Sex differences in carbohydrate metabolism are linked to gene expression in Caenorhabditis elegans

PLoS One. 2012;7(9):e44748. doi: 10.1371/journal.pone.0044748. Epub 2012 Sep 11.


The male and the hermaphrodite forms of the nematode Caenorhabditis elegans (C. elegans) differ markedly in anatomy, nervous system and behavior at adulthood. Using the male mutants fog-2, him-5, and him-8, we compared body proportions and composition, and aspects of carbohydrate metabolism and gene expression between the C. elegans sexes in three adult stages. In all experiments, both sexes were grown on the same plate and separated using flow cytometry. The fat to fat-free mass ratio and the body volume-adjusted fat mass is similar between the sexes, although the body size is more than 50% smaller in adult males than in age-matched hermaphrodites. The volume-adjusted total RNA content is approximately 2-fold lower in males. Biochemical and NMR-based analyses reveal higher trehalose levels and much lower glucose levels in males than in hermaphrodites. The resulting trehalose-to-glucose ratio is 5.4-fold higher in males. These sex differences are reflected in gene expression data because the genes encoding key enzymes of the glycolysis and trehalose synthesis pathways are more highly expressed in males than in hermaphrodites. Notably, expression of the phosphofructokinase gene (C50F4.2) is 29-fold higher in males. Comparative analysis of gene expression data identifies 285 male-specific and 160 hermaphrodite-specific genes. These include transcription factor and C-type lectin-encoding genes. More than 35% of all C-type lectin genes are more highly expressed in males. The expression of many C-type lectin genes differs by a factor of >100 between the sexes. In conclusion, we found sex differences in carbohydrate metabolism that are linked to gene expression and identified certain lectin genes that are differentially expressed by the C. elegans sexes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Size
  • Caenorhabditis elegans / metabolism*
  • Carbohydrate Metabolism*
  • Female
  • Flow Cytometry / methods
  • Gene Expression Regulation*
  • Green Fluorescent Proteins / metabolism
  • Lectins, C-Type / metabolism
  • Male
  • Phosphofructokinases / biosynthesis
  • RNA / metabolism
  • Sex Characteristics
  • Sex Factors
  • Trehalose / metabolism


  • Lectins, C-Type
  • Green Fluorescent Proteins
  • RNA
  • Trehalose
  • Phosphofructokinases

Grants and funding

This work was supported by a structural grand from the Deutsche Forschungsgemeinschaft in the context of the Cluster of Excellence “Inflammation at Interfaces” at the University of Kiel and by a grant form the German Ministry of Education and Research (BMBF 0315681). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.