To be or not to be the odd one out - Allele-specific transcription in pentaploid dogroses (Rosa L. sect. Caninae (DC.) Ser)

<p>Abstract</p> <p>Background</p> <p>Multiple hybridization events gave rise to pentaploid dogroses which can reproduce sexually despite their uneven ploidy level by the unique canina meiosis. Two homologous chromosome sets are involved in bivalent formation and are transmitted by the haploid pollen grains and the tetraploid egg cells. In addition the egg cells contain three sets of univalent chromosomes which are excluded from recombination. In this study we investigated whether differential behavior of chromosomes as bivalents or univalents is reflected by sequence divergence or transcription intensity between homeologous alleles of two single copy genes (<it>LEAFY</it>, <it>cGAPDH</it>) and one ribosomal DNA locus (<it>nrITS</it>).</p> <p>Results</p> <p>We detected a maximum number of four different alleles of all investigated loci in pentaploid dogroses and identified the respective allele with two copies, which is presumably located on bivalent forming chromosomes. For the alleles of the ribosomal DNA locus and <it>cGAPDH </it>only slight, if any, differential transcription was determined, whereas the <it>LEAFY </it>alleles with one copy were found to be significantly stronger expressed than the <it>LEAFY </it>allele with two copies. Moreover, we found for the three marker genes that all alleles have been under similar regimes of purifying selection.</p> <p>Conclusions</p> <p>Analyses of both molecular sequence evolution and expression patterns did not support the hypothesis that unique alleles probably located on non-recombining chromosomes are less functional than duplicate alleles presumably located on recombining chromosomes.</p

Tracking the origin of invasive Rosa rubiginosa populations in Argentina

The exact geographic origin of invasive species populations is rarely known; however, such knowledge is vital to understanding species’ invasion success, spread, and evolution as well as for assessing any biological control options. We investigated the shrub Rosa rubiginosa L., focusing on the presumed European origin of invasive populations in Argentina. We analyzed eight polymorphic microsatellite loci among 102 native (European) and 29 invasive (mainly central Argentinean and Patagonian) populations. Genetic diversity in the invasive range was clearly lower than in the native range, possibly because of a low number of introductions. Contrary to earlier hypotheses, the interpretation of principal coordinate analysis results and Jaccard dissimilarities contradicts the idea of the Argentinean populations having a Spanish origin. Instead, we found a close similarity between Argentinean samples and those from Germany, the Czech Republic, and Austria. We therefore assume that these neighboring countries are the most probable source regions for the Argentinean populations, which in some cases may also have arrived via Chile. According to historic information, emigrants from these regions may have introduced R. rubiginosa to South America in the nineteenth century on at least two occasions, either for food or as rootstock material for propagating living fences.Fil: Hirsch, Heidi. Martin-Luther-University Halle-Wittenberg; AlemaniaFil: Zimmermann, Heike. Martin-Luther-University Halle-Wittenberg; AlemaniaFil: Ritz, Christiane M.. Senckenberg Museum of Natural History Goerlitz; AlemaniaFil: Wissemann, Volker. Justus-Liebig-University Giessen; AlemaniaFil: von Wehrden, Henrik. Martin-Luther-University Halle-Wittenberg; Alemania. Leuphana University, Institute of Ecology and Environmental Chemistry; AlemaniaFil: Renison, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Wesche, Karsten. Senckenberg Museum of Natural History Goerlitz; AlemaniaFil: Welk, Erik. Martin-Luther-University Halle-Wittenberg; AlemaniaFil: Hensen, Isabell. Martin-Luther-University Halle-Wittenberg; Alemani

Untangling the hedge: Genetic diversity in clonally and sexually transmitted genomes of European wild roses, Rosa L.

While European wild roses are abundant and widely distributed, their morphological taxonomy is complicated and ambiguous. In particular, the polyploid Rosa section Caninae (dogroses) is characterised by its unusual meiosis, causing simultaneous clonal and sexual transmission of sub-genomes. This hemisexual reproduction, which often co-occurs with vegetative reproduction, defies the standard definition of species boundaries. We analysed seven highly polymorphic microsatellite loci, scored for over 2 600 Rosa samples of differing ploidy, collected across Europe within three independent research projects. Based on their morphology, these samples had been identified as belonging to 21 dogrose and five other native rose species. We quantified the degree of clonality within species and at individual sampling sites. We then compared the genetic structure within our data to current rose morpho-systematics and searched for hemisexually co-inherited sets of alleles at individual loci. We found considerably fewer copies of identical multi-locus genotypes in dogroses than in roses with regular meiosis, with some variation recorded among species. While clonality showed no detectable geographic pattern, some genotypes appeared to be more widespread. Microsatellite data confirmed the current classification of subsections, but they did not support most of the generally accepted dogrose microspecies. Under canina meiosis, we found co-inherited sets of alleles as expected, but could not distinguish between sexually and clonally inherited sub-genomes, with only some of the detected allele combinations being lineage-specific

Chemical Magnetoreception: Bird Cryptochrome 1a Is Excited by Blue Light and Forms Long-Lived Radical-Pairs

Cryptochromes (Cry) have been suggested to form the basis of light-dependent magnetic compass orientation in birds. However, to function as magnetic compass sensors, the cryptochromes of migratory birds must possess a number of key biophysical characteristics. Most importantly, absorption of blue light must produce radical pairs with lifetimes longer than about a microsecond. Cryptochrome 1a (gwCry1a) and the photolyase-homology-region of Cry1 (gwCry1-PHR) from the migratory garden warbler were recombinantly expressed and purified from a baculovirus/Sf9 cell expression system. Transient absorption measurements show that these flavoproteins are indeed excited by light in the blue spectral range leading to the formation of radicals with millisecond lifetimes. These biophysical characteristics suggest that gwCry1a is ideally suited as a primary light-mediated, radical-pair-based magnetic compass receptor

Highly reduced genetic diversity of rosa Rubiginosa L. Populations in the Invasive Range

Rosa rubiginosa (Rosaceae) populations introduced to Argentina successfully invade various habitats, forming extensive impenetrable thickets. To investigate the consequences of founder events and to track the native origin of Argentinean populations, the genetic diversity of invasive R. rubiginosa populations was compared with that of native populations in Europe, and genetic similarity was assessed between groups. We sampled 13 Argentinean populations and 20 native populations in Germany and Spain, and we applied two molecular marker techniques (simple sequence repeats and random amplification of polymorphic DNA [RAPD]). Genetic diversity within the invasive range was clearly lower than it was in the native range. Principle coordinate analysis and between-class analysis did not reveal the exact European origin of the invasive populations, but our data suggest that at least one Argentinean population originated in Germany. Overall, the strong similarity of RAPD and allelic phenotypes throughout Argentina suggests a limited number of introduction events, that the species spread through human transport, and that the few genetic phenotypes present in the species were conserved largely unaltered as a result of mainly asexual reproduction.Fil: Zimmermann, Heike. Martin-Luther University Halle; AlemaniaFil: Ritz, Christiane M.. Justus‐Liebig‐University Giessen; AlemaniaFil: Hirsch, Heidi. Martin‐Luther University Halle; AlemaniaFil: Renison, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Wesche, Karsten. Georg‐August‐University; Alemania. Senckenberg Natural History Museum Görlitz; AlemaniaFil: Hensen, Isabell. Martin‐Luther University Halle; Alemani

Genetic diversity in the locally declining Laserpitium prutenicum L. and the more common Selinum carvifolia (L.) L.: a "silent goodbye"?

International audienceEvaluating the consequences of the decline of threatened species on their population genetic structure is crucial for establishing effective conservation strategies in the strongly fragmented landscapes of Central Europe. Laserpitium prutenicum is a bi- to perennial forb occurring in intermittently wet meadows and light oak forests throughout central to eastern and south-eastern Europe. During the past 70 years, the western limit of its distributional range retracted dramatically, the number of populations decreased and the remaining populations faced a considerable increase of fragmentation. To study the effects of this decline on the genetic diversity of L. prutenicum, we conducted an AFLP study on 20 populations from Germany, Poland and the Czech Republic. For comparison, we collected the same data on Selinum carvifolia, a taxonomically related and both ecologically and morphologically similar species, which is still more common in the study area. Both species showed similarly weak spatial genetic structuring and intermediate genetic diversities. We attribute this result to the loss of habitat being faster than the loss of genetic diversity in smaller and fragmented populations. Depending on the ecological characteristics of a species, even a gradual disappearance is not necessarily accompanied by any detectable effect at the population genetic level ("silent goodbye"). In the case of L. prutenicum, habitat preservation should be given priority over all other conservation measures

Dataset and metadata.

While European wild roses are abundant and widely distributed, their morphological taxonomy is complicated and ambiguous. In particular, the polyploid Rosa section Caninae (dogroses) is characterised by its unusual meiosis, causing simultaneous clonal and sexual transmission of sub-genomes. This hemisexual reproduction, which often co-occurs with vegetative reproduction, defies the standard definition of species boundaries. We analysed seven highly polymorphic microsatellite loci, scored for over 2 600 Rosa samples of differing ploidy, collected across Europe within three independent research projects. Based on their morphology, these samples had been identified as belonging to 21 dogrose and five other native rose species. We quantified the degree of clonality within species and at individual sampling sites. We then compared the genetic structure within our data to current rose morpho-systematics and searched for hemisexually co-inherited sets of alleles at individual loci. We found considerably fewer copies of identical multi-locus genotypes in dogroses than in roses with regular meiosis, with some variation recorded among species. While clonality showed no detectable geographic pattern, some genotypes appeared to be more widespread. Microsatellite data confirmed the current classification of subsections, but they did not support most of the generally accepted dogrose microspecies. Under canina meiosis, we found co-inherited sets of alleles as expected, but could not distinguish between sexually and clonally inherited sub-genomes, with only some of the detected allele combinations being lineage-specific.</div

Results of AMOVA analyses regarding different taxonomic levels within European roses.

Results of AMOVA analyses regarding different taxonomic levels within European roses.</p

Contribution to the knowledge on the flora of Numrug Strictly Protected Area and some parts of East Mongolia

A floristic study of Eastern Mongolian Steppes has been conducted during the growing season of 2014 and continued in 2017, when we focused more on the Numrug Strictly Protected Area. Major objectives of this study were to assess floristic diversity of Eastern Mongolian Steppes and to review the conservation status of some endangered, rare, and very rare species. A total of 488 taxa of vascular plants, which belong to 254 genera of 75 families, including three endemic and 16 subendemic species were sampled. Among these were three endangered, three vulnerable, five near threatened, 16 very rare, and 39 rare species. Remarkably, Myriophyllum sibiricum and Typha latifolia are newly recorded for the flora of Mongolia. Moreover, new distribution records of some species were noted in four phytogeographical regions of Eastern Mongolia, such as Foothills of Great Khingan (30), East Mongolia (12), Mongolian Dauria (11), and Middle Khalkha (3). Finally, we assessed regional conservation status of the five species (two endangered and three vulnerable) from the East Mongolia using the International Union for Conservation of Nature Red List criteria and categories. Keywords: Conservation status, Floral diversity, New records, Numrug SP