[Frontiers in Bioscience S3, 408-415, January 1, 2011]

Haplotype complementarity under mutational pressure

Dietrich Stauffer1,2, Stanislaw Cebrat2

1Institute for Theoretical Physics, Cologne University, D-50923 Koln, Euroland, 2Department of Genomics, Wroclaw University, ul. Przybyszewskiego 63/77, 51-148 Wroclaw, Poland

TABLE OF CONTENTS

1. Abstract
2. Introduction
2.1. Definition: purification versus complementation
2.2. Mutations
3. Some computer models
3.1. Emerging complementarity
3.2. Gamete recognition
3.3. Role of mutational pressure on the emerging of complementarity
3.4. The role of inbreeding
4. Consequences
4.1. Sympatric speciation
4.2. Distribution of recombination events
4.3. Effect of gamete recognition
5. Discussion
6. References

1. ABSTRACTNatural populations do not correspond to Mendelian populations. Effective populations are much smaller, inbreeding higher, and organization of large number of genes into chromosomes connected with relatively low recombination rate invalidates the law of independent gene assortment. Under such conditions, a large number of genes is inherited as clusters and evolves as genetic units. Computer simulations have shown that mutations inside clusters are not eliminated independently by purifying selection but, instead, the whole clusters tend to complement each other. It means that whenever one haplotype carries one of two possible alleles, the other haplotype at that locus carries the other allele; thus inherited recessive deleterious diseases do not affect the health of the phenotype even if their fraction in the genome is high. This complementation seems to be a winning strategy in small or spatially distributed populations. We discuss possible consequences of this complementarity.