Meeting Abstract

118.4  Tuesday, Jan. 7 11:00  Population genomic analysis of the Pacific gooseneck barnacle Pollicipes elegans comparing two sampling strategies PLOUGH, L.V.*; MARKO, P.B.; University of Maryland Center for Environmental Sciences, Horn Point Laboratory; University of Hawaii lplough@umces.edu

Next generation sequencing (NGS) technologies, particularly restriction site-associated DNA (RAD) marker methods have revolutionized the field of population genetics, making it possible to examine 1000’s of markers in a non-model organism at relatively low cost. However, sequencing large numbers of individuals can be prohibitively expensive prompting alternative sampling strategies (pooling), and restriction digestion approaches still suffer from technical issues (null alleles) that plague standard population genetic analyses, especially in highly polymorphic species such as marine invertebrates. In this study we use genome-wide marker data generated with genotyping-by-sequencing (GBS; a restriction digestion method similar to RAD) to investigate population genetic structure in the Pacific gooseneck barnacle Pollicipes elegans, which has a relatively long-lived larval stage and is distributed in a disjunct fashion across the equator in the eastern Pacific ocean. We sequenced GBS libraries created with individuals and population pools made up of those individuals to examine the accuracy of a pooled sampling approach for estimating standard population genetic parameters such as allele frequency and F_st. Preliminary analysis of individual samples showed relatively high polymorphism, population structure over large geographic distances (Peru and Mexico), and evidence of null alleles at some markers. We will present the results of our F_st outlier analyses, compare population genetic parameter estimates between pooled and individual samples, and discuss how temperature and current patterns may be structuring populations in this species. Additionally, we will discuss the complexities of population genomic study design and the analysis of population genomic data in highly polymorphic marine invertebrates.