Ectomycorrhizal fungi of exotic pine plantations in relation to native host trees in Iran: evidence of host range expansion by local symbionts to distantly related host taxa

Introduction of exotic plants change soil microbial communities which may have detrimental ecological consequences for ecosystems. In this study, we examined the community structure and species richness of ectomycorrhizal (EcM) fungi associated with exotic pine plantations in relation to adjacent native ectomycorrhizal trees in Iran to elucidate the symbiont exchange between distantly related hosts, i.e. Fagales (Fagaceae and Betulaceae) and Pinaceae. The combination of morphological and molecular identification approaches revealed that 84.6 % of species with more than one occurrence (at least once on pines) were shared with native trees and only 5.9 % were found exclusively on pine root tips. The community diversity of ectomycorrhizal fungi in the pine plantations adjacent to native EcM trees was comparable to their adjacent native trees, but the isolated plantations hosted relatively a species-poor community. Specific mycobionts of conifers were dominant in the isolated plantation while rarely found in the plantations adjacent to native EcM trees. These data demonstrate the importance of habitat isolation and dispersal limitation of EcM fungi in their potential of host range expansion. The great number of shared and possibly compatible symbiotic species between exotic Pinaceae and local Fagales (Fagaceae and Betulaceae) may reflect their evolutionary adaptations and/or ancestral compatibility with one another.     

Migration patterns of the Osprey Pandion haliaetus on the Eastern European–East African flyway

We analysed migration strategies of the Osprey Pandion haliaetus on the poorly studied Eastern European–East African flyway. Four adult birds were equipped with GPS-based satellite-transmitters or data-loggers in their breeding sites in Estonia (north-eastern Europe) and tracked to their wintering grounds in Africa and back, during up to six migration cycles. Departure times, migration routes, as well as wintering and stopover sites varied remarkably between individuals but not much between years. Stopovers (2–30 days) were made mostly in Europe and less in the Middle East (Turkey) and north-eastern Africa (Egypt). The Ospreys did not avoid flying long distances over the sea, and the sea was crossed four times during the night. The current study adds to current knowledge on Osprey migration and should help to concentrate actions on protecting important flyways and stopover locations.     

Disuniting uniformity: a pied cladistic canvas of mtDNA haplogroup H in Eurasia

It has been often stated that the overall pattern of human maternal lineages in Europe is largely uniform. Yet this uniformity may also result from an insufficient depth and width of the phylogenetic analysis, in particular of the predominant western Eurasian haplogroup (Hg) H that comprises nearly a half of the European mitochondrial DNA (mtDNA) pool. Making use of the coding sequence information from 267 mtDNA Hg H sequences, we have analyzed 830 mtDNA genomes, from 11 European, Near and Middle Eastern, Central Asian, and Altaian populations. In addition to the seven previously specified subhaplogroups, we define fifteen novel subclades of Hg H present in the extant human populations of western Eurasia. The refinement of the phylogenetic resolution has allowed us to resolve a large number of homoplasies in phylogenetic trees of Hg H based on the first hypervariable segment (HVS-I) of mtDNA. As many as 50 out of 125 polymorphic positions in HVS-I were found to be mutated in more than one subcluster of Hg H. The phylogeographic analysis revealed that sub-Hgs H1*, H1b, H1f, H2a, H3, H6a, H6b, and H8 demonstrate distinct phylogeographic patterns. The monophyletic subhaplogroups of Hg H provide means for further progress in the understanding of the (pre)historic movements of women in Eurasia and for the understanding of the present-day genetic diversity of western Eurasians in general.     

Comparative FISH mapping of 32 loci reveals new homologous regions between donkey and horse karyotypes

A total of 32 loci comprising specific genes, microsatellites and anonymous BAC clones from horse and cattle were mapped on donkey chromosomes. Of these, 13 markers were also mapped for the first time in the horse. This information, together with that previously available in donkey and horse updates the comparative status of the karyotypes of the two species. The findings of the present study for the first time show correlation between eleven equine acrocentric autosomes and the donkey chromosomes and in part enable detection of rearrangements between them. There are still 7-8 pairs of chromosomes/arms for which no correspondence is known. At least 20 chromosome rearrangements (inversions, fusions and fissions) are already identified that differentiate the two karyotypes. More will be known once complete correspondence is deduced between them. These observations match similar differences observed between human-gibbon and mouse-rat karyotypes that show considerable rearrangements in relation to each other. How donkey and horse karyotypes gathered these differences within a short period of 5-10 Myr since divergence from a common ancestor will be known only after an ancestral equid karyotype is deduced, and the direction of change leading to chromosome rearrangements is clearly understood.     

HSA4 and GGA4: remarkable conservation despite 300-Myr divergence

The chicken (GGA) and human (HSA) genomes diverged around 300-350 Myr ago. Due to this large phylogenetic distance, significant synteny conservation has not been anticipated between the genomes of the two species. However, Zoo-FISH with HSA4 chromosome-specific paint on chicken metaphase chromosomes shows that the human chromosome corresponds largely to the GGA4cen-->q26 region. Comparative gene mapping data in the two species, though limited, provide strong support for these observations. The findings, together with the very recently published data on HSA9-GGAZ and HSA12-GGA1, show that some large chromosomal segments share conserved synteny in the two species. These syntenies are considerably disrupted in the mouse. This makes us believe that despite very early divergence, parts of the human and chicken genomes are more conserved than those of human and mouse, which radiated only 100-120 Myr ago. Moreover, the HSA4-GGA4q correspondence points to a "candidate" chromosome from the karyotype of a mammal-bird ancestor. The findings are thus a small but important step toward understanding the evolution of the two genomes.     

Redox-Specialized Bacterioplankton Metacommunity in a Temperate Estuary

This study explored the spatiotemporal dynamics of the bacterioplankton community composition in the Gulf of Finland (easternmost sub-basin of the Baltic Sea) based on phylogenetic analysis of 16S rDNA sequences acquired from community samples via pyrosequencing. Investigations of bacterioplankton in hydrographically complex systems provide good insight into the strategies by which microbes deal with spatiotemporal hydrographic gradients, as demonstrated by our research. Many ribotypes were closely affiliated with sequences isolated from environments with similar steep physiochemical gradients and/or seasonal changes, including seasonally anoxic estuaries. Hence, one of the main conclusions of this study is that marine ecosystems where oxygen and salinity gradients co-occur can be considered a habitat for a cosmopolitan metacommunity consisting of specialized groups occupying niches universal to such environments throughout the world. These niches revolve around functional capabilities to utilize different electron receptors and donors (including trace metal and single carbon compounds). On the other hand, temporal shifts in the bacterioplankton community composition at the surface layer were mainly connected to the seasonal succession of phytoplankton and the inflow of freshwater species. We also conclude that many relatively abundant populations are indigenous and well-established in the area.     

Rangewide analysis of fungal associations in the fully mycoheterotrophic Corallorhiza striata complex (Orchidaceae) reveals extreme specificity on ectomycorrhizal Tomentella (Thelephoraceae) across North America

Fully mycoheterotrophic plants offer a fascinating system for studying phylogenetic associations and dynamics of symbiotic specificity between hosts and parasites. These plants frequently parasitize mutualistic mycorrhizal symbioses between fungi and trees. Corallorhiza striata is a fully mycoheterotrophic, North American orchid distributed from Mexico to Canada, but the full extent of its fungal associations and specificity is unknown. Plastid DNA (orchids) and ITS (fungi) were sequenced for 107 individuals from 42 populations across North America to identify C. striata mycobionts and test hypotheses on fungal host specificity. Four largely allopatric orchid plastid clades were recovered, and all fungal sequences were most similar to ectomycorrhizal Tomentella (Thelephoraceae), nearly all to T. fuscocinerea. Orchid-fungal gene trees were incongruent but nonindependent; orchid clades associated with divergent sets of fungi, with a clade of Californian orchids subspecialized toward a narrow Tomentella fuscocinerea clade. Both geography and orchid clades were important determinants of fungal association, following a geographic mosaic model of specificity on Tomentella fungi. These findings corroborate patterns described in other fully mycoheterotrophic orchids and monotropes, represent one of the most extensive plant-fungal genetic investigations of fully mycoheterotrophic plants, and have conservation implications for the >400 plant species engaging in this trophic strategy worldwide.     

Assignment of six genes to bovine chromosomes 5 and 16 by fluorescence in situ hybridization, radiation hybrid mapping and genetic linkage analysis

Several quantitative trait loci for beef carcass traits have been mapped to bovine chromosome 5. The objective of this study was to map six candidate genes for these traits by fluoresence in situ hybridization, genetic linkage analysis and radiation hybrid mapping. MYF5 and MYF6 were assigned to 5q13, WIF1 to 5q23 and MMP19 to 5q25. A paralog of MYF5 (putatively MYOG) was assigned to 16q12. A novel microsatellite placed MYF5 and MYF6 10.4 cM from BM6026 and 19.1 cM from BL23 on the genetic linkage map. MYF5 (62.6 cR), WNT10B (319.5 cR), WIF1 (500.8 cR) and MMP19 (701.2 cR) were also integrated into the 5000(Rad) radiation hybrid map.