Fróðskaparrit - 01.01.1992, Blaðsíða 12

16
THEINTERNATIONAL RESEARCH . ..
Paternity and mating system using DNA
fingerprinting techniques
Patemity testing of foetuses using DNA
fingerprinting showed that they are seldom
(<12%) fathered by adult males in the same
school. This implies that there is consider-
able gene flow between schools and is con-
firmed by comparing foetuses bom in dif-
ferent cohorts within the same school.
These reveal an annually changing male
input. If patemal alleles are considered
within a cohort, strong allelic biases are
indicative of a non-random pattem, either
produced by males, each mating with sev-
eral females, or by related males entering a
school and mating with receptive females.
Analyses of females in different schools
show strong allelic biases, suggesting that
they are genetically distinct, and hence,
presumably, part of a matrilineal system.
Furthermore, by combining allelic data
with the age of individuals it is possible to
reconstmct the genetic history of a school.
Comparison between two schools caught
close together in time and space (Leynar,
220787 and Miðvágur, 240787) suggest a
shared origin and may represent the split-
ting of a school into two daughter schools.
Detailed analysis of the two pods men-
tioned above has modified and extended
this picture of school stmcture. The matri-
lineal stmcture has been strongly substanti-
ated and there is evidence that males do not
leave their natal pods. Not more than about
50% of animals are accompanied by their
mothers, not surprisingly since many indi-
viduals are too old to have surviving par-
ents. The maximum proportion of foetuses
accompanied by their fathers have been
further reduced to 3%. By inference, there-
fore, mating occurs by reciprocal fertilisa-
tions between the males of one school and
the females of another. A new, extremely
variable genetic locus (microsatellite) has
distinguished between the two possible pat-
tems of male mating: related males mate
with females in a school and that individual
males seldom mate with more than one
female. The data also suggest that mature
males neither disperse from nor mate with-
in their natal pods. Pilot whales must mate
when two or more pods meet or when
males pay short visit to other pods.
A complete genealogy for some schools
is on the way. Emphasis of future work will
be on relationships between schools,
school splitting and population size esti-
mates.
Amos, W. 1987. Pod-relatedness and population struture in
pilot whales. Cetus 7: 31-32.
Amos, W. 1993. The social structure of pilot whale pods in
the Faroe Islands. Genetic insights. ESC 7:13.
Amos, W., Barrett, J., Bancroft, D., Majerus, T., Bloch, D.,
Desportes, G. and Dover, G.A. 1989. Breeding system
and social structure in the Faroese pilot whale as revea-
led by DNA fingerprinting. Paper SC/41/SM30 pre-
sented to the IWC Scientific Committee, May 1989 (un-
published). 1-15.
Amos, W., Barrett, J., Bancroft, D., Majerus, T., Bloch, D.,
Desportes, G. and Dover, G.A. In press. A review of
molecular evidence relating to social organisation and
breeding system in the Long-ftnned Pilot whale.
Rep.int.Whal.Commn (Special Issue 14).
Amos, W., Barrett, J., and Dover, G.A. 1991a. Breeding
behaviour of pilot whales revealed by DNA fmgerprint-
ing. Heredity 67(1): 49-55.
Amos, W., Barrett, J., and Dover, G.A. 199 lb. Breeding
system and social structure in the Faroese pilot whale as
revealed by DNA fingerprinting. Rep.int.Whal.Commn
(Special Issue 13): 255-268.
Amos, W. and Dover, G.A. 1990. DNA fingerprinting and
the uniqueness of whales. Mammal Rev. 20: 23-30.
Amos, W. Schlotterer, C., and Tautz, D. 1993. Social struc-