Fig. 4: hoxc13 knockout frogs lack claws and do not express hair keratins homologs.
From: Evolutionary origin of Hoxc13-dependent skin appendages in amphibians
a Schematic depiction of hoxc13 knockout (KO) in X. tropicalis frogs. The number of animals bearing claws is shown on the right. Macroscopic appearance of a wildtype (WT) (b) and a KO (c) frog. Arrows point to claws. d–g Hindlimb phenotypes (d, e) and histology (f, g) of hindlimb inner (HI) toes of WT (d, f) and KO (e, g) frogs. Images in b-g are representative for at least 3 biological replicates. cl claw, ep epidermis. Scale bars: 2 mm (d, e), 200 µm (f, g). Quantitative RT-PCR analysis of krt34 (h) and krt59 (i) in HI toes of WT and KO. Statistics was calculated by unpaired two-tailed t-test. n = 4 biological replicates for WT and KO. Age of the frogs: 7 months. a.u., arbitrary units. Bars and error bars indicate means and standard deviations, respectively.
