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Regulation of the dominance of two flagella by cAMP in Chlamydomonas
Comparative Biochemistry and Physiology, Part B 151 (2008) 449–461
Contents lists available at ScienceDirect
Comparative Biochemistry and Physiology, Part B j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / c b p b
Oral and Poster Presentations 1. No abstract submitted doi:10.1016/j.cbpb.2008.09.002
2. Regulation of the dominance of two flagella by cAMP in Chlamydomonas Yu Saegusa, Kenjiro Yoshimura, Div. Struc. Biosci., Grad. Sch. Life Environ. Sci., Univ. Tsukuba, Tsukuba 305-8572, Japan Some flagellar proteins in Chlamydomonas have been shown to be phosphorylated in a cAMP dependent manner, but little is known how the flagellar bending is modified by cAMP. Here we examined the flagellar beating on increasing the cAMP concentration by cleaving caged cAMP, a photoactivatable analog of cAMP. Wild type and mutant cells were demembranated and reactivated by 1 mM ATP before the photocleavage. The amplitude of the helix of the swimming path of wild type cells increased on the photocleavage of caged cAMP. On the other hand, the amplitude did not change in phototaxis-deficient mutants, lsp1 and ptx1. The analysis of the waveform of isolated flagella indicated that the amplitude of flagellar beating decreases on photolysis. Interestingly, the decrease in the beating amplitude did not occur when uni1, a mutant that lacks cis-flagellum (flagellum far from eyespot), was used. The result above indicates that cAMP augment the helical turn by decreasing the beating amplitude of cis-flagellum.
Jumping spiders have four pairs of simple eyes (ocelli), like many other spiders do. It is suggested that the principal eyes and two kinds of lateral eyes of jumping spiders are involved in well-developed color vision and detection of a moving object, respectively, whereas the function of the posterior median eyes (PMEs) is unknown. To understand the molecular basis of the varied visual system including color vision, we previously isolated three kinds of opsin genes. Here, we isolated an additional opsin gene from the same species (Hasarius adansoni) and then investigated distributions of the four opsins in its four pairs of simple eyes by in situ hybridization. Interestingly, we found that one of the opsins was expressed specifically in PMEs, whereas the others were mainly expressed in principle eyes. Although the photoreceptive ability of PMEs has been questioned, spectroscopic and biochemical characterization of the opsin specific to the posterior median eyes could provide an insight into a particular function of the posterior median eyes in the jumping spider.
doi:10.1016/j.cbpb.2008.09.005
5. No abstract submitted doi:10.1016/j.cbpb.2008.09.006
6. No abstract submitted doi:10.1016/j.cbpb.2008.09.003
3. No abstract submitted
doi:10.1016/j.cbpb.2008.09.007
7. A new photosense of directly light-sensitive neuron called simple photoreceptor: LTP-like long-lasting potentiation
doi:10.1016/j.cbpb.2008.09.004
4. Identification and characterization of a visual pigment expressed in posterior median eyes of jumping spiders
Tsukasa Gotow a, Takako Nishi b, a Lab. Neuroanat., Dept. Neurol., Kagoshima Univ. Grad. Sch. Med.-Den. Sci., Kagoshima 890-8520, Japan; b Lab. Physiol., Inst. Natl. Sci., Senshu Univ., Kawasaki 214-8580, Japan
Takashi Nagata a, Mitsumasa Koyanagi a, Kunio Isono b, Shigeki Yamashita c, Fumio Tokunaga d, Kentaro Arikawa e, Akihisa Terakita a, a Department Biol. and Geosci., Grad. Sch. Sci., Osaka City Univ., Osaka 558-8585, Japan; b Grad. Sch. Information Sci., Tohoku Univ., c Sendai 980-8579, Japan; Fac. Design, Kyushu Univ., Fukuoka 815d 8540, Japan; Department Earth and Space sci., Grad. Sch. Sci., Osaka Univ., Toyonaka 560-0043, Japan; e Grad. Univ. for Advanced Studies (Sokendai), Shonan Village, Hayama 240-0193, Japan
The simple photoreceptors Ip-2 and Ip-1, directly light-sensitive neurons exist in the ganglion of the sea slug Onchidium. Both Ip-2 and Ip1 respond to light with a long-lasting hyperpolarization, caused by opening of light-dependent, cGMP-gated K+ channels. The previous study showed that these Ip-2/Ip-1, being the first-order photosensory cells are not only the second-order interneurons relaying pressure or touch sensory inputs, but also motoneurons innervating pneumostome, an aero-breathing organ. On the other hand, at low tide amphibian
Contents lists available at ScienceDirect
Comparative Biochemistry and Physiology, Part B j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / c b p b
Oral and Poster Presentations 1. No abstract submitted doi:10.1016/j.cbpb.2008.09.002
2. Regulation of the dominance of two flagella by cAMP in Chlamydomonas Yu Saegusa, Kenjiro Yoshimura, Div. Struc. Biosci., Grad. Sch. Life Environ. Sci., Univ. Tsukuba, Tsukuba 305-8572, Japan Some flagellar proteins in Chlamydomonas have been shown to be phosphorylated in a cAMP dependent manner, but little is known how the flagellar bending is modified by cAMP. Here we examined the flagellar beating on increasing the cAMP concentration by cleaving caged cAMP, a photoactivatable analog of cAMP. Wild type and mutant cells were demembranated and reactivated by 1 mM ATP before the photocleavage. The amplitude of the helix of the swimming path of wild type cells increased on the photocleavage of caged cAMP. On the other hand, the amplitude did not change in phototaxis-deficient mutants, lsp1 and ptx1. The analysis of the waveform of isolated flagella indicated that the amplitude of flagellar beating decreases on photolysis. Interestingly, the decrease in the beating amplitude did not occur when uni1, a mutant that lacks cis-flagellum (flagellum far from eyespot), was used. The result above indicates that cAMP augment the helical turn by decreasing the beating amplitude of cis-flagellum.
Jumping spiders have four pairs of simple eyes (ocelli), like many other spiders do. It is suggested that the principal eyes and two kinds of lateral eyes of jumping spiders are involved in well-developed color vision and detection of a moving object, respectively, whereas the function of the posterior median eyes (PMEs) is unknown. To understand the molecular basis of the varied visual system including color vision, we previously isolated three kinds of opsin genes. Here, we isolated an additional opsin gene from the same species (Hasarius adansoni) and then investigated distributions of the four opsins in its four pairs of simple eyes by in situ hybridization. Interestingly, we found that one of the opsins was expressed specifically in PMEs, whereas the others were mainly expressed in principle eyes. Although the photoreceptive ability of PMEs has been questioned, spectroscopic and biochemical characterization of the opsin specific to the posterior median eyes could provide an insight into a particular function of the posterior median eyes in the jumping spider.
doi:10.1016/j.cbpb.2008.09.005
5. No abstract submitted doi:10.1016/j.cbpb.2008.09.006
6. No abstract submitted doi:10.1016/j.cbpb.2008.09.003
3. No abstract submitted
doi:10.1016/j.cbpb.2008.09.007
7. A new photosense of directly light-sensitive neuron called simple photoreceptor: LTP-like long-lasting potentiation
doi:10.1016/j.cbpb.2008.09.004
4. Identification and characterization of a visual pigment expressed in posterior median eyes of jumping spiders
Tsukasa Gotow a, Takako Nishi b, a Lab. Neuroanat., Dept. Neurol., Kagoshima Univ. Grad. Sch. Med.-Den. Sci., Kagoshima 890-8520, Japan; b Lab. Physiol., Inst. Natl. Sci., Senshu Univ., Kawasaki 214-8580, Japan
Takashi Nagata a, Mitsumasa Koyanagi a, Kunio Isono b, Shigeki Yamashita c, Fumio Tokunaga d, Kentaro Arikawa e, Akihisa Terakita a, a Department Biol. and Geosci., Grad. Sch. Sci., Osaka City Univ., Osaka 558-8585, Japan; b Grad. Sch. Information Sci., Tohoku Univ., c Sendai 980-8579, Japan; Fac. Design, Kyushu Univ., Fukuoka 815d 8540, Japan; Department Earth and Space sci., Grad. Sch. Sci., Osaka Univ., Toyonaka 560-0043, Japan; e Grad. Univ. for Advanced Studies (Sokendai), Shonan Village, Hayama 240-0193, Japan
The simple photoreceptors Ip-2 and Ip-1, directly light-sensitive neurons exist in the ganglion of the sea slug Onchidium. Both Ip-2 and Ip1 respond to light with a long-lasting hyperpolarization, caused by opening of light-dependent, cGMP-gated K+ channels. The previous study showed that these Ip-2/Ip-1, being the first-order photosensory cells are not only the second-order interneurons relaying pressure or touch sensory inputs, but also motoneurons innervating pneumostome, an aero-breathing organ. On the other hand, at low tide amphibian