Natural reversal of left-right gut/gonad asymmetry in C. elegans males is independent of embryonic chirality.

TitleNatural reversal of left-right gut/gonad asymmetry in C. elegans males is independent of embryonic chirality.
Publication TypeJournal Article
Year of Publication2014
AuthorsCallander DC, Alcorn MR, Birsoy B, Rothman JH
Date Published2014 Jun
KeywordsAnimals, Body Patterning, Caenorhabditis elegans, Embryonic Development, Gonads, Male, Organogenesis

Anatomical left-right (L/R) asymmetry in C. elegans is established in the four-cell embryo as a result of anteroposterior skewing of transverse mitotic spindles with a defined handedness. This event creates a chiral embryo and ultimately an adult body plan with fixed L/R positioning of internal organs and components of the nervous system. While this "dextral" configuration is invariant in hermaphrodites, it can be reversed by physical manipulation of the early embryo or by mutations that interfere with mitotic spindle orientation, which leads to viable, mirror-reversed (sinistral) animals. During normal development of the C. elegans male, the gonad develops on the right of the midline, with the gut bilaterally apposed on the left. However, we found that in males of the laboratory N2 strain and Hawaiian ("Hw") wild isolate, the gut/gonad asymmetry is frequently reversed in a temperature-dependent manner, independent of normal embryonic chirality. We also observed sporadic errors in gonad migration occurring naturally during early larval stages of these and other wild strains; however, the incidence of such errors does not correlate with the frequency of L/R gut/gonad reversals in these strains. Analysis of N2/Hw hybrids and recombinant inbred advanced intercross lines (RIAILs) indicate that the L/R organ reversals are likely to result from recessively acting variations in multiple genes. Thus, unlike the highly reproducible L/R asymmetries of most structures in hermaphrodites, the L/R asymmetry of the male C. elegans body plan is less rigidly determined and subject to natural variation that is influenced by a multiplicity of genes.

Alternate JournalGenesis
PubMed ID24585712
PubMed Central IDPMC4065204
Grant List1R01 HD062922 / HD / NICHD NIH HHS / United States
1R21GM094649 / GM / NIGMS NIH HHS / United States
P40 OD010440 / OD / NIH HHS / United States
R01 HD062922 / HD / NICHD NIH HHS / United States
R21 GM094649 / GM / NIGMS NIH HHS / United States