Phosphoglucomutase-1 subtypes in two populations in Adriatic islands: presence of PGM1*W3 (PGM1*7+) allele.

Allele frequencies at the phosphoglucomutase-1 (PGM1) locus have been investigated in two Croatian (Yugoslavian) populations from neighboring islands, Silba and Olib. The genotype distributions are significantly different though the two islands are only 2 km apart. In the light of demographic and historical data, a few hypotheses explaining these results are discussed. A rare variant, PGM1*W3, usually found in Asia, is present in 4 inhabitants from the Olib island.     

Phosphoglucomutase-1 (PGM1) W23 and W26 variants detected in the Taiwanese Chinese population

Phosphoglucomutase-1 (PGM1) phenotyping among Taiwanese Chinese was carried out on thin layer agarose gel using isoelectric focusing techniques. During routine paternity testing, two new PGM1 variants not previously observed in Taiwanese Chinese were detected. These are PGM1 W23 and PGM1 W26.     

Gc and PGM subtypes in northern Greece

By isoelectric fucusing, Gc and PGM subtypes were examined in a sample of over 450 Greeks from Thessaloniki and surrounding areas. The gene frequencies are compared with those from other Greek and European samples.     

Genetic studies of phosphoglucomutase-1 (PGM1) subtypes: population aspects]

Distribution of the subtypes and gene frequencies of phosphoglucomutase-1 among some populations of Buryats, Kirghizes of the Pamir and Russians of Moscow district was analysed. The frequencies of PGM1 genes vary in Buryats being PGM1+(1) 0.647-0.743, PGM1-(1)-0.100-0.132, PGM2+(1)-0.122-0.199 and PGM2-(1)-0.007-0.037. Following frequencies of PGM1 genes were established for Kirghizes: PGM1+(1) = 0.614, PGM1-(1) = 0.114, PGM2+(1) = 0.217 and PGM2-(1) = 0.054; in Russian populations the frequencies were: PGM1+(1) = 0.578, PGM1-(1) = 0.110, PGM2+(1) = 0.253 and PGM2-(1) = 0.059. Peculiarities of PGM1 polymorphism in the USSR and all over the world were analysed. Parallel biodemographic investigations in Buryat population demonstrated differences in intensities of selection, related to concrete PGM genotypes.     

Substrate affinity in PGM1, PGM2, and PGM3 isozymes

Summary An easy method for routine detection of PGM₁, PGM₂, and PGM₃ isozymes is given. Differences in substrate affinity are discussed. Gene products pgm₁ can be differentiated from gene products pgm₃ by cofactor requirement.     

Phosphoglucomutase-1 subtypes in the Albanian ethnic minority of the province of Cosenza (Calabria-Southern Italy): Presence of a new variant

Allele frequencies of the phosphoglucomutase-1 (PGM1), in the Albanian ethnic minority of province of Cosenza (Calabria-Southern Italy) were compared with the corresponding data from neighbouring non-Albanian sample groups. The isoelectrofocusing evaluation in the two populations revealed the presence of a new variant PGM1^*W31 in Albanian sample group. Furthermore, a significant heterogeneity was observed between Albanian allele frequencies and those of the surrounding groups.     

A new partially deficient variant in the phosphoglucomutase 1 system,PGM1*W31

Summary In a case of disputed paternity an inherited hyposynthetical variant of the PGM1^*1A gene was identified. This variant could not be detected by conventional electrophoresis on cellulose acetate membranes but clearly appeared on polyacrylamide gels after isoelectric focusing. The enzyme activity of this variant was about 25% of the normal PGM1^*1A protein. The variant was designated PGM1^*W31.     

Differential function of the phosphoglucomutase isozymes PGM1 and PGM2

Summary A total of 13 metabolites thought to be possibly inhibitory were tested for their influence on PGM isozyme activities, each at several different concentrations. The analysis of statistical significance was based on enzyme activities obtained by densitometric measurements of starch gels. Five of the substances were found to inhibit PGM activity, three of which definitely and a further one probably led to a significantly stronger inhibition of the isozymes of the PGM₂ locus than of PGM₁ isozymes. They are (1) fructose-1,6-diphosphate, (2) adenosine triphosphate, (3) citrate, and (4) possibly 2,3-diphosphoglycerate. Thus, PGM₁ isozymes proved to function better in hard or perhaps marginal metabolic conditions. Related evolutionary aspects are discussed.     

Phosphoglucomutase (PGM1) subtypes in a Finnish population determined by isoelectric focusing in agarose gel

The red cell enzyme phosphoglucomutase first locus (PGM1) phenotypes of 639 adult Finns were determined by isoelectric focusing in agarose gel. All the ten commonly occurring phenotypes were detected and the frequencies of the four alleles at the PGM1 locus were as follows: PGMa11 = 0.5313, PGMa21 = 0.1800, PGMa31 = 0.2199 and PGMa41 = 0.0689. The PGM1 phenotypes of 221 mothers with 228 offspring were in accordance with autosomal codominant inheritance.     

bis-Azaaromatic quaternary ammonium analogues: ligands for alpha4beta2* and alpha7* subtypes of neuronal nicotinic receptors

A series of bis-nicotinium, bis-pyridinium, bis-picolinium, bis-quinolinium and bis-isoquinolinium compounds was evaluated for their binding affinity at nicotinic acetylcholine receptors (nAChRs) using rat brain membranes. N,N'-Decane-1,12-diyl-bis-nicotinium diiodide (bNDI) exhibited the highest affinity for [(3)H]nicotine binding sites (K(i)=330 nM), but did not inhibit [(3)H]methyllycaconitine binding (K(i) >100 microM), indicative of an interaction with alpha4beta2*, but not alpha7* receptor subtypes, respectively. Also, bNDI inhibited (IC(50)=3.76 microM) nicotine-evoked (86)Rb(+) efflux from rat thalamic synaptosomes, indicating antagonist activity at alpha4beta2* nAChRs. N,N'-Dodecane-1,12-diyl-bis-quinolinium dibromide (bQDDB) exhibited highest affinity for [(3)H]methyllycaconitine binding sites (K(i)=1.61 microM), but did not inhibit [(3)H]nicotine binding (K(i)>100 microM), demonstrating an interaction with alpha7*, but not alpha4beta2* nAChRs. Thus, variation of N-n-alkyl chain length together with structural modification of the azaaromatic quaternary ammonium moiety afforded selective antagonists for the alpha4beta2* nAChR subtype, as well as ligands with selectivity at alpha7* nAChRs.     

Human erythrocyte phosphoglucomutase: comparison of the kinetic properties of PGM1 and PGM2 isoenzymes

Kinetic properties of PGM1 and PGM2 phosphoglucomutase "primary" isoenzymes from human erythrocytes were studied. The two enzyme forms share a "ping-pong" kinetic mechanism and show similar Km for substrate (glucose 1-P) and cofactor (glucose 1,6-P2). Micromolar concentrations of fructose 1,6-P2 and glycerate 2,3-P2 inhibit both PGM1 and PGM2 isoenzymes to a similar extent. The sole PGM2 form is affected by ribose monophosphates (ribose 1-P and ribose 5-P) that act as mutase inhibitors vs. glucose 1,6-P2 and as apparent activators vs. glucose 1-P. The interaction between PGM2 isoenzyme and ribose monophosphates is discussed in the light of the ability of this form to also display phosphoribomutase activity.     

The distribution of HIV-1 subtypes in Fukuoka, Japan.

To determine the incidence of human immunodeficiency virus type-1 (HIV-1) subtypes in Fukuoka, Japan, viruses from 41 HIV-1 infected individuals were subtyped. Subtyping by V3-loop enzyme-linked immunosorbent assay (ELISA) showed 31 of the 41 subjects as subtype B (MN type), one as subtype A, one as subtype C, and eight untypable. The subject infected with subtype C was identified as a foreigner; the subtype A subject was Japanese. A phylogenetic analysis of nucleic acid sequences from the env C2-V3 region was also conducted. Genetic subtyping was successful for 25 samples: 23 samples were determined as subtype B, one subtype A and one subtype E. One of the individuals infected with subtype B, as well as the subtype A and subtype E subjects, were not Japanese. This study indicated that subtype B (USA and European type) is still dominant among HIV-1 infections in Fukuoka. Further, no Japanese were subtype E positive, which is increasing in the Kanto region. It is notable, however, that subtype A and subtype C infections, which are rare in Japan, were found in Fukuoka, located far from the metropolitan area of Tokyo.     

Density-dependent and geographical variation in bird immune response

Latitudinal gradients in parasitism are common, causing differences in the intensity of parasite-mediated natural selection. Such differences in selection pressures should affect optimal investment in anti-parasite defense, because defense levels should increase in response to increased intensity of parasite-induced selection. Likewise, latitudinal differences in population density may affect immune responses either by selecting for higher levels or defense, or by suppressing resources needed for mounting efficient immune responses. We tested these predictions in a study of T-cell mediated immune response in altricial bird species in subtropical Spain and temperate Denmark. There were highly consistent levels of T-cell mediated response between nestlings and adults in the two areas, with nestlings having stronger responses than adults. In addition, there were highly consistent levels of immune response in nestlings and adults between the two areas, with responses being consistently stronger in Denmark than in Spain, particularly in adults. Population density was much higher in Denmark than in Spain. We found evidence of density-dependent immune response in nestlings and adults, as shown by differences in T-cell response between study areas being positively related to differences in density. Given that the relationship between density and immune response was positive, we can reject the hypothesis that higher population densities suppressed immune response. Therefore, our results support the hypothesis that birds in areas with higher density allocate more resources to immune response, particularly in adults, suggesting that density-dependent effects of parasitism have selected for allocation strategies that minimize the risk of parasitism.     

Population distribution in North and Central America of PGM1 and Gc subtypes as determined by isoelectric focusing (IEF)

Gc subtypes of 20 North and Central American populations and PCM₁ subtypes in 11 populations were analyzed to identify interpopulation variation of the respective gene frequencies for common alleles. A total of 23,304 phenotypings were done. Absolute heterozygosity levels (D) generally increased twofold when phenotyping by isoelectric focusing was compared with conventional electrophoresis. Graphic representation of the Gc subtypes and multivariate analysis to identify genetic affinities of the populations under study reveal genetic clusters consistent with major historical and geographical groupings of man.     

中国广东人红细胞PGM_1亚型遗传性多态现象

采用薄层聚丙烯酰胺凝胶等电聚焦技术,调查了中国(广东)406名无亲缘关系的正常人红细胞磷酸葡萄糖变位酶-1(PGM_1)亚型的遗传多态性。除了常见的10种亚型外,还发现了由一个新的变异型等位基因和常见的4个等位基因杂合产生的9例变异型。PGM_1位点的等位基因频率PGM_1~(1+)、PGM_1~(1-)、PGM_1~(2+)、PGM-1~(2-)和PGM_1~(V丰)(变异型等位基因)分别为0.5973、0.1256、0.1724、0.0936和0.0111;群体处于Hardy-Weinberg式平衡状态。变异型等位基因以多态频率出现,可能成为该群体的一个重要的遗传性特征。     

Fluctuations in the occurrence of Escherichia coli O157:H7 on a Norwegian farm*

AIM: To describe the distribution of Escherichia coli O157:H7 on a sporadically positive dairy farm and on possible contact farms over a one-year period. METHODS AND RESULTS: Environmental and faecal samples from all animals at the farm, and faecal samples from animals at contact farms were analysed for E. coli O157:H7 by immunomagnetic separation methods or VIDAS.Confirmed isolates were tested for cytotoxicity in the Vero cell assay and typed by PFGE. Escherichia coli O157:H7 (stx2 and eae) of the same PFGE type were isolated from cattle, sheep, hens and environmental samples at variable levels during summer and fall 2002, but were not detected in 2003. CONCLUSIONS: Escherichia coli O157:H7 had a widespread distribution on the farm investigated, but the original source of contamination could not be identified. The occurrence of this bacterium on the farm did not result in any detectable increase in gastrointestinal disease in the associated population. SIGNIFICANCE AND IMPACT OF THE STUDY: Despite a low endemic level of E. coli O157:H7 in the Norwegian cattle population, the growth and spread of this potentially important bacterium may occur.     

Significance of avian linker histone (H1) polymorphic variation

Most of avian histone H1 non-allelic subtypes, i.e. eight out of nine, show polymorphic heterogeneity manifested by the presence of two or three allelic variants formed as a result of amino acid deletion and substitution. In addition, some of histone H1 non-allelic subtypes exhibit various allelic complements in different bird species leading to the widening of a whole pool of histone H1 polymorphic variation. A wide range of histone H1 heterogeneity may indicate that the polymorphic variants can individually modulate some histone H1-dependent cellular processes by showing allele-specific influence on chromatin organization and function. Although, the exact way of avian histone H1 allelic variants’ activity is not known, their structural separateness inferred from biochemical experiments and relationship with some characteristics of organism functioning disclosed in the genetic studies seem to confirm their importance. The aim of this review is to characterize the molecular origin of histone H1 polymorphisms and draw attention to the link between the histone H1 polymorphic variants and avian organismal features related to the physiological effects of bird individuals’ living in the natural and breeding populations.     

Tongue-rolling phenotypes and geographical variation in the United Kingdom

The distribution of tongue-rolling phenotypes in a sample (n = 477) of undergraduate students of the University College of Swansea (U.K.) was studied. The birthplaces of these students were also recorded. England was divided into six areas, and Wales was left as an area on its own. The data suggest that those students who come from north-east are more non-rollers, which may be due to mixture with Scandinavians.     

A morphometric assessment of geographical variation and subspecies in impala

The single species of Aepyceros, Aepyceros melampus (impala), is native to central and southern Africa, from Uganda to South Africa. It inhabits open woodlands, sandy bush country and acacia savannah. This study tested the morphological and geographical variation among specimens of impala and their possible relation with described subspecies. Nineteen skull and horn measurements were taken. A multivariate analysis was used and size and shape were explored. Facial coat patterns were also coded. The results supported four out of five traditionally described subspecies: Aepyceros melampus petersi from Angola/Namibia, Aepyceros melampus melampus from South Africa, Aepyceros melampus suara from East Africa and Aepyceros melampus johnstoni from Zambia and Malawi. We consider Aepyceros melampus rendilis to be a synonym of suara . A revised synopsis is suggested, with comments on the geographical ranges of the subspecies. Skull dimensions also allowed us to estimate the geographical origin and subspecies of some individuals of unknown provenance. Coat patterns showed no clear relation with subspecies or geographic location, with the exception of A. m. petersi .     

Some patterns of age and geographical variation in fish fecundity

Some patterns of age and geographical variation in fecundity indices were analyzed in three freshwater fishes (river perch, bream, and Sevan khramulya). A trend to increase in the ovarian relative weight and mature egg size with age has been revealed. Two species with a wide range (perch and bream) demonstrated a tendency to decrease in the ovarian relative weight and increase in the definitive oocyte weight in females of populations living in the geographical center of the range. The coefficient of correlation between the absolute individual fecundity and body weight of females was proposed as a population marker of the fish reproductive system.