Jin Liu et al. (2005) International Worm Meeting "Functional proteomic screens of nuclear envelope components"

Daniel A Starr, Peter Hamilton, Jin Liu

[International Worm Meeting, 2005]

Despite the importance of the nuclear envelope in the cell and its implication in a wide variety of diseases, very little is known about the function of individual components that make up this organelle. A recent proteomic study in mammalian cells (Schirmer et al, 2003) identified 67 new integral nuclear membrane components on top of the approximately a dozen components that were previously known. Our BLAST searches identified 51 potential new nuclear envelope components conserved in C. elegans. To gain some new insights into the nuclear envelope, we are using C. elegans as a model system and employing a reverse genetic approach using RNAi against 51 newly identified, evolutionarily conserved components of the nuclear envelope. We are screening progeny of dsRNA-injected animals for post-embryonic defects in nuclear migration and anchorage similar to null phenotypes in unc-83, unc-84, and anc-1. We are also screening for synthetic lethality with emr-1(gk119). Mutations in emerin have been shown to lead to Emery-Dreifuss muscular dystrophy in human, but are silent in worms (Gruenbaum et al, 2002). We confirmed that lem-2(RNAi); emr-1(gk119) animals are synthetic lethal, as previously shown (Liu et al, 2003). Finally, we are cloning the 51 new potential nuclear envelope proteins into GFP fusion vectors under control of the ubiquitous npp-1 promoter (kind gift of A. Schetter and K. Kemphues) to confirm their predicted localization to the nuclear envelope.

Jin YS et al. (1994) Worm Breeder's Gazette "unc-25 Encodes a C. elegans Glutamic Acid Decarboxylase (GAD)"

Horvitz HR, Jin YS

[Worm Breeder's Gazette, 1994]

unc-25 encodes a C elegans glutamic acid decarboxylase (GAD) Yishi Jin and Bob Horvitz, HHMI, Dept. Biology, Mrr, Cambridge, MA 02139, USA

Howell K et al. (2016) Neuron "Small Immunoglobulin Domain Proteins at Synapses and the Maintenance of Neuronal Features."

Hobert O, Howell K

[Neuron, 2016]

The integrity of neural circuits must be maintained throughout the lifetime of an organism. In this issue of Neuron, Cherra and Jin (2016) characterize a small, two-Ig domain protein, ZIG-10, and its role in maintaining synaptic density in a specific set of C.elegans neurons.

Kaplan HS et al. (2018) Neuron "Sensorimotor Integration for Decision Making: How the Worm Steers."

Zimmer M, Kaplan HS

[Neuron, 2018]

Animals' movements actively shape their perception and subsequent decision making. In this issue of Neuron, Liu etal. (2018) show how C.elegans nematodes steer toward an odorant: a dedicated interneuron class integrates oscillatory olfactory signals, generated by head swings, with corollary discharge motor signals.

Ali L et al. (2020) J Cell Biol "Mitochondrial translation, dynamics, and lysosomes combine to extend lifespan."

Ali L, Haynes CM

[J Cell Biol, 2020]

In this issue, Liu et al. (2019. J. Cell. Biol.https://doi.org/10.1083/jcb.201907067) find that the inhibition of mitochondrial ribosomes in combination with impaired mitochondrial fission or fusion increases C. elegans lifespan by activating the transcription factor HLH-30, which promotes lysosomal biogenesis.

Rahmani, Shapour et al. (2021) MicroPubl Biol

Tuck, Simon, Rahmani, Shapour

[MicroPubl Biol, 2021]

C. elegans males that have come into close proximity of hermaphrodites initiate copulatory behavior comprising at least five different steps termed response, turning, location of vulva, spicule insertion and sperm transfer (Loer and Kenyon 1993, Liu and Sternberg 1995, Chute and Srinivasan 2014). Mutations specifically affecting different steps have been isolated and characterized (Barr and Sternberg 1999, Hajdu-Cronin et al. 2017, Liu et al. 2017). However, our understanding of the molecular mechanisms acting in the neurons controlling copulation is far from complete. During the response step, males that have sensed the presence of a hermaphrodite move backwards in such a way that the males tail fan glides along the surface of the hermaphrodite until the tail reaches the vulva (or head or tail) (Loer and Kenyon 1993, Liu and Sternberg 1995, Sherlekar and Lints 2014). Response behavior is regulated by ciliated neurons in the tail whose dendrites lie in sensory rays within the fan (Liu and Sternberg 1995). If a male reaches the end of the hermaphrodite without having found the vulva, it executes a turn during which the tail bends tightly ventrally so that contact is established between the ventral surface of the fan and the other side of the intended mate (Loer and Kenyon 1993, Liu and Sternberg 1995). The ability to execute turns efficiently is dependent upon serotonergic neurons in the posterior ventral nerve cord (the CP neurons) and on their ability to produce serotonin (Loer and Kenyon 1993, Carnell et al. 2005). Serotonin stimulates the diagonal muscles in the tail to induce curling ventrally by stimulating a serotonin receptor, SER-1 (Loer and Kenyon 1993, Carnell et al. 2005). However, how serotonin affects diagonal muscles and ventral turning is not fully understood.

Kirkwood TB (2013) Cell Metab "Untangling functional declines in the locomotion of aging worms."

Kirkwood TB

[Cell Metab, 2013]

All physiological functions decline with age, but which changes are primary and which are secondary is not always clear. Liu et al. (2013), examining functional changes in the muscles and motor neurons of C. elegans, suggest that when it comes to locomotion, it is the nervous system that shows earlier age-related deterioration.

David S Peal et al. (2001) International C. elegans Meeting "Chemical and Genetic Inhibition of Sulfation in C. elegans"

David S Peal, Laura L Kiessling

[International C. elegans Meeting, 2001]

In order to examine the process of sulfation in C. elegans, sulfation was inhibited chemically using sodium chlorate, and genetically using the process of RNA-mediated interference (RNAi). Sodium chlorate inhibition during early larval stages resulted in a dose-dependant developmental delay. BLAST searches of characterized sulfotransferases against the worm genome resulted in the identification of 4 putative sulfotransferases: C34F6.4 and F08B4.6 (previously identified: [1] and [2]), F40H3.5, and Y34B4A.e. RNAi of the putative N-deacetylase/N-sulfotransferase F08B4.6 resulted in "stacking" of eggs in the gonad, along with eggs laid at the 2- and 4-celled stage. RNAi of the putative hexuronic 2-O sulfotransferase C34F6.4 resulted in a shortened, bulbous gonad. These initial results indicate that sulfation may be important during development of C. elegans. [1] Shworak, NW, Liu, J, Fritze, LMS, Schwartz, JJ, Zhang, L, Logeart, D, Rosenberg, RD. JBC 272: 28008-19 (1997). [2] Kobayashi, M, Sugumaran, G, Liu, J, Shworak, NW, Silbert, JE, Rosenberg, RD. JBC 274: 10474-80 (1999).

(2024) Development "The people behind the papers - Alyshia Scholl, Yihong Liu and Geraldine Seydoux."

[Development, 2024]

Germ granules have been hypothesized to deliver mRNAs of germ cell fate determinants to primordial germ cells. Now, a new study in Development finds that many mRNAs enriched in germ granules are not involved in germline development in Caenorhabditis elegans. To find out more about the story behind the paper, we caught up with first author Alyshia Scholl, second author Yihong Liu and corresponding author Geraldine Seydoux, Professor at Johns Hopkins University School of Medicine.

Gary Schindelman et al. (2002) West Coast Worm Meeting "Characterization of the sperm transfer step of male mating behavior of Caenorhabditis elegans ."

Gary Schindelman, Allyson J Whittaker, Shahla Gharib, Paul W Sternberg

[West Coast Worm Meeting, 2002]

C. elegans male mating behavior involves the proper execution of a series of sub-behaviors culminating in the transfer of sperm to the hermaphrodite (Liu, KS and Sternberg, PW. 1995. Neuron 14:79-89). These sub-behaviors are: Response to hermaphrodite, backing, turning, vulval location, spicule insertion and sperm transfer. We are analyzing the genetic control of this stereotyped behavior as it may provide insight into sensory perception and nervous system function.