Monoclonal Antibody MAT-1 Against Human Tyrosinase Can Detect Melanogenic Cells on Formalin-Fixed Paraffin-Embedded Sections

Immunohistochemical localization of tyrosinase was examined with a monoclonal antibody (MoAb MAT-1) against human tyrosinase on routine formalin-fixed paraffin-embedded sections of 3 normal skin specimens, 15 melanocytic tumors (6 pigmented nevi, 3 juvenile melanomas and 6 malignant melanomas) and 3 non-melanocytic tumors. In the melanotic melanomas, almost all tumor cells were clearly stained with the antibody. In the nevocytic nevi, the nevus cells in lower epidermis and upper dermis were positive for MoAb MAT-1, but negative in middle and lower dermis. All three juvenile melanomas, one amelanotic melanoma, and three non-melanocytic tumors were entirely negative for MoAb MAT-1. Thus, MoAb MAT-1 could recognize the cells with melanogenic activity on routine formalin-fixed paraffin-embedded sections. However, the staining quality was not adequate for normal epidermal melanocytes, indicating that small technical innovations in the immunostaining process such as formalin fixation after PBS washing are required. Nevertheless, MoAb MAT-1 can be expected to be very useful for identifying melanogenic cells on paraffin-embedded sections, because we have to date no other antibody available for it.     

A review of Asian Hediste species complex (Nereididae, Polychaeta) with descriptions of two new species and a redescription of Hediste japonica (Izuka, 1908)

Three Asian species of the genus Hediste (Nereididae, Polychaeta, Annelida), including two new species, are reviewed. Hediste japonica (Izuka, 1908) was redescribed based on recently discovered type material and on additional specimens newly collected from the Ariake Sea in Japan and the west coast of Korea. Two new species, H .  diadroma and H. atoka , were described based on specimens collected from Japan. These three species are morphologically similar, but distinguishable by some differences in parapodial and chaetal morphology, at least at the sexually mature stage. The presence of homogomph falcigers and the absence of heterogomph spinigers are unique characteristics of H. japonica among this genus. Inconspicuous epitokous metamorphosis occurred as a slight enlargement of the eyes and parapodial ligules in mature adults of H. diadroma sp. nov. and H. japonica in combination with their reproductive swarming and pelagic larval development. The epitoke-specific sesquigomph spinigers were added in mature adults of H. diadroma sp. nov., while the number of ordinary homogomph spinigers increased in some adults of H. japonica. Epitokous metamorphosis in the Hediste species was compared with that in other nereidid genera. No epitokous metamorphosis was observed in H. atoka sp. nov., corresponding to its reproduction without swarming and to its development without a planktonic larval stage. Significant differences in paragnath numbers in the maxillary ring of the proboscis were found among the three species, suggesting different feeding habits. In Japan, the present distribution of H. japonica is restricted to muddy tidal flats in the inner part of the Ariake Sea, probably due to recent human impact, while the other two species are widespread.  © 2003 The Linnean Society of London. Zoological Journal of the Linnean Society, 2003, 137, 403−445     

Differential resource utilization and co-occurrence of leaf miners on oak (Quercus dentata)

Abstract.

• 1 Spatial, temporal, and dietary differences in resource utilization and patterns of interspecific association on leaves were investigated for dominant and common leaf-mining species on an oak species, Quercus dentata Thunb., in Hokkaido, northern Japan.
• 2 Leaf miners were divided into two groups according to leaf tissues used for food: upper-layer-feeders which consume the palisade paren-chymatous layer (Stigrnella spp. and tenthredinid sp.), and full-depth-feeders which consume spongy and palisade parenchymatous layers (Phyllonorycter leucocorona (Kumata), P.similis Kumata, and Caloptilia sapporella (Matsumura)).
• 3 Differences in the position of mines on leaves were found among species: mines of P.similis were distributed more frequently in the middle section of leaves, whereas those of the remaining species were concentrated in the basal section.
• 4 Leaf size preference differed between species: C.sapporella and tenthredinid sp. tended to select larger leaves more frequently than did the other species.
• 5 Phenological differentiation was found among species: C.sapporella appeared earliest, followed by P.similis, P.leucocorona and a tenthredinid sp., and then Stigmella spp.
• 6 Each species showed a highly clumped distribution among leaves. Leaf miners of some species pairs co-occurred on leaves more frequently than expected by chance.

     

DWARF50 (D50), a rice (Oryza sativa L.) gene encoding inositol polyphosphate 5‐phosphatase,is required for proper development of intercalary meristem

Rice internodes are vital for supporting high‐yield panicles, which are controlled by various factors such as cell division, cell elongation and cell wall biosynthesis. Therefore, formation and regulation of the internode cell‐producing intercalary meristem (IM) are important for determining the shape of internodes. To understand the regulation of internode development, we analysed a rice dwarf mutant, dwarf 50 (d50). Previously, we reported that parenchyma cells in the elongated internodes of d50 ectopically deposit cell wall phenolics. In this study, we revealed that D50 encodes putative inositol polyphosphate 5‐phosphatase (5PTase), which may be involved in phosphoinositide signalling required for many essential cellular functions, such as cytoskeleton organization, endocytosis and vesicular trafficking in eukaryotes. Analysis of the rice genome revealed 20 putative 5PTases including D50. The d50 mutation induced abnormally oriented cell division, irregular deposition of cell wall pectins and thick actin bundles in the parenchyma cells of the IM, resulting in abnormally organized cell files of the internode parenchyma and dwarf phenotype. Our results suggest that the putative 5PTase, encoded by D50, is essential for IM formation, including the direction of cell division, deposition of cell wall pectins and control of actin organization.     

LPS-induced activation of phospholipase A_2 phospholipase Cand protein kinase C of murine macrophage-like cell lines （J774 and P388D1）

A murine macrophage-like cell line,J774,acquried,in response to LPS,an ability to kill tumor necrosisfactor(TNF)-insensitive target P815 mastocytoma cells,whereas another cell line,P388D1,did not.LPS-triggered signaling mechanisms between the two celllines were compared with an aim to inquire about thepossible nature of the above-mentioned difference.Theresults showed that two cell lines respond to LPS-treatment by parallel activation of both phospholipasesC and A_2(PLC and PLA_2)to approximately the sameextent.The maximum response of both enzymes of J774cells was noted within 10 min of the treatment,whereas that of P388D1 cells required more than 20min.The other properties of LPS-responsive enzymesstudied were similar between two cell lines,ineludingActivation of PLC and PLA_2 and PKC in macrophages by LPSCa~(2 )augmentation of enzyme activation,participationof guanine nucleotide binding (G) proteins in theinitial activation processes,and inhibition of enzymeactivation by the prior treatment of cells with choleraorpartussis toxins etc.Moreover,LPS-triggered activationof PLC and PLA2 was found to be followed by theincrease of PKC activities in both cell lines.In spite ofthese similarities,J774 cells possessed both basic andacidic forms of PKC activities,while P 388D1 cells ownedonly PKC of basic form.Nevertheless,the question whyJ774 cells,but not P388D1 cells,can acquire thetumoricidal actiyity,aganist P815 cells following LPS-treatment remains to be answered.     

Intra-guild predation and variation in egg defence between sympatric and allopatric populations of two species of ladybird beetles

Abstract.  1. Ladybird eggs are defended chemically against intra-guild predation, and are unsuitable to varying degrees as food for other ladybirds.
2. Ladybird eggs [ Coccinella septempunctata (Cs) and Harmonia axyridis (Ha); Coleoptera: Coccinellidae] from local Japanese versus North American populations were compared as food for two ladybirds (Cs and Ha) co-occurring in Japan.
3. Larvae of Cs exhibited high mortality, slow development, and reduced egg consumption and weight gain when they fed on Ha versus conspecific eggs, especially when Ha eggs were from the local (Japanese) population versus a distant (North American) population of Ha.
4. Larvae of Ha survived equally well on a diet of Cs or conspecific eggs, but developed more slowly and gained less weight on Cs eggs. Ha larvae were more reluctant to eat eggs from the local (Japanese) population of Cs than eggs from the distant (North American) population of Cs; however, other measures of performance did not differ significantly.
5. These results indicate greater egg chemical defence of Ha eggs against Cs larvae than vice versa, as expected from field observations of greater temporal overlap between Cs larvae and Ha eggs than between Ha larvae and Cs eggs. Furthermore, results also indicate that local populations of eggs are better defended than eggs from elsewhere against locally occurring intra-guild predators. Thus, it appears that the effectiveness of chemical defence of ladybird eggs reflects the degree to which specific pairings of ladybirds have the potential to interact in nature through egg predation.     

Distribution,Molecular Structure and Functional Analysis of Carnitine Transporter (SLC22A5) in Canine Lens Epithelial Cells

While carnitine has been reported to have an anti-oxidative role on the ocular surface,there has been no report on the existence of a carnitine transporter (SLC22A5) in thelens. Therefore, we investigated the carnitine transport activity of canine lensepithelial cells (LEC) and determined the molecular structure of canineSLC22A5. The carnitine transport activity was 7.16 ± 0.48 pmol/mgprotein/30 min. Butyrobetaine, the analogue of carnitine, reduced 30% of the activity at50 µM. A coding sequence of canine carnitine transporter was 1694 bplong and was predicted to encode 557 amino acid polypeptides. The deduced amino acidsequence of canine carnitine transporter showed >80% similarity to that of mouse andhuman. Western blot analysis detected the band at 60 kDa in the membrane of lensepithelial cells. The high content of carnitine in the lens is possibly transported fromaqueous humor by SLC22A5.     

First record of an Early Barremian caprinid rudist from Japan – implications for the palaeobiogeography of the Caprinidae (Bivalvia)

Abstract: Pachytraga Paquier, 1900, the stratigraphically oldest genus of caprinine caprinid rudist, was previously known from only two chronospecies from a single lineage, that is the Hauterivian P. tubiconcha Astre, 1961 and the early Aptian P. paradoxa (Pictet and Campiche, 1869). Here, a new species, Pachytraga? tanakahitoshii, is erected on the basis of isolated left valves recovered from the Osaka and Sanchu areas, south‐west Japan. This species has a moderate shell size (antero‐posterior commissural diameter c. 30 mm), and its left valve is characterized by at least one possibly autapomorphic character (narrow anterior myophore, inclined inwards), as well as a mosaic of primitive (single longitudinal carina developed on the anterior side) and derived (simple marginal canals in the antero‐dorsal valve margin) characters of Mediterranean and Middle East Tethyan Pachytraga. The Japanese Pachytraga? represents the first probable record of this genus outside the Mediterranean/Middle Eastern Tethyan province, and its early Barremian age partly fills the ‘gap’ in its previously known stratigraphical record, although the evolutionary relationship of the Japanese form with Mediterranean and Middle East Tethyan Pachytraga remains unsolved. However, the discovery of early Barremian Pachytraga? in Japan indicates that the evolutionary history of the genus is more complex than previously thought and should thus be discussed in a broader palaeogeographical context that must now include the Pacific.     

Asynchronization of Cell Division is Concurrently Related with Ciliogenesis in Sea Urchin Blastulae

During the early development of the sea urchins, Temnopleurus toreumaticus, Temnopleurus hardwickii and Hemicentrotus pulcherrimus , the division synchrony in all blastomeres lasted only until the 4th cleavage and a regional synchrony or a graded activity of cell division appeared. In the midblastula stage prior to hatching, the regional synchrony vanished simultaneously with the formation of cilia, then the division proceeded asynchronously. The analysis of cell pedigrees confirmed that a variable extension of intercleavage times occurred after the ciliogenesis. In blastomeres derived from mesomeres of T. toreumaticus embryos, the mean intercleavage time extended from 48 min of the 8th cycle (pre-ciliated) to 115 min of the 9th cycle (ciliated), and the coefficient of variation increased from 15% to 39%. We attempted a kinetic analysis of cell proliferation on the basis of the transition probability model of cell cycle control. We concluded that the minimum time required for the completion of the cell cycle was the decisive factor in the cell cycle succession of pre-ciliated blastomeres, and that a sudden and sharp decrease in the transition probability of the ciliated blastomeres probably interpreted the abrupt slowing and asynchronization of the cleavage cycle at the time of ciliogenesis.