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Distribution of three GnRHs in the brain and pituitary of the wild Japanese flounder Paralichthys olivaceus 总被引：1，自引：1，他引：1
Ky Xuan Pham Masafumi Amano Noriko Amiya Yutaka Kurita Kunio Yamamori 《Fisheries Science》2006,72(1):89-94
ABSTRACT: Wild adult maturing and immature female Japanese flounder Paralichthys olivaceus were collected in June 2004 and January 2005, respectively, to clarify a possible role of gonadotropin-releasing hormones (GnRHs) in reproduction. Levels of salmon GnRH (sGnRH), chicken GnRH-II (cGnRH-II) and sea bream GnRH (sbGnRH) in the brain and pituitary were examined by time-resolved fluoroimmunoassay. Three forms of GnRHs were detected in the discrete brain at various levels. In the pituitary of both maturing and immature fish, sbGnRH was abundant together with a pronounced amount of sGnRH, whereas cGnRH-II was almost below the detectable limit. In maturing fish, levels of sbGnRH were high in the telencephalon, hypothalamus and pituitary, while levels of sbGnRH of immature fish were very low in these regions. These results indicate that sbGnRH is mainly responsible for gonadotropin secretion, and that sbGnRH in the anterior part of the brain is associated with gonadal maturation in the Japanese flounder. 相似文献
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Mizuho Sakai Sei-Ichi Okumura Kanami Onuma Hiroaki Senbokuya Kunio Yamamori 《Fisheries Science》2007,73(1):77-80
The telomere sequence type (TTAGGG)n is known to be distributed in various phyla in the Animalia and in Mastigophora (Protista). However, the telomere type of
Porifera (sponges), a phylum comprising the lowest multicellular animals, has not been reported. In this study, we examined
the three sponge species Leucetta chagosensis, Halichondria japonica, and Halichondria panicea for the presence of the telomere type (TTAGGG)n by fluorescence in situ hybridization (FISH). The oligonucleotide probe (TTAGGG)7 clearly displayed signals on the interphase nuclei of all three sponges. In contrast, the (TTAGG)7 probe, which has one base fewer than (TTAGGG)7, did not display the signals. These results suggest that the telomeres of the three sponges consist of (TTAGGG)n, which is identical to the sequence type found in many higher multicellular animals and in Mastigophora. Additionally, this
is the first study to reveal a telomere sequence type for Porifera. Moreover, these results suggest that Porifera are phylogenetically
related to Mastigophora, and supports the general theory that Porifera evolved from Mastigophora. Further, this study strongly
suggests that the origin of the (TTAGGG)n telomere sequence is to be found in a common ancestor of either the Bilateria and Porifera, or the Protista. 相似文献
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Decrease of Waxy (Wx) Protein in Two Common Wheat Cultivars with Low Amylose Content 总被引：17，自引：0，他引：17
Two cultivars with a low amylose content, Kanto107 (K107) and K79, were discovered in Japanese common wheat (Triticum aestivum L.). The amount of Wx protein, identified as a single major starch granule-bound protein of about 61 kD by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), was greatly decreased in those two cultivars. Analysis of their Wx protein with a modified SDS-PAGE and two dimensional-PAGE showed that two of the three Wx proteins, produced by Wx-A1 and Wx-B1 loci, were not detected. It was thus concluded that only one locus, Wx-D1, was active in the two low amylose cultivars. These mutants were termed “partial waxy mutants” and considered to be very useful material for breeding waxy wheat. 相似文献
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Sei-Ichi Okumura Katsutoshi Arai Yoshitaka Harigaya Hirotaka Eguchi Mizuho Sakai Hiroaki Senbokuya Suehiro Furukawa Kunio Yamamori 《Fisheries Science》2007,73(2):237-243
ABSTRACT: In order to develop a highly efficient method for mass production of triploid Pacific abalone Haliotis discus hannai , caffeine treatment that is safe and inexpensive was optimized. To suppress the first meiotic division, fertilized eggs were exposed to either a 10- or 15-mM caffeine solution for 24 min beginning at 12 min after fertilization. In most treated batches, the rates of cleaved eggs showed no significant difference from the control batches. However, in most treated batches, the rates of occurrence of normal larvae and the survival rates of the early juveniles were significantly lower than those of the controls. The triploid rates at 6 days to 11 months after settlement in all the treated batches were extremely high (91–100%). There was no significant difference in the mean triploid rates between 10- and 15-mM caffeine treatments. These results suggest that both treatment conditions were conducive to triploid abalone production. One live 2n/3n mosaic specimen was found in the treated batches. However, since the frequency of mosaic was extremely low, the mosaicism would probably not have an adverse effect on the stable production of triploid abalones. 相似文献
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Yamamoto Y Mori M Saito S Amano M Yamanome T Taniguchi K Oikawa T Yamamori K Taniguchi K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(12):1609-1611
Differentiation of the histochemical characteristics of the olfactory receptor cells (ORC) was examined by immunohistochemistry for protein gene product 9.5 (PGP 9.5) and calretinin (CR) and lectin histochemistry for Phaseolus vulgaris agglutinin-L (PHA-L) in the developing olfactory epithelium (OE) of the barfin flounder. PGP 9.5 immunoreactivity was diffuse and CR immunoreactivity was restricted at day 7, but these immunoreactivities became intense in the OE toward day 91. Crypt cells were first identified at day 56. PHA-L staining was faint at day 28, but became intense toward day 91. These findings suggest that PGP 9.5-immunopositive cells, CR-immunopositive cells, crypt cells and PHA-L-reactive cells differentiate independently in the developing OE and constitute subsets of the ORC in the OE. 相似文献
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H. Chiba M. Amano H. Yamada Y. Fujimoto D. Ojima K. Okuzawa T. Yamanome K. Yamamori M. Iwata 《Fish physiology and biochemistry》2004,30(3-4):267-273
Effects of gonadotropin-releasing hormone (GnRH) on thyroxine (T4) release in vivo and in vitro were studied in barfin flounder Verasper moseri, masu salmon Oncorhynchus masou and goldfish Carassius auratus. Seabream GnRH (sbGnRH) at a dose of 200 ng/50 g body weight (BW) significantly increased plasma T4 levels 1 h after the in vivo injection in the barfin flounder, but thereafter the levels normalized. Salmon GnRH (sGnRH) significantly increased plasma
T4 levels l h after the injection with a significant return to initial levels in male masu salmon and male goldfish. In contrast,
sGnRH and cGnRH-II in barfin flounder, and cGnRH-II in male masu salmon and male goldfish were not effective in stimulating
T4 release. To clarify direct involvement of GnRH in T4 release, dissected lower jaw including scattered thyroid follicles was incubated with sbGnRH (1 μg/well) in barfin flounder,
and with two doses (0.1 and 1 μg/well) of sGnRH in masu salmon and goldfish in vitro. T4 concentrations of control were stable during 24 h. Incubation of lower jaw with high dose (1 μg/well) of GnRH significantly
(P<0.05) increased T4 concentrations of incubation medium at 1 h in all experimental fishes. These results indicate that direct stimulation of
T4 secretion by GnRH occurs widely in teleost fish. 相似文献