• Journal of Life Science
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• v.22 no.3
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• pp.293-297
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• 2012

The movement of vesicles from the neuronal cell body to specific destinations requires molecular motors. The squid giant axon represents a powerful model for studies of the axonal transport mechanism because the axoplasm can readily be separated from the sheath by simple extrusion. In a previous study, vesicular movements in the axoplasm of the squid giant axon were inhibited by the kinesin antibody. In the present study, we cloned and sequenced the cDNAs for squid brain KIFs. Amplification of the conserved nucleotide sequences of the motor domain by polymerase chain reaction (PCR) using first-strand cDNAs of the squid optic lobe identified six new KIF proteins. Motif analysis of the motor domains revealed that the squid KIFs are homologous to the consensus sequences of the mouse KIFs. The phylogenetic tree generated by using the maximum parsimony (MP) method, the neighbor-joining (NJ) method, the minimum evolution (ME) method, and the maximum likelihood (ML) method showed that squid KIFs are closest to mouse KIFs. These data prove the phylogenetic relationships between squid KIFs and mouse ones.

• Applied Microscopy
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• v.29 no.3
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• pp.303-313
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• 1999

In this paper, five kinds of neurosecretory cells-light green (LG) cell, dark green (DG) cell, caudo-dorsal (CD) cell, blue green (BG) cell, and yellow (Y) cell- and neuropils in the cerebral ganglion of the African giant snail, Achatina fulica, were observed with an electron microscope. The following results were obtained. The LG cells are circular or ovoid in shape, and about $60{\mu}m$ in size. The nucleus and cytoplasm of the LG cell look light due to their electron-low density. Large granular chromatins are evenly developed in the karyolymph, where round nucleoli are also found. In the cytoplasm, electron -high dense round granules of $0.4{\mu}m$ in average size are crowded. The DG cells are ovoid in shape, and $50\sim20{\mu}m$ in size. These relatively electron-high dense cells were rarely found. In their cytoplasm, cell organelles such as rough endoplasmic reticulum and mitochondria are found together with electron -high dense round granules of $0.2{\mu}m$ in average size. The CD cells are ellipsoidal cells densely distributed in caudo-dorsal parts of the cerebral ganglion. They have large nuclei compared with the cytoplasm. The developed granular heterochromatins are observed in the karyolymph, and lots of small round granules of $0.12{\mu}m$ in average size in the cytoplasm. The 3G cells, rarely found around endoneurium of the cerebral ganglion, take the shapes of long ellipses. They look dark due to their electron -high density. In the cytoplasm, small round granules of $0.1{\mu}m$ in average size are found. The Y cells are the smallest among the neurosecretory cells($9\times6.6{\mu}m$ in size). They are found mostly between the medio-dorsal parts and the caudo-dorsal parts of the cerebral ganglion. In the cytoplasm, tiny round granules of $0.08{\mu}m$ in average size form a group. The neuropils are found in the middle of the cerebral ganglion. In the axon ending, round granules with electron -high density ($0.07\sim0.03{\mu}m$ in diameter) and lucent vesicles ($0.03{\mu}m$ in diameter) are found in large quantities. They are excreted in the state of exocytosome formed by the invagination of the limiting membrane of the axon ending.