Effects of Developmental Exposure to Ethanol on Caenorhabditis elegans

Abstract

Background: We investigated the effects of chronic ethanol exposure on physical development, reproduction, and life expectancy of Caenorhabditis elegans, a microscopic nematode worm. It has a small nervous system of 302 neurons and a short lifespan of 2 to 3 weeks.Methods: In this study, the worms were chronically exposed to varying concentrations of ethanol for different periods of their life: for their entire lifespan, during larval development only, and during adulthood only. In addition, the worms were exposed to ethanol acutely during different stages of embryonic development.Results: Chronic exposure to ethanol during larval development temporarily delayed physical growth, slowed development, delayed the onset of reproductive maturity, and decreased both reproductive fecundity and longevity. Chronic exposure to ethanol beginning when worms completed development and reached reproductive maturity resulted in reduced C. elegans body length, decreased reproductive fecundity, and life expectancy. Finally, acute embryonic exposure of C. elegans eggs to high concentrations of ethanol at different stages of development resulted in a lower probability of exposed eggs hatching into larval worms depending on when eggs were exposed during development. Furthermore, some of the worms that did hatch displayed distinct physical dysmorphologies as a consequence of acute ethanol exposure during embryonic development.Conclusions: These data suggest that exposing C. elegans to ethanol during critical development periods results in characteristic phenotypic outcomes. Thus, C. elegans offers a novel model for exploring the mechanisms by which ethanol exposure affects development.

The Genetics of Alcohol Responses of Invertebrate Model Systems

“…The severity of the defects is dose dependent (Davis, Li, & Rankin, 2008), and the pathway of ethanol catabolism appears to be conserved between nematodes, flies, and mammals (Alaimo et al, 2012).…”

Effects of prenatal alcohol exposure (PAE): insights into FASD using mouse models of PAE

“…While this work is largely outside the scope of this review, it is noteworthy that studies utilizing C. elegans (Davis et al 2008), and chicken models (Pennington et al 1983; Cartwright and Smith 1995) have revealed important adverse effects of alcohol on craniofacial development, growth, the developmental trajectory, reproductive maturity, and overall longevity, and have elucidated how the dose and timing of alcohol exposure may contribute to outcomes. In support of the significance of these findings in non-mammalian models is work on the effects of alcohol on mammalian embryos.…”

A Comparison of the Different Animal Models of Fetal Alcohol Spectrum Disorders and Their Use in Studying Complex Behaviors

“…For FASD research, the microscopic nematode worm C. elegans is the most commonly used. While mammals offer significant advantages over invertebrates when examining brain structures or complex behaviors, simple invertebrates such as C. elegans can be extremely useful when examining basic biological development at the cellular, molecular, and genetic levels (145). The complete genome of C. elegans has been sequenced, and the simple nervous system contains only 302 neurons with 5000 synapses.…”

“…A significant disadvantage to using this model is that the egg develops outside of the body and therefore alcohol exposure cannot occur as it does in human beings (via the placental membrane following oral ingestion). Instead, C. elegans eggs or newly hatched larvae are exposed to ethanol through bath application (145). Another disadvantage with this model is that BACs cannot be directly measured.…”