Analysis of DYS19 and DYS287 polymorphisms in the Han population and three other ethnic groups of northeast China

The allelic distribution of the Y-chromosome specific microsatellite DYS19 in the Han population and in the Daur, Oroqen and Ewenki ethnic groups (Northeast China) was analyzed by PCR and denatured polyacrylamide gel electrophoresis. The allelic distribution in the Han population group is as follows: A = 2.90%, B = 26.09%, C = 26.09%, D = 29.98%, E = 15.94%. This allelic distribution differs statistically significant from that observed in the three other ethnic groups (p < 0.05). Furthermore the polymorphism of the Y-chromosome specific Alu insert sequence DYS287 was tested in these four groups. However, no Alu sequence insert was found.     

Geographical variation and successive adaptive radiations of yellow-floweredTeucrium (Labiatae) in the Mediterranean region

Study of the geographical variation of yellow-floweredTeucrium sect.Polium species using morphological, chemical, and cytological analyses shows that the group of North African taxa is both differentiated from the European group and homogeneous with it. It displays stable vegetative and floral characters that are common to all the taxa. The essential differences concern the indumentum structure and the habit of the plants. The diversity of environments has enhanced the expression of successive radiations of the group. The first doubtless originated in the Betic-Rif zone and in particular in the southeastern part of the Iberian Peninsula. These radiations probably first gave the groupT. aureum, now endemic in the Ibero-Provençal mountains. The species then became better differentiated in North Africa. Differentiation took place in the mountain ranges (Rif, Atlas, and Hoggar) and some Mediterranean islands (off the eastern coast of Tunisia) for the current species with narrow endemism and in desert regions (steppes and the Sahara) for those with wider endemism.     

Invasive species of Heracleum in Europe: an insight into genetic relationships and invasion history

Several species of the genus Heracleum (Umbelliferae) were introduced into Europe from south-west Asia in the 19th century and are now widespread in many countries. At least three invasive taxa with unresolved relationships to one another are thought to occur in Europe: Heracleum mantegazzianum Sommier & Levier, H. sosnowskyi Manden, and H. persicum Desf. ex Fischer. They are tall plants forming extensive stands with a high cover. To elucidate genetic relationships between the species, and gain insight into their invasion history, samples were collected from native ranges in Asia and invaded ranges of the three species in Europe and analysed using amplified fragment length polymorphism. Five other Heracleum species were also studied and in total, 189 samples from 72 populations were analysed. The results confirmed that there are three distinct tall Heracleum species invading in Europe. Within each of the three species, plants collected in the invaded range are genetically close to those from their native ranges. A close genetic relationship between the three invasive Heracleum species in Europe was also found. A high overall genetic variability detected in the invaded range suggests that the majority of invading populations were not affected by a genetic bottleneck and that rapid evolution, drift, or hybridization played a role in genetic structuring of invading populations. For H. mantegazzianum , genetic distance of populations in the native range significantly decreased with geographical distance, but not in the invaded range. It is likely that the current pattern of genetic diversity in Europe resulted from multiple introductions of all three species.     

DYS19 and DYS390 Y-STR polymorphism in the Iberian Peninsula: a multivariate analysis

Genetic polymorphism of two Y-specific short tandem repeats (DYS19 and DYS390) was investigated in six populations from the Iberian Peninsula (Andalusia, Castilla-La Mancha, Castilla-Leon, Extremadura, Galicia and South East Spain) comprising a total of 895 unrelated and native individuals, and a complete database of DYS19 and DYS390 allele frequency distributions in 34 world-wide populations collected from literature was analysed. DYS19 and DYS390 polymorphism was screened by automated fluorescence analysis of PCR-amplified labelled sample fragments performed with and ABI PRISM 377 Genetic Analyser. The degree of population differentiation was analysed using the STP Test to calculate G Statistic values. Correspondence Analysis based on the allelic frequencies of each locus and combining both was performed using the NTSYS-PC version 1.70 computer package. The diversity of the genetic profiles of gene frequencies suggests an important population heterogeneity in the Iberian Peninsula as a whole (DYS390 being particularly evident), which is corroborated after statistical analyses (G = 139.8457, p = 1.7822 x 10(-14) for DYS19, G = 116.0293, p = 4.6845 x 10(-12) for DYS390). However, multivariate analysis indicates a well defined cluster of the populations of the Central region, and sets them apart from the positions within which peripheral Iberian Peninsula populations are distributed. The Galician population shows trends which bring it closer to the positions throughout which European Atlantic populations are distributed. The results shown by the Central Iberian Peninsula seem to lend support to a model of settlement population stocks which came from the region of Castilla-Leon after the Islam invasions, whereas in the South-East populations the genetic record of Middle Eastern populations is still present, a consequence of the expansion of Islam in Southern Europe in the Middle Ages.     

The whiteflies (Hemiptera: Aleyrodidae) of Europe and the Mediterranean Basin

The whitefly fauna of Europe and the Mediterranean Basin comprises 56 species that are considered to be native or naturalized, accommodated within 25 genera. Presented here are a check-list, an identification key to puparia, and a brief account of each species including its distribution and host-plant range. The puparium of each species is illustrated. One new nomenclatural combination (Aleuroclava similis, from Aleurotuberculatus) and two new synonymies (Parudamoselis kesselyaki with Ceraleurodicus varus, Asterobemisia nigrini with A. paveli) are proposed. Three nominal species (Aleurodes capreae, A. fraxini, and Aleyrodes campanulae) are here treated as nomina dubia. Species which, in the study area, have only been recorded from glasshouses are discussed. Four additional species, not yet recorded from the region, are included in the discussion, two of them because a particular quarantine risk is perceived and two because they are notifiable pests in European Union quarantine legislation.     

Sequence diversity of the control region of mitochondrial DNA in Tuscany and its implications for the peopling of Europe

The control region of mitochondrial DNA has been widely studied in various human populations. This paper reports sequence data for hypervariable segments 1 and 2 of the control region from a population from southern Tuscany (Italy). The results confirm the high variability of the control region, with 43 different haplotypes in 49 individuals sampled. The comparison of this set of data with other European populations allows the reconstruction of the population history of Tuscany. Independent approaches, such as the estimation of haplotype diversity, mean pairwise differences, genetic distances and discriminant analysis, place the Tuscan sample in an intermediate position between sequences from culturally or geographically isolated regions of Europe (Sardinia, the Basque Country, Britain) and those from the Middle East. In spite of the remarkable genetic homogeneity in Europe, a degree of variability is shown by local European populations and homogeneity increases with the relative isolation of the population. The pattern of mitochondrial variation in Tuscany indicates the persistence of an ancient European component subsequently enriched by migrational waves, possibly from the Middle East. © 1996 Wiley-Liss, Inc.     

Allele frequencies of apolipoprotein E gene polymorphisms in the protein coding region and promoter region (-491A/T) in a healthy Norwegian population

This study examines the distribution of apolipoprotein E (APOE) alleles in a population of healthy male and female Norwegians (n = 798) below the age of 40. The -491A/T polymorphism of the promoter region of the APOE gene was also examined. A seminested polymerase chain reaction was applied in the genotyping. The results showed that the E3 allele had the highest frequency (0.744), followed by E4 (0.198) and E2 (0.058). The APOE frequencies found in this study differ significantly from those obtained in earlier Norwegian APOE phenotypings. The allele frequencies in the -491 site of the promoter region were 0.845 for the A allele and 0.155 for the T allele. The genotype frequency was highest for AA (0.707), followed by AT (0.277) and TT (0.016). Moreover, the A allele was in linkage disequilibrium to E4.     

Genetic variation inOrchis papilionacea (Orchidaceae) from the Central Mediterranean region: Taxonomic inferences at the intraspecific level

The genetic differentiation ofOrchis papilionacea from Italy, Corsica, Sardinia, Sicily, and Greece was analyzed by isozyme studies. No significant differences at any of the 28 loci tested were observed between samples of the putative subspeciespapilionacea from Italy,grandiflora from Sicily andheroica from Greece, or by comparing sympatricpapilionacea-like andgrandiflora-like subsamples from Sardinia and Corsica. The genetic relationships found among the populations studied reflect more their geographic origin than their taxonomic assignment;papilionacea, grandiflora, andheroica are, therefore, at least in the study area, not to be considered as subspecies, but as simple morphs, controlled by few genes (possibly two) with Mendelian inheritance. The genetic divergence observed among the samples studied is very low and consistent with that of geographic populations of a single cohesive gene pool, linked by a high gene flow (Nm = 5.9).     

Morphometric variation and divergence in the West Mediterranean Discoglossus (Amphibia: Discoglossidae)

Morphometrics of the four species of the genus Discoglossus occurring in the West Mediterranean area D. galganoi, D. montalentii, D. pictus and D. sardus ) was investigated. Univariate and multivariate statistics showed that the species are morphologically diverse and that populations of the same species form distinct and recognizable groups. Our results conflict in part with those derived from allozyme analysis of the same taxa. The major conflict involves the comparisons between D. montalentii and D. sardus , and between D. g. galganoi and D. g. jeanneae. . Whereas D. montalentii is genetically very distinct from D. sardus , their morphometric diversity is relatively low. On the other hand, morphometric divergence between D. g. galganoi and D. g. jeanneae (the latter described as a species by Busack, i.e. D. jeanneae , is high, but they are very similar genetically. Both adaptation to the different climatic regimes characterizing the West Mediterranean area and the phylogenetic history are suggested to account for the observed changes in the morphology.     

Temporal variation in the genetic structure of a drone congregation area: an insight into the population dynamics of wild African honeybees (Apis mellifera scutellata)

The mating system of the honeybee ( Apis mellifera ) has been regarded as one of the most panmictic in the animal kingdom, with thousands of males aggregating in drone congregation areas (DCAs) that virgin queens visit to mate with tens of partners. Although males from many colonies gather at such congregations, the temporal changes in the colonies contributing drones remain unknown. Yet, changes in the DCAs' genetic structure will ultimately determine population gene flow and effective population size. By repeatedly sampling drones from an African DCA over a period of 3 years, we studied the temporal changes in the genetic structure of a wild honeybee population. Using three sets of tightly linked microsatellite markers, we were able to reconstruct individual queen genotypes with a high accuracy, follow them through time and estimate their rate of replacement. The number of queens contributing drones to the DCA varied from 12 to 72 and was correlated with temperature and rainfall. We found that more than 80% of these queens were replaced by mostly unrelated ones in successive eight months sampling intervals, which resulted in a clear temporal genetic differentiation of the DCA. Our results suggest that the frequent long-range migration of colonies without nest-site fidelity is the main driver of this high queen turnover. DCAs of African honeybees should thus be regarded as extremely dynamic systems which together with migration boost the effective population size and maintain a high genetic diversity in the population.     

TheLecanactis grumulosa group (Opegraphaceae) in the Mediterranean region

The morphology, anatomy, and chemistry of five taxa belonging to theLecanactis grumulosa group from several localities of the Mediterranean area have been analysed in detail. One new saxicolous species,L. subgrumulosa, is described from Spain and Morocco. The new combinationL. farinosa is made.L. nothiza, L. monstrosa, L. ramosus, andOpegrapha alboatra are proposed as synonyms ofL. grumulosa. L. werneri andL. farinosa are cited for the first time in Europe and northern Africa, respectively. Anthraquinones are reported as new forLecanactis.     

Polymorphism of microsatellite loci DYS19, DYS393, and frequency of the T-C transition of the RBF5 locus on the Y-chromosome in inhabitants of the Volga-Ural region

Polymorphism of the DYS19 and DYS393 microsatellite loci and T-C transition at the RBF5 locus of the Y chromosome were analyzed in Volga-Ural populations of Bashkirs, Tatars, Chuvashes, Maris, Mordovians, Udmurts, and Komis. For the DYS19 locus, statistically significant differences were observed between Trans-Ural and Northeastern Bashkirs; between Trans-Ural Bashkirs and Tatars; and between Udmurts and other populations of the Volga-Ural region, excluding Trans-Ural Bashkirs. The DYS393 locus allele frequency distribution patterns were similar in all populations studied. The highest and the lowest frequencies of T-C transition at the RBF5 locus was detected in Udmurts (0.68) and in Mordovians (0.09), respectively. Association of C-alleles with the DYS19/DYS393 microsatellite haplotypes was investigated. The major haplotypes specific to the Turkic- and Finno-Ugric populations were revealed.     

Morphological variation of Juniperus oxycedrus subsp. oxycedrus (Cupressaceae) in the Mediterranean region

The intra- and inter-population variation of Juniperus oxycedrus subsp. oxycedrus were examined biometrically on the basis of morphological characters of needles, seeds and cones. Cluster analysis of Euclidean distances and discriminant analysis were performed to verify the hypothesis of geographic differentiation and origin from the West- and East-Mediterranean Pleistocene refugial regions. The West-Mediterranean populations of J. oxycedrus subsp. oxycedrus differed from the eastern ones. The intra-populational differentiation of three of the West-Mediterranean populations was significantly higher than within the other West- and all the East-Mediterranean ones.Results confirm the hypothesis of probable different origins of the East- and West-Mediterranean populations of the taxon.     

Spontaneous insertion of an IS2 element into the promoter region of the lac operon

A spontaneous mutation in pUC18 has revealed the insertion of a chromosomal insertion sequence (IS)2 element into the promoter region of the lac operon. The IS2 insertion site, at the pentanucleotide sequence TCGAG, is unlike previously described junctional sequences.     

Genetic insight into Mediterranean chukar (Alectoris chukar, Galliformes) populations inferred from mitochondrial DNA and RAPD markers

The chukar (Alectoris chukar, Galliformes) is one of the most important game birds as it is widely distributed and hunted over the whole of its range. The aim of this work was to assess the genetic differentiation as well as the possible presence of hybrid specimens in A. chukar populations from Italy, Greece and Cyprus. To provide phylogenetic context, conspecific, allopatric specimens from Israel, Georgia, Armenia, Kazakhstan, Afghanistan, Pakistan, Mongolia, China and USA were compared. Sequencing of the mitochondrial DNA (mtDNA) Control Region supplied information on the ancestry of A. chukar populations, whereas Random Amplified Polymorphic DNA (RAPD) fingerprinting was used to assess whether hybridization had occurred. The Italian population was found to be an inter-specific mixture of A. chukar and A. rufa (i.e., the red-legged partridge) mtDNA lineages, whereas the representatives from Greece and Cyprus showed only the A. chukar maternal line. RAPD markers revealed introgression with A. rufa genes in the Italian population, whereas no A. chukar × A. rufa hybrid specimens were detected in the eastern Mediterranean populations. The genetic data obtained from the Italian A. chukar population as well as from a few Greek specimens pointed against their Mediterranean kinship, suggesting relationships with A. chukar subspecies from the easternmost part of the Asian continent.     

Reverse gyrase: an insight into the role of DNA-topoisomerases

Reverse gyrase was discovered more than twenty years ago. Recent biochemical and structural results have greatly enhanced our understanding of their positive supercoiling mechanism. In addition to new biochemical properties, a fine tuning of reverse gyrase regulation in response to DNA damaging agents has been recently described. These data give us a new insight in the cellular role of reverse gyrase. Moreover, it has been proposed that reverse gyrase has been implicated in genome stability.     

The peopling of Sardinia (Italy): history and effects

Over the last ten years the population of the Mediterranean island of Sardinia has been object of numerous studies in the fields of anthropology and population genetics. Its insularity, central position in the Mediterranean area and rich historical past have made the island a veritable laboratory for the study and understanding of those interacting evolutionary mechanisms which determine a population's genetic structure. Indeed, from work performed at different levels on genetic structure analysis there emerges an extremely complex picture of the relationships between Sardinian and other Italian and Mediterranean populations, but also of relationships within the Sardinian population itself The diversification from Mediterranean and Italian populations can be explained by Sardinia's historical and demographic past. Internal heterogeneity can be attributed, in part, to strict isolation and the accompanying high levels of endogamy and inbreeding, and in part to the endemic presence of malaria which exerted a strong selective pressure on some characteristics; determining, for example, the differentiation between the plains and the mountain areas. Finally, an influence on Sardinia's biological history not to be neglected could be attributed to the demographic events, which triggered off phenomena of genetic drift and to cultural factors.     

Y chromosome haplotype distribution of brown bears (Ursus arctos) in Northern Europe provides insight into population history and recovery

High‐resolution, male‐inherited Y‐chromosomal markers are a useful tool for population genetic analyses of wildlife species, but to date have only been applied in this context to relatively few species besides humans. Using nine Y‐chromosomal STRs and three Y‐chromosomal single nucleotide polymorphism markers (Y‐SNPs), we studied whether male gene flow was important for the recent recovery of the brown bear (Ursus arctos) in Northern Europe, where the species declined dramatically in numbers and geographical distribution during the last centuries but is expanding now. We found 36 haplotypes in 443 male extant brown bears from Sweden, Norway, Finland and northwestern Russia. In 14 individuals from southern Norway from 1780 to 1920, we found two Y chromosome haplotypes present in the extant population as well as four Y chromosome haplotypes not present among the modern samples. Our results suggested major differences in genetic connectivity, diversity and structure between the eastern and the western populations in Northern Europe. In the west, our results indicated that the recovered population originated from only four male lineages, displaying pronounced spatial structuring suggestive of large‐scale population size increase under limited male gene flow within the western subpopulation. In the east, we found a contrasting pattern, with high haplotype diversity and admixture. This first population genetic analysis of male brown bears shows conclusively that male gene flow was not the main force of population recovery.