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Gross Dissection of the Stomach of the Lobster, Homarus Americanus
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Gross Dissection of the Stomach of the Lobster, Homarus Americanus

Published on: May 22, 2009

The mechanical function and structure of aortic microfibrils in the lobster Homarus americanus

Chantal T Bussiere1, Glenda M Wright, M Edwin DeMont

  • 1School of Biomedical Engineering, Dalhousie University, Halifax, Canada.

Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
|February 21, 2006
PubMed

Insights

Calcium levels significantly impact the stiffness and structure of connective tissues, revealing insights into Marfan syndrome. This study explored how calcium affects fibrillin microfibril mechanical properties.

Area of Science:

  • Biochemistry
  • Biophysics
  • Materials Science

Background:

  • Marfan syndrome is a connective tissue disorder linked to fibrillin gene mutations.
  • Mutations often impact calcium-binding domains, affecting protein structure and function.
  • Calcium's role in microfibril structure and mechanics is hypothesized but not fully understood.

Purpose of the Study:

  • To investigate the effect of varying calcium concentrations on the mechanical properties of lobster aortic rings.
  • To analyze the composition and ultrastructure of microfibrils under different calcium conditions.
  • To compare lobster aortic microfibrils with mammalian fibrillin.

Main Methods:

  • Mechanical testing of fresh and extracted lobster aortic rings at different calcium concentrations (1, 13, 30 mM).
  • Amino acid compositional analysis of extracted samples.
  • Immunohistochemical analysis using antibodies against lobster aortic material.
  • Transmission electron microscopy of strained and unstrained samples.

Main Results:

  • Increased calcium levels (30 mM vs. 1 mM) significantly increased the stiffness (tangent modulus) of fresh aortic rings.
  • Amino acid analysis showed compositional similarity between lobster fibrillin and mammalian fibrillin.
  • Ultrastructural examination revealed that higher calcium concentrations led to more defined microfibril interbead regions.

Conclusions:

  • Calcium ions play a crucial role in regulating the mechanical properties and structural organization of fibrillin-based microfibrils.
  • These findings provide a model for understanding calcium's influence on connective tissue disorders like Marfan syndrome.

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