• 한국응용곤충학회지
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• 제29권3호
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• pp.201-208
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• 1990

말매미충(Cicadella viridis L.)의 구기에 있는 미각감각기에 대한 주사전자현미경 관찰에서 전구강에 위치한 상인두의 D-sensilla는 10개이며, 상인두 함입부의 양쪽변에서 P-sensilla 8 개가, 하인두의 식도 중간부위에서 H -sensilla가 2개 관찰되었다. D- 및 P-sensilla는 형태적 으로 2군으로 분리되었다. 그리고 D- 및 P-sensilla로부터 유래된 신경다발 1쌍씩은 상인두 뒷면의 큐티클 안에서, H -sensilla로부터의 신경다발 1쌍은 하인두 뒷면의 큐티클 안에서 관찰되었다.

• Animal cells and systems
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• 제15권1호
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• pp.53-61
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• 2011

The fine structural characteristics of the antennal sensory organs of a female millipede Oxidus gracilis (Polydesmida: Paradoxomatidae) were observed with both field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). We could identify four apical cones and three basic types of antennal sensillae in a. gracilis as follows: chaetiform sensilla (CS), trichoid sensilla (TS) and basiconic sensilla (BS). Of these, both types of CS and TS can be observed throughout all antennal segments except the terminal 8th article, whereas the BS are observed within the cuticular depressed regions of the articles from the 5th to the 7th segment. According to their relative microstructure and location, the BS arc divided further into three subtypes: large ($BS_1$) small ($BS_2$) and spiniform ($BS_3$). The $BS_1$ can be seen on the 5th article only, while $BS_2$ can be seen on the 5th and 6th articles. The $BS_3$ is characteristically seen within the depressive region of the 7th article. Both the CS and TS of O. gracilis are similar in structure, and they are related to the function of mechanical reception; however, four large apical cones (AP) and three subtypes of BS are likely to function in gustatory and olfactory reception.

• Molecules and Cells
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• 제43권6호
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• pp.530-538
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• 2020

The Gustatory system enables animals to detect toxic bitter chemicals, which is critical for insects to survive food induced toxicity. Cucurbitacin is widely present in plants such as cucumber and gourds that acts as an anti-herbivore chemical and an insecticide. Cucurbitacin has a harmful effect on insect larvae as well. Although various beneficial effects of cucurbitacin such as alleviating hyperglycemia have also been documented, it is not clear what kinds of molecular sensors are required to detect cucurbitacin in nature. Cucurbitacin B, a major bitter component of bitter melon, was applied to induce action potentials from sensilla of a mouth part of the fly, labellum. Here we identify that only Gr33a is required for activating bitter-sensing gustatory receptor neurons by cucurbitacin B among available 26 Grs, 23 Irs, 11 Trp mutants, and 26 Gr-RNAi lines. We further investigated the difference between control and Gr33a mutant by analyzing binary food choice assay. We also measured toxic effect of Cucurbitacin B over 0.01 mM range. Our findings uncover the molecular sensor of cucurbitacin B in Drosophila melanogaster. We propose that the discarded shell of Cucurbitaceae can be developed to make a new insecticide.

• Molecules and Cells
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• 제40권10호
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• pp.731-736
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• 2017

Taste sensitivity to sugars plays an essential role in the initiation of feeding behavior. In Drosophila melanogaster, recent studies have identified several gustatory receptor (Gr) genes required for sensing sweet compounds. However, it is as yet undetermined how these GRs function as taste receptors tuned to a wide range of sugars. Among sugars, fructose has been suggested to be detected by a distinct receptor from other sugars. While GR43A has been reported to sense fructose in the brain, it is not expressed in labellar gustatory receptor neurons that show taste response to fructose. In contrast, the Gr64a-Gr64f gene cluster was recently shown to be associated with fructose sensitivity. Here we sought to decipher the genes required for fructose response among Gr64a-Gr64f genes. Unexpectedly, the qPCR analyses for these genes show that labellar expression levels of Gr64d and Gr64e are higher in fructose low-sensitivity flies than in high-sensitivity flies. Moreover, gustatory nerve responses to fructose in labellar sensilla are higher in Gr64d and Gr64f mutant lines than in mutant flies of the other Gr64a-Gr64f genes. These data suggest the possibility that deletion of GR64D or GR64F may indirectly induce enhanced fructose sensitivity in the labellum. Finally, we conclude that response to fructose cannot be explained by a single one of the Gr64a-Gr64f genes.