Range-wide population genetic analysis of the endangered northern riffleshell mussel, <Emphasis Type="Italic">Epioblasma torulosa rangiana</Emphasis> (Bivalvia: Unionoida)

The northern riffleshell (Epioblasma torulosa rangiana) is a critically endangered unionoid species in need of conservation throughout its range. It is the only unionoid to be federally protected in both Canada and the U.S. We use sequences from two mtDNA genes and 15 microsatellite loci to assess genetic variation among 86 individuals from the four populations in the three remaining drainages in which E. t. rangiana is known to be reproducing. All of these populations are in formerly glaciated landscapes that emerged <10 kya. The mtDNA sequence data do not indicate significant geographic structure among the populations. However, allelic data from the microsatellite loci reveal highly significant population structuring. Individuals of E. t. rangiana can be assigned to their own river of origin with 98.8% accuracy. Significant isolation-by-distance occurs. This analysis will be useful to conservation managers in documenting the genetic structure, patterns of isolation, and genetic variability within and among populations of E. t. rangiana.     

Population genetics of an invasive riparian species,<Emphasis Type="Italic"> Impatiens glandulifera</Emphasis>

We assess the population genetic structure of the invasive riparian weed Impatiens glandulifera, and where possible, determine whether natural or anthropogenic dispersal best explains the observed patterns. Results are compared with a similar contemporary analysis for Heracleum mantegazzianum undertaken in the same catchments, and we suggest that some of the observed differences in genetic structure could be because of life history differences between these species. Our results confirm the importance of at least occasional dispersal events mediated by human activity in the colonisation and subsequent spread of invasive plants in river catchments. However, processes related to river structure, dispersal range and genetic drift also appear to be structuring these populations over short temporal scales. The implication is that local populations can be established as small founders, and therefore eradication programs need to be thorough and undertaken at the catchment scale. Effective management needs to consider the natural spread of riparian species along rivers, but also prevent long-distance dispersal from sources outside the catchment. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Genetic analysis reveals two distinct Sacramento splittail (<Emphasis Type="Italic">Pogonichthys macrolepidotus</Emphasis>) populations

The Sacramento splittail is an endemic cyprinid fish of the San Francisco estuary and its tributaries, which is a highly manipulated, constantly changing ecosystem. Splittail is the only extant member of its genus and is listed as a federal and California Species of Special Concern due to uncertainties regarding long-term abundance trends. Determining population structure for splittail is important because unique populations may contain different adaptive genetic variation, which can allow one population to persist through future environmental or demographic stochasticity while others become extirpated. To assess splittail population structure, 13 microsatellite markers were used to genotype 489 young-of-year splittail from five major rivers draining into the estuary: Cosumnes, Napa, Petaluma, Sacramento, and San Joaquin Rivers. Two genetically distinct populations were found to exist within our study region; one largely comprised of splittail collected from the Petaluma and Napa Rivers and the second comprised of splittail collected from tributaries in Californiaȁ9s Central Valley: Cosumnes, Sacramento, and San Joaquin Rivers. These results were replicated in two consecutive years with both distance and model-based algorithms. The genetic distinction between these two populations appears correlated with salinity differences between migratory regions and spawning grounds. Splittail from the Petaluma River exhibited a significantly higher degree of differentiation from the Central Valley population than did Napa River splittail. Our results suggest on-going monitoring programs are probably highly biased towards sampling splittail from the Central Valley population. Understanding population dynamics of splittail could be improved if monitoring programs were expanded to include all splittail populations.     

Population genetic structure and conservation of marbled murrelets (<Emphasis Type="Italic">Brachyramphus marmoratus</Emphasis>)

Marbled murrelets (Brachyramphus marmoratus) are coastal seabirds that nest from California to the Aleutian Islands. They are declining and considered threatened in several regions. We compared variation in the mitochondrial control region, four nuclear introns and three microsatellite loci among194 murrelets from throughout their range except Washington and Oregon. Significant population genetic structure was found: nine private control region haplotypes and three private intron alleles occurred at high frequency in the Aleutians and California; global estimates of F _ST or Φ_ST and most pairwise estimates involving the Aleutians and/or California were significant; and marked isolation-by-distance was found. Given the available samples, murrelets appear to comprise five genetic management units: (1) western Aleutian Islands, (2) central Aleutian Islands, (3) mainland Alaska and British Columbia, (4) northern California, and (5) central California.     

<Emphasis Type="Italic">Amanita concentrica</Emphasis>: a new species in <Emphasis Type="Italic">Amanita</Emphasis> section <Emphasis Type="Italic">Amanita</Emphasis> from Japan

Amanita concentrica sp. nov. is described from an evergreen broad-leaved forest of Chiba Prefecture with Castanopsis cuspidata var. sieboldii and Quercus glauca. The fungus is a medium to large, white to yellowish-white mushroom characterized by many pyramidal warts on pileus, striate margin of pileus, distinct ascending concen-tric rings at upper part of stipe bulb, and inamyloid basidiospores. It is considered to belong to the section Amanita. Received: March 30, 2001 / Accepted: October 1, 2001     

Polymorphism of the <Emphasis Type="Italic">LEAFY</Emphasis> Gene in <Emphasis Type="Italic">Brassica</Emphasis> Plants

The arabidopsis gene LEAFY controls the induction of flowering and maintenance of the floral meristem identity. By comparing the primary structure of LEAFY and its homologs in other Brassicaceae species and beyond this family, we singled out four clusters corresponding to three systematically remote families of angiosperms, Brassicaceae, Solanaceae, and Poaceae, and to gymnosperms. Both structural and functional distinctions of LEAFY homologs from their arabidopsis prototype expanded in the range Brassicaceae—Solanaceae—Poaceae. A LEAFY homolog from B. juncea cloned in our laboratory was used as a hybridization probe to analyze the restriction fragment length polymorphism in six Brassica species comprising diploid (AA, BB, and CC) and allotetraploid (AABB, AACC, and BBCC) genomes. In this way we recognized LEAFY fragments specific of genomes A, B, and C; in contrast, the variations of the length and structure of the LEAFY intron 2 were not genome-specific. LEAFY polymorphism in the Brassica accessions comprising genome B was related to their geographic origin and apparently to the adaptation to day length.     

A PCR-RFLP method on faecal samples to distinguish <Emphasis Type="Italic">Martes martes</Emphasis>, <Emphasis Type="Italic">Martes foina</Emphasis>, <Emphasis Type="Italic">Mustela putorius</Emphasis> and <Emphasis Type="Italic">Vulpes vulpes</Emphasis>

A non-invasive genetic approach has been recently employed in the population genetics of wild species, using faeces that could be easily collected, particularly of elusive or endangered species. However, faeces of pine (Martes martes) and beech marten (M. foina) can be morphologically similar and could be confused with those of polecat (Mustela putorius) and red fox (Vulpes vulpes). On this basis, a rapid, simple and inexpensive RFLP protocol using a cytochrome b (Cyt b) gene fragment of mtDNA, isolated from faecal samples, was performed to distinguish the above-mentioned species.     

Phylogenetic analyses of <Emphasis Type="Italic">Uromyces viciae-fabae</Emphasis> and its varieties on <Emphasis Type="Italic">Vicia</Emphasis>, <Emphasis Type="Italic">Lathyrus</Emphasis>, and <Emphasis Type="Italic">Pisum</Emphasis> in Japan

A pea rust fungus, Uromyces viciae-fabae, has been classified into two varieties, var. viciae-fabae and var. orobi, based on differences in urediniospore wall thickness and putative host specificity in Japan. In principal component analyses, morphological features of urediniospores and teliospores of 94 rust specimens from Vicia, Lathyrus, and Pisum did not show definite host-specific morphological groups. In molecular analyses, 23 Uromyces specimens from Vicia, Lathyrus, and Pisum formed a single genetic clade based on D1/D2 and ITS regions. Four isolates of U. viciae-fabae from V. cracca and V. unijuga could infect and sporulate on P. sativum. These results suggest that U. viciae-fabae populations on different host plants are not biologically differentiated into groups that can be recognized as varieties.Contribution no. 184, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan     

New species of <Emphasis Type="Italic">Clohiesia</Emphasis> and <Emphasis Type="Italic">Paraniesslia</Emphasis> collected from freshwater habitats in China

Two fungi collected from submerged woody debris were found to represent hitherto undescribed species of the ascomycete genera Clohiesia and Paraniesslia. They are described as Clohiesia curvispora sp. nov. and Paraniesslia aquatica sp. nov. based on morphological characters. Clohiesia curvispora is characterized by immersed ascomata under a clypeus, and unitunicate, cylindrical asci containing one-celled, curved, elongate-fusiform ascospores. Paraniesslia aquatica is characterized by small, superficial, setose ascomata, and unitunicate, clavate asci containing verrucose, brown ascospores. Each species is illustrated with light micrographs and compared with similar taxa in this article.     

Conservation of Nuclear SSR Loci Reveals High Affinity of <Emphasis Type="Italic">Quercus infectoria</Emphasis> ssp. <Emphasis Type="Italic">veneris</Emphasis> A. Kern (Fagaceae) to Section <Emphasis Type="Italic">Robur</Emphasis>

Conservation of 16 nuclear microsatellite loci, originally developed for Quercus macrocarpa (section Albae), Q. petraea, Q. robur (section Robur), and Q. myrsinifolia, (subgenus Cyclobalanopsis) was tested in a Q. infectoria ssp. veneris population from Cyprus. All loci could be amplified successfully and displayed allele size and diversity patterns that match those of oak species belonging to the section Robur. At least in one case, limited amplification and high levels of homozygosity support the occurrence of “null alleles” caused by a possible mutation in the highly conserved primer areas, thus hindering PCR. The sampled population exhibited high levels of diversity despite the very limited distribution of this species in Cyprus and extended population fragmentation. Allele sizes of Q. infectoria at locus QpZAG9 partially match those of Q. alnifolia and Q. coccifera from neighboring populations. However, sequencing showed homoplasy, excluding a case of interspecific introgression with the latter, phylogenetically remote species. Q. infectoria ssp. veneris sequences at this locus were concordant to those of other species of section Robur, while sequences of Quercus alnifolia and Quercus coccifera were almost identical to Q. cerris.     

The genetic structure of endangered indigenous populations of the amago salmon, <Emphasis Type="Italic">Oncorhynchus</Emphasis><Emphasis Type="Italic">masou</Emphasis><Emphasis Type="Italic">ishikawae</Emphasis>, in Japan

The amago salmon, Oncorhynchus masou ishikawae, is an endemic subspecies of O. masou in Japan. Owing to the extensive stocking of hatchery fish throughout Japan, indigenous populations of O. m. ishikawae are now on the verge of extinction. We examined the genetic effects of stocking hatchery fish on wild populations in the River Koza, Japan, using microsatellite and mitochondrial DNA (mtDNA) markers. For mtDNA, haplotype mt1, which is common in wild populations, was present exclusively in isolated wild populations assumed to be unaffected by previous stocking, while it was never observed in hatchery fish. Genetic diversity was much higher in wild populations in the stocked area, which shared many mtDNA haplotypes with hatchery fish, than in isolated wild populations with haplotype mt1. Pairwise F _ST estimates based on microsatellites showed significant differentiation among the isolated populations with many microsatellite loci monomorphic. Significant deviation from Hardy–Weinberg equilibrium was observed in wild populations in the area subject to stocking, where a Bayesian-based assignment test showed a high level of introgression with hatchery fish. These results suggest that wild populations with haplotype mt1, which became isolated through anthropogenic environmental change in the 1950–1960s, represent indigenous populations of O. m. ishikawae in the River Koza. They have low genetic diversity, most likely caused by genetic bottlenecks following damming and environmental deterioration, while stocking of hatchery fish over the past 30 years apparently had a large impact on the genetic structure of wild populations in the main channel of the River Koza.     

The karyology of the cyprinid genera <Emphasis Type="Italic">Scardinius</Emphasis> and <Emphasis Type="Italic">Rutilus</Emphasis> in southern Europe

The chromosomes of eight species of Rutilus and Scardinius, mostly endemic to the Italian and the Balkan peninsula, were analyzed by conventional and other banding techniques. Parallel analyses were conducted also on two leuciscine species, Alburnus albidus, for which we provide the first karyological analysis, and Leuciscus cephalus. All species examined displayed the same karyotype (2n=50 chromosomes, 8 metacentric+13 submetacentric+4 subtelo/acrocentric pairs) with nucleolus organizer regions (NORs) on the ends of the shorter arms of a medium-sized submetacentric pair. In contrast, interspecific variation was observed in the distribution of constitutive heterochromatin. The variation observed in this genomic material proved to be systematically and phylogenetically informative. Indeed, a peritelomeric C-band on the first telocentric pair characterizes species of Rutilus and Scardinius. In both genera heterochromatin differentiation appears to be directed to a centromere–telomere direction, particularly evident along the metacentric elements of their karyotypes.An erratum to this article can be found at     

<Emphasis Type="Italic">Ty</Emphasis>1<Emphasis Type="Italic">/copia</Emphasis>- and <Emphasis Type="Italic">Ty</Emphasis>3<Emphasis Type="Italic">/gypsy</Emphasis>-like DNA sequences in <Emphasis Type="Italic">Helianthus </Emphasis>species

Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.     

<Emphasis Type="Italic">Exobasidium dubium</Emphasis> and <Emphasis Type="Italic">E. miyabei</Emphasis> sp. nov. causing Exobasidium leaf blisters on <Emphasis Type="Italic">Rhododendron </Emphasis>spp. in Japan

 Two Exobasidium species causing Exobasidium leaf blister on Rhododendron spp. are described. An Exobasidium leaf blister on Rhododendron yedoense var. yedoense f. yedoense has been recognized in Hokkaido Prefecture, Japan, since the first report was issued in 1950. The causal fungus is identified with Exobasidium dubium from the morphology of its hymenial structure and mode of germination of the basidiospores. Another Exobasidium leaf blister on Rhododendron dauricum has been observed in Hokkaido Prefecture, Japan. In comparison with morphology based on hymenial structure and mode of germination of the basidiospores of the 100 validly described taxa, this fungus differs from those known taxa in the size of basidia and basidiospores, the numbers of sterigmata and septa of basidiospores, and the mode of germination of basidiospores. Thus, a new species, Exobasidium miyabei, is established and illustrated. Received: February 13, 2002 / Accepted: September 25, 2002  Present address: National Institute of Agrobiological Sciences, Tsukuba 305-8602, Japan Acknowledgments We profoundly appreciate the cooperation of Dr. V. Melnik in providing Russian papers and Dr. L. Vasilyeva for translating them into English. We thank Prof. H. Takahashi for loaning the materials in the Herbarium of the Hokkaido University Museum and Dr. W. Abe, Graduate School of Science, University of Hokkaido, for his kind help with the sampling of R. dauricum in Teshikaga, Hokkaido Prefecture. This study was supported in part by a Grant-in-Aid for Scientific Research (B) (No. 13460019), Japan Society for the Promotion of Science (JSPS). Contribution No. 171, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba. Correspondence to:M. Kakishima     

<Emphasis Type="Italic">Drosophila</Emphasis><Emphasis Type="Italic">P</Emphasis> transposons of the urochordata <Emphasis Type="Italic">Ciona intestinalis</Emphasis>

P transposons belong to the eukaryotic DNA transposons, which are transposed by a cut and paste mechanism using a P-element-coded transposase. They have been detected in Drosophila, and reside as single copies and stable homologous sequences in many vertebrate species. We present the P elements Pcin1, Pcin2 and Pcin3 from Ciona intestinalis, a species of the most primitive chordates, and compare them with those from Ciona savignyi. They showed typical DNA transposon structures, namely terminal inverted repeats and target site duplications. The coding region of Pcin1 consisted of 13 small exons that could be translated into a P-transposon-homologous protein. C. intestinalis and C. savignyi displayed nearly the same phenotype. However, their P elements were highly divergent and the assumed P transposase from C. intestinalis was more closely related to the transposase from Drosophila melanogaster than to the transposase of C. savignyi. The present study showed that P elements with typical features of transposable DNA elements may be found already at the base of the chordate lineage. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Spatiotemporal genetic differentiation of Cuban natural populations of the pink shrimp <Emphasis Type="Italic">Farfantepenaeus notialis</Emphasis>

We analyzed the spatiotemporal genetic structure of Farfantepenaeus notialis populations using five microsatellites loci in order to understand the influence of natural events such as hurricanes on the genetic drift/migration balance as the main cause for the variation of allele frequencies over time. The results were compared with the previous ones obtained from allozymes and mtDNA. High and stable genetic diversity levels (He=0.879+/-0.0015) were found over eight years for the populations that inhabit the south Cuban platform, however significant changes of allele frequencies were detected over time. The F(ST) estimates, albeit low, revealed significant differences among populations inside the Ana Maria Gulf for 1995 but not for the 1999 and 2003 samples. The F(ST), AMOVA and the genetic distance analysis revealed the instability of the genetic structure over time in accordance with allozymes results. The correspondence of the microsatellite results with those obtained from allozymes confirm the effects of migration enhanced by natural events as the main cause of the temporal variation of allele frequencies. The genetic drift effect was discarded through the evaluation of Ne and the M ratio, while natural selection effects were rejected because of the lowest probability of microsatellite loci being under selective pressures. The microsatellite data are also consistent with the results obtained with mtDNA in detecting significant and persistent genetic differences between the Gulfs of Ana María and Batabanó for the years 1995 and 2003.     

Nine microsatellite DNA primers for <Emphasis Type="Italic">Hippophae rhamnoides</Emphasis> ssp. <Emphasis Type="Italic">sinensis</Emphasis> (Elaeagnaceae)

Hippophae rhamnoides ssp. sinensis occurs mainly in the arid regions of northwest China. The wood stands of this subspecies play an important role in maintaining the local ecosystems in these regions. In addition, the genetic characteristics are essential to understand the historical range changes of this subspecies and its morphological differentiation with other subspecies. In this study, we developed nine microsatellite loci for this subspecies for the first time. We used the combining biotin capture method to enrich AG/CT/AC/GT/CG/GTG/CCA microsatellites. Twenty-six microsatellites were isolated from the enriching library and nine of them were found to be polymorphic through screening 12 distantly distributed individuals. The number of alleles per locus ranged from three to twelve and expected heterozygosity from 0.2659 to 0.4767, respectively. We further performed cross-priming tests in another subspecies and two congeneric species. These firstly isolated loci will provide a useful tool to investigate the genetic structure of this subspecies and its morphological differentiation from the other subspecies.     

Effects of toxic <Emphasis Type="Italic">Alexandrium minutum</Emphasis> strains on the feeding and survival rates of pelagic marine copepods <Emphasis Type="Italic">Acartia grani</Emphasis> and <Emphasis Type="Italic">Euterpina acutifrons</Emphasis>

Coenagrionid damselflies are in general decline in the British Isles. Numerous factors have been implicated in the loss of these species including recent speculation that hybridisation between congeners may result in species decline. Here we use a panel of 12 microsatellite loci to examine levels of genetic divergence and the likely occurrence of hybridisation in five populations of Coenagrion puella and C. pulchellum using samples from four sites in south-east England. Coenagrion puella and C. pulchellum were highly genetically divergent, and there was no evidence of hybridisation between any of the populations examined, even where C. puella and C. pulchellum were sympatric. There was some suggestion that C. pulchellum was less genetically diverse than C. puella, though this may have been a result of ascertainment bias associated with cross-species application of microsatellite markers. We conclude that there is no evidence that hybridisation between C. puella/pulchellum could be responsible for the on-going demographic decline in C. pulchellum. Nevertheless, further genetic studies such as this one are likely to provide estimates of diversity, population structure and dispersal capacity that will be invaluable in future conservation management strategies for coenagrionid damselflies. Handling editor: S. Wellekens