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Wang, Yi, Emmons, Scott W., Bernstein, Max, Albertson, Donna G., Thomson, Nicole, Jarrell, Travis, Xu, Meng, Hall, David H.
[
International Worm Meeting,
2009]
We are carrying out reconstructions of the C. elegans male nervous system from serial section electron micrographs created at the MRC in Cambridge, UK, during the 1970''s. At that time, several adult animals of different ages were sectioned and photographed through critical regions of the male tail containing the neural circuits that underlie copulatory behavior. Our most complete reconstruction is that of an animal known as N2Y, annotated as an "old adult." We have compared selected neurons in the pre-anal ganglion of N2Y to corresponding neurons in a second worm, JSI, annotated as a "young adult." The neural network of N2Y is more complex than that of JSI. The number of synapses and the number of synaptic partners of individual neurons increases more than fourfold. Comparison of individual neuron maps revealed that the reason appears to be that neuron processes in JSI are not fully grown out. The absence in JSI of many apparently major synaptic interactions present in N2Y made it appear doubtful whether JSI could have mated properly. Accordingly, we tested the mating ability of young males immediately after their molt to adulthood. When presented with five paralyzed hermaphrodites, only one of 6 just-matured males mated during the first 3 hr, whereas males matured overnight mate within the first 20 min. Mating began thereafter, suggesting 3-5 hr are necessary for maturation of the male nervous system. Maturation of the connectivity during adulthood raised the possibility that experience could influence the wiring process and might improve performance. In order to generate mature males that had never experienced sensory inputs associated with mating or mating-type behaviors, we allowed L4 males to mature overnight in liquid. When placed with hermaphrodites on plates, such males mated immediately and performed as well as males matured on plates with other animals. Conversely, the performance of several day old, experienced males was not improved over that of inexperienced males. Therefore we found no evidence that mating competence either requires or is improved by experience. It appears that the pattern of synaptic interactions necessary for efficient mating is fully established a few hours after the L4/adult molt and is sufficiently well-specified genetically to support mating behavior.
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[
Yi Chuan,
2008]
Spermatogenesis in Caenorhabditis elegans, mainly consisting of meiosis and spermiogenesis (or sperm activation), is a complicated cell differentiation process. The germ cells develop into matured motile spermatozoa after the expression of specific genes during meiosis and protein posttranslational modification during spermiogenesis. The spermatozoa compete with each other, communicate with and finally fertilize the oocytes such that new individuals are generated. A group of mutants related to spermatogenesis, sperm motility and fertilization are obtained through the sterile screen. Some specific genes in spermatogenesis and fertilization have been cloned and their functions have been studied. C. elegans is an attractive model to dissect the complexities of spermatogenesis and fertilization. The advances in the study of C. elegans may give insights to important targets for the study of male infertility and contraceptives in humans.
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[
C.elegans Neuronal Development Meeting,
2008]
The nervous system of the C. elegans male contains more neurons than that of the hermaphrodite. Most of the male-specific neurons are found in the tail, where they are involved in sensory input for copulation and generate complex circuitry, primarily in the pre-anal ganglion, that drives the sex and body wall muscles during mating. We have reconstructed the neuronal connectivity in the male pre-anal ganglion by serial-section electron microscopy. Unlike most of the hermaphrodite nervous system, which consists of relatively stable one-dimensional bundles of processes, the male pre-anal ganglion is a volume filled irregularly with hundreds of branching processes running in all directions. It contains some 6,000 chemical and electrical synapses, similar to the number in the entire hermaphrodite nervous system. Sensory neurons from the male-specific sensilla and the phasmid sensilla are individually pre-synaptic to as many as 44 target cells with a range of synaptic strengths. The targets include male-specific neurons as well as neurons of the core nervous system, many of which are extensively sexually differentiated. Within this complex set of synaptic interactions, by analyzing the strongest interactions it is possible to discern discrete circuit modules that appear to underlie the various sub-behaviors of copulation and to assign functions to male-specific interneurons and motor neurons. Backing up appears to be controlled via PVY and PVZ separately from the AVA backup command interneurons. We suggest that PVV and PDC act together with core neuron PDB to control mating posture. PVX appears to be involved with CP1-9 to control the turn. A module receiving input from the hook and post-cloacal sensilla neurons may control vulva tracking. How this complex structure is genetically specified and constructed and how it functions as a coordinated sensory-motor system are questions that can now be more fully addressed.
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[
J Cell Biol,
2019]
Wang studies lysosomal degradation pathways using <i>C. elegans</i> as a model system.
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[
Curr Biol,
2014]
Wang and Seydoux discuss the functional importance of P granules - the germline-specific RNA granules of C. elegans.
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[
Zhonghua Yu Fang Yi Xue Za Zhi,
2009]
OBJECTIVE: To study the possibly transferable properties of multi-biological toxicities caused by aluminium exposure from exposed animals to their progeny. METHODS: Multi-biological toxicities in aluminium (2.5 micromol/L, 75 micromol/L, and 200 micromol/L) exposed animals and their progeny were analyzed by using model organism Caenorhabditis elegans. Endpoints of lifespan, development, reproduction, locomotion behavior and behavioral plasticity were selected for the assay of multiple toxicities and their transfer properties. Four groups of experiments were performed for each endpoint assay. Twenty animals were used for assay of lifespan, development, reproduction and locomotion behaviors, and 100 animals were used for assay of behavioral plasticity in each group experiment. The data were performed for statistical analysis using SPSS 13.0 software. RESULTS: Our data suggest that the aluminium exposure could result in multi-biological defects of phenotypes and behaviors. As compared to those average survival days, 24 d, body size, (1.30 +/- 0.05) mm; brood size, (278 +/- 20); generation time (64.0 +/- 1.2) h; body bend, (45.8 +/- 3.0) times, head thrash, (109.33 +/- 7.30) times, behavioral plasticity (3 +/- 4)% in 0 micromol/L aluminum exposed animals, the low-concentration (2.5 micromol/L) aluminium exposure caused severe defects of average survival days (20 d), body size [(1.12 +/- 0.02 ) mm, t = 14.55, P<0.01], brood size [(145 +/- 23), t = 30.62, P< 0.01], body bend [(29.8 +/- 3.0), t = 20.31, P<0.01], and head thrash, (95.8 +/- 6.2), t = 16.43, P < 0.01]. High-concentration aluminium exposure could further result in severe defects of generation time [75 micromol/L, (67.0 +/- 1.7 ) h, t = 8.92, P<0.01; 200 micromol/L, (70.7 +/- 1.5) h, t =15.13, P<0.01] and behavioral plasticity [75 micromol/L, (16.5 +/- 3.0)%, t = 27.11, P<0.05; 200 micromol/L, (23.5 +/- 4.0)%, t = 16.43, P<0.01]. Moreover, most of these toxicities caused by high-concentration aluminium exposure could be transferred from exposed animals to their progeny. In progeny animals, the phenotypic and behavioral defects might be only partially (such as body size, brood size, and locomotion behaviors) or very slightly (such as the lifespan defects induced by high concentrations of aluminium exposure) rescued. Especially, the generation time defects induced by aluminium exposure would become more severe in progeny animals than in their parents. CONCLUSION: The multi-biological defects caused by aluminium exposure might be largely transferred from exposed animals to their progeny in Caenorhabditis elegans.
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[
Dev Cell,
2017]
In this issue of Developmental Cell, Dickinson etal. (2017) and Rodriguez etal. (2017), along with Wang etal. (2017) in Nature Cell Biology, show how PAR protein oligomerization can dynamically couple protein diffusion and transport by cortical flow to control kinase activity gradients and polarity in the C.elegans zygote.
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[
Dev Cell,
2017]
Reporting in Nature Cell Biology, Lin and Wang (2017) show that bacterial methyl metabolism impacts host mitochondrial dynamics and lipid storage in C.elegans. The authors propose a model whereby bacterial metabolic products regulate a nuclear hormone receptor that promotes lipid accumulation through expression of a secreted Hedgehog-like protein.
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[
Cell,
2014]
The hexosamine biosynthetic pathway (HBP) generates metabolites for protein N- and O-glycosylation. Wang et al. and Denzel et al. report a hitherto unknown link between the HBP and stress in the endoplasmic reticulum. These studies establish the HBP as a critical component of the cellular machinery of protein homeostasis.
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[
Trends Genet,
2023]
Prenatal exposure to environmental agents can influence the fitness of not only the fetus, but also subsequent generations. In a recent study, Wang et al. demonstrated that feeding ursolic acid (UA), a plant-derived compound, to Caenorhabditis elegans mothers during their reproductive period prevented neurodegeneration in not only their offspring, but also the F2 progeny.