BACKGROUND: Mohawk (Mkx) is a homeodomain-containing transcription factor that is expressed in various mesoderm-derived tissues, particularly in developing tendons. In this study, we investigate the exact expression pattern and functions of Mkx in forelimbs. METHODS: We analyzed the forelimbs of Mkx knockout mice [from embryonic day (E) 18.5 to postnatal day (P) 28 weeks] by using knocked-in Venus signals, Masson trichrome staining, and hematoxylin and eosin (H&E) staining. RESULTS: We detected Venus signals in forelimb tendons, pulleys, and volar plates (VPs) in P21 mice. In-depth histological analysis showed that compared to the wild-type mice, the Mkx knockout mice showed significant hypoplasia in the flexor digitorum profundus tendons from E18.5. The VPs and pulleys appeared normal until P0; however, by P14, they became increasingly thicker in Mkx-null mice compared to wild-type mice. The fiber alignment was particularly disrupted in VPs of Mkx-null mice. CONCLUSIONS: These results suggest that Mkx is an important regulator of the differentiation of VPs and pulleys, as well as of tendon differentiation.
BACKGROUND: Mohawk (Mkx) is a homeodomain-containing transcription factor that is expressed in various mesoderm-derived tissues, particularly in developing tendons. In this study, we investigate the exact expression pattern and functions of Mkx in forelimbs. METHODS: We analyzed the forelimbs of Mkx knockout mice [from embryonic day (E) 18.5 to postnatal day (P) 28 weeks] by using knocked-in Venus signals, Masson trichrome staining, and hematoxylin and eosin (H&E) staining. RESULTS: We detected Venus signals in forelimb tendons, pulleys, and volar plates (VPs) in P21mice. In-depth histological analysis showed that compared to the wild-type mice, the Mkx knockout mice showed significant hypoplasia in the flexor digitorum profundus tendons from E18.5. The VPs and pulleys appeared normal until P0; however, by P14, they became increasingly thicker in Mkx-null mice compared to wild-type mice. The fiber alignment was particularly disrupted in VPs of Mkx-null mice. CONCLUSIONS: These results suggest that Mkx is an important regulator of the differentiation of VPs and pulleys, as well as of tendon differentiation.
Authors: Leon Espira; Lise Lamoureux; Stephen C Jones; Robert D Gerard; Ian M C Dixon; Michael P Czubryt Journal: J Mol Cell Cardiol Date: 2009-04-10 Impact factor: 5.000
Authors: R Schweitzer; J H Chyung; L C Murtaugh; A E Brent; V Rosen; E N Olson; A Lassar; C J Tabin Journal: Development Date: 2001-10 Impact factor: 6.868
Authors: Ingo Grafe; Stefanie Alexander; Jonathan R Peterson; Taylor Nicholas Snider; Benjamin Levi; Brendan Lee; Yuji Mishina Journal: Cold Spring Harb Perspect Biol Date: 2018-05-01 Impact factor: 10.005