The dangers of inbreeding in the Arabian horse

44 Pages·2015·1.27 MB·English

The dangers of inbreeding in
the Arabian horse
Dr. Steven Janssens
Livestock genetics
ECAHO, Prague
06 feb 2015
Livestock Genetics
Division Gene Technology,
Dep. Biosystems
KU Leuven
http://www.livestockgenetics.be
[email protected]
Kasteelpark Arenberg 30 – 2456
B-3001 Heverlee
Belgium
Tel: [phone]
Fax: [phone]
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Introduction
Diversity between breeds
• The species (Equus Caballus) covers a large number of
breeds that differ in many characteristics (e.g. body size)
• Breeds were linked to geographical location (cid:1) studbooks
• Studbooks organise selection
(impose restrictions on reproduction)
• (cid:2) Selection causes a reduction in the genetic variation
in breeds
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Subdivision of the breed may further reduce
diversity
• Sporthorses
show jumping <-> dressage
• In Arabians breeding for:
morphology <-> endurance <-> recreation, ….
keeping original maternal strains pure (RASANs???)
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Why do we need to bother about genetic
diversity?
• Capacity to adapt
(= can a population respond to natural and human selection)
• Linked to fitness
(= capacity to produce fertile offspring)
(cid:3)
Studbooks need to monitor the genetic diversity of breeds to
guarantee survival in the long run
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The origin of genetic
variation
Nuclear DNA
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The horse genome
• 62 autosomes + 2 (XX or XY)
• 2,7 109 basepairs (Wade et al. 2009)
• 20322 genes
• 3 106 locations of variation (2012) in
the genome !!!
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