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Fig. 3 | BMC Evolutionary Biology

Fig. 3

From: Homeotic transformations reflect departure from the mammalian ‘rule of seven’ cervical vertebrae in sloths: inferences on the Hox code and morphological modularity of the mammalian neck

Fig. 3

Relative warps analysis results of the intraneck dataset. The plots show the shape differences within the cervical vertebral column along relative warp (RW) 1 and RW 2 for each specimen (A-D). The morphological analysis allowed discrimination of the vertebrae in three different subunits (indicated by color coding) (E). The correlation between somitic Hox gene expression pattern and morphological modularity in the neck of the mouse (Mus musculus) is based on Böhmer et al. (2015b) [23] and Böhmer (2017) [17]. Hox4 and Hox5 genes are expressed in the cervical vertebral column of the mammal. The anterior expression limit of HoxC-6 (not shown in the figure) lies at the first thoracic vertebra (T1). Corresponding to the mouse, two distinct shape changes are revealed between successive CV in all analyzed sloths. The modular pattern in the neck of sloths with additional CV differs in displaying an expanded anterior region of the neck (yellow)

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