Supravital Methylene Blue Staining of Piloneural Complexes of Common Fur Hair Follicles in the Rat

Light microscopic observations employing supravital methylene blue staining are presented for piloneural complexes of common fur hairs in the mystacial pad of the rat snout. The investigation revealed anatomical details of piloneural complexes belonging to follicles of both vellus and guard hairs. In the methylene blue stained preparations, different types of palisade-like lanceolate nerve fiber endings could be discriminated. The thicker vellus and thinner guard hairs (hair diameter: 15-25 μm) exhibited a different innervation pattern compared to the thicker guard hairs, and two subtypes of piloneural complexes could be distinguished. Both subtypes were characterized by slightly stained lanceolate endings and the absence of a circular nerve fiber plexus. One subtype, however, showed strongly stained spines originating from the lanceolate endings. A few spines of adjacent lanceolate endings appeared in contact with each other. In the second subtype, these spines were replaced by anastomoses suggesting a delicate terminal nerve fiber network. The moderately stained lanceolate endings located primarily at the follicles of thicker guard hairs (hair diameter: 30-40 μm) showed smooth outlines, but were characterized by the occurrence of an intensely stained additional circular nerve fiber plexus. The differences in the morphology of piloneural complexes associated with the follicles of common fur hairs suggest differences regarding their mechanoreceptive tasks.     

Supravital Methylene Blue Staining of Piloneural Complexes of Common Fur Hair Follicles in the Rat

Light microscopic observations employing supravital methylene blue staining are presented for piloneural complexes of common fur hairs in the mystacial pad of the rat snout. The investigation revealed anatomical details of piloneural complexes belonging to follicles of both vellus and guard hairs. In the methylene blue stained preparations, different types of palisade-like lanceolate nerve fiber endings could be discriminated. The thicker vellus and thinner guard hairs (hair diameter: 15-25 μm) exhibited a different innervation pattern compared to the thicker guard hairs, and two subtypes of piloneural complexes could be distinguished. Both subtypes were characterized by slightly stained lanceolate endings and the absence of a circular nerve fiber plexus. One subtype, however, showed strongly stained spines originating from the lanceolate endings. A few spines of adjacent lanceolate endings appeared in contact with each other. In the second subtype, these spines were replaced by anastomoses suggesting a delicate terminal nerve fiber network. The moderately stained lanceolate endings located primarily at the follicles of thicker guard hairs (hair diameter: 30-40 μm) showed smooth outlines, but were characterized by the occurrence of an intensely stained additional circular nerve fiber plexus. The differences in the morphology of piloneural complexes associated with the follicles of common fur hairs suggest differences regarding their mechanoreceptive tasks.     

Sexually dimorphic mechanosensitive swimmeret sensilla affect abdominal posture in the lobster

The sensilla on the male and female second swimmerets are sexually dimorphic. Female swimmerets contain many long "smooth hairs" (long simple setae) on the coxa and rami. The endopodite of the male swimmeret has an accessory lobe covered with short "bristly spines" (serrate setae). In both sexes the swimmeret rami are lined by "feathered hairs" (plumose setae). The influence of mechanosensory stimulation of these sensilla upon abdominal tonic motor activity was analyzed in an in vitro swimmeret-nerve cord preparation. Movement of several clusters of smooth hairs produced an abdominal extension program by exciting the flexor inhibitor f5, inhibiting the flexor excitors, and activating several extensors. Stimulation of the male bristly spines excited the medium-sized flexor excitors f3 and f4. In both sexes the feathered hairs did not generate any response to mechanical stimulation. We infer that in nongravid females the smooth hairs are involved in receiving mechanosensitive cues to support abdominal extension. Bristly spines may contribute to postural adjustments that assist mating. The long latencies of these responses and their propagation to adjacent ganglia suggest that they are mediated by postural interneurons rather than by direct afferent terminations on postural motoneurons.     

褐边绿刺蛾幼虫刺毛结构及蛰伤机制初探

刺蛾科幼虫是我国常见的农林业害虫之一,其体表长有防御性的有毒刺毛,会伤害接触者,使其产生瘙痒、刺痛、丘疹、红肿、皮炎等症状.本研究利用体视显微镜、扫描电镜对褐边绿刺蛾Parasa consocia末龄幼虫的刺毛形态结构进行了观察,将不同刺毛提取物进行小鼠足底皮下注射,测试刺激活性,并使用SDS-PAGE电泳对提取物成分...     

Sensilla and Cuticular Appendages on the Female Abdomen of Lasioptera rubi (Schrank) (Diptera,Cecidomyiidae)

Studies by SEM and TEM revealed 6 types of integumental appendages on female uromeres VIII-X in Lasioptera rubi: microtrichia, not innervated; spines, probably without sensory function; nonporous sensory hairs, each containing one dendrite ending with a tubular body indicating a tactile function; uniporous sensory hairs, each innervated partly by 3 dendrites indicating a chemosensory function, partly by an additional dendrite with a tubular body indicating a tactile function; scoop-like sensilla, each containing partly a branched structure of dendrites in the distal half of the sensillum indicating an olfactory function, partly an unbranched dendrite ending at a pore near the base of the sensillum, most probably registrating chemical stimuli by contact or gustation; finally, nonporous bristles, all or some of them innervated, in a manner indicating a tactile function. In addition, two scolopophorous proprioceptors were found inside uromere X. The nonporous sensory hairs, the uniporous sensory hairs and the scolopophores may be used by the midge to determine the mechanical and chemical properties of potential oviposition sites. The spines and nonporous bristles may function as conidia carriers.     

Subdivision of mouse vibrissae on an embryological basis, with descriptions of variations in the number and arrangement of sinus hairs and cortical barrels in BALB/c (nu/+; nude, nu/nu) and hairless (hr/hr) strains.

Development of vibrissae was studied in dd/y mouse embryos by scanning electron microscopy. Arrangement of vibrissae and cortical barrels were also studied by light microscopy in adult dd/y, BALB/c(nu/+), nude (BALB/c, nu/nu) and hairless (hr/hr) mice to find genetic or epigenetic variations. Rudiments of vibrissae first appear on Day 12 of pregnancy as longitudinal ridges on the developing muzzle, and each hair rudiment is represented by a dome on the ridges. The dorsal two rows (A and B; Woolsey and Van der Loos, '70) of mystacial vibrissae are on the lateral nasal prominence, while the ventral three (C, D and E) are on the maxillary prominence. Smaller hairs of mystacial vibrissae appear at the labial part of the maxillary prominenceon Day 13. The rudiments of rhinal hairs also appear at this stage on the part of the muzzle derived from the medial nasal prominence. Thus the so-called mystacial vibrissae should be subdivided into three (or 4, including the rhinal) groups on an embryological basis. They are the lateral nasal, the maxillary and the labial. A supernumerary sinus hair and a corresponding barrel was observed between D and C rows uni-or bilaterally in one third of individuals of BALB/c, nude and hairless mice. It is suggested that supernumerary hairs tend to occur between the groups of hairs as defined above. In nude and hairless mice small barrels representing labial hairs are diminished in number. The number of hair follicles, however, is normal.     

Differences in pectoral fin spine morphology between vocal and silent clades of catfishes (Order Siluriformes): Ecomorphological implications

Stridulatory sound-producing behavior is widespread across catfish families, but some are silent. To understand why, we compared spine morphology and ecotype of silent and vocal clades. We determined vocal ability of laboratory specimens during disturbance behavior. Vocal families had bony (not flexible or segmented) spines, well-developed anterior and/or posterior serrations, and statistically significantly longer spines. We compared morphology of the proximal end of the pectoral spine between vocal and silent species. For vocal taxa, microscopic rounded or bladed ridges or knobs were present on the dorsal process. Most silent species had reduced processes with exclusively smooth, convoluted, or honeycombed surfaces very similar to spine-locking surfaces, or they had novel surfaces (beaded, vacuolated, cobwebbed). Most callichthyids had ridges but many were silent during disturbance. All doradid, most auchenipterid and most mochokid species were vocal and had ridges or knobs. Within the Auchenipteridae, vocal species had spines with greater weight and serration development but not length. Silent auchenipterids had thin, brittle, distally segmented spines with few microscopic serrations on only one margin and a highly reduced dorsal process lacking any known vocal morphology. Silent auchenipterids are derived and pelagic, while all vocal genera are basal and benthopelagic. This is the first phylogenetic evidence for stridulation mechanism loss within catfishes. Phylogenetic mapping of vocal ability, spine condition, and ecotype revealed the repeated presence of silence and vocal taxa, short and long spines, and ecotype shifts within clades. The appearance and loss of vocal behavior and supporting morphologies may have facilitated diversification among catfishes [Current Zoology 56 (1): 73-89 2010].     

Fine structure of tarsal sensilla of Aedes aegypti (L.) (Diptera: Culicidae)

The tarsi of all three pairs of legs of both sexes of Aedes aegypti (L.) bear spine sensilla, five types of hair sensilla, which are designated A, B, C1, C2 and C3, and campaniform sensilla. Type A and B hairs, spines, and cam-paniform sensilla are innervated by one neuron with a tubular body, a characteristic of cuticular mechanoreceptors. In particular the hairs and spines are tactile receptors and the campaniform sensilla are proprioceptors. The C1, C2, and C3 hair sensilla have the morphological features of contact chemoreceptors. Type C1 and C3 hairs are innervated by five and four neurons, respectively, which extend to the tip of the hair. Type C2 is innervated by five neurons, one of which terminates at the base of the hair in a tubular body while the remaining four extend to the tip of the hair. The role of the type C hairs in oviposition behavior, nectar feeding, and recognition of conspecific females is discussed. Presumed efferent neurosecretory fibers occur near the spine and hair sensilla.     

A note on the hairy achenes of four African species of Scleria Bergius (Cyperaceae)

Surface features of hirsute achenes of four African species of Scleria have been examined by SEM. All bear unicellular, terete hairs with swollen bases. As the achenes mature and dry, the hairs collapse, except for their partly silicified bases, which appear as pit-like depressions from which the now-flattened hairs emerge. If the achene surface is not smooth the hairs are localized on the interlacunar ridges. In addition to the hairs, three of the four species examined show minute papillate protuberances from the silicified outer tangential walls of the epidermal cells. These papillae form a further ornamentation to the achenes visible only at high magnification. The fourth species entirely lacks these papillae.     

TRICHOMES OF CANNABIS SATIVA L. (CANNABACEAE)

The diversity of non-glandular and glandular hairs of Cannabis sativa L. (marihuana) are described by scanning electron microscopy. The non-glandular hairs are of two major types, as distinguished by size differences and locations, and all of them are highly silicified. The presence of silica as well as cystoliths of calcium carbonate help in the identification of marihuana even in its ash residues. X-ray microanalyses of Cannabis hairs are compared with those of Humulus lupulus and Lantana camera, whose hairs have been considered to resemble those of marihuana. Glandular hairs are found to be of two major categories. One group consists of glands whose heads are generally made up of eight cells and the other group whose heads are generally made up of two cells but never more than four cells. All glands of both categories are stalked. Some glands of the first category are massively stalked and these are restricted solely to anthers and bracts of staminate and pistillate plants. The massive stalk is considered to be made up of epidermal and hypodermal cells that have grown in response to some stimulation during anthesis. Fine details of the shoot system of Cannabis, such as cuticular ridges on epidermal cells, warty protuberances on non-glandular hairs, and surface views of glands in developing stages are also reported. Glandular hairs on the bracts of Humulus lupulus resemble those of Cannabis.     

The fine structure of the fertilization membrane of the feather star Comanthus japonica (Echinodermata: Crinoidea)

Scanning electron microscopy reveals that the outer surface of the Comanthus fertilization membrane bears a network of 14 µ high ridges outlining rows of polygonal facets; however, no spines are present. The so-called spines reported previously by light microscopists were simply optical cross sections of the ridges. Transmission electron microscopy reveals that the fertilization membrane has (1) an outer component consisting mainly of dense, granular material, and (2) an inner component consisting mainly of an interlacing network of 50 Å fibers of moderate electron density. Associated with the fibers of the inner component are dense granular rods and dense lentoid discs.     

Schistosoma japonicum (Chinese): Changes of the tegument surface in cercariae, schistosomula and juvenile parasites during development

, , , and 1988. Schistosoma japonicum (Chinese): changes of the tegument surface in cercariae, schistosomula and juvenile parasites during development. International Journal for Parasitology18: 1093–1104. The surface of cercariae of S. japonicum (Chinese) and changes following their transformation into schistosomula were observed at 0.5,1, 3,6,12,24 and 48 hand 5,7,10 and 15 days by scanning electron microscopy. The cercarial surface shows two distinct regions: on the head and the body it is mildly undulating and covered throughout with numerous spines that are partially embedded in a thick layer of glycocalyx; on the tail it is highly folded into tall and thin circumferential ridges, spines are confined to the dorsal and ventral aspects and are prominent due to a thinner glycocalyx. Between 0.5 and 12 h following skin penetration, the surface of schistosomula is gradually cleared of glycocalyx, while small blebs and slender microvilli project out from the glycocalyx-free area and from spines. Subsequently, these structures are detached from the surface and thus responsible for the shedding of the original cercarial membrane and glycocalyx. Between 24 and 48 h, schistosomula show little change in the body size in comparison to earlier stages, and most of the surface is still covered with spines but devoid of blebs and microvilli. From day 2 onwards schistosomula are lengthened but with little net growth. Spines decrease in the middle region of the body; and the surface is invaginated by small pits and folded into thin ridges, which result in rapid increase of the surface area. Between days 5 and 7 schistosomula elongate further, and the disappearance of the spines in the middle region becomes even more pronounced, while those remaining are confined only to the anterior and posterior extremities. Ridges and pits are more developed, and the former begin to show regular foldings throughout all parts of the body. Between days 7 and 10 schistosomula grow rapidly and the body is quadrupled in size. Between days 10 and 15 sexes can be differentiated. The male has a flat ovoid shape body, whose ridges and pitting on the surface are highly developed almost to the same extent as in adult parasites, while spines remain mostly on the posterior end. Sensory papillae greatly increase in number, especially on the ventral and lateral aspects and around the suckers. The surface of the female is relatively smooth; ridges are developed only on the posterior part, while the remaining surface is flat and extensively pitted. Spines are present throughout but less concentrated in the middle region.     

Adhesion by Paired Pectoral and Pelvic Fins in a Mountain-Stream Catfish, Pseudocheneis sulcatus (Sisoridae)

We describe the adhesive nature of the pectoral and pelvic fins in the catfish Pseudocheneis sulcatus, as examined by scanning electron microscopy. The outer rays of these fins are modified into structures that bear prominent transverse ridges and grooves. The outer epidermal cells of the ridges are thrown into elongated spines. Mucous pores (openings of mucous glands) are frequently present (100m apart) in the epidermis of the ridges and show entangled mucus droplets. In the pectoral fins, they are present towards the contour areas of the outer rays, but they are absent in the pelvic fins. In the latter, mucous pores are present near the base of the ridges (distal to the inner rays). Spines as well as mucous pores are absent in the cells that line the groove between two adjacent ridges. We suggest that in this species adhesion is effected by suction pressure generated by the musculature attached to the grooves and ridges, and that mucus and the spines aid in this process.     

Pseudopollen in Eria Lindl. section Mycaranthes Rchb.f. (Orchidaceae)

BACKGROUND AND AIMS: Pseudopollen is a whitish, mealy material produced upon the labella of a number of orchid species as labellar hairs either become detached or fragment. Since individual hair cells are rich in protein and starch, it has long been speculated that pseudopollen functions as a reward for visiting insects. Although some 90 years have passed since Beck first described pseudopollen for a small number of Eria spp. currently assigned to section Mycaranthes Rchb.f., we still know little about the character of pseudopollen in this taxon. The use of SEM and histochemistry would re-address this deficit in our knowledge whereas comparison of pseudopollen in Eria (S.E. Asia), Maxillaria (tropical and sub-tropical America), Polystachya (largely tropical Africa and Madagascar) and Dendrobium unicum (Thailand and Laos) would perhaps help us to understand better how this feature may have arisen and evolved on a number of different continents. METHODS: Pseudopollen morphology is described using light microscopy and scanning electron microscopy. Hairs were tested for starch, lipid and protein using IKI, Sudan III and the xanthoproteic test, respectively. KEY RESULTS AND CONCLUSIONS: The labellar hairs of all eight representatives of section Mycaranthes examined are identical. They are unicellular, clavate with a narrow 'stalk' and contain both protein and starch but no detectable lipid droplets. The protein is distributed throughout the cytoplasm and the starch is confined to amyloplasts. The hairs become detached from the labellar surface and bear raised cuticular ridges and flaky deposits that are presumed to be wax. In that they are unicellular and appear to bear wax distally, the labellar hairs are significantly different from those observed for other orchid species. Comparative morphology indicates that they evolved independently in response to pollinator pressures similar to those experienced by other unrelated pseudopollen-forming orchids on other continents.     

POLLEN MORPHOLOGY AND DETAILED STRUCTURE OF FAMILY COMPOSITAE,TRIBE CICHORIEAE. I. SUBTRIBE STEPHANOMERIINAE

A survey of pollen morphology in 20 species representing the 11 genera of the North American subtribe Stephanomeriinae by light, scanning electron, and transmission electron microscopy revealed 10 of the 11 genera to have echinate, tricolporate pollen grains, Lygodesmia being the only genus with echinolophate pollen. Sectioned exines of most of the species examined are similar, being composed of ektexine and endexine. The ektexine surface is composed of spines which typically have globose perforate bases. A cavus occurs as a separation between the basis (foot layer) and the columellae in all of the genera examined except Chaetadelpha. Pollen of the two species of Glyptopleura were found to be strikingly different in exomorphology. Pollen of the putatively self-fertile G. marginata has much shorter spines than the closely related G. setulosa. Atrichoseris, Anisocoma, Calycoseris, Glyptopleura, Pinaropappus, Prenanthella, and most species of Malacothrix have pollen which lack paraporal ridges. The remaining genera, Chaetadelpha, Lygodesmia, Rafinesquia, and Stephanomeria have well-developed ridges of fused spine bases around the apertures. Pollen characters, particularly those of the aperture region, have been found to be systematically useful in the subtribe, therefore acetolyzed material gives more useful information than untreated pollen.     

Dew and the growth of the uredospore germ tube of Puccinia graminis on the wheat leaf

Water droplets simulating dew, formed on wheat leaves held in a condensation chamber, appeared first on the leaf hairs and coalesced into lines along the ridges of the leaf surface in close proximity to the stomata. On leaves thus wetted, germ tubes from uredospores of Puccinia graminis showed a thigmotropic response, growing at right angles to the ridges: when they reached the stomatal region the penetration of the stoma may be further assisted by chemotropic or hydrotropic attraction. Studies on plastic surfaces showed that germ-tube growth took place only between and not within water droplets.     

MORPHOLOGY AND PAEDOGAMOUS SEXUAL REPRODUCTION IN CHLOROGONIUM CAPILLATUM SP. NOV. (VOLVOCALES, CHLOROPHYTA)1

Morphology and sexual reproduction in Chlorogonium capillatum Nozaki, Watanabe & Aizawa sp. nov. (Volvocales, Chlorophyta) originating from Miyatoko Mire, Japan, were studied under controlled laboratory conditions. Vegetative cells of this new species were fusiform with blunt anterior and posterior ends, and they had a massive parietal chloroplast and numerous contractile vacuoles distributed throughout the protoplast. Several to many pyrenoids were randomly distributed in the chloroplast, but they disappeared under the light microscope when grown photoheterotrophically. During asexual reproduction, the first division took place transversely without a preceding rotation of the parental protoplast. In sexual reproduction, the parental protoplast divided successively to form 32 or 64 small, biflagellate isogametes. After gametogenesis, the gametes did not escape from the parental cell (gametangial) wall, within which pairs of the adjoining gametes fused to form quadriflagellate zygotes. Such zygotes were then released from the parental cell wall and developed into hypnozygotes, which at maturity developed numerous thin spines or hairs on the zygote wall. On zygote germination, four biflagellate germ cells were released from the zygote wall separately. This type of gametic union, "paedogamy," has not previously been described in the green algae except for Chlorococcum echinozygotum Starr . Chlorogonium capillatum can be clearly distinguished from other described species of Chlorogonium by its numerous contractile vacuoles and blunt anterior and posterior ends in vegetative cells as well as by its unique sexual reproduction, in which paedogamous conjugation occurs, and numerous thin spines or hairs that develop on the hypnozygote walls .     

Cuticular structures of the stomodeum in Paulinia acuminata (De Geer) and Marellia remipes Uvarov (Orthoptera : Pauliniidae)

The cuticular lining of the stomodeum in orthopteroid insects usually bears cuticular structures, consisting of ridges, teeth, and spines, which are sometimes fairly complex. In some of these insects, particularly cockroaches and Orthoptera s. str., some of these structures have systematic value, mainly at the higher systematic levels. The cuticular lining of the stomodeum in Paulinia acuminata (De Geer) and Marellia remipes (Uvarov) (Orthoptera : Pauliniidae) (the only 2 genera included within the family) have been studied. Wide differences in the pattern of the stomodeal armature, and also in the shape, size and distribution of the spines in its different parts, are recorded. The proportions and limits of the crop and proventriculus, and the form and spatial distribution of spines and other characters, relative to the ridges, appear to be of taxonomic significance. They indicate that the 2 genera may not be closely related, as has been suggested, based on other evidence. While Marelliaappears to be related to the Acrididae, Pauliniaseems to be isolated from other acridoids, except for certain features in common with Proscopiidae and Eumastacidae.     

Micromorphological studies on Verbascum (Scrophulariaceae) in Iran with emphasis on seed surface, capsule ornamentation and trichomes

Seed micromorphology in 22 species, capsule surface in 28 species and capsule hairs in 20 species of genus Verbascum distributed in Iran were studied using scanning electron microscopy. The seed surface is ridged or alveolate among the studied species. Depth and density of the alveoli or ridges, size of polygonal cells along with arrangement of vesicles on the walls separating the polygonal cells on the seed surface seem to be species-specific in Verbascum. The capsule surface is striate, distinctly or indistinctly, or even smooth in Verbascum. The capsules are rarely glabrous (in V. orientale and V. intricatum), densely covered by branched hairs, or loosely by glandular hairs, depending on species. From the results of this study it is obvious that no correlation exists between the studied species concerning the micromorphological aspects studied here.