Comparison of Vitellogenin Expression in both sexes of Orconectes obscurus in the Monocacy River

Abstract

Vitellogenin (Vtg) is a lipou,lycoprotein found in the hemolymph of female crustaceans that is identified as the precursor molecule of the major crustacean yolk protein lipovitellin (Vincent et al., 2001). If the Vtg gene is turned on in males, intersexual qualities and reproductive dysfunction begin to appear which can lead to a skewed sex ratio with an increased number of females in the population (Mills et al., 2003). According to the Maryland Department of Natural Resources (DNR), Fifteen Mile Creek Creek in Allegany County of Maryland retains normal sex skew ratios of Orconectes obscurus while the Monocacy River at Buckeystown Community Park of Maryland has an abnormally high female-to-male ratio. The purpose of this study is to determine if Vtg levels among both male and female Orconectes obscurus are elevated at the Monocacy site, where sex ratios have been reported to be skewed, compared to Fifteen Mile Creek, where sex ratios have been reported to be normal. However, analyzed data showed no significant differences among comparisons in Vtg expression.