Genetic differentiation among North Atlantic killer whale populations.
Population genetic structure of North Atlantic killer whale samples was resolved from differences in allele frequencies of 17 microsatellite loci, mtDNA control region haplotype frequencies and for a subset of samples, using complete mitogenome sequences. Three significantly differentiated populations were identified. Differentiation based on microsatellite allele frequencies was greater between the two allopatric populations than between the two pairs of partially sympatric populations. Spatial clustering of individuals within each of these populations overlaps with the distribution of particular prey resources: herring, mackerel and tuna, which each population has been seen predating. Phylogenetic analyses using complete mitogenomes suggested two populations could have resulted from single founding events and subsequent matrilineal expansion. The third population, which was sampled at lower latitudes and lower density, consisted of maternal lineages from three highly divergent clades. Pairwise population differentiation was greater for estimates based on mtDNA control region haplotype frequencies than for estimates based on microsatellite allele frequencies, and there were no mitogenome haplotypes shared among populations. This suggests low or no female migration and that gene flow was primarily male mediated when populations spatially and temporally overlap. These results demonstrate that genetic differentiation can arise through resource specialization in the absence of physical barriers to gene flow.
Institute of Biological and Environmental Sciences, University of Aberdeen, School of Biological Sciences, Tillydrone Avenue, Aberdeen, UK. footead@gmail.com
Andrew D
AD
Foote
Julia T
JT
Vilstrup
Renaud
R
De Stephanis
Philippe
P
Verborgh
Sandra C
SC
Abel Nielsen
Robert
R
Deaville
Lars
L
Kleivane
Vidal
V
Martín
Patrick J O
PJ
Miller
Nils
N
Oien
Monica
M
Pérez-Gil
Morten
M
Rasmussen
Robert J
RJ
Reid
Kelly M
KM
Robertson
Emer
E
Rogan
Tiu
T
Similä
Maria L
ML
Tejedor
Heike
H
Vester
Gísli A
GA
Víkingsson
Eske
E
Willerslev
M Thomas P
MT
Gilbert
Stuart B
SB
Piertney
D000818:Animals; D016000:Cluster Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D003710:Demography; D005260:Female; D005399:Fishes / Q000235:genetics; D005787:Gene Frequency / Q000235:genetics*; D049810:Genetic Speciation; D014644:Genetic Variation; D005838:Genotype; D006239:Haplotypes; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013997:Time Factors; D050685:Whale, Killer / Q000235:genetics*
D004272:DNA, Mitochondrial