Ecologia Mediterranea

Pilot study of genetic relatedness
in a solitary small carnivore, the weasel:
implications for kinship and dispersal
Étude pilote de la parenté génétique
chez un petit carnivore solitaire, la belette :
implications pour la parenté et la dispersion
Abstract
Few researches have been carried out on wild
populations of small carnivores involving animals
live trapping. Problems in field data collection
make spatial and reproductive dynamics
of these species still not understood. This
research used data about only 14 live trapped
individuals, because of the quoted problems,
nevertheless results showed important and preliminary
considerations on this topic. In the
study, genetic microsatellite methodology
applied to natural weasel population produced
data on kinship and dispersal patterns. All the
11 microsatellite analyzed loci were found polymorphic,
with an average number of alleles per
locus of 5.36; estimated expected heterozygosity
He (0.62) is at the highest end of the range
of other Mustela species. No significant deviations
from Hardy-Weinberg equilibrium were
found (p≥0.05). The analysis of genetic kinship
showed no full siblings and only one parent-offspring
pair: so only 1.09% of the total possible
pair wise comparisons (91) showed close genetic
kinship. The proportion of related animals from
the sampled population was 14,2%.
Keywords: dispersal, Hardy-Weinberg
equilibrium, heterozygosity, kinship, microsatellite
DNA, weasel.
ecologia mediterranea – Vol. 38 (2) – 2012
Caterina MAGRINI 1 , Michele CENTO 2 , Emiliano MANZO 1 ,
Massimo PIERPAOLI 3 , Livia ZAPPONI 2 , Roberto COZZOLINO 1
1. Ethoikos, Radicondoli, Siena, Italy
2. Animal and Human Biology Department, La Sapienza University, Roma, Italy
3. NGB Genetics, Ferrara, Italy
Corresponding author: Drs Caterina Magrini
E-mail: caterina.magrini@gmail.com
Introduction
The weasel (Mustela nivalis, Linnaeus 1766)
is the smallest living carnivore. Its behavioural
and ecological traits make it a typical
solitary (non-cooperative) (Sandell 1989)
species, typified by r-selected and opportunistic
life-history strategies (King 1983,
1989). Many ecological features of wild
solitary small carnivores populations are
still unknown (Clutton-Brock 1989) and
microsatellite DNA analyses seems to be the
best tools to investigate ecological traits like
mating systems and dispersal strategies (Sugg
et al. 1996) in such elusive animals.
Many parameters were used to define the
genetic variability of a population: for example
the proportion of polymorphic loci (Mitton
& Raphael 1990) or the number of distinct
alleles (genetic variation or diversity). Here
we used the genetic variance, measured by
mean heterozygosity (H), the proportion of
loci that are heterozygous in an average individual.
Using H, the amount of genetic variance
carried by a small sample of population
will closely approximate the magnitude of
genetic variance of that population in the
whole (Caughley & Sinclair 1994).
The primary aim of this study was to provide
an example for the usefulness of molecular
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