Braeckman BP et al. (2002) Aging Cell "Rebuttal to Van Voorhies: 'the influence of metabolic rate on longevity in the nematode Caenorhabditis elegans'."

Braeckman BP, Houthoofd K, Vanfleteren JR

[Aging Cell, 2002]

The papers by Van Voorhies in Free Radical Biology & Medicine (33, 587-596, 2002) and in this journal claim that the major longevity-extending mutations in C. elegans essentially act by reducing metabolic rate as predicted by the rate-of-living theory, and do not alter any metabolically independent mechanism specific to aging. In contrast, we found no evidence of a reduction in metabolic rate in these mutants using different experimental approaches. Now, Van Voorhies challenges the accuracy of our experimental results.

Dehn AS et al. (2022) PLoS Biol "Binucleation ramps up gene expression meeting the physiological demands of an organism."

Dehn AS, Losick VP

[PLoS Biol, 2022]

In this issue of PLOS Biology, van Rijnberk and colleagues show how polyploidy, via binucleation, enables Caenorhabditis elegans intestinal cells to ramp up gene expression supplying the oocytes with the necessary lipids for optimal organismal growth and reproductive fitness.

Sendinc E et al. (2015) Cell "Remodeling Your Way out of Cell Cycle."

Sendinc E, Shi Y, Jambhekar A

[Cell, 2015]

Throughout development, proliferative progenitors lose their mitotic potential, exit the cell cycle, and differentiate. In this issue, Ruijtenberg and van den Heuvel identify an important lineage-specific role for a SWI/SNF chromatin-remodeling complex that collaborates with core cell-cycle regulators to promote cell-cycle exit and terminal muscle cell differentiation.

Partridge L et al. (1992) Nature "Evolutionary biology. What the sperm count costs."

Partridge L, Harvey PH

[Nature, 1992]

Dissecting the sex life of the nematode worm Caenorhabditis elegans has already provided surprises for biologists interested in life-history theory. In a report on page 456 of this issue, Van Voorhies throws another spanner in the works by demonstrating that the costs of producing sperm are not as negligible as we might have thought.

Mizushima N (2014) Nat Cell Biol "Sugar modification inhibits autophagosome-lysosome fusion."

Mizushima N

[Nat Cell Biol, 2014]

Autophagy is an intracellular degradation system that is mediated by orchestrated functions of membranes and proteins. A genetic screen in Caenorhabditis elegans revealed that O-linked N-acetylglucosamine modification of the SNARE protein SNAP-29 negatively regulates SNARE-dependent fusion between autophagosomes and lysosomes. This regulatory mechanism is conserved in mammals.

Vincenz L et al. (2014) Cell "Sugarcoating ER Stress."

Vincenz L, Hartl FU

[Cell, 2014]

The hexosamine biosynthetic pathway (HBP) generates metabolites for protein N- and O-glycosylation. Wang et al. and Denzel et al. report a hitherto unknown link between the HBP and stress in the endoplasmic reticulum. These studies establish the HBP as a critical component of the cellular machinery of protein homeostasis.

Van Voorhies WA (2002) Aging Cell "Rebuttal to Braeckman et al: 'Assessing metabolic activity in again Caenorhabditis elegans: concepts and controversies'."

Van Voorhies WA

[Aging Cell, 2002]

The reviews by Braechman et al. and Van Voorhies in this issue of Aging Cell concur on the potential importance of metabolic rate and function to longevity in C. elegans. These reviews differ though, on their assessment of whether long-lived C. elegans mutants have a reduced metabolic rate compared to wild-type worms. At the centre of this disagreement are two main issues: the importance of measurement conditions when conducting metabolic assays on C. elegans, and which techniques are appropriate for measuring the metabolic rate of an organism and subsequent analysis of such data. These issues are interconnected; if the conditions under which an organism's metabolic rate are measured have a large impact on the resulting data, conclusions drawn from data collected from animals under different conditions may be invalid irrespective of the validity of the measurement methods. Conversely, measurement techniques which produce spurious data cannot be used to draw accurate conclusions about the metabolic rate of an organism, regardless of the conditions under which the organism was maintained.

Podbilewicz B (2004) Nat Cell Biol "Sweet control of cell migration, cytokinesis and organogenesis."

Podbilewicz B

[Nat Cell Biol, 2004]

Why are proteins glycosylated? On the basis of new studies, I propose two models to clarify the specific functions of glycosylation in worms. The first explains how intra- and inter-cellular trafficking of an N-glycosylated disintegrin-metalloprotease guides somatic gonadal cells through their migratory route, determining the shape of an organ. The second explains how rigid coats of secreted chondroitin proteoglycans bend membranes to drive cytokinesis and epithelial invagination.

Hodgkin J (2002) Genes Dev "The remarkable ubiquity of DM domain factors as regulators of sexual phenotype: ancestry or aptitude?"

Hodgkin J

[Genes Dev, 2002]

The CM domain is a cysteine-rich DNA-binding motif first recognized in proteins encoded by the Drosophila set determination gene doublesex (Erdman and Burtis 1993; Zhu et al. 2000). As the name doublesex (dsx) suggests, this gene has functions in both sexes: Its transcripts undergo sex-specific alternative splicing, so that it can encode either a male-specific isoform, DSX(M), or a female-specific isoform, DSX(F) (Baker and Wolfner 1988; Burtis and Baker 1989). These proteins have the same N-terminal DNA-binding domain, but different C termini that confer different regulatory properties on the two forms. The expression of DSX(M) directs male development, and the expression of DSX(F) directs female development, throughout most of the somatic tissues of the fruit fly.