Molecular Ecology Notes (2007) 7, 208 – 212 doi: 10.1111/j.1471-8286.2006.01622.x © 2006 The Authors Journal compilation © 2006 Blackwell Publishing Ltd Blackwell Publishing Ltd TECHNICAL ARTICLE Urine — a source for noninvasive genetic monitoring in wildlife ROLAND HAUSKNECHT,* ROMAN GULA,† BARTOSZ PIRGA† and RALPH KUEHN* *Molecular Ecology and Conservation Genetics Unit, Wissenschaftszentrum Weihenstephan, TU Muenchen, Am Hochanger 13, D-85354 Freising, Germany, †Carpathian Wildlife Research Station, Museum and Institute of Zoology, Polish Academy of Sciences, Ogrodowa 10, 38-700 Ustrzyki Dolne, Poland Abstract Noninvasive samples are of increasing importance to study wild populations. In this study, we investigate the applicability of urine samples as the sole source of DNA for routine non- invasive genetic monitoring of wildlife using wolves (Canis lupus) as an example. Within the scope of a long-term wolf population survey, we collected during winter snow tracking in Bieszczady Mountains, Poland 41 urine samples considered as utilizable for genetic analyses. DNA concentration was determined by quantitative real-time polymerase chain reaction (qPCR) and six microsatellite loci were genotyped in threefold repeated genotyp- ing experiments to assess the reliability of genetic analyses of urine. DNA concentration of 33 urine samples was successfully quantified and of 14 samples, we obtained congruent results for all analysed loci and all repeated genotyping experiments. The gender of urine samples was identified with a Y-chromosome-linked marker. Considering the high discov- ery rate of urine in conjunction with its genotype reliability, our study confirms that urine is a valuable source in noninvasive genetic monitoring. Additionally, preselection of samples via qPCR proved to be a powerful tool contributing to a beneficial cost-value ratio of genetic analyses by minimizing genotyping errors. Keywords: individual molecular tracking, molecular sexing, qPCR, sampling efficiency, snow tracking, wolf Received 14 May 2006; revision accepted 23 October 2006 Introduction Noninvasive monitoring of wildlife using genetic data offers great opportunities to record information of endangered species. Scats, urine, hairs, feathers and regurgitates provide valuable sources of DNA. The noninvasive genetic approach is applied in various research on species differentiation (Dalen et al. 2004), population size and habitat use (Kohn et al. 1999; Lucchini et al. 2002), recolonization (Valiere et al. 2003), tracking of individuals and sexing (Constable et al. 2001; Murphy et al. 2003). Despite its usefulness, genotyping errors, i.e. allelic dropout and false alleles, need to be taken into account (Taberlet & Luikart 1999; Pompanon et al. 2005). These errors can lead to misinterpretation of genotypes (Taberlet et al. 1999) and sex (Murphy et al. 2003), and to distorting results in population studies (Creel et al. 2003). With increasing relevance of the noninvasive approach, different methods such as the multiple-tube approach (Taberlet & Luikart 1999), the maximum-likelihood approach (Miller et al. 2002), the consensus-genotype approach (Valiere 2002) and the pairwise-mismatching method (Paetkau 2003) have been proposed to circumvent these errors or to avoid misinterpretation of genotypes, respectively. Morin et al. (2001) suggested the prescreening of template DNA via quantitative polymerase chain reaction (qPCR) to set threshold DNA contents, which allow the reduction of genotyping repetitions. Faecal, hair and feather samples are widely recognized as source of DNA for genetic monitoring, however, only a few studies have shown that urine samples can support molecular genetic analysis (Vu et al. 1999; Valiere & Taberlet 2000; Hedmark et al. 2004). Using the example of wolves, we demonstrate that urine collected in the field has a Correspondence: Ralph Kuehn, Fax: +49-8161-714615; E-mail: kuehn@wzw.tum.de