Key PointsThe gene map for the extended major histocompatibility complex (xMHC) comprises 421 loci (excluding RNA genes) in a sequence length of 7.6 Mb — extending the previous gene map of the ...classical MHC, which was 3.6 Mb long and contained 224 loci.All 421 xMHC loci have been assigned definitive and approved gene symbols.About 50% of the xMHC gene loci are present in clusters or superclusters that are not restricted only to immune genes. The two largest clusters, comprising histone and tRNA genes are the largest of their type in the genome.Transcription hotspot analysis indicates that it is just as likely that the classical MHC is hitch-hiking with gene clusters of the xMHC as the reverse.About 22% of the expressed xMHC genes show a higher than average number of non-synonymous coding polymorphisms.About 28% of the xMHC genes can be associated with immune system function.About 10% of the xMHC genes are currently known to be disease-causing or disease-associated.About 20% of the xMHC genes have putative paralogues elsewhere in the genome, indicating considerable potential for functional redundancy.The gene map of the xMHC provides an invaluable resource for the study of the most important genetic region of the human genome in relation to infectious, inflammatory and autoimmune diseases.The major histocompatibility complex (MHC) is the most important region in the vertebrate genome with respect to infection and autoimmunity, and is crucial in adaptive and innate immunity. Decades of biomedical research have revealed many MHC genes that are duplicated, polymorphic and associated with more diseases than any other region of the human genome. The recent completion of several large-scale studies offers the opportunity to assimilate the latest data into an integrated gene map of the extended human MHC. Here, we present this map and review its content in relation to paralogy, polymorphism, immune function and disease.The gene map of the xMHC is also available as a poster, which accompanies this issue and is available at http://www.nature.com/nrg/posters/mhcmap/index.html.
The introduction of livestock species in Europe has been followed by various genetic events, which created a complex spatial pattern of genetic differentiation. Spatial principal component (sPCA) ...analysis and spatial metric multidimensional scaling (sMDS) incorporate geography in multivariate analysis. This method was applied to three microsatellite data sets for 45 goat breeds, 46 sheep breeds, and 101 cattle breeds from Europe, Southwest Asia, and India. The first two sPCA coordinates for goat and cattle, and the first sPCA coordinate of sheep, correspond to the coordinates of ordinary PCA analysis. However, higher sPCA coordinates suggest, for all three species, additional spatial structuring. The goat is the most geographically structured species, followed by cattle. For all three species, the main genetic cline is from southeast to northwest, but other geographic patterns depend on the species. We propose sPCA and sMDS to be useful tools for describing the correlation of genetic variation with geography.
Making inferences in population genetics Beaumont, Mark A.; Bruford, Michael W.
Zoo Biology,
1998, 1998-00-00, Letnik:
17, Številka:
2
Book Review, Journal Article
Future directions in conservation genetics Bertorelle, Giorgio; Bruford, Michael W.; Hauffe, Heidi C. ...
Population Genetics for Animal Conservation,
01/2001
Book Chapter
Molecular approaches and applications Bertorelle, Giorgio; Bruford, Michael W.; Hauffe, Heidi C. ...
Population Genetics for Animal Conservation,
01/2001
Book Chapter
Over the last ten years DNA fingerprinting has been and continues to be applied in many diverse areas of biological science, and has now become a standard technique for rapidly screening genetic ...variation in animals, plants, and other eukaryotes. This chapter outlines the techniques of both multilocus and single-locus DNA fingerprinting using minisatellite sequences and out lines the various uses of these techniques in population genetics, evolutionary studies, and behavioural ecology.
An Overview of the Issues Mace, Georgina M.; Smith, Thomas B.; Bruford, Michael W. ...
Molecular Genetic Approaches in Conservation,
10/1996
Book Chapter
Conservation planning operates at many levels, from whole ecosystems and communities down to individual organisms. At each of these levels, molecular genetic techniques may provide appropriate tools ...to evaluate processes and to develop management strategies. In this chapter, we present an overview of the questions that may be relevant at each of these hierarchical levels, discuss how molecular genetic analyses may be used to address these questions, and provide examples of the use of molecular techniques in conservation (see Table 1-1). We do not aim to present an exhaustive review but rather to focus on examples from our own research so as to introduce some of the approaches presented in later chapters.
Microsatellites, or simple sequences, consist of tandemly repeated units, each between 1 and 10 bp (base pairs) in length, such as (TG)n or (AAT)n (Litt and Luty, 1989; Tautz, 1989; Weber and May, ...1989). They are widely dispersed throughout eukaryotic genomes (e.g., Gyapay et al., 1994), and are often highly polymorphic owing to variation in the number of repeat units (e.g., Amos et al., 1993). Although the application of microsatellite markers to population genetic studies is quite recent, with a relatively small number of plant and animal studies published (still fewer of these studies have been carried out from a conservation genetics perspective), this will certainly change completely within the next few years. This is because the potential for the use of these markers in small populations, and especially in endangered species, is very great, primarily since material for microsatellite analysis can potentially be sampled noninvasively from free-living populations (e.g., Morin et al., 1994a). This fact, together with the high information content of the genetic data yielded by microsatellite loci, will serve to make these markers one of the tools of choice for many future conservation genetic studies.
