Award Abstract # 2025434
ISS: Unveiling the Mechanical Roles of Gravity and Buoyancy in Embryonic Brain and Heart Torsion

NSF Org: CMMI
Division of Civil, Mechanical, and Manufacturing Innovation
Recipient: TRUSTEES OF DARTMOUTH COLLEGE
Initial Amendment Date: August 20, 2020
Latest Amendment Date: October 13, 2020
Award Number: 2025434
Award Instrument: Standard Grant
Program Manager: Laurel Kuxhaus
CMMI
 Division of Civil, Mechanical, and Manufacturing Innovation
ENG
 Directorate for Engineering
Start Date: October 1, 2020
End Date: June 30, 2021 (Estimated)
Total Intended Award Amount: $400,000.00
Total Awarded Amount to Date: $400,000.00
Funds Obligated to Date: FY 2020 = $27,855.00
History of Investigator:
  • Zi Chen (Principal Investigator)
    zichen@alumni.princeton.edu
Recipient Sponsored Research Office: Dartmouth College
7 LEBANON ST
HANOVER
NH  US  03755-2170
(603)646-3007
Sponsor Congressional District: 02
Primary Place of Performance: Trustees of Dartmouth College
Thayer School, 14 Engineering Dr
Hanover
NH  US  03755-4401
Primary Place of Performance
Congressional District:
02
Unique Entity Identifier (UEI): EB8ASJBCFER9
Parent UEI: T4MWFG59C6R3
NSF Program(s): Special Initiatives,
Engineering of Biomed Systems,
BMMB-Biomech & Mechanobiology
Primary Program Source: 01002021DB NSF RESEARCH & RELATED ACTIVIT
Program Reference Code(s): 020E, 028E, 9150
Program Element Code(s): 164200, 534500, 747900
Award Agency Code: 4900
Fund Agency Code: 4900
Assistance Listing Number(s): 47.041

ABSTRACT

Life originates in water. Most embryos develop in fluids with buoyancy, a force that only exists when there is gravity. Many species are pseudo-symmetric, and as such, breaking the left-right symmetry is essential for proper development. For example, axial rotation occurs in the development of many mammals and birds, and is one of the earliest developmental events that breaks the left-right symmetry. During axial rotation, the embryonic brain undergoes rotation to correctly place the organs. If it fails to do this correctly, significant birth defects can result. The research goal of this award is to understand how body forces such as gravity and buoyancy affect embryonic development and symmetry breaking. The project will examine how the absence of buoyancy and gravity change the growth and brain torsion in chicken embryos in experiments to be conducted on the International Space Station. These experiments, together with computational simulations, will be employed to identify the key mechanical factors driving axial rotation. The research results will be incorporated into solid mechanics and biomechanics courses, and the development of high school and undergraduate research experiences. Computational models will be made available on a website, and videos of this research will be uploaded to YouTube. An annual workshop will be held to host visitors and share scientific knowledge. The results of this work will benefit life on earth by increasing our understanding of embryonic development, which may lead to new ways to prevent birth defects.

This research combines embryo experiments in space with computational modeling to identify the regulative role of physical forces in the early development. The team will study how changes in buoyancy and gravity can affect the growth of brain and heart, and how the development of brain and heart are interdependent during the process of embryonic brain torsion, an important symmetry-breaking event that is essential for establishing the correct body plan. Physical forces drive and regulate the twisting of the brain. Thus, the idea that brain torsion not only depends on body curvature (flexure) and the forces exerted by the vitelline membrane, but is also a result of heart development and body forces such as gravity and buoyancy will be explored. The hypothesis that buoyancy helps the heart and brain tube maintain the right morphology, and that the disturbance in buoyancy or heart development will be detrimental for symmetry breaking and embryonic development will be tested. The work will unveil new mechanical aspects of morphogenesis and develop new models for embryonic development that take into account the effects of body forces. Insights gained from this work will enhance our understanding of mechanics of embryogenesis, particularly the development of left-right asymmetry.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Please report errors in award information by writing to: awardsearch@nsf.gov.

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