Molecular Regulation of Muscle Growth in Crustacea

Abstract

Tissue growth in Crustacea occurs at specific stages of the moult cycle and is influenced by a number of physical, hormonal and environmental factors. In order to understand the mechanisms responsible for controlling intermittent muscle growth in Crustacea, the effects of various factors on rates of protein synthesis and gene expression for the myofibrillar proteins, have been examined. These studies include the effects of mechanical stretch on muscle fibres; the influence of the moulting hormones, ecdysteroids; and the effect of temperature which is an important environmental variable. Sarcomeric proteins have been cloned and used to measure mRNA levels of actin, myosin HC and tropomyosin in various muscles over the moult cycle. Results from these studies demonstrate that both transcriptional and translational regulation occurs in response to hormonal and mechanical stimulation. Temperature has a direct effect on rates of protein synthesis and transcription in intermoult muscles but overall protein turnover may remain unchanged due to a concomitant increase in protein degradation rates.

Thermal tolerance and oxygen consumption of Macrobrachium rosenbergii acclimated to three temperatures

“…Over the last few years, there has been an emerging interest in the effects of temperature on metabolic activity in crustaceans (Whiteley et al, 1996;Whiteley and El Haj, 1997;El Haj and Whiteley, 1997). Rate of oxygen consumption is an indication of energy utilization by the animals (Brett, 1964;Kutty, 1968).…”

Nucleic acids as indicators of nutritional condition in the Norway lobster Nephrops norvegicus

“…However, recent investigations on decapods have found no influence of moult stage on the nucleic acid concentrations of whitemuscle tissue from either the abdomen (Moss 1994a, El Haj et al 1996, El Haj & Whiteley 1997 or the legs (including claws) (El Haj et al 1996). El Haj et al (1996) did record an increase in protein synthesis during pre-moult, but suggested that an increase in ribosomal activity, rather than RNA concentration, was responsible.…”

Eyestalk Ablation Has Little Effect on Actin and Myosin Heavy Chain Gene Expression in Adult Lobster Skeletal Muscles

“…hormones are responsible for such molt-related changes in skeletal muscles as the atrophy of the large cheliped muscles in some decapod crustaceans (El Haj and Houlihan, 1987;Ismail and Mykles, 1992;El Haj et ai. 1996;El Haj and Whiteley, 1997;Whiteley and El Haj, 1997). Moreover, an ecdysteroid receptor has been detected in lobster muscle (El Haj et ai, 1994).…”