Schreier J et al. (2022) Nat Cell Biol "Membrane-associated cytoplasmic granules carrying the Argonaute protein WAGO-3 enable paternal epigenetic inheritance in Caenorhabditis elegans."

Gleason EJ, Oorschot V, Seistrup AS, Butter F, Schreier J, de Jesus Domingues AM, Phillis S, Dietz S, Bronkhorst AW, Phillips CM, Nguyen DAH, Boermel M, Ketting RF, L'Hernault SW

[Nat Cell Biol, 2022]

Epigenetic inheritance describes the transmission of gene regulatory information across generations without altering DNA sequences, enabling offspring to adapt to environmental conditions. Small RNAs have been implicated in this, through both the oocyte and the sperm. However, as much of the cellular content is extruded during spermatogenesis, it is unclear whether cytoplasmic small RNAs can contribute to epigenetic inheritance through sperm. Here we identify a sperm-specific germ granule, termed the paternal epigenetic inheritance (PEI) granule, that mediates paternal epigenetic inheritance by retaining the cytoplasmic Argonaute protein WAGO-3 during spermatogenesis in Caenorhabditis elegans. We identify the PEI granule proteins PEI-1 and PEI-2, which have distinct functions in this process: granule formation, Argonaute selectivity and subcellular localization. We show that PEI granule segregation is coupled to the transport of sperm-specific secretory vesicles through PEI-2 in an S-palmitoylation-dependent manner. PEI-like proteins are found in humans, suggesting that the identified mechanism may be conserved.

Schreier, Jan et al. (2021) International Worm Meeting "A novel sperm-specific compartment secures a cytoplasmic Argonaute protein for paternal epigenetic inheritance of small RNA-mediated gene silencing"

Boermel, Mandy, Butter, Falk, Dietz, Sabrina, Schreier, Jan, Ketting, Rene, Seistrup, Ann-Sophie, Domingues, Antonio, Bronkhorst, Alfred, Oorschot, Viola, L'Hernault, Steven, Phillips, Carolyn, Nguyen, Dieu

[International Worm Meeting, 2021]

Germ cells possess specialized perinuclear, phase-separated compartments, also named condensates. Amongst others, they contain the mRNA surveillance machinery responsible for transposon silencing and fertility. In the nematode Caenorhabditis elegans, three condensates, P granules, Z granules and Mutator foci, are home to RNA interference-related pathways, driven by a highly diversified Argonaute sub-clade (WAGO) that mediates gene silencing. Intriguingly, it has been shown that WAGO-mediated gene silencing can be inherited via both oocyte and sperm. Especially the inheritance via sperm is remarkable, since significant amounts of cellular material, including Argonaute proteins, are expelled from maturing spermatids into so-called residual bodies. How then does sperm-mediated inheritance of cytoplasmic RNAi work? We genetically identify WAGO-3 as a major Argonaute protein required for the paternal inheritance of endogenous small RNAs. Just like other Argonaute proteins, like WAGO-1 and ALG-3, WAGO-3 localizes to P granules in naive germ cells. During spermatogenesis, however, P granules disappear and WAGO-3, but not WAGO-1 and ALG-3, accumulates in a newly identified condensate, the PEI granule. In contrast to P granules, PEI granules remain stable during later stages of spermatogenesis. They are retained within maturing spermatids and selectively keep WAGO-3 from accumulating in the residual body. Using immunoprecipitation experiments followed by label-free quantitative mass spectrometry, we identified two uncharacterized proteins: PEI-1 and PEI-2. Both proteins are specifically expressed during spermatogenesis and we dissect their roles in PEI granule transport and function. Based on correlative light and electron microscopy (CLEM) and genetic studies, proper segregation of PEI granules in mature sperm is coupled, likely via S-palmitoylation, to the myosin-driven transport of membranous organelles. Our results identify a new sperm-specific condensate, which we call PEI granules. While not essential for spermatogenesis, PEI granules are required for paternal inheritance of small RNAs and we reveal a novel mechanism for the subcellular sorting of condensates through coupling to transport of membranous structures. pei-like genes are also found in human and often expressed in testis, suggesting that the here identified mechanism of subcellular transport of membraneless organelles may be more broadly conserved.

Maine EM et al. (1994) Worm Breeder's Gazette "Mutations That Enhance glp-1 Identify Genes Required For Various Aspects of Germline Development."

Gelber MB, Smardon AM, Shu P, Qiao L, Maine EM, Lissemore JL

[Worm Breeder's Gazette, 1994]

Mutations that enhance glp-1 identify genes required for various aspects of germline development. Eleanor Maine, Li Qiao, Jim Lissemore-, Pei Shu, Anne Smardon, and Melanie Gelber. Biology Dept., Syracuse University, Syracuse, NY 13244 and Biology Dept., John Carroll University, Cleveland, OH 44118.

Chang SY et al. (2017) J Microbiol Biotechnol "Erratum to: Genome Characteristics of Lactobacillus fermentum Strain JDFM216 for Application as Probiotic Bacteria."

Lee HK, Heo J, Chang SY, Jeong DY, Oh S, Jo SH, Kim Y, Park MR, Song MH, Kim JN

[J Microbiol Biotechnol, 2017]

This erratum is being published to correct the 1st author's name of above manuscript by Jang et al. that was published in Journal of Microbiology and Biotechnology (2017, 27: 1266-1271). The 1st author name(Sung Yong Jang) should appear as 'Sung Yong Chang'.

Opperman CH et al. (1992) Parasitol Today "Nematode acetylcholinesterases--molecular forms and their potential role in nematode behavior."

Chang S-H, Opperman CH

[Parasitol Today, 1992]

Nematode movement is reliant upon the somatic musculature that runs longitudinally along the body wall. Neuromuscular synapses occur in the ventral and dorsal cords and employ the excitatory neurotransmitter, acetylcholine (ACh), for modulation of muscle activity. Acetylcholine activity is terminated by hydrolysis by acetylcholinesterase (AChE). Here, Charles Opperman and Stella Chang discuss the molecular forms and potential role of this enzyme.

Chang Y et al. (2022) STAR Protoc "Non-invasive chimeric HaloTag labeling to study clustering and diffusion of membrane proteins."

Chang Y, Dickinson DJ

[STAR Protoc, 2022]

As live imaging plays an increasingly critical role in cell biology research, the desire to label and track individual protein molecules in vivo has been growing. To address this, in this protocol we describe steps for sparse labeling using two different HaloTag ligand dyes in C. elegans. This labeling approach is simple, is non-invasive, and preserves the view of the bulk protein population. We further describe how to carry out single-particle tracking experiments and extract information about particle diffusion behavior. For complete details on the use and execution of this protocol, please refer to Chang and Dickinson (2022).¹.

Yang XL et al. (1998) Science "Essential role of CED-4 oligomerization in CED-3 activation and apoptosis."

Chang HY, Yang XL, Baltimore D

[Science, 1998]

Control of the activation of apoptosis is important both in development and in protection against cancer. In the classic genetic model Caenorhabditis elegans, the pro-apoptotic protein CED-4 activates the CED-3 caspase and is inhibited by the Bcl-2-like protein CED-9. Both processes are mediated by protein-protein interaction. Facilitating the proximity of CED-3 zymogen molecules was found to induce caspase activation and cell death. CED-4 protein oligomerized in cells and in vitro. This oligomerization induced CED-3 proximity and competed with CED-4:CED-9 interaction. Mutations that abolished CED-4 oligomerization inactivated its ability to activate CED-3. Thus, the mechanism of control is that CED-3 in CED-3:CED-4 complexes is activated by CED-4 oligomerization, which is inhibited by binding of CED-9 to CED-4.AD - Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.FAU - Yang, XAU - Yang XFAU - Chang, H YAU - Chang HYFAU - Baltimore, DAU - Baltimore DLA - engID - CA51462/CA/NCIPT - Journal ArticleCY - UNITED STATESTA - ScienceJID - 0404511RN - 0 (Biopolymers)RN - 0 (Calcium-Binding Proteins)RN - 0 (Ced-4 protein)RN - 0 (Ced-9 protein)RN - 0 (Cysteine Proteinase Inhibitors)RN - 0 (Enzyme Precursors)RN - 0 (Helminth Proteins)RN - 0 (Oligopeptides)RN - 0 (Proto-Oncogene Proteins)RN - 0 (Proto-Oncogene Proteins c-bcl-2)RN - 0 (Recombinant Fusion Proteins)RN - 0 (bcl-x protein)RN - 109581-93-3 (Tacrolimus)RN - EC 3.4.22 (Cysteine Endopeptidases)RN - EC 3.4.22.- (Ced-3 protein)SB - IM

Chen, Yuan-Hua et al. (2021) International Worm Meeting "Distinct neural circuits drive bimodal ethanol chemotaxis in C. elegans"

Xue, Wei-Kang, Yu, Yanxun V, Wang, Bo, Wang, Yuan-Xia, Chang, Pei, Chen, Yuan-Hua

[International Worm Meeting, 2021]

Environmental factors can modulate animals' perception of a stimulus and thus change the elicited downstream behavior. It has been shown that ethanol can cause intoxication in C. elegans, therefore ethanol may be a cue worms would like to avoid. However, ethanol may also represent information about food availability worms would like to seek since fruit fermentation often produces ethanol. In the process of looking for ethanol-elicited behavior, we find that ethanol elicits distinct chemotaxis behavior in C. elegans depending on the concentration of sodium chloride. Worms are attracted toward ethanol in the low sodium environment (positive chemotaxis), while they exhibit strong repulsive behavior to ethanol in the high sodium environment (negative chemotaxis). In sharp contrast, C. elegans exhibits unimodal behavior in response to other odorants such as isoamyl alcohol, diacetyl, or 2-nonanone, regardless of the sodium concentration. Interestingly, we have discovered only sodium but not potassium or osmolality as the determining factor for worm's bimodal ethanol chemotaxis behaviors. In searching for the signaling molecules involved, we have discovered that the positive chemotaxis depends on DAF-11, while the negative chemotaxis depends on CHE-1, GPA-3 and OSM-3. Ethanol chemotaxis in both directions depends on TAX-4 and EAT-4, while ODR-1 or ODR-3 is involved in neither. Analysis of the related neural circuit reveals that the negative chemotaxis to ethanol is likely mediated by the ASE chemosensory neurons, while the positive chemotaxis involves the AWC neurons. Our study provides novel insight into how environmental factors can bias chemotaxis behavior by engaging distinct chemotactic neural circuits. And it may provide a model to dissect how environmental factors modulate behavior.

Rahman MM et al. (2021) Bio Protoc "A Workflow for High-pressure Freezing and Freeze Substitution of the Caenorhabditis elegans Embryo for Ultrastructural Analysis by Conventional and Volume Electron Microscopy."

Chang IY, Narayan K, Rahman MM, Cohen-Fix O

[Bio Protoc, 2021]

The free-living nematode <i>Caenorhabditis elegans</i> is a popular model system for studying developmental biology. Here we describe a detailed protocol to high-pressure freeze the <i>C. elegans</i> embryo (either <i>ex vivo</i> after dissection, or within the intact worm) followed by quick freeze substitution. Processed samples are suitable for ultrastructural analysis by conventional electron microscopy (EM) or newer volume EM (vEM) approaches such as Focused Ion Beam Scanning Electron Microscopy (FIB-SEM). The ultrastructure of cellular features such as the nuclear envelope, chromosomes, endoplasmic reticulum and mitochondria are well preserved after these experimental procedures and yield accurate 3D models for visualization and analysis ( Chang <i>et al.</i>, 2020 ). This protocol was used in the 3D reconstruction of membranes and chromosomes after pronuclear meeting in the <i>C. elegans</i> zygote ( Rahman <i>et al.</i>, 2020 ).

Ren P et al. (1996) Worm Breeder's Gazette "Expression of DAF-7 in chemosensory neurons"

Albert PS, Riddle DL, Ren P

[Worm Breeder's Gazette, 1996]

Mutations in daf-7 result in constitutive formation of dauer larvae. The daf-7 gene encodes a secreted protein that is a novel member of the TGF- beta superfamily (Chang-Su Lim, Ph.D. Thesis, 1994). Laser ablation experiments have determined that amphid sensory neurons ADF, ASG, ASI and ASJ function in the regulation of dauer formation (Bargmann et al., Science 251,1243). Our hypothesis is that daf-7 might be expressed in the amphid neurons to promote non-dauer development in response to food stimuli. Secreted DAF-7 ligand may then bind the DAF-1 and/or DAF-4 receptors which are transmembrane receptor serine/threonine kinases in the TGF-beta receptor family (Georgi et al., Cell 61, 635; Estevez et al., Nature 365, 644). Our expression data indicated that daf-1 and daf-4 are expressed in interneurons and in amphid neurons (Georgi and Estevez, unpublished).