Nariya, Hardik et al. (2017) International Worm Meeting "An investigation of the effects of artificial light at night on C. elegans offspring production and lifespan."

Buchanan, Bryant, Wise, Sharon, Zhushma, Rosa, Nariya, Hardik, Shinn-Thomas, Jessica

[International Worm Meeting, 2017]

Artificial light at night (ALAN) has many broad-scale and global implications for ecosystems and wildlife that have evolved under a 24-h circadian cycle. With increased urbanization, artificial light at night has directly altered natural photoperiods and nocturnal light intensity. Artificial light at night can disrupt behavioral patterns such as foraging activity and mating in animals. Disturbances in natural light and dark cycles also affect melatonin-regulated circadian and seasonal rhythms in Drosophila. We investigated the impact of ecologically relevant levels of light pollution on an important invertebrate model, Caenorhabditis elegans, as the impact of night lighting at these light levels is currently unknown. In this study, we exposed worms to artificial light at four intensities: 10-4 lx (control, comparable to natural nocturnal darkness), 10-2 lx (comparable to full-moon lighting and a low level of light pollution), 1 lx (comparable to dawn/dusk or intense light pollution), and 100 lx (dim daylight level comparable to extreme light pollution) on a 12L:12D photoperiod (100 lx treatments experienced constant light). We measured the impact of these light treatments on offspring production in hermaphroditic C. elegans. We grew worms for 2 generations in each light treatment, and then recorded the lifespan and counted the number of hatched offspring produced in the F3 generation. Our data show no significant differences among light levels for lifespan or offspring production suggesting that at least for these life history traits, ALAN does not affect these soil nematodes. Future directions include measuring additional life history traits and circadian gene expression for worms exposed to ALAN.

Morita K et al. (1997) International C. elegans Meeting "FUNCTIONAL ANALYSIS OF A BMP-RELATED GENE IN C. ELEGANS"

Ueno N, Morita K

[International C. elegans Meeting, 1997]

We have identified a cDNA sequence that encodes a BMP-related protein by PCR using degenerate oligonucleotide primers designed in mature protein sequence conserved among vertebrate BMP subfamily members. Sequencing of a full-length cDNA has revealed that the predicted protein is most similar to mammalian nodal and BMP-5~7 subfamily members (over 50% amino acid identity in so-called functional domain resides between 3rd and 4th conserved cysteine residues in the mature protein). Northern blot analysis demonstrated that the gene is expressed throughout the development. CEBMP/GFP-fusion expression was detected in some neurons including CAN and ventral nerve cord. Functional analysis was performed by overexpressing CEBMP and its mutant cDNA under the control of a heat-shock promotor. Overexpression of wild type CEBMP did not perturb normal development. However, worms expressing unprocessed form of CEBMP which functions dominant negatively ( Wittbrodt, Rosa Gen.Dev. 8.1448-1462 1994) displayed small phenotype (approximately 30% of transgenic worms), suggesting that CEBMP mediates a signal through sma-2,3,4, a C. elegans homologue of Drosophila mad which act downstream of dpp. Taken together, CEBMP may be a homologue of dpp and thus provide another genetical probe to explore the intracellular TGF-beta signaling. Null mutant is currently being searched from Tc1 insertion mutants.

Veuthey, Tania et al. (2021) International Worm Meeting "Tyramine modulates the systemic stress response by stimulating the release of intestinal insulin like-peptides (ILPs)"

Rayes, Diego, Alkema, Mark, Giunti, Sebastian, Veuthey, Tania, De Rosa, Maria Jose, Florman, Jeremy

[International Worm Meeting, 2021]

Multicellular organisms trigger a complex and coordinated response against systemic stress. We have recently shown that in C. elegans, the neural stress-hormone tyramine supplies a state-dependent neural switch between acute flight- and long-term environmental-stress responses (De Rosa et al, 2019). Tyramine release during the flight response, stimulates the DAF-2/Insulin/IGF-1 signaling (IIS) pathway and precludes the nuclear translocation of the DAF-16/FOXO transcription factor through the activation of an adrenergic-like receptor TYRA-3 in the intestine. We hypothesize that tyramine stimulates the release of agonist ILPs from the intestine which acts as an autocrine and/or paracrine signal to systemically activate the DAF-2/IIS pathway. To test this hypothesis we are screening ILPs mutants for their resistance to environmental stressors (oxidative and thermal stress). The C. elegans genome encodes 40 ILPs, 28 of which expressed in the intestine. We performed a screening of intestinal peptides described as strong DAF-2 agonist, by silencing individual intestinal ILPs and testing worm resistance to environmental stressors (oxidative and thermal stress). Thus, so far we found that ins-3 and ins-7 mutants are resistant to environmental stress, like tyramine-deficient and tyra-3 mutants. We are further testing whether tyramine directly stimulates the release of these ILPs from the intestine through a Gq-protein mediated signaling pathway. These studies will provide insight into how a neurohormone coordinates systemic cellular stress responses.