Dynamics of balanced polymorphism morphs in blue rock pigeon (Columba livia) from Moscow

Analysis of the 30-year dynamics (from 1978 to 2008) of phenotype frequencies in the Moscow blue rock pigeon population revealed changes in the frequency distribution of several plumage color phenotypes. The frequency of the melanistic phenotype decreased as a result of the decrease in the total population size and, consequently, population density in colonies. This decrease in the pressure of the melanistic phenotype led to increased proportions of wild-type and aberrantly colored birds throughout the town and an increased frequency of transitory phenotypes in the central region. A predominance of one phenotype suppressed genetic diversity of plumage color phenotypes. The changes in the phenotype distribution in populations were associated with changes in the social structure of the human population. As the feeding resources grew poorer because of social anthropogenic factors, the pigeon population size decreased. This decrease in population size changed the phenotype frequencies, which was considered to be an adaptive response of the population to environmental changes.     

Dynamics of balanced polymorphism morphs in blue rock pigeon <Emphasis Type="Italic">Columbia livia</Emphasis>

Analysis of the 30-year dynamics (from 1978 to 2008) of phenotype frequencies in the Moscow blue rock pigeon population revealed changes in the frequency distribution of several plumage color phenotypes. The frequency of the melanistic phenotype decreased as a result of the decrease in the total population size and, consequently, population density in colonies. This decrease in the pressure of the melanistic phenotype led to increased proportions of wild-type and aberrantly colored birds throughout the town and an increased frequency of transitory phenotypes in the central region. A predominance of one phenotype suppressed genetic diversity of plumage color phenotypes. The changes in the phenotype distribution in populations were associated with changes in the social structure of the human population. As the feeding resources grew poorer because of social anthropogenic factors, the pigeon population size decreased. This decrease in population size changed the phenotype frequencies, which was considered to be an adaptive response of the population to environmental changes.     

Genetic structures in the population of Veneto.

The genetic structures of the population residing in the provinces of Venice and Rovigo in the Veneto region at the north of the Po delta in Italy was studied in 1,210 individuals residing in 18 sampling areas, using the phenotype and gene frequencies of 7 red cell enzymes: acid phosphatase (ACP1), esterase D (ESD), glyoxalase I (GLOI), glutamic-pyruvic transaminase (GPT), 6-phosphogluconate dehydrogenase (6-PGD), phosphoglucomutase 1 (PGM1), and phosphoglycollate phosphatase (PGP). For the analysis of the distributions of phenotype and gene frequencies, standardized variance and kinship profiles were used. It was found that the genetic differentiation within each province is low, and that only two systems, GPT and PGP, are significantly different between the two provinces. The samples studied seem to belong to a mainly homogeneous population.     

Effects of Social Structure on the Behaviour and Performance of Alternative Reproductive Phenotypes in Male Rock Shrimp, Rhynchocinetes typus

Males that adopt alternative mating tactics within a conditional strategy often undergo costly morphological changes when switching to the next phenotype during ontogeny. Whether costs of changing to a subsequent reproductive phenotype are outweighed by a higher mating probability may depend on the frequencies of different phenotypes in a group of competitors. Benefits and costs associated with different phenotype frequencies depend on interactions within and between alternative phenotypes, but the underlying behavioural mechanisms have rarely been studied. Herein, we used the rock shrimp Rhynchocinetes typus as a model: ontogenetic male stages of this species differ in morphological and behavioural traits that indicate alternative reproductive phenotypes. The small, subordinate, male stage (typus) develops via several intermediate stages (intermedius) to the dominant male stage (robustus): in competitive interactions the typus males usually employ the sneaking tactic, while the robustus males invariably employ the monopolizing fighter tactic. In laboratory experiments, we manipulated phenotype frequencies to examine whether there are frequency‐dependent effects on searching behaviour, aggressiveness and mating probability. With increasing frequency of robustus males, the rate of aggressive interactions among them increased. Furthermore, robustus males increased walking velocity when more than one robustus male was present. In contrast, typus males did not adjust their searching or aggressive behaviour. The increase of aggressive interactions among robustus males provided more opportunities for typus males to seize a temporarily unguarded female. While typus males exploit fights among robustus males that produce mating opportunities for them, robustus males benefit from typus males, which reveal the presence of receptive females. We suggest that each phenotype benefits from the presence of the other phenotype and suffers costly interference among individuals of the same phenotype. Whether frequency‐dependent effects on the mating probability of subordinates also affect their ontogenetic switchpoint should be examined in future studies.     

Temporal changes of gene frequencies in Cepaea hortensis

There have been few studies analysing long-term changes of gene frequencies in natural populations. This work is the first report of such changes in the land snail Cepaea hortensis (Mull).
Collections of C. hortensis were made at Silbury Hill, Wiltshire in 1957, 1963 and 1978. The banded phenotype significantly declined in frequency between 1963 and 1978. It is argued that the decline, which was statistically homogeneous at 15 separate sites within the area, was a consequence of natural selection. The average selection coefficient against the banded homozygote is estimated to have been greater than 1096.     

Phenotype-phenotype analysis: field application of the gene-for-gene hypothesis in host-pathogen relations

The frequency of occurrence of a virulence phenotype in a pathogen population is equivalent to its probability of occurrence in that population. From the compound probability law it can thus be shown that the expected frequency of occurrence of phenotypes with combined virulences is a product of the observed frequencies of the individual virulences. In many host-pathogen interactions, observed and expected frequencies of combined virulences are closely similar. Deviations from expectation, in both directions, do occur however, and these may be of crucial importance in disease control.     

A comparison of high frequency switching in the yeast Candida albicans and the slime mold Dictyostelium discoideum

Recently, high frequency switching systems have been identified in the infectious yeast Candida albicans and the cellular slime mold Dictyostelium discoideum. In C. albicans, cells can switch at spontaneous frequencies as high as 10(-2) between seven general colony morphologies in the case of strain 3153A or between two major phenotypes in the white-opaque transition in strain WO-1. In the latter system, dramatic changes occur in cellular phenotype as well. In D. discoideum, cells can switch at spontaneous frequencies of roughly 10(-2) between a number of colony phenotypes which include alterations in developmental timing, blocks at particular morphogenetic stages, morphological aberrations, and aggregation-minus. In the C. albicans and D. discoideum switching systems, the following characteristics are shared: 1) a limited number of switch phenotypes; 2) heritability; 3) high frequency reversibility; 4) low and high frequency modes of switching; and 5) ultraviolet (UV) stimulation of switching of cells in a low frequency mode of switching.     

Red cell enzyme polymorphisms in the greek populations.

The frequency of variant forms of 6 red cell enzymes, adenylate kinase, adenosine deaminase, phosphoglucomutase, acid phosphatase, 6-phosphogluconate dehydrogenase and glutathione reductase, were determined in 9 Greek populations. The frequencies of the variants in these populations were similar to those previously reported in most other European populations. However, several differences, particularly in the 6-phosphogluconate dehydrogenase, phosphoglucomutase and acid phosphatase alleles, were found in a comparison of Greeks and Bulgarians, in accordance with their separate ethnic origins. The Macedonians resembled the other Greeks and differed from the Bulgarians.     

Red cell adenylate kinase phenotypes in the affective disorders

Summary The red cell adenylate kinase (AK) phenotype was determined by starch gel electrophoresis in 96 adult Caucasian subjects with affective disorders (24 with bipolar illness and 72 with unipolar illness). The phenotype frequencies and the gene frequencies of the bipolar group closely resembled that of the control subjects (180 subjects drawn from the population of a large institution for the mentally retarded), the unipolar group however, showed a significant increase in the frequency of the AK² allele.The significance of these results have been discussed in relation to the known genetic and biochemical findings in the affective disorders. It is suggested that the mechanism involved may be a reduction of the enzyme activity in the tissues of subjects with the AK 2:1 phenotype. This may present a selective disadvantage in the form of a decrease in control of energy metabolism in general, and control of adenine nucleotide levels in nervous tissue in particular.     

五个鸡群中催乳素基因密码子使用频率与产蛋量的关系分析

通过鸡催乳素基因编码区基因扫描,发现3个SNP位点,分别是外显子2的C1607T、外显子5的C5749T和T5821C,3个SNP均没有改变氨基酸的编码.同时发现不同的单倍型间存在不同的密码子使用频率.对5个鸡群共370只鸡进行SSCP的基因型检测,共发现7种单倍型,结合44周龄产蛋量分析,发现不同单倍型的平均产蛋量存在显著性差异.结合密码子使用频率分析,发现使用高频密码子的单倍型个体产蛋量相对高.通过酶联免疫方法检测催乳素表达量,结果显示,使用高频密码子的个体,激素水平较高,其中使用2个高频密码子的单倍型个体和使用1.5个密码子的单倍型个体之间存在极显著差异.研究结果表明,密码子使用频率与产蛋量在一定的范围内呈现正相关趋势.     

Red cell enzyme types in rheumatic diseases

We studied the frequencies of red cell enzyme types, AcP, PGM1 and EsD in 213 patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), rheumatic heart disease (RHD), scleroderma (Scl) and psoriatic arthropathy (PsA). The differences in frequency of AcP phenotypes between RA, Scl, and PsA and the Moscow population were significant. In PsA the PGM1 phenotype 1-1 frequency was significantly decreased, while the phenotype 2-1 frequency was significantly increased.     

A worldwide correlation of lactase persistence phenotype and genotypes

Background  

The ability of adult humans to digest the milk sugar lactose - lactase persistence - is a dominant Mendelian trait that has been a subject of extensive genetic, medical and evolutionary research. Lactase persistence is common in people of European ancestry as well as some African, Middle Eastern and Southern Asian groups, but is rare or absent elsewhere in the world. The recent identification of independent nucleotide changes that are strongly associated with lactase persistence in different populations worldwide has led to the possibility of genetic tests for the trait. However, it is highly unlikely that all lactase persistence-associated variants are known. Using an extensive database of lactase persistence phenotype frequencies, together with information on how those data were collected and data on the frequencies of lactase persistence variants, we present a global summary of the extent to which current genetic knowledge can explain lactase persistence phenotype frequency.     

Phosphoglycolate phosphatase (PGP. E. C. 3..3.18) polymorphism in Magadan inhabitants

PGP phenotype and gene frequency distribution in 457 Russians and 33 Chuckchies is presented. Gene frequencies are: PGP1-0.887 and 0.970; PGP2-0.101 and 0.030; PGP3-0.030 and 0.000, correspondingly. It is shown that frequency of heterozygotes decreases in healthy Russians with increase of duration of dwelling under the North conditions. Such a dynamics causes approaching of PGP phenotype distribution of "long-livers" of the North to that of aboriginal population and moving away from European distribution type.     

Radiosensitivity detected by the micronucleus test is not generally increased in sporadic prostate cancer patients

The micronucleus test (MNT) has shown increased micronuclei (MN) frequencies in BRCA associated and sporadic breast cancer patients, Ataxia telangiectasia and Nijmegen Breakage Syndrome patients, demonstrating a common cellular phenotype of increased radiosensitivity. Some genes, causative of these diseases, have also recently been associated with prostate cancer. In order to investigate if prostate cancer exhibits the cellular phenotype of increased radiosensitivity, we performed MNT analysis on 22 sporadic prostate cancer patients and 43 male controls. We determined the baseline MN frequency, in order to see in vivo chromosomal damage without radiation, and induced (after irradiation with 2 Gy) frequency of MN, both in binucleated cells (BNC) obtained from cultured peripheral blood lymphocytes. An automated image analysis system was used to score the MN employing two different classifiers (Classifier A and B) for detection of BNC. The mean baseline frequencies were 48/43 MN/1000 BNC (A/B) for the controls and 42/50 (A/B) for prostate cancer patients. The induced MN frequencies amounted to 107/111 MN/1000 BNC (A/B) for controls and 111/114 MN/1000 BNC (A/B) for prostate cancer patients. The obtained MN frequencies did not result in a statistically significant difference between unselected cases and controls. However, restricting the analysis to young patients (50-60 years, N = 7) and age-matched controls (N = 7) revealed marginally significant higher MN frequencies in patients. We conclude that increased radiosensitivity is not a property of prostate cancer patients in general.     

Genetic polymorphism of the alpha 1-antitrypsin system in the native population of the Kazakh SSR

Phenotypes of alpha 1-antitrypsin of 218 natives from three ethno-historical regions of the Kazakh SSR were detected by isoelectric focusing in ultrathin layer polyacrylamide gel. Gene frequencies of the PiM1, PiM2, PiM3 subtypes in the summary extract were as follows: 0.8477, 0.1372 and 0.0106, respectively; the total gene frequency of two rare variants (PiN and PiZ) was 0.0046. The observed distribution of Pi subtypes shows good agreement with the Hardi-Weinberg equation. The analysis of the interpopulation intraethnic variability of the alpha 1-antitrypsin phenotype and allele frequencies in Kazakhs revealed clear local diversity. The frequency of PiM1 in the natives from North-Central ethno-historical region was reliably lower and that of PiM2 higher than in populations from South-East and West regions. The extracts analysed did not differ in the PiM3 incidences. The results of these studies were compared with the literature data for alpha 1-antitrypsin polymorphism in populations of the Euro-Asia. It is shown that PiM1 and PiM2 frequencies in the Kazakhs differ from the corresponding mean values both in mongoloid and europeoid groups. At the same time, they do not correspond to the intermediate frequency estimations, which could be expected from the fact of mixed origin of the Kazakh people and their border-line geographical position between Europe and Asia. Possible reason for such discrepancy is discussed.     

Prolein polymorphism in a randombred chicken population

Polymorphism in plasma amylase, plasma alkaline phosphatase, non-specific esterase and red cell esterase-D of the Athens-Canadian randombred (ACRB) population of chickens was determined by polyacrylamide and starch gel electrophoresis. Amylase alleles Amy-1^A and Amy-1^B were segregating in the ACRB population with frequencies of 0.45 and 0.55 respectively. For the plasma alkaline phosphatase the F and S bands, the B band and a new isozyme migrating at a faster rate than the previously reported F band were detected. A genetic nomenclature for plasma alkaline phosphatase is suggested which considers the difference between the F and S bands as the presence or absence of sialic acid attached to a primary protein.
Plasma esterase activity was observed in all four of the regions previously reported, but there was no polymorphism found in any of the loci. All birds in this population showed the same red-cell esterase-D phenotype which consisted of a main band with sub-bands on each side.     

Population genetics study of the functional asymmetry of the brain in native and migrant population of the north-eastern USSR

It is shown that ethnic groups of the North-East of the USSR (eskimos, coast and reindeer chukchi, koryaks and evens) differ significantly in phenotype frequencies of hemisphere interrelations, and the extent of differences conforms to non-similarity of the cultural and economic structure of these populations. Significant phenotype frequency dynamics observed in new-coming population, depending on the duration of dwelling under the North conditions, makes the phenotype of "long-livers" of the North more distant from the population of middle latitudes and closer to the aboriginal populations. Such a dynamics of phenotypic structure of new-coming populations is due to selective migration of the population. Great adaptability of the right hemisphere relationship type individuals of aboriginal as well as new-coming population to the North-East conditions is grounded. The role of hemisphere relationship type in adaptation to the environmental conditions is under discussion.     

An analysis of red cell enzymatic markers in the province of Bologna (Italy).

About 280 unrelated individuals living in the province of Bologna (Northern Italy) have been studied for the following red cell enzymatic markers: phosphoglucomutase (PGM), adenylate kinase (AK), adenosine deaminase (ADA) and phosphohexose isomerase (PHI). 116 subjects from the same sample have also been analysed for red cell acid phosphatase (ACP). The observed gene frequencies are PGM21 = 0.280; AK2 = 0.030; ADA2 = 0.091; ACPa = 0.297; ACPb = 0.647; ACPc = 0.056. In the PHI system two individuals with the variant PHI 3-1 phenotype have been found.     

Null allele in a human polymorphism restricted to the placenta: call for a search

The identification of a null allele in a human genetic system restricted to the placenta is a great challenge for two reasons: the impossibility of carrying out family studies and the unviability of sample recollections because the placenta itself is a disposable universe. Thus, in addition to reporting the finding of a null phenotype of placental alkaline phosphatase in a dark mulatto newborn from a black mixed population of Bahia, Brazil, here we present other evidence for the presence of the ALPP*Q0 allele with considerably high frequency in this population.     

Properdin factor B frequencies in four Asian populations

The distribution of Properdin factor B (Bf) phenotypes and their gene frequencies were investigated in four Asian populations (Chinese, Filipino, Thai and Japanese). The frequency of the BfS phenotype in Filipinos (0.717) was significantly lower than that in Chinese (0.900) and Thai (0.889) (p less than 0.01), but not different from the Japanese (0.840). One variant, BfF 0.65 S, was identified in a Japanese subject. Thus, in the Asian populations studied, Bfs frequencies were high and the frequency of variants other than F and S were low.