A method for studying histochemical reactions in intact human dentine with a polarizing incident light microscope

Localization and distribution of non-specific esterases has been studied in intact human dentine, by reflected light microscopy. The method of specimen preparation described here permits the visualization of optical sections in depth within the specimen at high optical resolution. Non-specific esterase was found deposited as discrete bands across the tubules. or as droplets, or as a diffuse microsomal variety in the dentinal tubules and in the interglobular spaces. It was possible to distinguish the droplet variety from the microsomal variety, of esterase within the same tubule, by means of a novel optical method using antiflex and differential interference contrast systems of reflected light microscopy. It was found that the coefficient of reflection of dentine diminished gradually from the enamel to the pre-dentine and was inversely related to the scattering of light in dentine. This scattering plays an important role in the formation of the image with reflected light microscopy. The reflected light microscope offers an economically attractive alternative or a supplementary mode of microscopy to the confocal scanning microscopes for studying intact dentine at varying depths.     

Mouthparts in Leptotrombidium larvae (Acariformes: Trombiculidae)

Mouthparts of Leptotrombidium larvae (Acariformes: Trombiculidae), potential vectors of tsutsugamushi disease agents, were studied in detail using light microscopy, scanning electron microscopy, and transmission electron microscopy. The mouthparts incorporated within the pseudotagma gnathosoma are composed of the infracapitulum ventrally and the chelicerae dorsally. The ventral wall of the infracapitulum is formed by a wide mentum posteriorly and a narrowed malapophysis anteriorly. The malapophysis firmly envelops the distal cheliceral portions by its lateral walls. The lateral lips of the malapophysis are flexible structures hiding the cheliceral blades in inactive condition and turning back forming a type of temporary sucker closely applied to the host skin during feeding. The roof of the infracapitulum is formed by a weakly sclerotized labrum anteriorly and a cervix with the capitular apodemes extending posteriorly. The labral muscles are lacking. The capitular apodemes serve as origin for pharyngeal dilators running to the dorsal wall of the pharynx fused with the bottom of the infracapitulum. The basal cheliceral segments are separated from each other besides the very posterior portions where they are movably joined by the inner walls. The sigmoid pieces serve for insertion of the cheliceral elevators originating at the posterior portions of the basal segments. The movable digits reveal the solid basal sclerite and the cheliceral blade curved upward with a tricuspid cap on its tip. Dendrites of nerve cells run along the digits to their tips. The ganglia are placed within the basal segments just behind the movable digits. The chelicerae also reveal well developed flexible fixed digits overhanging the basal portions of the blades. The gnathosoma possesses several sets of extrinsic muscles originating at the scutum and at the soft cuticle behind it. Laterally, the gnathosoma bears five‐segmented palps with a trifurcate palpal claw. J. Morphol. 277:424–444, 2016. © 2016 Wiley Periodicals, Inc.     

Skeletal and muscular pelvic morphology of hillstream loaches (Cypriniformes: Balitoridae)

The rheophilic hillstream loaches (Balitoridae) of South and Southeast Asia possess a range of pelvic girdle morphologies, which may be attributed to adaptations for locomotion against rapidly flowing water. Specifically, the connectivity of the pelvic plate (basipterygium) to the vertebral column via a sacral rib, and the relative size and shape of the sacral rib, fall within a spectrum of three discrete morphotypes: long, narrow rib that meets the basipterygium; thicker, slightly curved rib meeting the basipterygium; and robust crested rib interlocking with the basipterygium. Species in this third category with more robust sacral rib connections between the basipterygium and vertebral column are capable of walking out of water with a tetrapod-like lateral-sequence, diagonal-couplet gait. This behavior has not been observed in species lacking direct skeletal connection between the vertebrae and the pelvis. The phylogenetic positions of the morphotypes were visualized by matching the morphological features onto a novel hypothesis of relationships for the family Balitoridae. The morphotypes determined through skeletal morphology were correlated with patterns observed in the pelvic muscle morphology of these fishes. Transitions towards increasingly robust pelvic girdle attachment were coincident with a more anterior origin on the basipterygium and more lateral insertion of the muscles on the fin rays, along with a reduction of the superficial abductors and adductors with more posterior insertions. These modifications are expected to provide a mechanical advantage for generating force against the ground. Inclusion of the enigmatic cave-adapted balitorid Cryptotora thamicola into the most data-rich balitorid phylogeny reveals its closest relatives, providing insight into the origin of the skeletal connection between the axial skeleton and basipterygium.     

The phylogeny of Patrinieae sensu Graebner (Valerianaceae) revisited: additional evidence from ndhF sequence data

 DNA sequences of both 5′ and 3′ regions of the plastid ndhF gene were generated in order to study the position of Patrinia and Nardostachys, to check the potential paraphyletic nature of Patrinieae, and to evaluate the possible link between the tribe and Linnaeaceae. Parsimony analysis showed very strong support for Patrinia as sister to all members of Valerianaceae (including Nardostachys) and indicated the paraphyletic nature of the tribe Patrinieae. Additionally, trees were constructed from available rbcL data separately and supplemented with ndhF sequences. Topologies of these combined cladograms are in agreement with the ndhF phylogeny, suggesting that the traditionally circumscribed Patrinieae can no longer be recognized but must be considered as part of a basal grade in Valerianaceae. Parsimony analysis based on a morphological data set supported a monophyletic Patrinieae; combination with the molecular data showed a paraphyletic Patrinieae. Furthermore, the possible link between Patrinieae and Linnaeaceae is evaluated. Received July 12, 2001 Accepted February 25, 2002     

Medullary structure differences in Gelidium and Pterocladia (Gelidiales, Rhodophyceae): Taxonomic meaning

Study of the apical portions of vegetative thalli of 21 species of the genera Gelidium and Pterocladia (Gelidiales-Rhodophyta) revealed the existence of six patterns of medullary structure. Each pattern is characterized by the organization of the medullary tissue and the changes in cellular dimensions from apex to subapex. These characters can be used to separate groups of species within each genus.     

Cuticular sensilla on newly hatched larvae of Gasterophilus intestinalis and Oestrus ovis

Abstract. Cuticular sensilla on newly hatched larvae of Gasterophilus intestinalis De Geer (Diptera: Gasterophilidae) and Oestrus ovis (L.) were studied by scanning electron microscopy. Two types of trichoid sensilla, two types of coeloconic sensilla and a pit sensillum were present on the thoracic and abdominal segments of G. intestinalis larvae. Sensilla on larvae of O. ovis were similar although only one type of trichoid sensillum was present. Total number of sensilla were higher for O. ovis than for G. intestinalis (248 v . 214). Variation in numbers of sensilla is consistent with the concept that increasing numbers of sensilla are associated with increasingly complex searching behaviour required to locate suitable habitats for development.     

Evolution in Aeschynanthus (Gesneriaceae) inferred from ITS sequences

 Aeschynanthus Jack, an epiphytic genus with c.160 species, is widespread in SE Asia. We selected 50 species for ITS nrDNA sequencing, to include all biogeographic areas and all infrageneric groupings, which are currently based on seed morphology. Some species were sequenced directly from PCR product; others cloned because of ITS length polymorphisms. The clone sequences were analysed individually and combined in an elision matrix. Results extend earlier findings that Aeschynanthus is divided into two clades, one occurring primarily in mainland SE Asia and the other in Malesia. This pattern is interpreted as indicating an ancient vicariance event followed by dispersal and plate fusion. Clade I has straight or clockwise spiral orientation of the testa cells and clade II anticlockwise spiral orientation. In clade I some species of section Microtrichium form a basal group with other sections being polyphyletic or paraphyletic. In clade II the monophyletic section Aeschynanthus is nested within the paraphyletic basal Microtrichium. Received February 8, 2001 Accepted June 8, 2001     

Assessment of the cryoprotectant concentration inside a bulky organ for cryopreservation using X-ray computed tomography

Cryoprotection of bulky organs is crucial for their storage and for subsequent transplantation. In this work we demonstrate the capability of the X-ray computed tomography (CT) as a non-invasive method to measure the cryoprotectant (cpa) concentration inside a tissue or an organ, specifically for the case of dymethil sulfoxide (Me₂SO). It is remarkable that the use of Me₂SO has been leader in techniques of cells and tissues cryopreservation. Although CT technologies are mainly based in density differences, and many cpas are alcohols with densities similar to water, the use of very low energies as acceleration voltage (∼70 kV) and the sulfur atom in the molecule of Me₂SO makes possible the visualization of this cpa inside tissues. As result we obtain a CT signal proportional to the Me₂SO concentration with a spatial resolution up to 50 μm in the case of our device.     

Intraspecific variation of Eolophiodon laboriense,a basal Lophiodontidae (Mammalia,Perissodactyla) from the early Eocene of Southern France

The Lophiodontidae is an emblematic and well-documented Eocene family of perissodactyls from Western Europe. However, after more than a century and a half of studies, lophiodontids still display a complex systematics associated with blurry intraspecific variation and a poorly known early radiation. The locality of La Borie, located near the city of Toulouse, France, has yielded numerous remains of Eolophiodon laboriense. This abundance of remains allows for the first time the study of the intraspecific variation of a basal lophiodontid. The variation has been investigated for dental and cranio-mandibular characters, notably dental polymorphism, size variation and sexual dimorphism. The intraspecific variation of E. laboriense is high with more than 20 polymorphic characters of the dentition, including many additional crests and conules. This dental polymorphism is similar to the one observed in the Bartonian lophiodontid Lophiodon lautricense. E. laboriense also displays an important degree of sexual dimorphism, with male specimens having broader and longer mandibles with larger canines than females. Despite this high intraspecific variation, the low size variation of teeth and the consistency of diagnostic characters strengthen the validity of the genus Eolophiodon and does not impact the previous lophiodontid phylogeny.