title: Sex determination in the wild: a field application of loop-mediated isothermal amplification successfully determines sex across three raptor species.
abstract: PCR-based methods are the most common technique for sex determination of birds. Although these methods are fast, easy and accurate, they still require special facilities that preclude their application outdoors. Consequently, there is a time lag between sampling and obtaining results that impedes researchers to take decisions in situ and in real time considering individuals' sex. We present an outdoor technique for sex determination of birds based on the amplification of the duplicated sex-chromosome-specific gene Chromo-Helicase-DNA binding protein using a loop-mediated isothermal amplification (LAMP). We tested our method on Griffon Vulture (Gyps fulvus), Egyptian Vulture (Neophron percnopterus) and Black Kite (Milvus migrans) (family Accipitridae). We introduce the first fieldwork procedure for sex determination of animals in the wild, successfully applied to raptor species of three different subfamilies using the same specific LAMP primers. This molecular technique can be deployed directly in sampling areas because it only needs a voltage inverter to adapt a thermo-block to a car lighter and results can be obtained by the unaided eye based on colour change within the reaction tubes. Primers and reagents are prepared in advance to facilitate their storage at room temperature. We provide detailed guidelines how to implement this procedure, which is simpler (no electrophoresis required), cheaper and faster (results in c. 90 min) than PCR-based laboratory methods. Our successful cross-species application across three different raptor subfamilies posits our set of markers as a promising tool for molecular sexing of other raptor families and our field protocol extensible to all bird species.
authors.affiliation: Movement Ecology Lab, Department of Ecology, Evolution and Behaviour, Faculty of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.|Estación Biológica de Doñana (EBD-CSIC), Avda. Américo Vespucio, s/n, Isla de la Cartuja, Seville, 41092, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Centeno-Cuadros
authors.affiliation: Kuvin Center, Hadassah Medical School, The Hebrew University of Jerusalem, Jerusalem, Israel.
authors.forename: I
authors.initials: I
authors.lastname: Abbasi
authors.affiliation: Movement Ecology Lab, Department of Ecology, Evolution and Behaviour, Faculty of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
authors.forename: R
authors.initials: R
authors.lastname: Nathan
mesh_terms: D000818:Animals; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D046093:Falconiformes / Q000145:classification* / Q000235:genetics*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods* / Q000639:trends; D017422:Sequence Analysis, DNA; D012730:Sex Chromosomes; D012732:Sex Determination Analysis / Q000379:methods*
chemical_list: D017931:DNA Primers; D004268:DNA-Binding Proteins
keywords: 
  Gyps fulvus
  ; 
  Milvus migrans
  ; 
  Neophron percnopterus
  ; CHD-W; CHD-Z; loop-mediated isothermal amplification