Design Principles of Reptilian Muscles: Calcium Cycling Strategies

ABSTRACT The ultrastructure of the sarcoplasmic reticulum (SR) in skeletal muscles was compared among different reptile species (watersnake, boa constrictor, lizard, and turtle) and a mammal (mouse). Morphometric analysis demonstrates a pattern of increasing calsequestrin (CASQ) content in the lumen...

Full description

Saved in:
Bibliographic Details
Published in:Anatomical record (Hoboken, N.J. : 2007) N.J. : 2007), 2016-03, Vol.299 (3), p.352-360
Main Authors: Perni, Stefano, Close, Matthew, Franzini‐Armstrong, Clara
Format: Article
Language:English
Subjects:
Animals
Boa constrictor
Calcium - metabolism
calsequestrin
Calsequestrin - metabolism
Lacertilia
Mice
reptiles
Reptiles - physiology
sarcoplasmic reticulum
Sarcoplasmic Reticulum - physiology
Sarcoplasmic Reticulum - ultrastructure
Sarcoplasmic Reticulum Calcium-Transporting ATPases - metabolism
skeletal muscle
Squamata
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:ABSTRACT The ultrastructure of the sarcoplasmic reticulum (SR) in skeletal muscles was compared among different reptile species (watersnake, boa constrictor, lizard, and turtle) and a mammal (mouse). Morphometric analysis demonstrates a pattern of increasing calsequestrin (CASQ) content in the lumen of SR from turtle to lizard, watersnake, and boa constrictor, and this content is in all cases higher than in mouse. In all reptiles sampled except turtle, CASQ is not confined to the junctional sarcoplasmic reticulum (jSR) cisternae as it is in other species. It instead fills the entire longitudinal (free) SR (fSR) regions, and in the extreme case of snakes, the shape of the SR is modified around the extra CASQ. We suggest that high CASQ content may represent an ATP‐saving adaptation that permits relatively low metabolic rates during prolonged periods of fasting and inactivity, particularly in watersnake and boa constrictor. Anat Rec, 299:352–360, 2016. © 2015 Wiley Periodicals, Inc.
ISSN:1932-8486
1932-8494
DOI:10.1002/ar.23302