Evolution and Variation of Multigene Families

1 Organization and Properties of Antibody Genes and Other Multigene Families.- 1.1 Multigene family.- 1.2 Antibody gene families.- 1.3 Coincidental evolution.- 2 Models of Unequal Crossing-Over.- 2.1 Simulation studies of the model of unequal crossing-over.- 2.2 Diffusion approximation of coincidental evolution.- 2.3 Coincidental evolution as a birth-death process.- 3 Population Genetics Approach.- 3.1 Model.- 3.2 Approximate analyses by double diffusion process.- 4 Decrease of Genetic Correlation with Distance Between Gene Members on the Chromosome.- 4.1 Unequal crossing-over by shift of one gene unit.- 4.2 Unequal crossing-over by shift of more than one gene.- 4.3 Average identity coefficient.- 5 Genetic Differentiation of Multigene Families.- 5.1 Identity coefficient between the populations.- 5.2 Variance and covariance of identity coefficients.- 5.3 Numerical examples and some applications.- 6 Statistical Analyses on Sequence Variability of Immunoglobulins.- 6.1 Average identity coefficient.- 6.2 Identity coefficient in association with subfamilies of variable region sequences.- 6.3 Variance and covariance of identity coefficients.- 7 Linkage Disequilibrium Between Amino Acid Sites in a Multigene Family.- 7.1 Variance of linkage disequilibrium coefficients.- 7.2 Application to sequence variability of immunoglobulins.- 8 Prospects for Future Research.- 8.1 Gene conversion and other mechanisms to increase homogeneity.- 8.2 Non-constant gene family size.- 8.3 Accumulation of non-functional genes.- 8.4 Natural selection on gene diversity.- 8.5 Possible other examples to apply the theory.- 8.6 Multigene family of small size.- 8.7 Concluding remarks.- References.