Star S Ranch Auction Catalog - Flipbook - Page 6
DNA - MITOCHONDRIAL & NUCLEAR
A NOTE FROM PROFESSOR BETTINE VAN VUUREN:
Mitochondria are cellular organelles, outside the nucleus, and are responsible for energy generation in cells. The mitochondrial
DNA is inherited through the maternal lineage, with no contribution from the father. Mitochondrial DNA is therefore a good
marker to trace female lineages, and provides information about the historical origin of lineages. It can also be used to trace
the number of family lineages in a specific area or population. It is the equivalent of male surname transmission in humans.
Nuclear DNA is in the nucleus of cells. It contains coding and non-coding DNA, and is packaged as chromosomes (in antelope,
there are typically 60 chromosomes per cell). Nuclear DNA is passed on from both the mother and father; with an offspring
related to each parent by 50%, (full siblings are related to one another by 50%). Nuclear DNA provides valuable information
about parentage and relatedness,and reflects the membership of a specific individual to different genetic groups (i.e.,
whether an individual is admixed, or pure within a specific genetic group).
Mitochondrial and nuclear DNA, either singly or in combination, provide valuable information that can assist in the selection
process. Various strategies present themselves, but it is crucial that the breeder makes a decision early on in the selection
process, and then adheres to it throughout the breeding program; otherwise, there will not be any real progress towards
a specific end goal. For example, a breeder may decide that high levels of genetic diversity and variation is crucial in the
management of specific herds. It would then be important to maximize the different lineages included in the breeding core,
which would include animals from across the range of the species. A typical nuclear result may take the form of 20% Eastern,
50% Zambian, 30% Southern, with mitochondrial membership to any of the genetic groups. At the other side of the breedingstrategy spectrum, a breeder may decide on pure populations. Here, the mitochondrial result will indicate the historical
origin of the maternal lineage, while the nuclear result should indicate membership within only a single genetic group,
preferably the same group as the mitochondrial result. A typical result may take the form of 90% Zambian, with mitochondrial
membership also in the Zambian, or Wes Zambian group (indicating a pure Zambian, or Wes Zambian animal). All, or the
overriding majority of animals in the core breeding group, should follow these results. It is important that breeder keep in
mind that some calves may show unexpected membership to non-selected groups. This is common and it reflects ancestral
polymorphisms, also known as old blood. A grandparent, or even great grandparent, may have had membership to a different
group (this is natural, and we even see these results in wild animals naturally occurring in areas).
TXPGB DNA, LLC
WILDLIFE GENOMICS 2.0
SYBRAND MOSTERT
DNA@TXPGB.COM
WWW.TEXASPREMIUMGAMEBREEDERS.COM
SANDRA DURAND
(+27) 83 406 6071
SANDRA@WILDLIFEGENOMICS.CO.ZA
