Methods to Assess Subcellular Compartments of Muscle in <em>C. elegans</em>

Abstract

Muscle is a dynamic tissue that responds to changes in nutrition, exercise, and disease state. The loss of muscle mass and function with disease and age are significant public health burdens. We currently understand little about the genetic regulation of muscle health with disease or age. The nematode C. elegans is an established model for understanding the genomic regulation of biological processes of interest. This worm's body wall muscles display a large degree of homology with the muscles of higher metazoan species. Since C. elegans is a transparent organism, the localization of GFP to mitochondria and sarcomeres allows visualization of these structures in vivo. Similarly, feeding animals cationic dyes, which accumulate based on the existence of a mitochondrial membrane potential, allows the assessment of mitochondrial function in vivo. These methods, as well as assessment of muscle protein homeostasis, are combined with assessment of whole animal muscle function, in the form of movement assays, to allow correlation of sub-cellular defects with functional measures of muscle performance. Thus, C. elegans provides a powerful platform with which to assess the impact of mutations, gene knockdown, and/or chemical compounds upon muscle structure and function. Lastly, as GFP, cationic dyes, and movement assays are assessed non-invasively, prospective studies of muscle structure and function can be conducted across the whole life course and this at present cannot be easily investigated in vivo in any other organism.

Loss of MTX2 causes mandibuloacral dysplasia and links mitochondrial dysfunction to altered nuclear morphology

“…To check whether complete mtx-2 inactivation in C. elegans recapitulated the mitochondrial fragmentation seen in patients’ fibroblasts, we assessed mitochondrial network morphology in body wall muscle cells of mtx-2 KO worms expressing mitogfp ( mtx-2 KO; mitogfp strain) and assigned it to either normal (“tubular” and “intermediate”) or abnormal (“disordered”, “fragmented” and “very fragmented”) category (Fig. 5i and methods) 51 . Despite some variability among individual body-wall muscle cells and animals, we observed normal mitochondrial morphology in wild-type mitogfp individuals (100%; n = 17), consistent with previously published results 52 .…”

A human-origin probiotic cocktail ameliorates aging-related leaky gut and inflammation via modulating the microbiota/taurine/tight junction axis

“…One leftward and 1 rightward bend were considered as 1 stroke, and counting was repeated 5 times in 50-100 animals in each group. The numbers were multiplied by 6 to give the movement rate per minute, as described elsewhere (88).…”

Degenerin channel activation causes caspase-mediated protein degradation and mitochondrial dysfunction in adultC. elegansmuscle

“…Synchronized worms were grown to early adulthood. Twenty animals per trial were processed as described in 4.7 μM CMXRos …”

“…Twenty animals per trial were processed as described in 4.7 μM CMXRos. 24 JC-10 in vivo accumulation assay. Synchronized worms were grown from the L1 stage in the presence of 83 μM JC-10 (Enzo Life Sciences, NY, USA).…”