bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic differentiation inHippocrepis emerus(Leguminosae): allozyme and DNA fingerprint variation in disjunct Scandinavian populations
Authors: Lönn M. , Prentice H. C. , Tegelström H. 
Published: April 2008

AbstractThe structure of genetic variation in disjunct Scandinavian populations ofHippocrepis emeruswas studied using allozymes and DNA fingerprinting. Variation in the three native regional populations in Scandinavia was compared with that in a recently introduced population in Sweden. In contrast to the recently introduced population, the native Scandinavian isolates ofH. emerusshowed high levels of allozyme fixation and low levels of DNA diversity. Variation in allozymes and at DNA fingerprint loci showed closely congruent patterns of geographic variation, with pronounced differentiation between the native Norwegian and Swedish isolates of the species. The structure of genetic variation in native ScandinavianH. emerusis interpreted in terms of historical population bottlenecks and founder events during the species' postglacial immigration into Scandinavia.
Postglacial expansion and genome subdivision in the European grasshopper Chorthippus parallelus
Authors: Cooper S. J. B. , Ibrahim K. M. , Hewitt G. M. 
Published: April 2008

AbstractA noncoding nuclear DNA marker sequence (Cpnl‐1) was used to investigate subdivision in the grasshopper Chorthippus parallelus and deduce postglacial expansion patterns across its species range in Europe. Investigation of the spatial distribution of 71 Cpnl‐1 haplotypes and estimation of levels of genetic differentiation (KST values) between populations and geographic regions provided evidence for subdivision of C. parallelus into at least five major geographic regions and indicated that the French form of C. parallelus originated after range expansion from a Balkan refugium, Further evidence for subdivision of C. parallelus between Italy and northern Europe suggests that the Alps may have formed a significant barrier to gene flow in this grasshopper.
Generation of RAPD‐PCR primers for the identification of isolates of Glomus mosseae, an arbuscular mycorrhizal fungus
Authors: Lanfranco L. , Wyss P. , Marzachi C. , Bonfante P. 
Published: April 2008

AbstractMycorrhizal fungi are usually identified on the basis of the morphological characters shown by fruit bodies, spores, vegetative mycelia or symbiotic structures. The development of molecular techniques provides a valuable and alternative approach to identify mycorrhizal fungi, especially when it is difficult to gather a sufficient number of data on morphological features. Short arbitrary oligonucleotides were used as primers for the amplification of genomic DNA extracted from spores of arbuscular fungi. The RAPD fingerprints showed banding patterns which allowed us to distinguish between species and even isolates within Glomales. In order to identify mycorrhizal fungi during their symbiotic phase, a nonpolymorphic RAPD band identified as marker for some isolates of Glomus mosseae was purified from agarose gels and cloned in a bluescript vector. The fragment was sequenced and specific primers (PO‐M3) were designed for the mycorrhizal fungus. They specifically and successfully amplified the DNA not only from G. mosseae spores, but also from roots of pea, clover, leek and onion plants when they were colonized by G. mosseae isolates.
Monoandry and polyandry in bumble bees (Hymenoptera; Bombinae) as evidenced by highly variable microsatellites
Authors: Estoup A. , Scholl A. , Pouvreau A. , Solignac M. 
Published: April 2008

AbstractHighly variable microsatellites enabled a precise assessment of the number of queen matings in the colonies of five bumble bee species. Fifteen of the sixteen microsatellites initially cloned from B. terrestris had flanking regions similar enough to allow PCR amplification on the other Bombus species analysed. The microsatellites selected for intracolony study (four per species) were characterized by a high heterozygosity (0.58–0.93) and a large number of alleles (3–18) in the local populations from which the colonies originated. A single male appeared to have inseminated the queens in the colonies of four species, B. terrestris, B. lucorum, B. lapidarius and B. pratorum, which belong to three subgenera, whereas two of the three analysed colonies of B. hypnorum were polyandrous (minimum number of two and four patrilines, respectively).
Parentage analysis within a semi‐free‐ranging group of Barbary macaques Macaca sylvanus
Authors: von SEGESSER F. , SCHEFFRAHN W. , MARTIN R. D. 
Published: April 2008

AbstractThis study of a group of semi‐free‐ranging Barbary macaques Macaca sylvanus aimed to determine paternity, to establish whether any individual male achieved prominent mating success and to assess genetic variability. Analyses involved electrophoresis of 15 blood protein systems and multilocus DNA fingerprinting (isotopic and nonisotopic). Genetic variability was low; only two blood protein systems were polymorphic. Although all DNA‐fingerprints were individual‐specific, they showed a high average band‐sharing index value (0.67). Nevertheless, a combination of all methods permitted inference of paternity in 11 out of 15 (73%) cases tested. Several males from different age classes fathered infants.
Mitochondrial DNA diversity in an apomictic Daphnia complex from the Canadian High Arctic
Authors: van RAAY T.J. , CREASE T. J. 
Published: April 2008

AbstractCyclic parthenogenesis is the ancestral mode of reproduction in the cladoceran crustacean, Daphnia pulex, but some populations have made the transition to obligate parthenogenesis and this is the only mode of reproduction known to occur in arctic populations. Melanism and polyploidy are also common in arctic populations of this species. Prior allozyme studies of arctic D. pulex revealed substantial levels of clonal diversity on a regional scale. Clonal groupings based on cluster analysis of allozyme genotypes do not conform to groupings based on the presence/absence of melanin or on ploidy level. In order to further elucidate genetic relationships among arctic D. pulex clones, mitochondrial DNA (mtDNA) variation was examined in 31 populations from two Canadian high‐arctic sites. The data were also compared to a previous study of mtDNA variation in populations from a Canadian low‐arctic site. Cladistic analysis of restriction site variation of the entire mitochondrial genome and nucleotide sequence variation of the mitochondrial control region was used to construct genetic relationships among mitochondrial genotypes. Three distinct mitochondrial lineages were detected. One lineage was associated with diploid, nonmelanic clones and is the same as the lineage that is found in temperate populations of D. pulex. The other two lineages (A & B) were associated with polyploid, melanic clones. Sequence divergence between the A and B lineages was 2.4%. Sequence divergence between D. pulex and either of these two lineages exceeded 3%. It is suggested that the melanic, polyploid clones are hybrids between males of D. pulex (and/or a closely related congener, D. pulicaria) and females of either of two ancestral melanic species that have mitochondrial lineages A and B. Geographic patterns of mitochondrial diversity in ‘melanic’ lineage B support the hypothesis of an high‐arctic refuge for the ancestral species during the last glacial period.
Introgression of Luxilus cornutus mtDNA into allopatric populations of Luxilus chrysocephalus (Teleostei: Cyprinidae) in Missouri and Arkansas
Authors: DUVERNELL D. D. , ASPINWALL N. 
Published: April 2008

AbstractThe cyprinid fishes Luxilus cornutus and Luxilus chrysocephalus hybridize extensively in a zone extending through the Great Lakes region with extensive introgression of L. cornutus mtDNA occurring in populations of L. chrysocephalus south of the present hybrid zone in Ohio. Western populations of these two species occur adjacent to one another in Missouri but hybridization has never been observed. In order to determine if hybridization has occurred historically in Missouri, allopatric populations of L. chrysocephalus were analysed for mtDNA introgression. Extensive introgression of L. ***cornutus mtDNA was observed in most populations of L. chrysocephalus in Missouri resulting in the elimination of L. chrysocephalus mtDNA in many populations. Luxilus cornutus mtDNA in L. chrysocephalus is found approximately 300 km south of extant L. cornutus populations in Missouri. Luxilus chrysocephalus mtDNA was replaced by four unique L. cornutus mtDNA haplotypes, with one particular haplotype becoming fixed in several L. chrysocephalus populations. The pattern of introgression suggests that historically L. cornutus occupied a more southern distribution in Missouri bringing it into contact with western populations of L. chrysocephalus and resulting in a hybrid zone.
Relative genetic structure of a population of Rhizobium meliloti isolated directly from soil and from nodules of alfalfa (Medicago sativa) and sweet clover (Melilotus alba)
Authors: BROMFIELD E. S. P. , BARRAN L. R. , WHEATCROFT R. 
Published: April 2008

AbstractInsertion sequence (IS) hybridization was used to define the structure of a population of Rhizobium meliloti isolated directly from soil and from nodules of Medicago sativa (alfalfa) and Melilotus alba (sweet clover) grown under controlled conditions and inoculated with a suspension of the same soil. The detection of R. meliloti isolated from soil on agar plates was facilitated by use of a highly species specific DNA probe derived from ISRm5. All R. meliloti obtained directly from soil proved to be symbiotic (i.e. nodulated and fixed nitrogen with alfalfa). Analysis of 293 R. meliloti isolates revealed a total of 17 distinct IS genotypes of which 9, 9 and 15 were from soil, M. alba and M. sativa, respectively; 8 genotypes were common to soil and both plant species. The frequency of R. meliloti genotypes from soil differed markedly from that sampled from nodules of both legume species: 5 genotypes represented about 90% of the isolates from soil whereas a single genotype predominated among isolates from nodules accounting for more than 55% of the total. The distribution of genotypes differed between M. sativa and M. alba indicating species variation in nodulation preferences for indigenous R. meliloti. The data are discussed in the context of competition for nodulation of the host plant and the selection of Rhizobium strains for use in legume inoculants. This study has ecological implications and suggests that the composition of R. meliloti populations sampled by the traditionally used host legume may not be representative of that actually present in soil.
Recombinant and wild‐type Pseudomonas aureofaciens strains introduced into soil microcosms: effect on decomposition of cellulose and straw
Authors: ENGLAND L. S. , LEE HUNG , TREVORS J. T. 
Published: April 2008

AbstractThe effect of a genetically engineered Pseudomonas aureofaciens (Ps3732RNL11) strain (GEM) and the parental wild‐type (Ps3732RN) on decomposition of cellulose paper, straw and calico cloth was assessed after 18 weeks incubation in laboratory soil microcosms. Effect(s) of inoculum density (103, 105, and 108 cells/ g dry soil) and single versus multiple bacterial inoculations were also investigated. Cellulose paper was completely decomposed after 18 weeks in all treatments. There were no significant differences (95% level), between treatments, in percentage decomposition of either straw or calico cloth. Recovery of the GEM at 18 weeks, using viable plating, was limited to treatments originally receiving 108 cells/g dry soil. Log 1.8 CFU/g dry soil were recovered from the single dose treatment while log 4.2 CFU/g dry soil were recovered from the multiple dose treatment Biolog metabolic tests were used to determine if the GEM or parental wild‐type had any effect on overall carbon utilization in soil. Results suggested they did not. Detection of the recombinant lacZY gene sequence in soil using PCR suggested the possibility of viable but nonculturable cells and/or persistence of chromosomal DNA.
Microsatellites reveal high genetic diversity within colonies of Camponotus ants
Authors: GERTSCH P. , PAMILO P. , VARVIO S. L. 
Published: April 2008

AbstractIn order to characterize the sociogenetic structure of colonies in the carpenter ants Camponotus herculeanus and C. ligniperda, we have developed microsatellite markers. The three loci studied were either fixed for different alleles in the two species or showed different patterns of polymorphisms. Genotyping of workers and males showed that the broods of C. ligniperda include several matrilines, a rare phenomenon in the genus. Five alleles from a locus polymorphic in both species were sequenced from the respective PCR‐products. A part of the length variation appeared to be due to changes outside the repeat sequence, and some PCR products of an equal length had a different number of dinucleotide repeats.
DNA fingerprinting provides evidence of discriminate suckling and non‐random mating in little brown bats Myotis lucifugus
Authors: WATT E. M. , FENTON M. BROCK 
Published: April 2008

AbstractRecent advances in DNA extraction and fingerprinting techniques allowed examination of genetic similarity of groups of Myotis lucifugus at maternity roosts. Mean percentage band‐sharing between young was significantly higher than between mothers, suggesting fertilization success skewed for individual males or male lineages. Mean percentage band‐sharing between presumed mothers and young was significantly higher than band‐sharing between all other groups, suggesting that Myotis lucifugus preferentially suckle their own young.
Multilocus DNA fingerprinting and RAPD reveal similar genetic relationships between strains of Oreochromis niloticus (Pisces: Cichlidae)
Authors: NAISH K. A. , WARREN M. , BARDAKCI F. , SKIBINSKI D. O. F. , CARVALHO G. R. , MAIR G. C. 
Published: April 2008

AbstractTwo molecular techniques which reveal highly variable DNA polymorphisms, RAPD and multilocus DNA fingerprinting, were used to evaluate genetic diversity between six aquacultural strains of Oreochromis niloticus (tilapia) from the Philippines. The results using both techniques were in close agreement Within‐strain heterozygosity values were similar and were correlated between the two data sets, but statistical errors associated with the RAPD data set were lower. Although genetic distances between strains were greater using DNA fingerprinting, the distances measured using both methods were significantly correlated. Both methods were useful in estimating variation between strains, but they offered different advantages. RAPD was technically easier to perform and produced results with low statistical error, whereas DNA fingerprinting detected greater genetic differentiation between strains. The theoretical basis for using RAPD and multilocus minisatellite markers for population studies is discussed.
Intraspecies differentiation in the powdery mildew Erysiphe cichoracearum determined with rDNA RFLPs
Authors: ZELLER K. A. , LEVY M. 
Published: April 2008

AbstractThe powdery mildew species Erysiphe cichoracearum has a described host range of over 300 plant species from among several families. Host‐range testing indicates host‐specialized subdivision within this taxonomic species. However, the extent of subdivision remains largely undetermined among host‐limited forms. We have characterized diversity among field collections of E. cichoracearum from a variety of hosts, and from other powdery mildew species, with RFLPs from a PCR amplified ribosomal DNA (rDNA) segment The E. cichoracearum samples expressed six distinct RFLP haplotypes. Each haplotype was specific to either a single host or to a set of related host species. These haplotypes formed a continuum of divergence ranging from about 18–35% average pairwise distance from one another, while those from other mildew species clustered at consistently higher average pairwise distances from E. cichoracearum and from each other. Our findings support earlier suggestions, based on host‐range and morphological characterizations, that E. cichoracearum is a complex of morphologically similar, but host‐limited forms. Also, comparisons of rDNA haplotype distance between E. cichoracearum and Blumeria (Erysiphe) graminis were consistently greater than between E. cichoracearum and Sphaerotheca fulginea. This result supports earlier questions concerning the monophyletic nature of Erysiphe.
Genetic diversity of trout (genus Salmo) from its most eastern native range based on mitochondrial DNA and nuclear gene variation
Authors: BERNATCHEZ L. , OSINOV A. 
Published: April 2008

AbstractRussia and western Asia harbour trout populations that have been classified as distinct species and subspecies, most often on the basis of morphological and ecological variation. In order to assess their origins and to verify whether traditional taxonomy reflects their evolutionary distinctiveness, we documented their genetic relationships on the basis of mitochondrial DNA (mtDNA) RFLP, mtDNA sequence analysis, and allozyme variation. Both mtDNA and nuclear gene variation defined two ancient phylogenetic assemblages of populations distributed among northern (Baltic, White, Barents), and southern (Black, Caspian, Aral) sea basins, between which gene flow has been possible but limited in postglacial times. These results supported the traditional taxonomic differentiation between populations of these two regions. They provided weak support for the taxonomic distinction of southern brown trout (Salmo trutta) populations based on their basin of origin. They also refuted the hypothesis that L. Sevan trout (Salmo ischchan) diverged from a primitive brown trout ancestor. Nevertheless, all trout populations from southern sea basins possessed private alleles or mtDNA genotypes and were genetically distinct Therefore, they represent unique gene pools that warrant individual recognition for conservation and management.
Population subdivision and gene flow in Danish house mice
Authors: DALLAS J. F. , DOD B. , BOURSO P. , PRAGER E. M. , BONHOMME F. 
Published: April 2008

AbstractGenetic subdivision in local populations of the European house mice, Mus musculus domesticus and M. m. musculus, was analysed to study patterns of gene flow. The data consisted of frequencies of microsatellite alleles in 16 samples (250 individuals) from a total of 11 sites in Jutland, which included successive samples from three sites. Sequences of the control region of mitochondrial DNA in three successive samples from one site were also analysed. Microsatellite genotype frequencies within samples were close to Hardy‐Weinberg expectations. Levels of microsatellite differentiation among samples (θ= 0.05–0.21) corresponded to limited gene flow at migration‐drift equilibrium (Nm= 1–5). Weak isolation by distance for microsatellites in M. m. musculus suggested that gene flow tends to occur among neighbouring sites. Estimates of effective population size over a few generations were much lower than those corresponding to the long periods needed for arrival at mutation‐drift equilibrium. This suggested that subpopulations had been influenced by gene flow since formation, or had originated recently from genetically diverse founders.
Microsatellite analysis of population structure in Canadian polar bears
Authors: PAETKAU D. , CALVERT W. , STIRLING I. , STROBECK C. 
Published: April 2008

AbstractAttempts to study the genetic population structure of large mammals are often hampered by the low levels of genetic variation observed in these species. Polar bears have particularly low levels of genetic variation with the result that their genetic population structure has been intractable. We describe the use of eight hypervariable microsatellite loci to study the genetic relationships between four Canadian polar bear populations: the northern Beaufort Sea, southern Beaufort Sea, western Hudson Bay, and Davis Strait ‐ Labrador Sea. These markers detected considerable genetic variation, with average heterozygosity near 60% within each population. Interpopulation differences in allele frequency distribution were significant between all pairs of populations, including two adjacent populations in the Beaufort Sea. Measures of genetic distance reflect the geographic distribution of populations, but also suggest patterns of gene flow which are not obvious from geography and may reflect movement patterns of these animals. Distribution of variation is sufficiently different between the Beaufort Sea populations and the two more eastern ones that the region of origin for a given sample can be predicted based on its expected genotype frequency using an assignment test. These data indicate that gene flow between local populations is restricted despite the long‐distance seasonal movements undertaken by polar bears.
One hundred years of Spartina altemiflora (Poaceae) in Willapa Bay, Washington: random amplified polymorphic DNA analysis of an invasive population
Authors: STILLER J. W. , DENTON A. L. 
Published: April 2008

Abstract Spartina altemiflora (smooth cordgrass) has invaded Willapa Bay, Washington, covering bare mud flats and seagrass beds. At current expansion rates it threatens to occupy most of the intertidal habitat in the bay within 40 years. Although a major mitigation effort is underway, nothing is known about the genetic structure of the Willapa Bay S. altemiflora population or the underlying causes for the dramatic increase in seed set that has occurred in the last 15 years. Random amplified polymorphic DNA (RAPD) analysis was assessed as a method of DNA fingerprinting to analyse the genetic history and current structure of the Willapa population. The results suggest that all S. alterniflora clones in Willapa Bay are descended from a single genet. Given the limited genetic variability expected in a clonally founded population, we discuss the utility of RAPDs as genetic markers to explore the large morphological and reproductive differences reported among Willapa clones. Cluster analysis of RAPD fragments was used to show relatedness among S. alteniflora genets and may be helpful in locating the most prolific clones for mitigation efforts. Overall, RAPDs show great potential in genetic analysis of S. altemiflora, particularly in invasive populations where isozyme variability is low or nonexistent.