Troponin T3 expression in skeletal and smooth muscle is required for growth and postnatal survival: Characterization of Tnnt3tm2a(KOMP)Wtsi mice. Issue 9 (9th July 2013)

• Record Type: Journal Article
• Authors: Ju, Yawen; Li, Jie; Xie, Chao; Ritchlin, Christopher T.; Xing, Lianping; Hilton, Matthew J.; Schwarz, Edward M.
• Is Part Of: Genesis. Volume 51:Issue 9(2013:Sep.)
• Page Start: 667
• Page End: 675
• Publication Date: 2013-07-09
• Subjects: Developmental genetics -- Periodicals; Genetics -- Periodicals; Developmental biology -- Periodicals; Embryology -- Periodicals; Genetic regulation -- Periodicals; 576.5
• DOI: 10.1002/dvg.22407
• Languages: English
• ISSNs: 1526-954X

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The troponin complex, which consists of three regulatory proteins (troponin C, troponin I, and troponin T), is known to regulate muscle contraction in skeletal and cardiac muscle, but its role in smooth muscle remains controversial. Troponin T3 (TnnT3) is a fast skeletal muscle troponin believed to be expressed only in skeletal muscle cells. To determine the in vivo function and tissue‐specific expression of <italic>Tnnt3</italic>, we obtained the heterozygous <italic>Tnnt3</italic>+/flox/<italic>lacZ</italic> mice from Knockout Mouse Project (KOMP) Repository. <italic>Tnnt3<sup>lacZ/+</sup></italic> mice are smaller than their WT littermates throughout development but do not display any gross phenotypes. <italic>Tnnt3<sup>lacZ/lacZ</sup></italic> embryos are smaller than heterozygotes and die shortly after birth. Histology revealed hemorrhagic tissue in <italic>Tnnt3<sup>lacZ/lacZ</sup></italic> liver and kidney, which was not present in <italic>Tnnt3<sup>lacZ/+</sup></italic> or WT, but no other gross tissue abnormalities. X‐gal staining for <italic>Tnnt3</italic> promoter‐driven <italic>lacZ</italic> transgene expression revealed positive staining in skeletal muscle and diaphragm and smooth muscle cells located in the aorta, bladder, and bronchus. Collectively, these findings suggest that troponins are expressed in smooth muscle and are required for normal growth and breathing for postnatal survival. Moreover, future studies with this mouse model can explore TnnT3 function in adult muscle function using the conditional‐inducible gene deletion approach genesis 51:667–675. © 2013 Wiley Periodicals, Inc.</p> </abstract>