Dental Eruption Series and Replacement Pattern in Miocene <Emphasis Type="Italic">Prosantorhinus</Emphasis> (Rhinocerotidae) as Revealed by Macroscopy and X-ray: Implications for Ontogeny and Mortality Profile

Fossil evidence of complete sequences of dental ontogeny in extinct mammals is rare but contains valuable information on the animal’s physiology, life history, and individual age. Here, we analyzed an exceptionally high number of juvenile dentaries at different developmental stages including highly fragile tooth germs of the extinct rhinoceros Prosantorhinus germanicus from the Miocene fossil lagerstätte Sandelzhausen in Germany. We used dental wear stages, eruption stages, and tooth germ development in order to reconstruct the tooth replacement pattern for P. germanicus. The results allow for the distinction of 11 dental eruption stages and document a tooth eruption sequence of (d2, d3), (d1, d4), m1, m2, p2, p3, p4, m3; a pattern identical to that reported for the extant African rhinoceros, Diceros bicornis. Moreover, our findings indicate that P. germanicus falls into the life history category of slow-growing, long-living mammals. The dental eruption stages of the fossil rhinoceros were correlated with data of living rhinoceroses in order to gain insight into the age-at-death distribution of P. germanicus at Sandelzhausen. The juvenile mortality profile of P. germanicus shows a trend of selective mortality at an inferred age range of about 3 months to 3 years. As this age range represents a life phase of increased natural risk of mortality, our findings indicate a gradual accumulation of corpses (attritional fossil assemblage). This result supports the interpretation of a taphocenosis found at the Sandelzhausen fossil site.     

Mastication and enamel microstructure in <Emphasis Type="Italic">Cambaytherium</Emphasis>, a perissodactyl-like ungulate from the early Eocene of India

The dentition of Cambaytherium was investigated in terms of dental wear, tooth replacement and enamel microstructure. The postcanine tooth row shows a significant wear gradient, with flattened premolars and anterior molars at a time when the last molars are only little worn. This wear gradient, which is more intensive in Cambaytherium thewissi than in Cambaytherium gracilis, and the resulting flattened occlusal surfaces, may indicate a preference for a durophagous diet. The tooth replacement (known only in C. thewissi) shows an early eruption of the permanent premolars. They are in function before the third molars are fully erupted. During the dominant phase I of the chewing cycle the jaw movement is very steep, almost orthal, with a slight mesiolingual direction and changes into a horizontal movement during phase II. The enamel microstructure shows Hunter-Schreger-bands (HSB) in the inner zone of the enamel. In some teeth the transverse orientation of the HSB is modified into a zig-zag pattern, possibly an additional indicator of a durophagous diet.     

Molecular phylogeny and genetic diversity of genus <Emphasis Type="Italic">Capparis</Emphasis> (Capparaceae) based on plastid DNA sequences and ISSR markers

Capparis (Capparaceae) has been used as a medicinal plant since ancient time. Capparis species were divided into Old World and New World taxa as described by the sectional division of Capparis. However, plastid DNA sequence data of Indian Capparis species were not analyzed in previous phylogenetic studies. Here, we have added Indian Capparis data in previous phylogeny and analyzed the relationship of Indian Capparis with Old World and New World taxa. The plastid phylogeny presented here includes Capparis taxa from its major distribution areas, New World and African capparoids. The presented phylogeny is used for the determination of biogeographic history of Capparis and recently segregated genera. Phylogenetic analyses of the combined plastid data revealed that the Indian Capparis are more closely related to Old World taxa and have connections with African, Australian and Eastern Asian species. Sectional classification of Old World and Indian Capparis considered in this study is reflected from the presented plastid phylogeny. The ancestral area reconstruction using Bayesian Binary Markov Chain Monte Carlo method strongly supports for the Africa as the ancestral region for both Old World and New World Capparis. Molecular marker-based genetic diversity studies on Indian Capparis are scarce. This work also includes the genetic diversity study of Indian Capparis species. Utility and efficacy of ISSR markers to study inter- and intraspecies variation in Capparis is evident from the AMOVA results.     

Prevalence of <Emphasis Type="Italic">Borrelia burgdorferi</Emphasis> sensu lato and <Emphasis Type="Italic">Anaplasma phagocytophilum</Emphasis> in questing <Emphasis Type="Italic">Ixodes ricinus</Emphasis> ticks in relation to the density of wild cervids

Background

Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum have been considered as pathogens in animals and humans. The role of wild cervids in the epidemiology is not clear. We analyzed questing Ixodes ricinus ticks collected in spring for these pathogens from sites with high (Fjelløyvær and Strøm) and low density (Tjore, Hinnebu and Jomfruland) of wild cervids to study the spread of the pathogens in questing ticks.

Methods

For detection of Anaplasma phagocytophilum a 77-bp fragment in the msp 2 gene was used. Detection of Borrelia burgdorferi sensu lato was performed using the FL6 and FL7 primers according to sequences of conserved regions of the fla gene. The Osp A gene located on the linear 49-kb plasmid was used as target in multiplex PCR for genotyping. Genospecies-specific primers were used in the PCR for Borrelia burgdorferi sensu stricto, B. afzelii and B. garinii.

Results

Infection rates with Borrelia spp. were significantly lower at Fjelløyvær and Strøm compared to Tjore and Hinnebu; Fjelløyvær vs. Tjore (χ² = 20.27, p < 0.0001); Fjelløyvær vs. Hinnebu (χ² = 24.04, p < 0.0001); Strøm vs. Tjore (χ² = 11.47, p = 0.0007) and Strøm vs. Hinnebu (χ² = 16.63, p < 0.0001). The Borrelia genospecies were dominated by. B. afzelii (82%) followed by B. garinii (9.7%) and B. burgdorferi sensu stricto (6.9%). B. burgdorferi s.s. was only found on the island of Jomfruland. The infection rate of Anaplasma phagocytophilum showed the following figures; Fjelløyvær vs Hinnebu (χ² = 16.27, p = 0.0001); Strøm vs. Tjore (χ² = 13.16, p = 0.0003); Strøm vs. Hinnebu (χ² = 34.71, p < 0.0001); Fjelløyvær vs. Tjore (χ² = 3.19, p = 0.0742) and Fjelløyvær vs. Støm (χ² = 5.06, p = 0.0245). Wild cervids may serve as a reservoir for A. phagocytophilum. Jomfruland, with no wild cervids but high levels of migrating birds and rodents, harboured both B. burgdorferi s.l. and A. phagocytophilum in questing I. ricinus ticks. Birds and rodents may play an important role in maintaining the pathogens on Jomfruland.

Conclusion

The high abundance of roe deer and red deer on the Norwegian islands of Fjelløyvær and Strøm may reduce the infection rate of Borrelia burgdorferi sensu lato in host seeking Ixodes ricinus, in contrast to mainland sites at Hinnebu and Tjore with moderate abundance of wild cervids. The infection rate of Anaplasma phagocytophilum showed the opposite result with a high prevalence in questing ticks in localities with a high density of wild cervids compared to localities with lower density.

     

Comparative wood anatomy of the Cupressaceae and correspondence with phylogeny,with special reference to the monotypic taxa

Wood anatomy is one of the tools used for taxonomic classification of species. By combining this tool with molecular phylogeny, the current groupings made in morphological studies can be discussed. This study describes the wood anatomy of the monotypic genera of Cupressaceae and analyses the features that could represent synapomorphies of the principal clades recovered by molecular phylogeny. The wood anatomical study shows the high homogeneity of this family, revealing the presence of common ancestral features that support the union between Taxodiaceae and Cupressaceae s.s. and the separation of Sciadopitys. It also supports the group formed by Taxodiaceae in Cupressaceae s.l. No clear division was observed between the callitroid and cupressoid clades. Some wood anatomical differences were observed in the Fitzroya–Diselma–Pilgerodendron and Microbiota–Platycladus–Tetraclinis associations. The wood anatomical features common to the family, such as axial tracheids without helical thickenings, homogeneous rays, cupressoid cross-field pits and the presence of a warty layer, are put forward as possible synapomorphies for Cupressaceae s.l. The clade-specific synapomorphies are taxodioid cross-field pits for taxodioid and sequoioid clades, absence of a well-defined torus in Thuja–Thujopsis and torus extensions in Diselma–Fitzroya–Widdringtonia.     

Phylogenetic analysis reveals the origins of tetraploid and hexaploid species in the Japanese <Emphasis Type="Italic">Lepisorus thunbergianus</Emphasis> (Polypodiaceae) complex

The Japanese Lepisorus thunbergianus complex contains diploid and tetraploid races of L. thunbergianus and a hexaploid species, L. mikawanus. Here, we performed molecular phylogenetic analysis on this complex to delimit species and to elucidate the evolutionary origins of tetraploid and hexaploid species. Chloroplast DNA (cpDNA) phylogeny supported the monophyly of the complex. Based on a single-copy nuclear gene (PgiC) tree, the tetraploid L. thunbergianus samples could be classified into two variants: an allotetraploid of hybrid origin between diploid L. thunbergianus and Japanese L. angustus and another allotetraploid of hybrid origin between diploid L. thunbergianus and an unknown diploid race of L. tosaensis. These variants can be recognized morphologically and distinguished from their parent species. Hence, here we described these allopolyploids as new species, L. nigripes and L. kuratae, respectively. The hexaploid species L. mikawanus has three types of PgiC alleles, each of which was derived from diploid L. thunbergianus, L. tosaensis, and Japanese L. angustus, while cpDNA shows that it is included in Japanese L. thunbergianus clade. Based on the cpDNA phylogeny and PgiC nucleotide sequences, we therefore concluded that L. mikawanus is an allohexaploid that originated through hybridization between tetraploid species, L. nigripes and an unknown ancestral diploid race of L. tosaensis.     

Evolutionary pattern of the forewing shape in the Neotropical genus of jumping plant-lice (Hemiptera: Psylloidea: <Emphasis Type="Italic">Russelliana</Emphasis>)

Geometric morphometric and phylogenetic analyses, applied to 43 species of Russelliana, shed light on the evolution of insect wing shape. Unconstrained and constrained ordination techniques are introduced to detect patterns of the forewing shape variation within genus. Results show a high congruence between forewing shape variation and host-plant preference supporting monophyly of most phylogenetic groups in Russelliana. Reconstruction of the ancestral forewing state shows its similarity to a forewing shape of Solanaceae feeding species defined as ancestors by the phylogenetic study supporting a hypothesis as to a primary association of Russelliana with Solanaceae. In contrast to some other comparative studies on insect wing shape, results of the present study reveal a strong correlation between variation of forewing shape in Russelliana and its phylogeny. Potential influence of vicariant events and host shifts on the evolution of forewing shape is discussed.     

Morphological variation in pollen grains of <Emphasis Type="Italic">Mucuna</Emphasis> (Leguminosae): new biogeographic and evolutionary patterns

Mucuna comprises 105 species with an overall pantropical distribution and is divided into three subgenera: M. subg. Mucuna, M. subg. Stizolobium and M. subg. Macrocarpa. Although phylogenetic studies have supported the occurrence of three main clades, evolutionary relationships among them are not fully resolved. The objective of this study was to examine pollen grain morphology from representatives of all three subgenera and map these onto the phylogenetic trees generated by analysis of other characters. Pollen grain surface, form, size, and aperture number were compared. A Bayesian inference tree using matK sequences was constructed. The results indicate that the representatives of M. subg. Macrocarpa have the smallest pollen grains in the genus (a synapomorphic character here identified for this subgenus) and that species of subgenus Mucuna (those with umbelliform inflorescences) have the largest pollen grains. Additional morphological diversity of the pollen grain surface was noted: reticulate and/or micro-reticulate (in all three subgenera), perforate, gemmate or verrucose (only in M. subg. Mucuna). For all studied taxa, the pollen grains are triaperturate, except for two species of M. subg. Mucuna, which have tetraperturate pollen. The phylogenetic tree obtained using the matK marker resolved M. subg. Stizolobium as the earliest diverging lineage in Mucuna. Based on this phylogeny, a reticulate ornamentation pattern of the pollen surface may represent the ancestral state for the genus, while the larger pollen size and the foraminate, gemmate, and verrucose ornamentations are derived characteristics within the genus. These putative derived ornamentations have been observed only in neotropical species.     

Identification and expression analysis of cytokinin response regulators in <Emphasis Type="Italic">Fragaria vesca</Emphasis>

Cytokinin response regulators (RRs) are important components of the two component signal systems, which are involved in the regulation of plant growth and development, and in the response to abiotic stress. In this study, 18 cytokinin RR genes were identified in Fragaria vesca through the genome-wide search. They were further classified into three types: type-A (FvRR1–7), type-B (FvRR8–14) and type-C (FvRR15–18) according to the domain architecture and the phylogeny. Phylogenetic analysis demonstrated that most cytokinin response regulators of F. vesca and Arabidopsis formed clear orthologous pairs. Expression patterns of the cytokinin FvRR genes in various tissues and organs at reproductive stages were detected in this study. Additionally, gene expression response patterns to ABA and abiotic stresses including high temperature and osmotic stress were investigated. The results showed that different types of cytokinin FvRRs have different expression patterns, suggesting the functional differentiation of cytokinin FvRRs during the evolution. This systematic study provides insights into possible functions of the cytokinin FvRR genes and a basis for further functional analysis.     

Incipient speciation in a neotropical Gesneriaceae: <Emphasis Type="Italic">Columnea kucyniakii</Emphasis> is nested within <Emphasis Type="Italic">C. strigosa</Emphasis>

Speciation is an ongoing process. Many recognized species are fully divergent from each other and their ancestors, whereas others are in earlier stages in the diversification process. Such incipient speciation may create patterns when one or a few populations are phenotypically distinct, but lack genomic level coalescence from each other or from their ancestral species. As a result, such progenitor-derivative species pairs are likely to lack reciprocal monophyly or generate paraphyletic ancestral species. Here we examine phylogenetic patterns in the Columnea strigosa (Gesneriaceae) complex to evaluate whether populations that have been named C. kucyniakii are reciprocally monophyletic with C. strigosa, its presumed ancestral species. Molecular phylogenetic results do not support reciprocal monophyly of the two species, implying that incipient speciation is occurring within the C. strigosa complex. We hereby recommend that C. kucyniakii be recognized at the specific rank despite the fact that it creates a paraphyletic C. strigosa. These findings bear importance in taxonomic decisions about paraphyletic taxa and recognizing evolutionary and morphologically distinct lineages.     

Congruence between comparative morphology and molecular phylogenies: the final stage of evolution of the skeletal characters of male genitalia in the subtribe Polyommatina (Lepidoptera,Lycaenidae). Part 2. Uncus and subunci

The morphology of the male terminalia (uncus and subunci) was studied in 39 species of the subtribe Polyommatina (Lycaenidae). Traces of nine established characters were mapped on the molecular phylogeny of the subtribe proposed by Talavera et al. (2013). The ancestral character states for these morphological structures were established in Plebejus s. l. and Polyommatus s. l. According to the time calibration of the proposed molecular tree, the studied skeletal structures (uncus and subunci) evolved very slowly within the last million years. It was shown that the similar shape of the uncus and subuncus branches arose independently and underwent parallel morphological transformations. In particular, wide and, as a rule, ventrally directed uncus lobes arose independently in Polyommatus s. str., Alpherakya, Glabroculus, and Aricia. Yet, in various evolutionary lines of Polyommatina similar changes in the length ratio of the proximal and distal parts of the subunci as well as in the shape of their apical hooks were observed. The character states marking the groups Polyommatus s. str. and Aricia were established. The evolutionary changes in the uncus morphology were highly non-uniform in the various monophyletic lines of Polyommatina. As a result, representatives of some “old” lines have more specialized features of the uncus morphology in comparison with those belonging to “young” lines that retain ancestral character states. In Polyommatina, the transformation of the male terminalia was directed toward development of the most effective mechanism of female fixation during copulation. This goal was reached in similar ways in various evolutionary lines of Polyommatina, which explains numerous parallelisms in morphology of these structures.     

Effect of coat color genes on the hair pigmentation morphology in the american mink (<Emphasis Type="Italic">Mustela vison</Emphasis> Schr. L.)

The morphological patterns of hair pigmentation (the size and shape of pigment granules and their distribution among layers) have been studied in four compound coat color forms of the American mink: moil-sapphire also known as violet (genotype m/m a/a p/p); moil-silver or sage (genotype m/m p/p); the color form determined by genotype m/+ a/a; and platinum leopard (S ^k /+ a/+ p/p). The hair pigmentation pattern specific for each coat color form and its difference from the standard coat color of the American mink (genotype +/+) has been determined. The possible mechanisms of the phenotypic expression of the nonallelic genes contributing to the described compound color forms are discussed.     

Comparative phylogeography of diadromous and freshwater daces of the genus <Emphasis Type="Italic">Tribolodon</Emphasis> (Cyprinidae)

Far Eastern daces, genus Tribolodon (Cyprinidae), are thought to have diversified and developed unique diadromous life histories under changing conditions in the Sea of Japan and the surrounding environment. To examine the relationships between life history traits, distribution, and genetic population structures, we conducted a comparative phylogeographic analysis using partial mtDNA sequence data from samples collected over almost the full ranges of all four Tribolodon species. Phylogenetic analyses revealed several intraspecific haplotype groups that differentiated in the early Pleistocene to the Pliocene with or without geographic overlaps. A time-calibrated phylogeny suggested that the relatively smaller geographic ranges of the strictly freshwater species, T. sachalinensis and T. nakamurai, were explained not by the recent origins of these species, but by their limited dispersal abilities and smaller historical population sizes. The wider-ranging diadromous species, T. brandtii and T. hakonensis, exhibited similar major phylogeographic structures in their distributions, but the chronological order and timing of formation of this structure largely differed between the two species. In addition to those differences, the overlapping patterns of the differentiated intraspecific lineages in these species suggest dynamic, but somewhat restricted dispersal during the Plio-Pleistocene. Tribolodon hakonensis, one of the most widespread species of East Asian freshwater fishes, included both common and unique phylogeographic patterns compared to other fish species; the unique patterns (i.e., its wide range across freshwater biogeographic boundaries like the sea and mountains) would reflect its ecological features as a remarkable generalist inhabiting lakes, upper and lower reaches of rivers, and even coastal areas.     

New phylogenetic insights into <Emphasis Type="Italic">Saprolegniales</Emphasis> (Oomycota,Straminipila) based upon studies of specimens isolated from Brazil and Argentina

Saprolegniales is a complex and monophyletic order of oomycetes. Their members inhabit terrestrial, freshwater, and marine ecosystems and have a worldwide distribution. In these ecosystems, they are found as saprobes, parasites, or even pathogens of animals and plants of economic importance. In this study, a concatenate phylogeny of the partial LSU and complete ITS rDNA regions is presented, including isolates from Brazil and Argentina, which were sequenced after a detailed morphological analysis. Among the sequenced species, Achlya orion, Leptolegnia eccentrica, Phragmosporangium uniseriatum, and Pythiopsis irregularis are included for the first time in a phylogeny. Our results are in agreement with the recent informal proposals outlined in taxonomic overviews of the Oomycota of G.W. Beakes and collaborators, who placed the family Verrucalvaceae into the Saprolegniales and introduced the family Achlyaceae to group Achlya s.s., Brevilegnia, Dictyuchus, and Thraustotheca. These results also support the transference of Achlya androgyna to Newbya. Leptolegnia appears as paraphyletic, with the separation of L. eccentrica from the other species of this genus. In addition, Phragmosporangium, which is herein sequenced for the first time, clustered as sister to some species of Aphanomyces, including the type species, A. stellatus.     

Evolution of errantiviruses of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>. Strategy 2: From retroviruses to retrotransposons

Drosophila melanogaster retrotransposons of the gypsy group are considered to be potential errantiviruses. Their infectivity is caused by the functional activity of the third open reading frame (ORF3) encoding the Env protein, which was probably captured from baculoviruses. Mobile genetic elements (MGEs) of the gypsy group can be conventionally divided into three subgroups: with three ORFs, with a defective ORF3, and without the ORF3. To establish the patterns of evolution of gypsy retrotransposons in D. melanogaster, the members of the three subgroups were examined. Structural analysis of retrotransposons opus and rover, which carry a defective ORF3, as well as retrotransposons Burdock, McClintock, qbert, and HMS-Beagle, which lack the ORF3, suggests that the evolution of these MGEs followed the pattern of loosing the ORF3. At the same time, an MGE of the same subgroup, Transpac, may be an ancestral form, which had acquired the env gene and gave rise to the first errantiviruses. The capture of the ORF3 by retrotransposons provided their conversion to a fundamentally new state. However, the ORF3 in the genome is not subjected to strong selective pressure, because it is not essential for intragenomic transpositions. Because of this, the process of its gradual loss seems quite natural.     

Morphological and molecular taxonomy of novel species <Emphasis Type="Italic">Pleurotheciaceae</Emphasis> from freshwater habitats in Yunnan,China

The diversity of lignicolous freshwater fungi of the Greater Mekong Subregion are currently being studied. In this paper, 18 fresh collections of Pleurotheciaceae from submerged wood in freshwater are characterized based on morphological characters and analyses of ITS, LSU, SSU and RPB2 sequence data. Six new species of Pleurotheciella (P. aquatica, P. fusiformis, P. guttulata, P. lunata, P. saprophytica, P. submersa), one new Phaeoisaria species (Ph. aquatica) and one new Pleurothecium species (Pl. aquaticum) are introduced based on their distinct morphology and evidence from molecular phylogeny. Pleurotheciella uniseptata, Phaeoisaria clematidis and Pleurothecium pulneyense are also redescribed and phylogenetic relationships assessed herein, these species are the first records for China.     

The evolutionary history of <Emphasis Type="Italic">Senna</Emphasis> ser. <Emphasis Type="Italic">Aphyllae</Emphasis> (Leguminosae–Caesalpinioideae), an endemic clade of southern South America

In the legume genus Senna, series Aphyllae includes seven species of leafless shrubs and subshrubs from arid, semiarid and xerophilous areas of three different biogeographic subregions in southern South America. In this study, we investigated the evolutionary history of Aphyllae in a molecular phylogenetic framework. We reconstructed phylogenetic relationships among Aphyllae species based on DNA sequence data of four plastid (rpS16, rpL16, matK, trnL-F) and one nuclear (ITS) region from 23 accessions, analyzed with parsimony, Bayesian and maximum likelihood methods. We inferred the evolutionary and biogeographic history estimating divergence times and reconstructing ancestral character states and ancestral areas of distribution. Series Aphyllae was found to be monophyletic, and the taxa formed two main clades: Clade A gathering S. aphylla var. aphylla, S. crassiramea, S. rigidicaulis and S. spiniflora; and Clade B grouping S. acanthoclada, S. aphylla var. divaricata, S. aphylla var. pendula and S. pachyrrhiza. The morphologically complex S. aphylla appears thus polyphyletic. Molecular dating and ancestral area reconstructions suggest that the Aphyllae clade started to diversify in the South American Transition Zone in the Late Pliocene. Based on these results, we hypothesize that this diversification occurred during the last period of Andean uplift with the aridification in South America. The ancestral character state reconstructions suggest that, in addition to the loss of leaves in adult plants, series Aphyllae evolved various morphological features, such as fastigiate, thickened or decumbent–subdecumbent branches during the colonization and establishment in different arid and semiarid lands in South America.