Wyniki wyszukiwania

1

A few characters of the adult compound eye and its peripheral area in some Tortricidae [Insecta: Lepidoptera]

100%

Razowski J., Wojtusiak J.

Genus. International Journal of Invertebrate Taxonomy

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2004

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tom 15

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nr 2

2

Postembryonic photoreceptor development in the fishlouse Argulus coregoni Thorell, 1865 [Crustacea, Branchiura]

100%

Keskinen E., Meyer-Rochow V. B.

Acta Parasitologica

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2004

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tom 49

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nr 4

Both kinds of photoreceptors nauplius and compound eye, were examined in the fishlouse Argulus coregoni. A 1 st stage metanauplius larval compound eye resembles that of the adult fishlouse compound eye (Meyer-Rochow et al. 2001), but its diameter measures only approximately one tenth of that of the mature eye of an adult. However, in relation to total body length the adult eyes were actually smaller. All ommatidia in the metanauplius compound eye had a well developed dioptric apparatus as well as a rhabdom already at the time of hatching. A seemingly functioning nauplius eye was found in all postembryonic developmental stages of A. coregoni. The size of the nauplius eye increased less rapidly than body length did. The same held true for the compound eye. In the nauplius eye of 1st stage larvae the two lateral ocelli were elongated, but in 8th stage larvae all three ocelli were circular like those in the adult eye. The nauplius eye continued to grow throughout the postembryonic development, but the structure of the eye remained mostly unchanged. There was no reason to doubt that both types of photoreceptor, nauplius and compound eyes, were functional even in the metanauplius larvae. Thus, it seems entirely possible that even the smallest larvae could use vision to detect and attack a possible host.

3

Light activation of phospholipase A2 in the photoreceptor of the crayfish [Procambarus clarkii]

80%

Kashiwagi T., Meyer-Rochow V. B., Nishimura K., Eguchi E.

Acta Neurobiologiae Experimentalis

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2000

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tom 60

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nr 1

Retinal lipids of crayfish, kept at 4°C under continuous darkness for 3 weeks, consisted mainly of phosphatidylcholine (PC) and phosphatidylethanolamine (PE); sphingomyelin (SM), phosphatidylinositol (PI) and phosphatidylserine (PS) were minor contributors. PI, involved in the phototransduction cascade, never reached greater concentrations than 7% of the total. High concentrations of polyunsaturated fatty acids (PUFA) such as 20:4n-6, 20:5n-3 and 22:6n-3 (DHA, docosahexaenoic acid) were present in PC, PE and PS, but scarce in SM and PL In retinae of crayfish kept at 4°C in darkness for 3 weeks and then exposed to white light (6 h; ca. 4,500 lx), SM and PS remained seemingly unaffected. PC, however, significantly decreased within 10 min to 65% of the initial value and 50% at 180 min. To study the reduction of PC, lipids of retinae suspended in physiological solution with/without phospholipase C (PLC) and phospholipase A2 (PLA2) inhibitors such as DMDA (=DEDA), manoalide, ET-I8-OCH3, and U-73122 were measured. Only free fatty acids (FFA) of retinae with inhibitors of PLA2 like DMDA and manoalide decreased. Retinae irradiated by white light for 3 h displayed a significant reduction of PC, compared with those that had remained in continuous darkness. However, the PC of retinae with PLA2-inhibitors was not decreased by light. Our results provide evidence that not only photoreceptor cell PLC, but also PLA2 is activated by light.

Ograniczanie wyników

1 Acta Neurobiologiae Experimentalis

1 Acta Parasitologica

1 Genus. International Journal of Invertebrate Taxonomy

2 Meyer-Rochow V. B.

1 Eguchi E.

1 Kashiwagi T.

1 Keskinen E.

1 Nishimura K.

1 Razowski J.

1 Wojtusiak J.

2 2004

1 2000

A few characters of the adult compound eye and its peripheral area in some Tortricidae [Insecta: Lepidoptera]

Postembryonic photoreceptor development in the fishlouse Argulus coregoni Thorell, 1865 [Crustacea, Branchiura]

Light activation of phospholipase A2 in the photoreceptor of the crayfish [Procambarus clarkii]