify gene products required for detecting temperature changes or for mediating the effects of temperature on behaviour. A recent study has used automated imaging and multidimensional phenotyping to characterize behavioural responses to aversive temperature changes and to identify mutants with specific defects in these processes.
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[
Am J Trop Med Hyg,
2016]
Onchocerciasis is one of the two filarial helminth "neglected tropical diseases" (the other being lymphatic filariasis) that has been targeted for geographically local elimination followed by global eradication. The last known areas of Onchocerca volvulus transmission in the Americas have recently been reported to be eliminated. In contrast, achieving metrics for interruption of O. volvulus transmission in Africa, thus removing the requirement for continued monitoring and mass drug administration (MDA) with ivermectin, has been more challenging. To date, transmission cessation of O. volvulus has been validated only in the Mount Elgon region of eastern Uganda. Annual and biannual ivermectin MDA was delivered in this endemic focus from 1994 to 2011, in combination with sustained vector control aimed at reducing the local larval Simulium neavei vectors that have a phoretic association with freshwater crabs. Subsequent to this accomplishment, the World Health Organization (WHO) updated in 2016 the criteria for stopping MDA as a result of transmission interruption. The technical procedures and the corresponding cutoff values to signify transmission interruption included the following: 1) screening pools of black flies by polymerase chain reaction for the DNA repeat sequence Ov150; minimal elimination value is < 1/2,000 Ov150-positive flies and 2) serologic screening of school-aged children < 10 years of age for immunoglobulin G4 antibodies to the Ov16 antigen; elimination value is antibody prevalence < 0.1%. In this issue of the American Journal of Tropical Medicine and Hygiene, Zarroug and others describe results of a 3-year post-MDA treatment survey that confirm elimination of O. volvulus transmission by these criteria in Abu Hamed, a geographically isolated endemic focus in northern Sudan inhabited by approximately 120,000 people. Of the 5,266 children tested for Ov16 antibody, one 9-year-old child was positive. This child had never traveled outside her home village and had a negative skin snip for Ov150 DNA, indicating that she probably did not have a patent infection with skin microfilariae, but had previously been exposed to O. volvulus infective larvae. Lymphatic filariasis or other parasitic worm infections that may elicit antibodies that cross-react with Ov16 are not endemic in the study area.
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[
Genetics,
2015]
A little over 50 years ago, Sydney Brenner had the foresight to develop the nematode (round worm) Caenorhabditis elegans as a genetic model for understanding questions of developmental biology and neurobiology. Over time, research on C. elegans has expanded to explore a wealth of diverse areas in modern biology including studies of the basic functions and interactions of eukaryotic cells, host-parasite interactions, and evolution. C. elegans has also become an important organism in which to study processes that go awry in human diseases. This primer introduces the organism and the many features that make it an outstanding experimental system, including its small size, rapid life cycle, transparency, and well-annotated genome. We survey the basic anatomical features, common technical approaches, and important discoveries in C. elegans research. Key to studying C. elegans has been the ability to address biological problems genetically, using both forward and reverse genetics, both at the level of the entire organism and at the level of the single, identified cell. These possibilities make C. elegans useful not only in research laboratories, but also in the classroom where it can be used to excite students who actually can see what is happening inside live cells and tissues.