Cattle are vitally important to American agriculture industry, generating over 24.6
billion pounds of beef (by carcass weight), and 79.5 billion dollars in 2005, and over 27
billion dollars in milk sales in 2004. As of July 2006, the U.S. beef and dairy industry is
comprised of 104.5 million head of cattle, 32.4 million of which were processed in 2005.
The health of the animals has always been an important concern for breeders, as healthy
animals grow faster and are more likely to reach market weight. Animals that exhibit
natural resistance to disease do not require chemicals to stimulate normal weight gain,
and are less prone to disease related wasting.
The major histocompatibility complex (MHC) is a collection of genes, many of
which function in antigen processing and presentation. The bovine MHC (BoLA) differs
from typical mammalian MHCs in that the class II region was disrupted by a
chromosomal inversion into two subregions, designated BoLA IIa and BoLA IIb. BoLA
IIb was transposed to a position near the centromere on bovine chromosome 23,while
BoLA IIa retains its position in BoLA. Comparative sequence analysis of BoLA IIb with
the human MHC revealed the location of the region containing the proximal inversion breakpoint. Gene content, order and orientation of BoLA IIb are consistent with the single
inversion hypothesis when compared to the corresponding region of the human class II
MHC (HLA class II). BoLA IIb spans approximately 450 kb.
The genomic sequence of BoLA IIb was used to detect sequence variation
through comparison to other bovine sequences, including data from the bovine genome
project, and two regions in the BAC scaffold used to develop the BoLA IIb sequence.
Analysis of the bovine genome project sequence revealed a total of 10,408 mismatching
bases, 30 out of 231 polymorphic microsatellites, and 15 sequences corresponding to the
validated SNP panel generated by the bovine genome sequencing project. The two
overlapping regions in the BoLA IIb BAC scaffold were found to have 888
polymorphisms, including a total of 6 out of 42 polymorphic microsatellites indicating
that each BAC derived from a different chromosome.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/4821 |
| Date | 25 April 2007 |
| Creators | Childers, Christopher P. |
| Contributors | Skow, Loren C. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 1527669 bytes, electronic, application/pdf, born digital |
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