Population Genetics 2002 WORKSHOP GENETIC ESTIMATES OF DISPERSAL Joop Ouborg Dept. of Ecology Univ. of Nijmegen

GENETIC ESTIMATES OF DISPERSAL TWO BASIC APPROACHES INDIRECT APPROACH : how much dispersal must there have been to cause the observed pattern of genetic differentiation INDIRECT APPROACH : how much dispersal must there have been to cause the observed pattern of genetic differentiation DIRECT APPROACH : who is the parent of who and where does he/she come from

INDIRECT APPROACH DEMOGRAPHIC MODEL DEMOGRAPHIC MODEL GENETIC MARKER SYSTEM GENETIC MARKER SYSTEM POPULATION GENETIC MODEL POPULATION GENETIC MODEL PARAMETER ESTIMATOR PARAMETER ESTIMATOR

DEMOGRAPHIC MODEL INFINITE ISLAND MODEL INFINITE ISLAND MODEL ISOLATION-BY-DISTANCE MODEL ISOLATION-BY-DISTANCE MODEL CONTINUOUS MODEL CONTINUOUS MODEL DISPERSAL MATRIX MODEL DISPERSAL MATRIX MODEL

Moleculaire merkers Oplossend vermogen allozymen (eiwit-electroforese) chloroplastDNA PCR-RFLP RAPD (random amplified polymorphic DNA) AFLP (Amplified Fragment Length Polymorphism) Multi-locus fingerprints Microsatellieten (SSRs) Sequencing (SNPs)

POPULATION GENETIC MODEL Fst = 1 / (1 + 4 NeM) Fst = 1 / (1 + 4 NeM) Fst = 1 / (1 + 4 NeM + 4Neμ) Fst = 1 / (1 + 4 NeM + 4Neμ) Coalescence model Coalescence model

POPULATIE 1 POPULATIE 2

Estimators Fst : standardized variance in allele frequencies over populations Theta θ : Estimated from variance components of ANOVA (Cockerham and Weir 1993) Rst : microsatellite specific estimator (correction for stepwise mutation process) (Slatkin 1995) PhiST : estimator based on simmilarity indices, useful for data where no allelefrequencies are available (AMOVA, Excoffier et al. 1992)

GENETIC DISPERSAL CURVES Plot of log (NeM) versus log (distance) Plot of log (NeM) versus log (distance) Testable with Mantel test of correlation between distance matrix and genetic distance matrix Testable with Mantel test of correlation between distance matrix and genetic distance matrix Log NeM Log D

POLLEN- VERSUS SEED DISPERSAL Fst influenced by both Fst influenced by both Models to separate the two (Ennos 1994; Hu and Ennos 1997) Models to separate the two (Ennos 1994; Hu and Ennos 1997) Based on comparison of nuclear marker patterns (e.g. microsatellites) and cytoplasmic marker patterns (e.g. cpDNA)

Nuphar lutea L.

ctgtagtg gagagaga gtaatggc gacatcac ctctctct cattaccg Ind. 1 gtagtg gagaga gtaatg gtagtg gagaga gtaatg Ind. 3 gtagtg gagagaga gtaatg Ind. 2 gtagtg gagagaga gtaatg gtagtg gagagaga gtaatg gtagtg gagaga gtaatg Ind.1Ind.3Ind.2 Microsatellites or SSR’s

Sample output Base ImagIR Nuphar lutea clones

Microsatellite variation in Nuphar lutea

Rhône-1Rijn-1 NLF Microsatellite variability within and among Dutch and French populations of Nuphar lutea

50 km # migranten: Met de stroom mee 5.4 Tegen de stroom in: 0.5 ODER duitsland polen

DIRECT APPROACH Parental analyses Parental analyses Seed flow : percentage of seedlings having no parent in the population Pollen flow : percentage of seeds having no father in the population

Indirect approach: GDA (Weir) ??? FSTAT (Goudet) GENEPOP (Rousset) MIGRATE (BEERLI)

ISOLATION BY DISTANCE Mantel test in GENEPOP, NTSYS. Etc. Mantel test in GENEPOP, NTSYS. Etc. Spatial autocorrelation tests (Epperson) like AIDA