Document Type

Article

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

We report here on the generation of a new fluorescent protein reporter transgenic mouse line, Col10a1 -mCherry, which can be used as a tool to study chondrocyte biology and pathology. Collagen, Type X, alpha 1(Col10a1) is highly expressed in hypertrophic chondrocytes and commonly used as a gene marker for this cell population. TheCol10a1-mCherry reporter line was generated using a bacterial recombination strategy with the mouse BAC clone RP23-192A7. To aid in the characterization of this animal model, we intercrossed Col10a1-mCherry mice with Collagen, Type II, alpha 1 (Col2a1) enhanced cyan fluorescent protein (ECFP) reporter mice and characterized the expression of both chondrocyte reporters during embryonic skeletal development from days E10.5 to E17.5. Additionally, at postnatal day 0, Col10a1-mCherry reporter expression was compared to endogenous Col10a1 mRNA expression in long bones and revealed that mCherry fluorescence extended past the Col10a1 expression domain. However, in situ hybridization for mCherry was consistent with the zone of Col10a1 mRNA expression, indicating that the persistent detection of mCherry fluorescence was a result of the long protein half life of mCherry in conjunction with a very rapid phase of skeletal growth and not due to aberrant transcriptional regulation. Taking advantage of the continued fluorescence of hypertrophic chondrocytes at the chondro-osseus junction, we intercrossed Col10a1 -mCherry mice with two different Collagen, Type 1, alpha 1, (Col1a1 ) osteoblast reporter mice, pOBCol3.6-Topaz and pOBCol2.3-Emerald to investigate the possibility that hypertrophic chondrocytes transdifferentiate into osteoblasts. Evaluation of long bones at birth suggests that residual hypertrophic chondrocytes and osteoblasts in the trabecular zone exist as two completely distinct cell populations.

Comments

Genesis. Author manuscript; available in PMC 2017 Oct 12. Published in final edited form as: Genesis. 2011 May; 49(5): 410–418. doi: 10.1002/dvg.20733 PMCID: PMC5638041 NIHMSID: NIHMS909938

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