The metaconule: A morphologic and familial analysis of a molar cusp in humans

Incidence and size variability of the metaconule, an accessory maxillary molar cusp, is analyzed in a series of 1,217 living Melanesians. The range of morphologic variation is quantified on a six-grade ordinal scale developed to standardize observations. Total incidence of the metaconule decreases along a mesial-to-distal gradient, while mean size and size variability increase from M1 to M3. So, while the trait is less common on distal molars, it is on average larger. Estimation of the additive genetic component is 65% for the first molar but only 15% for the second. Trait incidence and heritability estimates are generally higher for females indicating the need for separate analysis by sex.     

Pollen morphology of Rhododendron subgen. Tsutsusi and its systematic implications

Eighty-four pollen samples were obtained for 80 taxa, of which, 13 species and one variety are from sect. Brachycalyx Sweet, 58 species and two varieties from sect. Tsutsusi Sweet, and six species from subgen. Pentanthera (G. Don) Pojarkova, respectively. Pollen morphology of all samples was observed using LM and SEM. Pollen grains are revealed to be spheroidal and tetrahedral with tricolporate apertures. Pollen sizes of sub-gen. Tsutsusi (Sweet) Pojarkova range from 37.67 μm to 61.06 μm, and the exine sculptures are more or less compactly granulated. Pollen sizes are significantly different between sect. Brachycalyx and sect. Tsutsusi of subgen. Tsutsusi. Rhododendron tashiroi Maxim. of sect. Tsusiopsis Sleumer shows a close affinity to sect. Brachycalyx. Pollen size and exine are consistent with general morphology in differentiating species in sect. Tsutsusi. Rhododendron huadingense B. Y. Ding & Y. Y. Fang, once placed as a member of sect. Brachycalyx, should be considered as a species in subgen. Pentanthera.     

Pollen morphology of Astragalus section Hymenostegis (Fabaceae) and evaluation of its systematic implications

Astragalus is with nearly 3000 described species the largest genus of flowering plants. So far analyses of pollen characters have only been conducted for a few species of the groups within the genus. Here we analyse pollen grains of 22 species representative for Astragalus section Hymenostegis using scanning electron microscopy. We found the basic shape of the pollen grains to be oblate-spheroidal and apertures to be tricolpate as for other eudicots. The sculpturing pattern of the exine is micro-reticulate. Pollen grains show low morphological variation among different species of this section, but differences occur between sections of the genus. We conclude that the vast morphological differentiation that occurred during the rapid radiation of section Hymenostegis was not accompanied by comparable differentiation in pollen morphology.     

A new ichnospecies of Fuersichnus from the Cretaceous of Antarctica and its paleoecologic and stratigraphic implications

A new ichnotaxon is recognized in the Hidden Lake Formation, Upper Cretaceous of James Ross Island, Antarctica. Fuersichnus striatus consists of horizontal to subhorizontal, isolated or loosely clustered, U‐shaped, curved to banana‐like burrows, characterized by distinctive striations parallel to the trace axis. It is interpreted as a dwelling structure probably produced by crustaceans or polychaetes. This recording of Fuersichnus extends its stratigraphic range from the Triassic‐Jurassic to the Cretaceous and its environmental setting from nonmarine to marine environments. F. striatus typified consolidated, but unlithified substrates. Accordingly, it must be considered a member of the Glossifungites ichnofacies.     

Enamel microstructure ofTribosphenomys (Mammalia,glires): Character analysis and systematic implications

Enamel distribution on the upper and lower incisors ofTribosphenomys minutus (from Late Paleocene-Early Eocene of Inner Mongolia of China) is typically rodent-like, i.e., primarily confined to the anterior surface throughout these transversely compressed, evergrowing teeth. AlthoughTribosphenomys incisor enamel is differentiated into two layers, it does not possess Hunter-Schreger bands (HSB). The incisor and molar enamels are radial in type, a condition regarded as either an autapomorph or a primtive retention forTribosphenomys. Character polarities concerning enamel thickness, enamel layer number, HSB, enamel types, and functional and phylogenetic implications of the enamel structures are discussed. Overall, enamel microstructural evolution at high taxonomic levels within Glires displays considerably more homoplasy than generally appreciated. A phylogenetic definition of Rodentia is proposed.Tribosphenomys is the sister-group of a taxon here named Rodentia, and thus is not itself a member of the order, from a systematic viewpoint.     

On the origin systematic position of the calcareous-shelled inarticulate brachiopods

Available data on the anatomy, ontogeny embryology of Brachiopoda ( sensu lato ) suggest that this Phylum in the traditional view is in fact a clade of organization includes two stocks of lophophorate organisms of quite different origins. Their rank does not correspond to existing Class divisions. The phosphatic-shelled in articulates are regarded as a separate Class Lingulata. The Phylum Brachiopoda ( sensu stricto ) is restricted to the calcareous-shelled inarticulate articulate lineages. Ancestors of the calcareous-shelled brachiopods probably differentiated from the protolophophorates before the radiation of the other lophophorate stocks took place. The articulation of the valves appeared independently in several lineages during the early stages of brachiopod evolution.     

Anthropometric analysis of homosexuals and heterosexuals: implications for early hormone exposure

Early exposure to sex steroids is thought to be important in mediating the differentiation of male-typical sexual orientation. Bone morphology is a marker of childhood sex steroid exposure, because estrogens and androgens control sexual dimorphism in skeletal size. Anthropometric analysis of heterosexuals and homosexuals indicates that those bones, which become sexually dimorphic in childhood, but not those which become sexually dimorphic after puberty, are different in length in homosexuals and heterosexuals. Persons with a sexual preference for males have less long bone growth in the arms, legs and hands, than those with sexual preference for females. The data support the hypothesis that male homosexuals have had less steroid exposure during development than male heterosexuals and that female homosexuals have had greater steroid exposure during development than their heterosexual counterparts.     

The mitochondrial genome of Aelurostrongylus abstrusus—diagnostic,epidemiological and systematic implications

Aelurostrongylus abstrusus (Railliet, 1898) is a metastrongylid nematode of major clinical relevance in felids, causing aelurostrongylosis. In spite of its clinical importance in cats, the genetics, epidemiology and biology of this parasite are not entirely understood. mt DNA can provide markers for studies of these areas, but genetic data are scant for A. abstrusus and related lungworms. Here, the mt genome was amplified by long-range polymerase chain reaction (long-PCR) from a single male adult of A. abstrusus, sequenced using 454 technology and annotated using an established bioinformatic pipeline. This circular mt genome is 13,913 bp and contains two ribosomal RNA, 12 protein-coding and 22 transfer RNA genes, consistent with most other chromadorean nematodes. This genome should provide a source of markers for future investigations of the epidemiology and ecology of A. abstrusus. Molecular tools, employing such mt markers, are likely to find utility for explorations into the epidemiology, biology and systematics of this parasite, and the diagnosis of feline aelurostrongylosis.     

Reproductive morphology ofMegaleranthis saniculifolia Ohwi (Ranunculaceae) and its systematic implications

To confirm the taxonomic treatment ofMegaleranthis saniculifolia Ohwi, an endemic genus and species in Korea, we compared its reproductive morphological characteristics with those ofTrollius and other genera within the Ranunculaceae. Although its external morphology might suggest thatMegaleranthis differs fromTrollius, Calathodes, and etc., we found no distinctly different features in this genus. Likewise, previous studies of their pollen structures, chromosome data, and petal morphology have indicated no differences betweenMegaleranthis andTrollius. In fact, related genera share similar characteristics, such as a tetrasporangia anther, glandular tapetum, simultaneous cytokinesis, an anatropous and bitegmic ovule, embryo sac formation of thePolygonum type, exarillate and copious albuminous seed, and several apocarps. Although the unique feature of having both tenuinucellate and crassinucellate ovules simultaneously may initially seem particular toMegaleranthis, it is present in other genera of the same family. Therefore, based on this evidence of reproductive morphology and other information, we suggest thatM. saniculifolia is closely related toTrollius, and should be included within that genus, i.e., asT. chosenensis Ohwi. Nevertheless, we have tentatively placedMegaleranthis within its own monotypic and endemic genus until definitive data become available.     

Vergleichende Morphologie des Schmetterlingsrüssels und seiner Sensillen — Ein Beitrag zur phylogenetischen Systematik der Papilionoidea (Insecta, Lepidoptera)

Comparative morphology of the butterfly proboscis and its sensilla — a contribution to the phylogenetic systematics of Papilionoidea (Insecta, Lepidoptera) The morphology of the proboscis was investigated in more than 70 European representatives of Papilionoidea using light microscopy and scanning electron microscopy. The composition of the proboscis wall, its surface structures, as well as the shape and distribution of the different types of sensilla are compared. Special attention is given to the tip region and the diversity of the sensilla styloconica. Plesiomorphic features of the proboscis of Papilionoidea were found to include vertically extended exocuticular ribs composing the galeal wall, cuticular spines restricted to the ventral side of the proximal galea, and two rows of fluted sensilla styloconica restricted to the tip region. Apomorphic features of the proboscis in Papilionidae are three rows of small sensilla styloconica. The presence of cuticular spines all over the galeae was identified as an autapomorphy of Pieridae. Possible apomorphies of Nymphalidae are oblique exocuticular ribs of the galeal wall and the great number and length of the sensilla styloconica (significant at p < 0.01, t-test). A possible synapomorphy of Lycaenidae and Riodinidae are cuticlar spines up to the distal galeae. Distinct transformation series of sensilla styloconica give evidence that divergent evolutionary trends led from fluted shafts to a multitude of other shapes in Papilionidae, Nymphalidae (sensu lato), and Lycaenidae. Long smooth-shafted, club-shaped sensilla styloconica, bearing apical spines, are found in Nymphalinae, Apaturinae and Limenitidinae. Highly derived sensilla styloconica evolved in Heliconiinae and Melitaeini, which are arranged in only one row in both taxa. Their shafts are smooth, flattened and bear an excentral sensory cone. Further apomorphic character states are dented flutes which evolved several times, independently from each other in Satyrinae, Lycaeninae and Riodinidae. The results are discussed in a systematical context and provide the basis for a better understanding of the function of different morphological structures of the proboscis in feeding.     

Setal morphology and cirral setation of thoracican barnacle cirri: adaptations and implications for thoracican evolution

Thoracic cirripedes are sessile crustaceans that use six pairs of thoracic appendages (the cirri) to catch and handle food. We used scanning electron microscopy to examine the cirri, which include one to three pairs of maxillipeds in six species of thoracican barnacles, in search of correlations between cirral setation and feeding mode. The species studied comprise both pedunculate and sessile forms and represent a wide range of marine habitats as well as morphologies, viz., Ibla cumingi , Octolasmis warwickii , Capitulum mitella , Pollicipes polymerus , Tetraclita japonica japonica and Megabalanus volcano . Of the pedunculates, I. cumingi has the least complex setation pattern consisting of only serrulate types. This is consistent with its very simplified feeding mode and an apparent inability to discriminate between food items. Octolasmis warwickii is slightly more modified, while both P. polymerus and C. mitella have a more diversified setation. The balanomorphan species exhibit by far the most complex cirral setation. This is consistent with the several types of suspension feeding seen in these species, their ability to identify and sort captured food items and even to perform microfiltration in the mantle cavity using the setae on their three pairs of maxillipeds. Our results indicate that in thoracican barnacles, adaptations in feeding behaviour are associated with changes in the setation pattern of the cirri. In addition, the setal types and their distribution on the cirri are potential new characters in future morphology-based analyses of the phylogeny of the Cirripedia Thoracica.     

Growth,morphologic, and invasive characteristics of early and late passages of a human endometrial carcinoma cell line (RL95-2)

Summary Two in vitro passages of a human endometrial adenocarcinoma continuous cell line (RL95-2), an early (subcultured <30 times) and a late passage (subcultured >200 times) have provided an interesting model to study the growth, morphologic, and invasive properties of endometrial tumors. The early passage, which has been shown to be estrogen-receptor positive, has characteristics closely resembling a primary tumor, whereas the estrogen receptor negative late passage exhibits several features of the metastatic phenotype. Compared to the early passage cells, the late passage cells were less serum dependent, formed foci, demonstrated a faster rate of growth (due to their shorter doubling times), and attained higher saturation densities. The late passage cells also displayed an altered morphology which was accompanied by alterations in the distribution of F-actin. Even though early and late passages showed similar invasive potential in an in vitro invasion assay, the late passage cells, by virtue of their several transformed characteristics, maintain distinctive properties compared with their early passage counterparts.     

Microsporogenesis of Cycas and its systematic implications

Taxonomists are divided over the infrageneric classification and species delimitation within the genus Cycas.The division is largely determined by whether a broad or narrow species concept is adopted,t...     

Benzoxazinone — kanamycin derivative: a new fluorescent probe for flow cytometry analysis of bacteria (Agrobacterium tumefaciens)

Abstract A new polycation fluorescent dye (BVC-kinamycin-conjugate) has been synthesized and used to detect alive bacteria by flow cytometry. This fluorescent chromophore has the noteworthy property of being excited at the same wavelength as fluoresceinylated conjugates (488 nm) and to show a much longer emission wavelength (616 nm) than fluoresceinylated derivates (520 nm); furthermore its fluorescence intensity is not quenched at low pH in contrast with fluorescein. In such conditions, bacteria can easily be detected with cytofluorimeter equipped with a single excitation wavelength beam. The binding of fluoresceinylated lectins and antibodies onto a strain of Agrobacterium tumefaciens has been studied by this method.     

Biomechanical analysis ofPitus dayi: Early seed plant vegetative morphology and its implications on growth habit

A biomechanical method to distinguish self-supporting and non self-supporting growth habits is applied to exceptionally preserved “twigs” ofPitus dayi Gordon. The analysis investigates whether these isolated stem segments are consistent with a self-supporting tree-like habit as suggested by the stumps, trunks and branches of the genusPitus Witham preserved more commonly in the fossil record. Because of difficulties in accurately identifying certain fossil tissues, three centrisymmetrical models were constructed to test a range of possible tissue combinations over five ontogenetic stages. The results suggest a self-supporting habit with trends in mechanical parameters during ontogeny similar to those of extant, self-supporting plants. Less explicitly constrained to the analysis of habit, the investigation also examines the structural significance of specific tissues during ontogeny as observed from contributions of individual tissues to cross-sectional area, axial second moment of area and flexural stiffness.Pitus dayl produced a physiologically “cheap” primary cauline cortex which was rapidly replaced by the development of a rhytidome. A mechanically significant, cauline hypoderm comprising thickwalled sclerenchymatous tissue is absent. This arrangement differs from other tested Palaeozoic pteridosperms interpreted as semi-self-supporting such asLyginopteris oldhamia andCalamopitys sp. in which the primary cortex is mechanically significant and secondary growth of the wood does not reach mechanically significant thresholds within the primary body.     

Toward next-generation sequencing of mitochondrial genomes — Focus on parasitic worms of animals and biotechnological implications

Helminths (worms) include parasitic nematodes (roundworms) and platyhelminths (flatworms). These worms are abundant, and many of them are of agricultural, aquacultural, veterinary and medical importance and cause substantial socioeconomic losses worldwide. The genetic characterization of parasitic nematodes using advanced molecular tools is central to the diagnosis of infections and the control of parasitism. The accurate analysis of genetic variation also underpins studies of their taxonomy, epidemiology and evolutionary history. Although the nuclear genome contains suitable genetic markers (e.g., in ribosomal DNA) for the identification of many species, the large size and high variability of the mt genome consistently provides a rich source of such markers for informative systematic and epidemiological studies both within and among species. There is significant value in establishing a practical platform for the rapid sequencing, annotation and analysis of mt genomic datasets to underpin such fundamental and applied studies of parasitic worms (= helminths). In the last decade, there have been some important advances in the mt genomics of helminths, but next-generation sequencing (NGS) technologies now provide opportunities for high throughput sequencing, assembly and annotation. In this article, we provide a background on mt genomics, cover technological challenges and recent advances, and provide a perspective on future mt genome research of parasitic helminths and its fundamental scientific and biotechnological implications.