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Nature,
1991]
Populations of the soil nematode Caenorhabditis elegans normally consist almost exclusively of self-fertilizing hermaphrodites. The animal first matures about 300 sperm and then a much larger number of oocytes (eggs). Nearly every sperm is used to fertilize an egg and so the maximum fecundity is around 300. Why doesn't the nematode mature more sperm and thus increase its fecundity? In a paper in the Proceedings of the Royal Society (B246, 19-24; 1991), J. Hodgkin and T.M. Barnes provide both an elegant answer and a rare insight into the mechanistic basis of an important life-history trade-off.
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J Mol Biol,
2021]
The COVID-19 pandemic entered its third and most intense to date wave of infections in November 2020. This perspective article describes how combination therapies (polytherapeutics) are a needed focus for helping battle the severity of complications from SARS-CoV-2 infection. It outlines the types of humanized systems that are needed for fast and efficient combinatorial assessment of therapeutic candidates. Proposed are micro-physiological systems using human iPSC as a format for tissue specific infection modeling, the use of gene-humanized zebrafish and C. elegans for combinatorial drug screens due to the animals being addressable in liquid multi-well formats, and the use of engineered pseudo-typing systems to safely model infection in the transgenic animals and engineered tissue systems.
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Biochem Soc Trans,
2004]
IFT (intraflagellar transport) assembles and maintains sensory cilia on the dendritic endings of chemosensory neurons within the nematode Caenorhabditis elegans. During IFT, macromolecular protein complexes called IFT particles (which carry ciliary precursors) are moved from the base of the sensory cilium to its distal tip by anterograde IFT motors (kinesin-II and Osm-3 kinesin) and back to the base by retrograde IFT-dynein [Rosenbaum and Witman (2002) Nat. Rev. Mol. Cell Biol. 3, 813-825; Scholey (2003) Annu. Rev. Cell Dev. Biol. 19, 423-443; and Snell, Pan and Wang (2004) Cell 117, 693-697]. In the present study, we describe the protein machinery of IFT in C. elegans, which we have analysed using time-lapse fluorescence microscopy of green fluorescent protein-fusion proteins in concert with ciliary mutants.
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Cell Death Differ,
2017]
Caspases are at the core of executing apoptosis by orchestrating cellular destruction with proteolytic cascades. Caspase-mediated proteolysis also controls diverse nonlethal cellular activities such as proliferation, differentiation, cell fate decision, and cytoskeletal reorganization. During the last decade or so, genetic studies of Drosophila have contributed to our understanding of the in vivo mechanism of the non-apoptotic cellular responses in developmental contexts. Furthermore, recent studies using C. elegans suggest that apoptotic signaling may play unexpected roles, which influence ageing and normal development at the organism level. In this review, we describe how the caspase activity is elaborately controlled during vital cellular processes at the level of subcellular localization, the duration and timing to avoid full apoptotic consequences, and also discuss the novel roles of non-apoptotic caspase signaling in adult homeostasis and physiology.Cell Death and Differentiation advance online publication, 19 May 2017; doi:10.1038/cdd.2017.36.
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[
Biol Bull,
1998]
In certain invertebrate muscles, adjacent narrow columns of sarcomeres are displaced along the fiber axis, providing an obliquely striated myofilament pattern in certain section planes. Although this architecture is described in many phyla and has been the subject of much discussion (1-12), its mechanical significance has yet to be resolved. In nematodes, where ultrastructural details of the obliquely striated muscle have long been known (12-19), another unique and prominent feature is the attachment of every sarcomere to the plasmalemma and basal lamina via dense bodies (Z-disc analogs). Unfortunately, the importance of this feature to the transmission of the contractile force to the cuticle is not understood outside the Caenorhabditis elegans literature: it was overlooked in recent reviews covering obliquely striated muscle (9-11). Here we consider transmission of force and oblique striation together. We compare the contractile architecture in C. elegans with that in the more complex muscle type of larger nematodes. Both types are designed to transmit the force of contraction laterally to the cuticle rather than longitudinally to the muscle ends. In the second type, folding of the contractile structure around an inward extension of the basal lamina enables a higher number of sarcomeres to be linked to cuticle per unit length. We suggest that the mechanical significance of the oblique arrangement of sarcomeres in both types is that it distributes the force application sites of the sarcomeres more evenly over the basal lamina and cuticle. With this muscle architecture, smooth bending of the nematode body tube would be possible, and kinking would be prevented.