Ultrastructure of calcareous dinophytes (Thoracosphaeraceae, Peridiniales) with a focus on vacuolar crystal-like particles.

Biomineralization in calcareous dinophytes (Thoracosphaeracaea, Peridiniales) takes place in coccoid cells and is presently poorly understood. Vacuolar crystal-like particles as well as collection sites within the prospective calcareous shell may play a crucial role during this process at the ultrastructural level. Using transmission electron microscopy, we investigated the ultrastructure of coccoid cells at an early developmental stage in fourteen calcareous dinophyte strains (corresponding to at least ten species of Calciodinellum, Calcigonellum, Leonella, Pernambugia, Scrippsiella, and Thoracosphaera). The shell of the coccoid cells consisted either of one (Leonella, Thoracosphaera) or two matrices (Scrippsiella and its relatives) of unknown element composition, whereas calcite is deposited in the only or the outer layer, respectively. We observed crystal-like particles in cytoplasmic vacuoles in cells of nine of the strains investigated and assume that they are widespread among calcareous dinophytes. However, similar structures are also found outside the Thoracosphaeraceae, and we postulate an evolutionarily old physiological pathway (possibly involved in detoxification) that later was specialized for calcification. We aim to contribute to a deeper knowledge of the biomineralization process in calcareous dinophytes

Reliable determination of Prorocentrum micans Ehrenb. (Prorocentrales, Dinophyceae) based on newly collected material from the type locality

The Prorocentrales are a unique group of dinophytes based on several apomorphic traits, but species delimitation is challenging within the group. The type species of Prorocentrum, namely P. micans, cannot be determined unambiguously, as important characters are not preserved in the original material collected in the first half of the 19th century. Water samples were taken at the type locality of P. micans in the Baltic Sea off Kiel (Germany) and strains with a morphology consistent with the protologue were established. An in-depth morphological analysis was performed, illustrating minute traits such as the periflagellar platelets and three different types of thecal pores. rRNA sequence data allowed for molecular characterization of the species. The newly collected material of P. micans was used for epitypification with the result that the type species of Prorocentrum can now be determined unambiguously

Isolation of three novel rat and mouse papillomaviruses and their genomic characterization.

Despite a growing knowledge about the biological diversity of papillomaviruses (PV), only little is known about non-human PV in general and about PV mice models in particular. We cloned and sequenced the complete genomes of two novel PV types from the Norway rat (Rattus norvegicus; RnPV2) and the wood mouse (Apodemus sylvaticus; AsPV1) as well as a novel variant of the recently described MmuPV1 (originally designated as MusPV) from a house mouse (Mus musculus; MmuPV1 variant). In addition, we conducted phylogenetic analyses using a systematically representative set of 79 PV types, including the novel sequences. As inferred from concatenated amino acid sequences of six proteins, MmuPV1 variant and AsPV1 nested within the Beta+Xi-PV super taxon as members of the Pi-PV. RnPV2 is a member of the Iota-PV that has a distant phylogenetic position from Pi-PV. The phylogenetic results support a complex scenario of PV diversification driven by different evolutionary forces including co-divergence with hosts and adaptive radiations to new environments. PV types particularly isolated from mice and rats are the basis for new animal models, which are valuable to study PV induced tumors and new treatment options

First Miocene fossils of Vivianiaceae shed new light on phylogeny, divergence times, and historical biogeography of Geraniales

The origin of Geraniales (approximately 900 species in three families: Geraniaceae, Melianthaceae, and Vivianiaceae) is traced back to the Cretaceous of Gondwana, yet their geotemporal history is largely unknown because of a limited fossil record and incomplete phylogenies. In the present study, we provide the first fossil record of Vivianiaceae and a highly resolved molecular phylogeny for all extant Geraniales genera. Our results support the hypothesis that five (instead of three) families should be recognized in the order Geraniales: Francoaceae A. Juss. (Francoa, Greyia, Tetilla), Geraniaceae Juss. (Erodium, Geranium, Monsonia, Pelargonium), Hypseocharitaceae Wedd. (monogeneric), Melianthaceae Horan. (Bersama, Melianthus), and Vivianiaceae Klotzsch (Balbisia, Rhynchotheca, Viviania). The four major lineages (i.e. Geraniaceae, Francoaceae+Melianthaceae, Hypseocharitaceae, Vivianiaceae) all originated within a narrow time frame during the Eocene (36.9-49.9Mya) based on the five fossil calibration points. The divergence of most of the extant genera occurred much later, from the Miocene onwards. The South American-South African disjunction in Francoaceae apparently goes back to long distance dispersal with an estimated divergence time of the lineages in the Middle Miocene [11.2 (5.9-17.7)Mya]. Diversification in Melianthus appears to be much more recent than previously assumed [starting approximately 3.4 (1.9-5.2)Mya rather than approximately 8-20Mya]. However, divergence of the Andean Hypseocharis lineage [36.9 (31.9-42.8)Mya] significantly predates the main Andean uplift: Current distributions likely go back to northward migrations and subsequent extinctions in Patagonia. Similarly, Rhynchotheca, Balbisia, and Viviania have a current southern distribution limit >10°N of the fossil finds, indicating a massive northward displacement. The present evidence suggests that niche conservatism likely played a major role in the historical biogeography of Geraniales. © 2012 The Linnean Society of London.Fil: Palazzesi, Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina. Freie Universität Berlin; AlemaniaFil: Gottschling, Marc. Ludwig Maximilians Universitat; AlemaniaFil: Barreda, Viviana Dora. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Weigend, M. Freie Universität Berlin; Alemani

A preliminary phylogeny of Loasaceae subfam. Loasoideae (Angiospermae: Cornales) based on trnL(UAA) sequence data, with consequences for systematics and historical biogeography

AbstractThe phylogeny of Loasaceae subfam. Loasoideae is investigated with sequences of the chloroplast trnL(UAA) intron, all genera and infrageneric entities are included in the analysis. Loasaceae subfam. Loasoideae is monophyletic, and the two most speciose, and monophyletic, clades (which account for approximately 90% of the species total) are Nasa and the so-called Southern Andean Loasas (Blumenbachia, Caiophora, Loasa s.str., Scyphanthus), but the phylogeny of the remainder is not completely resolved. The data underscore a basal position for Chichicaste, Huidobria, Kissenia, and Klaprothieae (Xylopodia, Klaprothia, Plakothira). High bootstrap support values confirm the monophyly both of Klaprothieae and Presliophytum (when expanded to include Loasa ser. Malesherbioideae). Aosa and Blumenbachia are not resolved as monophyletic, but have clear morphological apomorphies. Within Nasa, “N. ser. Saccatae” is paraphyletic, and “N. ser. Carunculatae” is polyphyletic. However, the N. triphylla group in “N. ser. Saccatae” is a well-supported monophyletic group, as is N. ser. Grandiflorae. “Loasa” in its traditional circumscription is paraphyletic, but Loasa s.str. (L. ser. Macrospermae, L. ser. Deserticolae, L. ser. Floribundae) is monophyletic. The remainder of “Loasa” (L. ser. Pinnatae, L. ser. Acaules, L. ser. Volubiles) is probably closely allied to the essentially Patagonian-High Andean group comprising also Scyphanthus and Caiophora. These findings are congruent with morphology and phytogeography. Nasa seems to have undergone its primary radiation at moderate elevations (1500–2500m) in the Andes of northern Peru (Amotape-Huancabamba Zone) and subsequently diversified into high elevations (above 4000m) of the tropical Central Andes. South Andean Loasas appear to have undergone their primary diversification in the southern temperate and mediterranean regions of Chile and Argentina, with a subsequent northwards expansion of Caiophora into the high elevations of the tropical Andes. Hummingbird pollination has evolved independently from melittophily in High Andean clades of Nasa and Caiophora

Observations on flower and fruit anatomy in dioecious species of Cordia (Cordiaceae, Boraginales) with evolutionary interpretations

Detailed anatomical studies of flowers and fruits may render traits of phylogenetic importance, but are still rare in the Boraginales. An Old World clade of Cordia comprises many dioecious species, but the floral anatomy is largely unexplored and, hence, the structural basis for sex separation. Fresh material of buds, functionally unisexual flowers and fruits were studied using a stack shot camera. Fixed such material of Cordia crenata, C. cf. grandicalyx and C. sinensis was sectioned using a microtome and stained with safranin red and astra blue, and the gynoecial surface was studied using SEM. The stamens of the female flowers are largely intact, but do not produce pollen, whereas the gynoecium of the male flowers is highly reduced though develops ovules lacking an embryo sac. The morphologically rather unreduced stamens of the female flower may have undergone a shift of function from producing pollen towards attracting pollinators by optical signals. The outer parenchyma of the gynoecium is strongly stained and after fertilisation, one through three ovules are maturing towards seeds. The presence of more than a single seed enclosed in the undivided endocarp is rare in Cordiaceae