On the population genetics of the ceruloplasmin polymorphism

Summary The frequencies of Cp-variants in 3 European, 1 Asiatic and 3 African populations are reported. The most striking fact is the high incidence of the Cp^A-allele not only in the African but also in 2 European samples.

---

Zusammenfassung An 3 europäischen, 1 asiatischen und 3 afrikanischen Stichproben werden die populationsgenetischen Daten von Coeruloplasmin-Varianten erhoben. Der auffallendste Befund ist die erhöhte Cp^A-Frequenz nicht nur in den afrikanischen, sondern auch in 2 europäischen Stichproben.

---

---

Supported by the Deutsche Forschungsgemeinschaft.     

DNA polymorphism in population genetics

In the review, the literature evidence on DNA polymorphism obtained in the last 10-15 years using various molecular-genetic methods is summarized. All main types of DNA variation are considered but attention is focused on those extensively used in population genetics. The areas of using DNA markers are outlined and the limitations of their potential in analyzing genetic processes in populations are discussed. Particular emphasis is placed on the relationship between the earlier developed biochemical genetics based on protein polymorphism analysis and modern molecular population genetics based on DNA polymorphism. The possible role of selection in maintaining DNA variation is considered.     

Genetic polymorphism of ceruloplasmin in the rat

The genetic heterogeneity of ceruloplasmin in serum was studied in the progeny of the (LEW X BN)F1 X (LEW X BN)F1 rats. The results of the statistical analysis showed that the Hbb and c loci were linked. However, the autosomal Ces gene was not linked to the Hbb or c loci. The Ces gene was expressed in normal Mendelian pattern and had two alleles that manifested a low (Cesl) or high (Cesh) level of the enzyme in serum. The Cesl gene was expressed as a dominant in the F1 generation. Two phenotypes CES-H and CES-L were found in the F2 rats; the females in the parental strain and hybrid had higher ceruloplasmin concentration than the male rats.     

Common polymorphism of peptidase A: Formal genetics and population data

Summary Peptidase A polymorphism was investigated in 83 mother-child pairs and in a population sample of 182 unrelated individuals from southwestern Germany. Hereby the formal hypothesis that there are two common alleles, PepA¹ and PepA⁸, at an autosomal locus PepA, was confirmed. The frequency of the PepA⁸ allele was calculated to be 0.27±0.02.     

The population genetics of the B-chromosome polymorphism of Myrmeleotettix maculatus (Orthoptera: Acrididae)

A simple difference equation model of the dynamics of the B-chromosome of Myrmeleotettix maculatus is developed, validated with field data, and analysed. The maintenance of the B in a population is due to a frequency-dependent balance between a net meiotic drive and strong selection against karyotypes containing 2 B's. This equilibrium will be subject to substantial fluctuations even in moderately large populations. In the long run a B is likely to be maintained in a population despite the selection of suppressor genes, which will tend to remain polymorphic in the population. These qualitative conclusions are likely to apply to many B-chromosome systems.     

Bacterial population genetics

Bacterial population genetics is the study of natural bacterial genetic diversity arising from evolutionary processes. The roles of molecular mistakes, restriction–modification, plasmids and gene transfer in bacteria are also important components of population genetics. These aspects are of considerable scientific importance from a fundamental perspective, because of the short generation times of bacteria, their microscopic cell size, the large population sizes bacteria can achieve and their different mechanisms of gene transfer.     

Bacterial population genetics

Bacterial population genetics is the study of natural bacterial genetic diversity arising from evolutionary processes. The roles of molecular mistakes, restriction–modification, plasmids and gene transfer in bacteria are also important components of population genetics. These aspects are of considerable scientific importance from a fundamental perspective, because of the short generation times of bacteria, their microscopic cell size, the large population sizes bacteria can achieve and their different mechanisms of gene transfer.     

HLA-DR polymorphism in a Senegalese Mandenka population: DNA oligotyping and population genetics of DRB1 specificities.

HLA class II loci are useful markers in human population genetics, because they are extremely variable and because new molecular techniques allow large-scale analysis of DNA allele frequencies. Direct DNA typing by hybridization with sequence-specific oligonucleotide probes (HLA oligotyping) after enzymatic in vitro PCR amplification detects HLA allelic polymorphisms for all class II loci. A detailed HLA-DR oligotyping analysis of 191 individuals from a geographically, culturally, and genetically well-defined western African population, the Mandenkalu, reveals a high degree of polymorphism, with at least 24 alleles and a heterozygosity level of .884 for the DRB1 locus. The allele DRB1*1304, defined by DNA sequencing of the DRB1 first-domain exon, is the most frequent allele (27.1%). It accounts for an unusually high DR13 frequency, which is nevertheless within the neutral frequency range. The next most frequent specificities are DR11, DR3, and DR8. Among DRB3-encoded alleles, DR52b (DRB3*02) represents as much as 80.7% of all DR52 haplotypes. A survey of HLA-DR specificities in populations from different continents shows a significant positive correlation between genetic and geographic differentiation patterns. A homozygosity test for selective neutrality of DR specificities is not significant for the Mandenka population but is rejected for 20 of 24 populations. Observed high heterozygosity levels in tested populations are compatible with an overdominant model with a small selective advantage for heterozygotes.