Determination of genetic diversity and paternity analysis of elephants in Tarangire National park using genomic dna microsatellites
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Date
2003
Journal Title
Journal ISSN
Volume Title
Publisher
Sokoine University of Agriculture
Abstract
A study was conducted on elephants of Tarangire National Park (TNP) in Tanzania
with the aim of determining their genetic diversity and paternity using elephant
specific genomic DNA microsatellite markers.
DNA was extracted from faecal
samples collected from known elephants in the northern (n=61) and 12 adult males as
well as unidentified females from Central (n=8) and Southern (n=6) subpopulations.
The faecal samples were preserved either in absolute ethanol or silica prior to DNA
extraction. The extracted DNA was PCR-amplified in duplicates using eight highly
polymorphic microsatellite markers and PCR products were subsequently analysed
on ABI 3100 Genetic Sequencer Analyser and alleles were scored using ABI PrismĀ®
GeneScanĀ® analysis software. The obtained data was analysed using CERVUS
program. The amplification and genotyping success per locus for both ethanol and
silica-preserved samples ranged from 81.40 to 91.90% (n=86). All 8 microsatellite
markers were polymorphic with a total of 60 alleles in the sampled population and
the mean number of alleles per locus being 7.50. The number of alleles per locus
ranged from 3 to 11 while the mean polymorphic information content (PIC) was
66%. The observed heterozygosity varied from 51.90 to 80.90% and the expected
heterozygosity per locus ranged from 53.80 to 82.0% while the mean expected
heterozygosity for all loci was 70.60%. Test for Hardy-Weinberg equilibrium (HWE)
was not significant for all loci. The genotype data enabled assignment of 38% and
83% of offspring (n=29) at 80% confidence level to their fathers using 30% (12/40)
and 100% (12/12) simulation, respectively with respect to the proportion of the
sampled breeding males within the TNP. Further assessment of mating success
among bulls in the Park revealed that 7.50% of all potential breeding bulls were responsible for fathering 31.0% and 52% of all 29 offspring at 30% and 100%
simulation, respectively. This study provides for the first time an important genetic
database that has wide applications in future studies of African elephants in TNP and
other conservation areas in Tanzania. The data obtained will be used to assess the
genetic relatedness of elephants residing in the park as well assist in providing an
insight on the effects of poaching on the current elephant social structure in TNP.
This information will imperatively be useful in the understanding and conserving the
endangered African elephants in different range states in Africa.
Description
Masters Theses
Keywords
Genetic diversity-elephants, Elephants, Paternity analysis-elephants, Genomic DNA microsatellites