Genetic Variation Within and Among Metal-Tolerant and Non-Tolerant Populations of Armeria maritima (Mill.) Willd. s.l. (Plumbaginaceae) in Central and Northeast Germany

Abstract: Six metal-tolerant populations and sub-populations of Armeria maritima ssp. halleri, ssp. hornburgensis, and ssp. bottendorfensis and two non-tolerant populations of ssp. elongata in Central and Northeast Germany have been analysed using RAPD markers. The populations show very strong genetic differentiation (Φ_ST = 0.46), corresponding gene flow between them is low (N_em = 0.29). A moderate positive correlation between the matrices of genetic and geographical distances was found between the seven populations and sub-populations of central Germany (r = 0.68, p < 0.001). Calculated parameters of genetic variability are molecular variance, percentage of heterozygosity and percentage of polymorphic loci. A significant correlation between population size and parameters of genetic variability was not recognisable. Genetic structure was investigated by an analysis of molecular variance (AMOVA). The studied populations show strong genetic differentiation. Genetic variation within populations ("normal" as well as metalliferous) is higher (53.9 %) than among them (46.1 %). Six hypotheses of possible genetic relatedness between the studied populations have been tested by AMOVA. A data set structure above the populational level is hardly recognisable. It was impossible to combine the populations to edaphic (tolerant and "non-tolerant") or taxonomic groups. A. maritima ssp. halleri of the north Harz mountains and ssp. hornburgensis are clearly separated from a geographical group containing all other populations (across taxonomic and edaphic boundaries). These results are a further indication for a polyphyletic origin of metal-tolerant populations of A. maritima s.l. by multiple colonizations of metalliferous sites from neighbouring populations on non-metalliferous soil.     

Phenotypic variability and correlation between skinfold thickness and arterial pressure level]

Contribution of genetic and environmental factors in phenotypic variability of blood pressure level and skinfold thickness, and phenotypic correlation between these characters was calculated on the basis of familial correlations. It was shown that genetic determinant explains considerable portion of blood pressure level and skinfold thickness variability. Among common environmental effects, the factors affecting one generation are important with regard to variability of these characters. Maternal effect is expressed in the variability of systolic and diastolic blood pressure. Correlation between blood pressure level and triceps skinfold thickness is determined by genetic factors, whereas that between blood pressure level and subscapular skinfold thickness is mediated by environmental factors. The results obtained may be applied in populational prevention of cardiovascular disease.     

Genetic and Phytochemical Analysis to Evaluate the Diversity and Relationships of Mate (Ilex paraguariensis A.St.‐Hil.) Elite Genetic Resources in a Germplasm Collection

The aim of this study was to evaluate the phytochemical and genetic diversity, relationships and identification of mate (Ilex paraguariensis A.St .‐Hil .) elite genetic resources belonging to the Brazilian germplasm collection and mate breeding program. Mate has been studied due to the presence of phytochemical compounds, especially methylxanthines and phenolic compounds. The samples were collected from the leaves of 76 mate elite genetic resources (16 progenies × 5 localities). Total DNA was extracted from mate leaves and 20 random primers were used for DNA amplification. Methylxanthines (caffeine and theobromine) and phenolic compounds (chlorogenic, neochlorogenic, and criptochlorogenic acids) were quantified by HPLC. The genetic divergence estimated was higher within (92%) than among (8%) the different populations. Analysis of genetic distance between origins provided the formation of two groups by UPGMA cluster analysis, with higher polymorphism (94.9%). The average content of caffeine ranged from 0.01 to 1.38% and theobromine of 0.10 – 0.85% (w/w). The caffeoylquinic acids concentrations (1.43 – 5.38%) showed a gradient 3‐CQA > 5‐CQA > 4‐CQA. The coefficient of genetic variation (CVg) was of low magnitude for all mono‐caffeoylquinics acids. Significant correlations (positive and negative) were observed between the phytochemical compounds. Genetic diversity analysis performed by RAPD markers showed a greater intra‐populational diversity; genetic resources with low caffeine and higher theobromine content were identified and can be used in breeding programs; the correlation between methylxanthines and phenolic compounds can be used as a good predictor in future studies.     

人类群体遗传结构的协方差阵主成分分析方法

目的:探讨基因频率矩阵的中心化(或均值化)协方差阵主成分分析方法在人类群体遗传结构研究中的适用性和合理性。方法:从基因频率矩阵的结构特征入手,分析中心化、均值化协方差阵主成分分析与标准化相关阵主成分分析在特征根、特征向量以及降维效果等方面的差异,并通过实例比较不同方法在解释群体遗传结构特征上合理性。结果:中心化(或均值化)协方差阵的主成分不仅反映了基因变异程度的“方差信息量权”,而且反映了基因间相互影响程度的“相关信息量权”;标准化相关阵的主成分反映的仅是“相关信息量权”,不包括“方差信息量权”。通过比较中国26个汉族人群HLA-A基因座中心化协方差阵和标准化相关阵2种主成分分析结果,证实中心化协方差阵主成分分析方法在特征根与特征向量、保留主成分的个数和对主成分的群体遗传学解释的合理性等方面均优于标准化相关阵主成分分析方法。结论:在对群体遗传结构进行主成分分析时,应使用中心化(或均值化)变换消除基因频率矩阵中量级的影响,然后在用其协方差阵提取主成分。     

Change in certain indices of the muscle tissue energy metabolism of rats depending on their initial level under the action of vibration]

The response of isolated muscle tissue of white rats to low-frequency vibration has been studied. It was shown on single individuals that a negative correlation exists between the values of changes in respiration intensity, creatinephosphate, and lactic acid contents, and the initial lewel of these indices. Such individual response of muscles to vibration is a non-specific cellular reaction to injury. Notwithstanding the changes of these indices in single individuals, the average populational level of these indices remains unchanged. Hence, the average level is insufficient for the characteristics of cellular reaction.     

Changes in the sexual dimorphism of triatominae in the transition from natural to artificial habitats.

A shift from large to small average sizes was observed in Triatoma infestans and Rhodnius domesticus between field and domestic (or laboratory) conditions of life. It was more pronounced in the female specimens, leading to a subsequent reduction of sexual size dimorphism. This feature is discussed in terms of genetic and populational changes occurring from natural to artificial habitats, in particular those related to population densities. Sexual size dimorphism is then recommended as a new character to be used in the study of species of Triatominae adapting to domestic ecotopes.     

Genetic relationships and population structure within taxa of the endemic Sideritis pusilla (Lamiaceae) assessed using RAPDs

RAPD analysis has been performed for 15 plant populations, covering eight different infraspecific taxa of Sideritis pusilla (Lange) Pau, member of the Lamiaceae endemic to southeastern Spain, and their putative parental species Sideritis hirsuta L. and Sideritis Uucantha Cav. Genetic distances, together with the presence of numerous fixed molecular markers differentiating S. pusilla from its putative ancestors, indicate that it should be considered as a true species. Cladistic and populational analysis led to the allocation of S. pusilla populations into three major groups– osteoxylla, jlavovirens and pusilla/almeriensis –which include taxa previously described as ranging from the varietal to the specific level. Low genetic differentiation among groups revealed by a reduced number of specific molecular markers justify their assignment under the infraspecific range. Moreover, the existence of both morphological and biogeographical differences, supports a status for these groups as subspecies of S. pusilla. Highly significant ( P <0.002) variance partitioning data (AMOVA) extracted from the analysis of individuals within S. pusilla populations show that, of the total genetic diversity, 68.8% was attributable to individual differences within populations, 19.9% to populational differences within groups, and only 11.3% to divergence between groups. This distribution is in agreement with the outcrossing nature of these plants. Comparative analysis of variance within populations reveals a reduced genetic variation for the osteoxylla group, thus supporting its previous consideration as an endangered taxon.     

Locale-specific Vocal Behaviour of the Tamarin (Saguinus I. labiatus)

A quantitative acoustic analysis of long calls of red-chested moustached tamarins (Saguinus l. labiatus) was undertaken after capture in the primary forest of Northwestern Bolivia, comparing two populations. Two acoustic parameters are statistically significantly different. Acoustic properties distinguishing individual heterogeneity are quite consistent between the groups and completely different from cues separating population variability. As these two study groups were only 27 km apart when trapped, and as no geographical barriers prevented genetic exchanges between them, we assume populational vocal variability comparable to dialects in birds.     

Molecular aspects of blood pressure regulation.

After 100 years of measurement, reasons for interindividual and populational variation in blood pressure have proven difficult to identify. Use of 24-hr blood pressure monitoring has revealed additional intra-individual variation. Variability in kidney function, extracellular sodium and potassium (Na:K) balance, and factors affecting water, sodium, and potassium resorption obviously affect blood pressure. Alterations in these and additional factors predict development of hypertension. In recent decades the molecular revolution has increased scrutiny of genetic factors contributing to interindividual and populational differences in blood pressure and hypertension. Most investigations across populations and environments have focused on components of the renin-angiotensin-aldosterone system. DNA polymorphisms within this system clearly are associated with blood pressure and hypertension; however, these associations tend to vary across race and ethnicity, ecological settings, and sex. There is clear evidence that polymorphisms at the renin, angiotensinogen, and angiotensin-converting enzyme loci influence both blood pressure and hypertension. In addition, evidence suggests gene-gene and gene-environment interactions along with sex-specific actions of these loci on blood pressure.     

Evolution in fine-grained environments I. Environmental runs and the evolution of homeostasis

In this paper we discuss the problem of evolution when individual organisms are subjected to heterogeneous environments within their own lifetimes. We first develop a model of environmental heterogeneity in which there are two discrete environmental states. Transitions between states are governed by a stochastic matrix. Next, we examine how an organism responds to this heterogeneity. We assume that L consecutive time units of the environmental process are sampled during the normal life span of the organism, and that the individual's fitness is determined in part by a component unrelated to this heterogeneity and by other components that describe the fitness response to the heterogeneity. The fitness responses are functions of the environmental state and of how long the organism has been previously exposed to that state; i.e., fitness response is dependent upon the environmental context. We then discuss how this individually experienced heterogeneity is translated to the populational level. Finally, genetic constraints are overlaid so that the tools of population genetics may be used to make evolutionary predictions.     

Quantitative genetics of skeletal nonmetric traits in the rhesus macaques on Cayo Santiago. II. Phenotypic,genetic, and environmental correlations between traits

The general lack of phenotypic correlation among skeletal nonmetric traits has been interpreted as indicating a lack of genetic correlation among these traits. Nonmetric traits scored on animals in the skeletal collection of rhesus macaques from Cayo Santiago are used to calculate phenotypic, genetic, and environmental correlations between traits. The results show that even when phenotypic correlations are low, there may be large, significant genetic correlations among these traits. The genetic correlation pattern suggests that genes which affect nonmetric trait variation act primarily at a local level in the cranium, even though there are genes with pleiotropic effects on skeletal nonmetric traits throughout the cranium. Environmental and phenotypic correlations do not show this neighborhood pattern of correlation.     

Heritability of circulating growth factors involved in the angiogenesis in healthy human population

The present study examined the extent of genetic and environmental influences on the populational variation of circulating growth factors (VEGF, EGF) involved in angiogenesis in healthy and ethnically homogeneous Caucasian families. The plasma levels of each of the studied biochemical indices were determined by enzyme-linked immunoassay in 478 healthy individuals aged 18-75 years. Quantitative genetic analysis showed that the VEGF and EGF variation was appreciably attributable to genetic effects, with heritability estimates of 79.9% and 48.4%, respectively. Yet, common environmental factors, shared by members of the same household, also played a significant role (P < 0.01) and explained between 20.1% and 32.6% of the variation. The present study additionally examined the covariations between these molecules and either transforming growth factor-beta 1 (TGF-beta 1) or tissue inhibitors of matrix metalloproteinases 1 (TIMP-1), likewise relevant for angiogenesis. Bivariate analysis revealed significant phenotypic correlations (P < 0.002) between all pairs of variables, thus indicating the possible existence of common genetic and environmental factors. The analysis suggested that the pleiotropic genetic effects were consistently the primary (or even the sole) source of correlation between all pairs of studied molecules. The results of our study affirm the existence of specific and common genetic pathways that commonly determine the greater part of the circulating variation of these molecules.     

ANCIENT URBANIZATION PREDICTS GENETIC RESISTANCE TO TUBERCULOSIS

A link between urban living and disease is seen in recent and historical records, but the presence of this association in prehistory has been difficult to assess. If the transition to urban living does result in an increase in disease‐based mortality, we might expect to see evidence of increased disease resistance in longer‐term urbanized populations, as the result of natural selection. To test this, we determined the frequency of an allele (SLC11A1 1729 + 55del4) associated with natural resistance to intracellular pathogens such as tuberculosis and leprosy. We found a highly significantly correlation with duration of urban settlement—populations with a long history of living in towns are better adapted to resisting these infections. This correlation remains strong when we correct for autocorrelation in allele frequencies due to shared population history. Our results therefore support the interpretation that infectious disease loads became an increasingly important cause of human mortality after the advent of urbanization, highlighting the importance of population density in determining human health and the genetic structure of human populations.     

Populational structure of three fish species (Cypriniformes: Cyprinidae) living in rivers of the Ob-Irtysh basin,by the data of isoenzyme analysis

Data are presented on genetic subdivision of populations of roach Rutilus rutilus lacustris, ide Leuciscus idus, and dace L. leuciscus baicalensis living in rivers of West Siberia. These fish species have comparable levels of variation of allozyme loci and similar populational structure which well agrees with geography of the river network of the Ob-Irtysh basin. The populational differentiation is more expressed in ide than in roach and dace.     

Medico-genetic study of the population of the Samarkand region. II. Population-genetic description of 4 kishlaks of the Urgut district]

This report is a second one in a series of works devoted to the medico-genetical screening of Uzbekistan populations. The paper comprises the results of the analysis of the populational structure of one of the village councils (soviets) of the Urgut District of the Samarkand Region. The main parameters of the population studied were as follows: total number 1529 persons, the average number of inhabitants of one village--328. The proportion of the inhabitants studied--56%, the average number of persons per family--5.22; the average period between subsequent generations--30-35 years, the gametic index--0.8, the inbreeding coefficient inferred from pedigrees--0.018899--0.00781, Fst = 0.03577, the average genetic distanse according to Edwards--0.0231-0.0671. The distribution of Mendelian markers (ABO, Rh, Hp and Ptc) was studied. The observed ratio between a high degree of inbreeding and a relatively low extent of isolation of populations permits to explain satisfactorily the distribution and frequencies of hereditary pathology in the Urgut District of the Samarkand Region pointed out in the previous report.     

Clonal genetic diversity and populational genetic differentiation in Phragmites australis distributed in the Songnen Prairie in northeast China as revealed by amplified fragment length polymorphism and sequence-specific amplification polymorphism molecular markers

Genetic variation within and between four naturally occurring Phragmites australis land populations, DBS, QG, SS1 and SS2 (named after locality), which colonise distinct habitats (different edaphic conditions) in the Songnen Prairie in northeast China, were investigated by amplified fragment length polymorphism (AFLP) and sequence‐specific amplification polymorphism (S‐SAP) markers. It was found that the selected primer combinations of both markers were highly efficient in revealing the inter‐clonal genetic diversity and inter‐populational genetic differentiation in P. australis from a molecular ecological perspective. Cluster analysis categorised the plants into distinct groups (DBS, QG and SS groups), which were in line with their localities, albeit the two SS group populations (SS1 and SS2) showed a lower degree of inter‐populational differentiation. These results were strongly supported by multiple statistical analysis including Mantel’s test, principal coordinate analysis, allocation test and analysis of molecular variance, which further suggested that gene flow, genetic drift and differences in as yet unidentified edaphic factors may all underpin the inter‐clonal genetic diversity and inter‐populational differentiation at the nucleotide sequence level. Analysis of intra‐population clonal diversity also revealed that the QG population harboured a strikingly lower amount of within‐population variation compared with those of the other three populations, presumably being caused by genetic drift and followed by physical and/or biological isolation. Homology analysis of a subset of population‐specific or population‐private AFLP and S‐SAP bands suggested that regulatory genes and retroelements might play important roles in the ecological adaptation and differentiation of the P. australis populations. Possible causes for and implications of the extensive genetic variability in P. australis were discussed for its future genetic conservation and use in ecological revegetation.     

Inversion polymorphism in the malaria mosquito Anopheles messeae. VII. Fertility and the population genetics structure of the species

The role of chromosomal inversional complexes of different fecundity has been studied in the process of formation of karyotypic populational structure. Females with homozygotes 2R11 and "north-est" inversional combinations are shown to have maximal total egg production, while females with three or four inversional heterozygotes from XL01, XL12, 2R01, 3R01 and 3L01 demonstrated lower level of fecundity. It is found that the seasonal conversion from r-selection to K-selection occurs in the period of population "prosperity" (July). The results of such conversion are destruction of "northest" genocomplexes and reduction of relative fecundity of inversional homozygotes 2R11-Alternative tendencies take place at the beginning of the reproductive period.     

Dermatoglyphics in patients with hypothyreosis

About 15% of all females and 3% of all males suffers from hypothyreosis. The thyroid disease is the most frequent cause of hypothyreosis, and among people in Croatia who are suffering from that disease 90% have been affected by its autoimmune form. The thyroid diseases are supposed to be caused by the influence of various genetic and external factors and some forms of genetic influences have not yet been studied. Analysis of digito-palmar dermatoglyphics has been used in the research of the role of genetic predisposition in many various diseases. We have analyzed correlation of qualitative and quantitative traits between the group of 50 females suffering from hypothyreosis and a control group of 100 phenotypically healthy females. Quantitative statistical analysis using t-test has indicated only few significantly different variables, while the discriminant analysis has shown 76.9% correctly classified samples. The factor analysis has shown a high percentage of total variance within patients suffering from hypothyreosis, as well as the different structure of individual factors. Qualitative analysis has shown the heterogeneity between the two examined groups. The results of the research have proved that the qualitative characteristics are more unstable than the quantitative ones and they have also shown the instability of genes taking part in hypothyreosis development implying genetic predisposition of the disease.     

Systematics on the threshold of the XXI century. Traditional principles and fundamentals from today's point of view

Systematics as regarded is a purely theoretical domain of biology, and its product, system, as a specific biological theory, or a topologo-genetic model of the biota. Linnaeus was the first to introduce the idea of system and the systematic approach into the natural history. The advent of evolutionism brought new meaning to the old term "affinity", so Linnaeus' slogan of natural system got new life, and Linnaeus taxonomy assimilated the evolutionary ideology quite naturally and much easier than many other departments of biology. The difference between natural and artificial systems is remaining, and it is in their goals, as formulated by Linnaeus: heuristic of the former and cataloguing of the latter. Linnaeus' clairvoyance discovered the existence of an infrageneric level of genetic integration provable by naturalists' experience. He chose for it the designation of "species" and laid it down as primary, basic unit of his system. This is plainly evident from his own writings; the story about Linnaean species being products of a logical division of genera is a pure fiction. Modern populational model of species, by 3 important criteria, appears to be more akin to the Linneaean one than to the ideas of Lamarckism and early Darwinism. Systematic approach focuses rather on the interrelations among elements and their relative position, then on the properties and qualities of separately treated individual elements. In the development of systematics the aspect of "nexification" (study of connections) has been continuously gaining attention especially regarding the nomenclature where connotation has been totally forced out by denotation.     

The genetic structure of fermentative vineyard-associated <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> populations revealed by microsatellite analysis

From the analysis of six polymorphic microsatellite loci performed in 361 Saccharomyces cerevisiae isolates, 93 alleles were identified, 52 of them being described for the first time. All these isolates have a distinct mtDNA RFLP pattern. They are derived from a pool of 1620 isolates obtained from spontaneous fermentations of grapes collected in three vineyards of the Vinho Verde Region in Portugal, during the 2001–2003 harvest seasons. For all loci analyzed, observed heterozygosity was 3–4 times lower than the expected value supposing a Hardy–Weinberg equilibrium (random mating and no evolutionary mechanisms acting), indicating a clonal structure and strong populational substructuring. Genetic differences among S. cerevisiae populations were apparent mainly from gradations in allele frequencies rather than from distinctive “diagnostic” genotypes, and the accumulation of small allele-frequency differences across six loci allowed the identification of population structures. Genetic differentiation in the same vineyard in consecutive years was of the same order of magnitude as the differences verified among the different vineyards. Correlation of genetic differentiation with the distance between sampling points within a vineyard suggested a pattern of isolation-by-distance, where genetic divergence in a vineyard increased with size. The continuous use of commercial yeasts has a limited influence on the autochthonous fermentative yeast population collected from grapes and may just slightly change populational structures of strains isolated from sites very close to the winery where they have been used. The present work is the first large-scale approach using microsatellite typing allowing a very fine resolution of indigenous S. cerevisiae populations isolated from vineyards.