Genetic determinants of sense organ identity in Drosophila: regulatory interactions between cut and poxn

Development ◽  
1995 ◽  
Vol 121 (9) ◽  
pp. 3111-3120 ◽  
Author(s):  
M. Vervoort ◽  
D. Zink ◽  
N. Pujol ◽  
K. Victoir ◽  
N. Dumont ◽  
...  
Keyword(s):  
Regulatory Region ◽  
Sense Organ ◽  
Sense Organs ◽  
Genetic Determinants ◽  
Regulatory Interactions ◽  
Organ Identity ◽  
Small Domain

Two genes involved in defining the type of sense organ have been identified in Drosophila. The gene cut differentiates the external sense organs (where it is expressed) from the chordotonal organs (where it is not); among the external sense organs poxn differentiates the poly-innervated organs (where it is expressed) from the mono-innervated organs (where it is not). Here we show that the expression of poxn in normal embryos does not depend on cut, and that poxn is capable of inducing the expression of cut. We have identified a small domain of the very large cut regulatory region as a likely target for activation by poxn.

The fine morphology of the osphradial sense organs of the mollusca. III. Placophora and bivalvia

1987 ◽  
Vol 315 (1169) ◽  
pp. 37-61 ◽  
Keyword(s):  
Fine Structure ◽  
Sense Organ ◽  
Mantle Cavity ◽  
Sense Organs ◽  
Physiological Evidence ◽  
Anal Papillae ◽  
Fine Morphology

The fine morphology of the osphradia of six placophorans and eight bivalves, representing all major subgroups of both classes, is described. In addition the branchial and lateral sense organs of Lepidopleurus cajetanus (Placophora) have been investigated ultrastrucurally. Whereas osphradial fine structure is very uniform within the Bivalvia there are differences between Ischnochitonina and Acanthochitonina, supporting the separation of both groups. Major differences in the conditions of the mantle cavity divide Recent Placophora into the orders Lepidopleurida and Chitonida. The homology of the molluscan osphradium throughout the phylum is discussed in detail. It is concluded that the terminal sense organ (Caudofoveata, Solenogastres), the adanal sensory stripes (Placophora—Chitonida), the interbranchial and post-anal papillae of Nautilus (Cephalopoda), and the organ of Lacaze (Gastropoda-Basommatophora) are homologous with the organs of Spengel (Prosobranchia, Opisthobranchia, Bivalvia), all to be called osphradial sense organs (or osphradia). After discussion it is concluded that the osphradium is a chemoreceptor and not a mechanoreceptor as suggested by many authors. This is shown by the physiological evidence so far reported but mainly by the existence of paddle cilia in the osphradial epithelia throughout the Mollusca, which are typical of molluscan chemoreceptors. It is suggested that the osphradium is primarily used in sexual biology (coordination of spawning, search for a mate), a role altered within the Gastropoda (search for food, osmoreceptor, p O2 -receptor).

scholarly journals Drug Susceptibility Profiling and Genetic Determinants of Drug Resistance inMycobacterium kansasii

2018 ◽  
Vol 62 (4) ◽  
pp. e01788-17 ◽  
Author(s):  
Zofia Bakuła ◽  
Magdalena Modrzejewska ◽  
Lian Pennings ◽  
Małgorzata Proboszcz ◽  
Aleksandra Safianowska ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Target Genes ◽  
Regulatory Region ◽  
Drug Susceptibility ◽  
Dilution Method ◽  
Broth Microdilution ◽  
Genetic Determinants ◽  
Content Type ◽  
Microdilution Method

ABSTRACTVery few studies have examined drug susceptibility ofMycobacterium kansasii, and they involve a limited number of strains. The purpose of this study was to determine drug susceptibility profiles ofM. kansasiiisolates representing a spectrum of species genotypes (subtypes) with two different methodologies, i.e., broth microdilution and Etest assays. To confirm drug resistance, drug target genes were sequenced. A collection of 85M. kansasiiisolates, including representatives of eight different subtypes (I to VI, I/II, and IIB) from eight countries, was used. Drug susceptibility against 13 and 8 antimycobacterial agents was tested by using broth microdilution and Etest, respectively. For drug-resistant or high-MIC isolates, eight structural genes (rrl,katG,inhA,embB,rrs,rpsL,gyrA, andgyrB) and one regulatory region (embCA) were PCR amplified and sequenced in the search for resistance-associated mutations. All isolates tested were susceptible to rifampin (RIF), amikacin (AMK), co-trimoxazole (SXT), rifabutin (RFB), moxifloxacin (MXF), and linezolid (LZD) according to the microdilution method. Resistance to ethambutol (EMB), ciprofloxacin (CIP), and clarithromycin (CLR) was found in 83 (97.7%), 17 (20%), and 1 (1.2%) isolate, respectively. The calculated concordance between the Etest and dilution method was 22.6% for AMK, 4.8% for streptomycin (STR), 3.2% for CLR, and 1.6% for RIF. For EMB, INH, and SXT, not even a single MIC value determined by one method equaled that by the second method. The only mutations disclosed were A2266C transversion at therrlgene (CLR-resistant strain) and A128G transition at therpsLgene (strain with STR MIC of >64 mg/liter). In conclusion, eight drugs, including RIF, CLR, AMK, SXT, RFB, MXF, LZD, and ethionamide (ETO), showed highin vitroactivity againstM. kansasiiisolates. Discrepancies of the results between the reference microdilution method and Etest preclude the use of the latter for drug susceptibility determination inM. kansasii. Drug resistance inM. kansasiimay have different genetic determinants than resistance to the same drugs inM. tuberculosis.

The determination of sense organs in Drosophila: effect of the neurogenic mutations in the embryo

Development ◽  
1991 ◽  
Vol 113 (4) ◽  
pp. 1395-1404 ◽  
Author(s):  
A. Goriely ◽  
N. Dumont ◽  
C. Dambly-Chaudiere ◽  
A. Ghysen
Keyword(s):  
Progenitor Cell ◽  
Sense Organ ◽  
The Other ◽  
Sense Organs ◽  
Mutual Inhibition ◽  
Competent Cells ◽  
Mother Cells

We have examined the early pattern of sensory mother cells in embryos mutant for six different neurogenic loci. Our results show that the neurogenic loci are required to restrict the number of competent cells that will become sensory mother cells, but are not involved in controlling the localization or the position-dependent specification of competent cells. We conclude that these loci are involved in setting up a system of mutual inhibition, which transforms graded differences within the proneural clusters into an all-or-none difference between one cell, which becomes the sense organ progenitor cell, and the other cells, which remain epidermal.

Prospero distinguishes sibling cell fate without asymmetric localization in the Drosophila adult external sense organ lineage

Development ◽  
1999 ◽  
Vol 126 (10) ◽  
pp. 2063-2071 ◽  
Author(s):  
L. Manning ◽  
C.Q. Doe
Keyword(s):  
Cell Fate ◽  
Asymmetric Cell Division ◽  
Protein Localization ◽  
Sense Organ ◽  
Cell Loss ◽  
Sense Organs ◽  
Cell Fates ◽  
Dendrite Morphology ◽  
And Function ◽  
Sheath Cells

The adult external sense organ precursor (SOP) lineage is a model system for studying asymmetric cell division. Adult SOPs divide asymmetrically to produce IIa and IIb daughter cells; IIa generates the external socket (tormogen) and hair (trichogen) cells, while IIb generates the internal neuron and sheath (thecogen) cells. Here we investigate the expression and function of prospero in the adult SOP lineage. Although Prospero is asymmetrically localized in embryonic SOP lineage, this is not observed in the adult SOP lineage: Prospero is first detected in the IIb nucleus and, during IIb division, it is cytoplasmic and inherited by both neuron and sheath cells. Subsequently, Prospero is downregulated in the neuron but maintained in the sheath cell. Loss of prospero function leads to ‘double bristle’ sense organs (reflecting a IIb-to-IIa transformation) or ‘single bristle’ sense organs with abnormal neuronal differentiation (reflecting defective IIb development). Conversely, ectopic prospero expression results in duplicate neurons and sheath cells and a complete absence of hair/socket cells (reflecting a IIa-to-IIb transformation). We conclude that (1) despite the absence of asymmetric protein localization, prospero expression is restricted to the IIb cell but not its IIa sibling, (2) prospero promotes IIb cell fate and inhibits IIa cell fate, and (3) prospero is required for proper axon and dendrite morphology of the neuron derived from the IIb cell. Thus, prospero plays a fundamental role in establishing binary IIa/IIb sibling cell fates without being asymmetrically localized during SOP division. Finally, in contrast to previous studies, we find that the IIb cell divides prior to the IIa cell in the SOP lineage.

Perception of Surface Waves by the Blackstripe Topminnow, Fundulus notatus

1966 ◽  
Vol 23 (9) ◽  
pp. 1331-1352 ◽  
Author(s):  
Erich Schwartz ◽  
Arthur D. Hasler
Keyword(s):  
Surface Waves ◽  
Lateral Line ◽  
Sense Organ ◽  
Dorsal Surface ◽  
Longitudinal Axis ◽  
Intensity Difference ◽  
Sense Organs ◽  
Wave Source ◽  
Fundulus Notatus ◽  
The Individual

The function of the cephalic lateral line in perceiving surface waves and its ecological significance was examined in the topminnow, Fundulus notatus (Rafinesque), a fish which frequents the surface waters. The sense organs are located in groups on the dorsal surface of the flatish head and are prominently visible on the skin. The individual organs of each group form a specific angle when related to the fish's midline. These organs perceive the force of slight surface waves and the perceptional field is omnidirectional. A great number of enucleated fish respond spontaneously, but when trained they orient toward the source of the disturbance on the surface up to a distance of 15 cm. The fact that the radiating wave is curved enables fish to locate the origin accurately. Fundulus notatus does not distinguish between two waves of equal strength striking simultaneously; it does so, however, if a time or intensity difference is present. A fish with sense organs removed from one side of the head deviates at a constant angle from the wave source. The perceptional field of individual organs or canals circumscribes a line drawn through the longitudinal axis of the organ or canal. A wave, therefore, traveling parallel to the longitudinal axis of the oval sense organ and hence the cupula, stimulates to the greatest extent whereas a wave perpendicular to it does not. The individual organs possess a directional property and, therefore, their arrangement on the head is functionally meaningful. The lateral line supplements the vision of the fish in finding its prey at the water surface.

Pathology of Benign Paroxysmal Positional Vertigo Revisited

2003 ◽  
Vol 112 (7) ◽  
pp. 574-582 ◽  
Author(s):  
Richard R. Gacek
Keyword(s):  
Benign Paroxysmal Positional Vertigo ◽  
Ganglion Cells ◽  
Sense Organ ◽  
Inhibitory Effect ◽  
Otolith Organs ◽  
Pathological Changes ◽  
Sense Organs ◽  
Posterior Canal ◽  
Positional Vertigo ◽  
Paroxysmal Positional Vertigo

The pathophysiology of benign paroxysmal positional vertigo (BPPV) is not completely understood. Although the concept of degenerated otoconia transforming the posterior canal (PC) crista into a gravity-sensitive sense organ has gained popular support, several temporal bone (TB) series have revealed similar deposits in normal TBs, suggesting they are a normal change in the aging labyrinth. Furthermore, some TBs from patients with BPPV do not contain particles in the posterior canal. Five TBs from patients with BPPV were studied quantitatively and qualitatively. A small PC cupular deposit was found in 1 TB, while none was seen in the other 4 TBs. The major pathological changes were 1) a 50% loss of ganglion cells in the superior vestibular division of all 5 TBs and 2) a 50% loss of neurons in the inferior division of 3 TBs, and a 30% loss in 2 TBs that contained abnormal saccular ganglion cells. These observations support a concept in the pathophysiology of BPPV that includes loss of the inhibitory effect of otolith organs on canal sense organs.

Sense organs of monogenean skin parasites ending in a typical cilium

Parasitology ◽  
1969 ◽  
Vol 59 (3) ◽  
pp. 611-623 ◽  
Author(s):  
Kathleen M. Lyons
Keyword(s):  
Electron Microscope ◽  
Phase Contrast ◽  
Research Council ◽  
Sense Organ ◽  
Science Research ◽  
Sense Organs ◽  
Marine Biological Laboratory ◽  
Sensory Neurone ◽  
Research Fellowship ◽  
Contrast Microscopy

Single receptors seen with the electron microscope to consist of a terminal cilium embedded in a nerve bulb have been found in the skin parasitic monogenean Gyrodactylus sp., adult and larval Entobdella soleae, Leptocotyle minor (adult) and in the endoparasitic juvenile of Amphibdella flaviolineata. Their distribution in Gyrodactylus sp. has been mapped using phase-contrast microscopy, and staining with the indoxyl acetate method for non-specific esterases revealed a nervous connexion between the lateral ventral nerve cord and the ‘tangoreceptor’. The general relationships of the nervous system in Gyrodactylus were investigated by staining with the thiocholine method for cholinesterase. The ‘sensory’ neurone contains vesicles, microtubules and mitochondria and the whole nerve bulb is sealed into the epidermis by means of septate desmosomes. The basal body of the cilium is not greatly modified and there is no obvious rootlet system. The terminal cilium of single receptors in Entobdella soleae has a 9 + 2 structure. A compound sense organ from the head of Entobdella soleae has also been described. The significance of the fibre arrangement in the terminal cilia and the possible roles of these sense organs have been discussed.I should like to thank Dr D. L. Lee for training in electron microscope techniques and for his encouragement, Dr P. Tate for his continued interest and the staff of the Marine Biological Laboratory, Plymouth, especially Mr G. Best and Mr J. E. Green, for their assistance. This work was conducted during tenure of a Science Research Council Fellowship and the Tucker-Price Research Fellowship of Girton College.

The effect of lethal mutations and deletions within the bithorax complex upon the identity of caudal metameres in the Drosophila embryo

Development ◽  
1986 ◽  
Vol 93 (1) ◽  
pp. 153-166
Author(s):  
J. R. S. Whittle ◽  
S. Y. K. Tiong ◽  
C. E. Sunkel
Keyword(s):  
Abdominal Segment ◽  
Sense Organ ◽  
Drosophila Embryo ◽  
Bithorax Complex ◽  
Sense Organs ◽  
Head Region ◽  
Lethal Mutations ◽  
Segment 8 ◽  
Derivatives Of ◽  
Cuticular Structures

Mutations and deletions of the abdA and AbdB functions in the bithorax complex of Drosophila melanogaster have been examined for their effect upon the hypodermal derivatives of the caudal segments of the embryo, employing light- and scanning electron microscopy. No cuticular structures located posterior to the denticle belt of abdominal segment 8 are affected in abdA− embryos. Embryos of AbdB− genotype no longer have six of the seven pairs of sense organs present in this region, lack posterior spiracles but instead have sclerotized cuticle and sense organs typical of the head region and a rudimentary extra ventral denticle belt. The anal pads, tuft and sense organ 1 do not require BX-C functions for their specification. We discuss the provenance of these cuticular structures and the domain of function of elements within the bithorax complex in terms of parasegmental metameric units.

SEM Study of Skin Sense Organs in Two Uromastyx Species (Sauria: Agamidae) and Sphenodon punctatus (Rhynchocephalia: Sphenodontidae)

2011 ◽  
Vol 4 (1) ◽  
pp. 46-49
Author(s):  
Natalia B. Ananjeva ◽  
Tatjana N. Dujsebayeva
Keyword(s):  
Large Diameter ◽  
Sense Organ ◽  
External Morphology ◽  
Sense Organs ◽  
Sem Study ◽  
Sphenodon Punctatus

External morphology and distribution of sense organs in the integument of Uromastyx assmussi and U. hardwickii and also of tuatara, Sphenodon punctatus were studied using SEM. Bristless skin organs in both species of Uromastyx and Sphenodon have large diameter (to 160 μm) and are few in the number (0 – 1 per scale) on cephalic and flank body scales. The reduction of sense organ number is discussed with respect of possible significance of this character in agamid system.

Comparative studies on the sense organs on the antennae and maxillary palps of selected male culicine mosquitoes

1971 ◽  
Vol 49 (2) ◽  
pp. 235-239 ◽  
Author(s):  
Susan McIver
Keyword(s):  
Carbon Dioxide ◽  
Aedes Aegypti ◽  
Comparative Studies ◽  
Culex Pipiens ◽  
Sense Organ ◽  
Sense Organs ◽  
Sensilla Basiconica ◽  
Aedes Atropalpus ◽  
The Difference ◽  
Maxillary Palps

The sense organs on the antennae and maxillary palps of male Aedes atropalpus (Coquillett), Aedes aegypti (L.), Culex territans Walker, and Culex pipiens L. are similar to those observed on female culicines including water, olfactory, and carbon dioxide receptors. Although males have the same variety, they have fewer of each type of sense organ. The difference in number of any one type of sense organ is more variable in the female than the male except for the sensilla basiconica.

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