Candidate ionotropic taste receptors in the Drosophila larva

We examine in Drosophila a group of ∼35 ionotropic receptors (IRs), the IR20a clade, about which remarkably little is known. Of 28 genes analyzed, GAL4 drivers representing 11 showed expression in the larva. Eight drivers labeled neurons of the pharynx, a taste organ, and three labeled neurons of the body wall that may be chemosensory. Expression was not observed in neurons of one taste organ, the terminal organ, although these neurons express many drivers of the Gr (Gustatory receptor) family. For most drivers of the IR20a clade, we observed expression in a single pair of cells in the animal, with limited coexpression, and only a fraction of pharyngeal neurons are labeled. The organization of IR20a clade expression thus appears different from the organization of the Gr family or the Odor receptor (Or) family in the larva. A remarkable feature of the larval pharynx is that some of its organs are incorporated into the adult pharynx, and several drivers of this clade are expressed in the pharynx of both larvae and adults. Different IR drivers show different developmental dynamics across the larval stages, either increasing or decreasing. Among neurons expressing drivers in the pharynx, two projection patterns can be distinguished in the CNS. Neurons exhibiting these two kinds of projection patterns may activate different circuits, possibly signaling the presence of cues with different valence. Taken together, the simplest interpretation of our results is that the IR20a clade encodes a class of larval taste receptors.

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Memoirs: The Development of the Serpiilid Pomatoeeros Triqueter L

Journal of Cell Science ◽

10.1242/jcs.s2-82.327.467 ◽

1941 ◽

Vol s2-82 (327) ◽

pp. 467-540 ◽

Cited By ~ 1

Author(s):

F. SEGROVE

Keyword(s):

Body Wall ◽

Feeding Activity ◽

Dorsal Surface ◽

The Body ◽

Single Pair ◽

Feeding Apparatus ◽

Food Material ◽

Locomotor Apparatus ◽

Adult Feeding ◽

Branchial Crown

1. The larvae of Pomatoceros triqueter L. were obtained by artificial fertilization and reared through metamorphosis and for several months afterwards. Larval development took three weeks in summer, and about the same time in winter when the temperature was maintained at 65° F. 2. The eggs are small and give rise to typical trochosphere larvae with well-developed prototroch, metatroch, neurotroch, and feeding cilia, a spacious blastocoelic body-cavity and paired protonephridia. A head-vesicle and a conspicuous anal vesicle are also present. The right eye develops before the left. The larva is very active and grows rapidly at the expense of collected food material. 3. Three setigerous segments arise simultaneously; a fourth is added prior to metamorphosis. The lateral collar-folds develop in two capacious pockets which arise by invagination of the body-wall behind the metatroch, the ventral collar-fold by outgrowth of the ventral body-wall. The rudiments of the thoracic membrane appear above the lateral collar-folds. 4. Metamorphosis commences with the shrinkage of the locomotor apparatus, which leads to the exposure of the lateral collar-folds. The larva settles to the bottom and creeps about on its ventral surface by means of the neurotroch. The branchial crown arises as tripartite outgrowths on the sides of the head. The remaining tissues of the head, apart from the cerebral ganglion and eyes, are gradually resorbed. No tissue is thrown off. 5. The neurotroch gradually disappears and is replaced by cilia on the dorsal surface. The worm begins to secrete a calcareous tube. The resorption of the head is completed and the mouth assumes a terminal position surrounded by the branchial crown. 6. A fourth pair of filaments is added to the branchial crown. The dorsal pair of filaments develops into 'palps'. The third filament on the left side is modified as the operculum; the remaining filaments develop pinnules. 7. Further segments are added to the trunk. Those first added are of the thoracic type from the beginning. The eighth and succeeding setigers are of the abdominal type. The thoracic membrane gradually extends backwards to the posterior end of the thorax. 8. The thoracic nephridia arise as a single pair of cells which give rise to the dorsal unpaired duct by outgrowth. 9. The influence of the egg on the course of development is discussed. It is suggested: (a) that the small size of the egg is responsible for the active habits and protracted pelagic life of the larva; (b) that the mode of development of the collar is significant in that interference with the locomotor and feeding apparatus is thereby avoided; (c) that the general shrinkage which occurs at metamorphosis is related to a suspension of feeding activity in the period between the degeneration of the larval and the establishment of the adult feeding apparatus. 10. The development of Pomatoceros is compared with that of the Serpulid Psygmobranchus and the Sabeilid Branchiomma.

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The spatial relationship between the musculature and the 5-HT and FMRFamide immunoreactivities in cercaria, metacercaria and adult Opisthorchis felineus (Digenea)

Acta Parasitologica ◽

10.2478/s11686-010-0024-4 ◽

2010 ◽

Vol 55 (2) ◽

Cited By ~ 10

Author(s):

Oleg Tolstenkov ◽

Nadezhda Terenina ◽

Elena Serbina ◽

Margaretha Gustafsson

Keyword(s):

Nervous System ◽

Body Wall ◽

General Pattern ◽

Spatial Relationship ◽

The Body ◽

Muscle Fibres ◽

Neuromuscular System ◽

Opisthorchis Felineus ◽

Larval Stages ◽

The Individual

AbstractThe organisation of the neuromuscular system in cercariae, metacercariae and adult Opisthorchis felineus was studied. The patterns of nerves immunoreactive (IR) to antibodies towards serotonin (5-HT) and FMRFamide are described in relation to the musculature, stained with TRITC-conjugated phalloidin. The general organisation of the musculature in the body wall, suckers, pharynx, intestine and sphincter of the excretory pore remains the same from the larval stages to the adult worms. However, the diameter of the individual muscle fibres increases distinctly in the adult worms. The general pattern of 5-HT IR fibres in cercariae, metacercariae and adult O. felineus remains the same. Despite the large increase in body size, the number of 5-HT IR neurones remains almost the same in the cercariae and metacercariae and only a modest increase in number of neurones was observed in the adult worms. Thus the proportion of 5-HT IR neurones/body mass is greatest in the actively moving cercariae. Anti-FMRFamide stains the nervous system strongly.

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Genetic evidence for the subdivision of the arthropod limb into coxopodite and telopodite

Development ◽

10.1242/dev.122.12.3921 ◽

1996 ◽

Vol 122 (12) ◽

pp. 3921-3928 ◽

Cited By ~ 12

Author(s):

S. Gonzalez-Crespo ◽

G. Morata

Keyword(s):

Signaling Pathway ◽

Ground State ◽

Body Wall ◽

Homeobox Gene ◽

The Body ◽

Genetic Evidence ◽

Genetic Mechanism ◽

Present Evidence ◽

Larval Stages ◽

Hh Signaling

Arthropod appendages are thought to have evolved as outgrowths from the body wall of a limbless ancestor. Snodgrass, in his Principles of Insect Morphology (1935), proposed that, during evolution, expansion of the body wall would originate the base of the appendages, or coxopodite, upon which the most distal elements that represent the true outer limb, or telopodite, would develop. The homeobox gene Distal-less (Dll), which is required in the Drosophila appendages for development of distal regions, has been proposed to promote formation of telopodite structures above the evolutionary ground-state of non-limb or body wall. Here, we present evidence that another homeobox gene, extradenticle (exd), which is required for appropriate development of the trunk and the proximal parts of the appendages, represents a coxopodite gene. We show that exd function is eliminated from the distal precursors in the developing limb and remains restricted to proximal precursors throughout development. This elimination is important because, when ectopically expressed, exd prevents distal development and gives rise to truncated appendages lacking distal elements. Moreover, the maintenance of exd expression during larval stages, contrary to Dll, does not require the hedgehog (hh) signaling pathway, suggesting that the proximal regions of the appendages develop independently of hh function. Finally, we show that in the crustacean Artemia, exd and Dll are expressed in comparable patterns as in Drosophila, suggesting a conserved genetic mechanism subdividing the arthropod limb.

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Studies on the Anatomy of Cimex lectularius L. II.

Parasitology ◽

10.1017/s0031182000020102 ◽

1924 ◽

Vol 16 (3) ◽

pp. 269-278 ◽

Cited By ~ 8

Author(s):

I. M. Puri

Keyword(s):

Larval Stage ◽

Body Wall ◽

The Body ◽

Cimex Lectularius ◽

Epithelial Lining ◽

Compound Structure ◽

Larval Stages ◽

First Time

The stink organs are different in structure and position in the adult and the larval stages.The stink organs of the adult are composed of (a) a pair of glands, (b) a central reservoir with two backwardly-directed lateral reservoirs, (c) a median kidney-shaped organ in the central reservoir, and (d) a pair of lateral external openings.Each gland is a multicellular compound structure, opening into the central reservoir. It is described for the first time in this paper.The whole of the stink organ of the adult is formed in the last larval stage from a pair of invaginations of the epithelial lining of the body-wall.In the larval stages the stink organs are simple glands, situated dorsally in abdominal segments III to V.The function of the stink organs is defensive and in the adult perhaps also sexual.

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Feeding in tornaria larvae and the development of gill slits in enteropneust hemichordates

Canadian Journal of Zoology ◽

10.1139/z82-384 ◽

1982 ◽

Vol 60 (12) ◽

pp. 3010-3020 ◽

Cited By ~ 14

Author(s):

T. H. J. Gilmour

Keyword(s):

Body Wall ◽

Dorsal Surface ◽

Structure And Function ◽

The Body ◽

Flow Lines ◽

Water Currents ◽

Larval Stages ◽

Excess Water ◽

Preoral Lobe ◽

And Function

The food-collecting and waste-rejecting systems of the tornaria larval stages of enteropneust hemichordates are similar to those of larval and adult lophophorates and adult pterobranch hemichordates. Water entering the oral grooves is deflected towards the mouth and the impetus of heavy, potentially inedible particles may take them across the flow lines of the water currents inferred from the movements of suspended particles to impinge on cilia which reject them into the outgoing water currents. Lighter, potentially edible material remaining suspended in the deflected water currents is intercepted by cilia on an oral hood which is similar in structure and function to the preoral lobe of the actinotroch larvae of phoronids. Excess water carried into the mouth by cilia on the dorsal surface of the esophagus is rejected via lateral grooves which develop into pouches prior to metamorphosis. Following metamorphosis the pouches make contact with the body wall to form gill slits which continue to allow water to escape from the pharynx. This finding that the function of allowing excess water to escape is performed by lateral grooves in the esophagus of tornariae supports previous speculations on the evolution of gill slits and provides further evidence for relationships between lophophorates, hemichordates, and chordates.

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Descriptions of the tadpoles of two species of Gephyromantis, with a discussion of the phylogenetic origin of direct development in mantellid frogs

Zootaxa ◽

10.11646/zootaxa.1401.3 ◽

2007 ◽

Vol 1401 (1) ◽

pp. 53 ◽

Cited By ~ 8

Author(s):

ROGER-DANIEL RANDRIANIAINA ◽

FRANK GLAW ◽

MEIKE THOMAS ◽

JULIAN GLOS ◽

NOROMALALA RAMINOSOA ◽

...

Keyword(s):

Dna Barcoding ◽

Body Wall ◽

Direct Development ◽

The Body ◽

Oral Disc ◽

Larval Stages ◽

Type Iv ◽

Frog Species ◽

Phylogenetic Origin

We describe the larval stages of two Malagasy frog species of the genus Gephyromantis, based on specimens identified by DNA barcoding. The tadpoles of Gephyromantis ambohitra are generalized stream-living Orton type IV type larvae with two lateral small constrictions of the body wall at the plane of spiracle. Gephyromantis pseudoasper tadpoles are characterized by totally keratinised jaw sheaths with hypertrophied indentation, a reduced number of labial tooth rows, enlarged papillae on the oral disc, and a yellowish coloration of the tip of the tail in life. The morphology of the tadpole of G. pseudoasper agrees with that of G. corvus, supporting the current placement of these two species in a subgenus Phylacomantis, and suggesting that the larvae of G. pseudoasper may also have carnivorous habits as known in G. corvus. Identifying the tadpole of Gephyromantis ambohitra challenges current assumptions of the evolution of different developmental modes in Gephyromantis, since this species is thought to be related to G. asper, a species of supposedly endotrophic direct development.

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Descriptions of the tadpoles of two species of Gephyromantis, with a discussion of the phylogenetic origin of direct development in mantellid frogs

Zootaxa ◽

10.11646/zootaxa.1401.1.3 ◽

2007 ◽

Vol 1401 (1) ◽

pp. 53 ◽

Cited By ~ 2

Author(s):

ROGER-DANIEL RANDRIANIAINA ◽

FRANK GLAW ◽

MEIKE THOMAS ◽

JULIAN GLOS ◽

NOROMALALA RAMINOSOA ◽

...

Keyword(s):

Dna Barcoding ◽

Body Wall ◽

Direct Development ◽

The Body ◽

Oral Disc ◽

Larval Stages ◽

Type Iv ◽

Frog Species ◽

Phylogenetic Origin

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THE SYSTEMATICS AND TRANSMISSION OF NEW AND PREVIOUSLY DESCRIBED METASTRONGYLES (NEMATODA : METASTRONGYLIDAE) FROM MUSTELA VISON

Canadian Journal of Zoology ◽

10.1139/z62-081 ◽

1962 ◽

Vol 40 (5) ◽

pp. 893-920 ◽

Cited By ~ 11

Author(s):

Roy C. Anderson

Keyword(s):

Salivary Gland ◽

Body Wall ◽

Prepatent Period ◽

The Body ◽

Albumen Gland ◽

Terrestrial Gastropods ◽

Larval Stages ◽

Infective Larvae ◽

Buccal Mass ◽

Anguispira Alternata

Crenosoma hermani n. sp., Aelurostrongylus pridhami n. sp., and Filaroides martis from mink are described. A. pridhami developed in the terrestrial gastropods Zonitoides arboreus, Discus cronkhitei, Deroceras gracile, Succinea ovalis, and Anguispira alternata and the aquatic snails Physa integra, Gyraulus deflexus, Armiger crista, and Ampullaria cuprina. F. martis developed in P. integra and G. deflexus as well as in the foregoing terrestrial gastropods. Larvae of A. pridhami and F. martis infected gastropods by penetrating the foot but those ingested penetrated the gut wall and developed successfully. Besides the foot, larvae developed on, or within, the body wall, in the mantle, on the gut, on the surface of the liver, in the buccal mass, salivary gland, and rarely in the albumen gland of molluscs. At 22–23 °C the first molt occurred on the 5th to 6th day, the second on the 13th; the three larval stages are described. The prepatent period of A. pridhami was 21–28 days, F. martis 41–53 days. Mink invariably vomited when fed infective larvae of A. pridhami but not when fed F. martis. Infective larvae of A. pridhami became encapsulated in the liver of mice, small birds, and frogs but on the intestines and mesenteries of goldfish. F. martis larvae became encapsulated in the liver of mice. There is a sigmoidal relationship between temperature and activity of first-stage larvae of A. pridhami. Young D. gracile fed and became infected with A. pridhami and F. martis at temperatures as low as 5 °C. Desiccation killed larvae in a few minutes and they survived freezing temperatures for only 4 to 5 days.

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