Characterization and Quantification of the Neutral Lipids in the Lizard Uta stansburiana stansburiana by HPTLC-Densitometry

Abstract

We performed high-performance thin-layer chromatography (HPTLC) to characterize and quantify the various neutral lipid classes in organs (livers, abdominal fat bodies, and tails) of 6 male and 6 female northern side-blotched lizards (Uta stansburiana stansburiana) with a range of body sizes (from young-of-the-year to adult). We determined the percentage of each organ that was comprised of free sterols, free fatty acids, triacylglycerols, methyl esters, and steryl esters. Regardless of lizard sex or body size, the greatest concentrations of neutral lipids in all organs examined were triacylglycerols. Statistical analyses revealed that the organs of females contained roughly twice the percentage of triacylglycerols compared to males. No other neutral lipid amounts were significantly different between the sexes. We detected only one significant relationship based on size: larger lizards contained more steryl esters in their livers than smaller lizards. Our results are consistent with previous studies showing that females contain more energy reserves (particularly triacylglycerols) than males. This is the first report of the use of TLC or HPTLC with densitometry to analyze any type of analytes in lizard samples.