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Cessation of Reproduction‐Related Spine Elongation After Multiple Breeding Cycles in Female Naked Mole‐Rats
Author(s) -
DenglerCrish Christine M.,
Catania Kenneth C.
Publication year - 2009
Publication title -
the anatomical record: advances in integrative anatomy and evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.678
H-Index - 62
eISSN - 1932-8494
pISSN - 1932-8486
DOI - 10.1002/ar.20793
Subject(s) - spine (molecular biology) , elongation , lumbar spine , reproduction , pregnancy , vertebral column , lactation , skeleton (computer programming) , anatomy , biology , medicine , surgery , bioinformatics , ecology , materials science , genetics , metallurgy , ultimate tensile strength
The breeding female or “queen” naked mole‐rat has a uniquely elongated body morphology attributed to the lengthening of the lumbar vertebral column that occurs during pregnancy. It is unknown whether this vertebral growth is a continuous process, or associated only with early reproductive experience. We compared pregnancy‐related bone elongation in nascent primiparous queens and established queens to determine if this vertebral expansion was a lifelong process in these females. We also investigated the impact of lactation on vertebral elongation in these mole‐rats because it is known to be a time of significant bone loss in other mammals. Our data show that after eight or more pregnancies, established queens no longer experienced a net gain in lumbar spine length over the reproductive cycle, whereas the nascent breeders demonstrated significant spine lengthening over this time. Despite the lack of net spine lengthening in established breeders, our results indicated that these queens still experienced some pregnancy‐specific vertebral elongation. In naked mole‐rats, pregnancy‐induced bone elongation may serve the dual purposes of first lengthening the spine, and then once optimal spine size is achieved, serving as a homeostatic mechanism that prepares the spine for the mineral demands of lactation. Anat Rec, 2009. © 2008 Wiley‐Liss, Inc.