Genetic Variation is the Spice of Life. Microsatellite Marker Analysis of Lake Mohave Razorback Sucker

Authors: Melody J. Saltzgiver, Paul C. Marsh, Thomas E. Dowling

Year: 2010 (xlii)

Abstract

The endangered Razorback Sucker (Xyrauchen texanus) is indigenous to the Colorado River system. The largest aggregations of Razorback Suckers are currently in Lake Mohave; however, there has not been natural recruitment in Mohave for many years mostly due to predation from a suite of non-native fish. The current conservation protocol is to collect the wild razorback larvae from the lake, and rear them until they are large enough reduce the frequency of predation. Previous studies using mitochondrial DNA (mtDNA) have shown that genetic variation is maintained using this strategy, with no differences in levels of variation and allele frequency among larvae, repatriated individuals, and wild adults over the last 13 years. Because mtDNA is maternally inherited, previous studies did not examine the male component of the system; therefore, we characterized highly polymorphic nuclear DNA markers (15 microsatellite markers) to assess the joint male-female contribution to larval production. This approach corroborated results provided by analyses of mtDNA, with levels of microsatellite variation maintained across years. This indicates the management strategy is not impacted by behavior of males and it reliably maintains genetic variation.