EXPRESSION PATTERNS OF SHH AND CONSERVATION OF ITS LIMB ENHANCER IN SQUAMATES WITH LIZARD CELL LINE ANALYSIS FOR ABNORMALITIES

Partial or complete limb loss is present within squamates such as snakes and legless lizards. To understand patterns of sequence conservation and divergence contributing to limb loss in some squamates, homologous sequences for the Sonic Hedgehog (shh) enhancer ZRS were compared. All snakes analyzed, had the deltaB region deleted. In legless lizards, the Lialis burtonis lizard had no significant changes, but the two Bachia legless lizards had a large indel at least from the start of the ZRS sequence up to the ETS1 site within the deltaB region. Anolis sagrei embryos exhibit shh expression from when the limb bud begins to form up to when the digital plate forms and digital condensations are observable. An immortalized lizard embryonic fibroblast cell line that was previously generated for mechanistic studies of Sonic Hedgehog signaling was analyzed with DNA and RNA sequencing. A likely duplication was discovered on scaffold 3, and likely deletions were found on scaffolds 6 and 7.