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991.
Retinoid signaling determines germ cell fate in mice 总被引:1,自引:0,他引:1
Bowles J Knight D Smith C Wilhelm D Richman J Mamiya S Yashiro K Chawengsaksophak K Wilson MJ Rossant J Hamada H Koopman P 《Science (New York, N.Y.)》2006,312(5773):596-600
Germ cells in the mouse embryo can develop as oocytes or spermatogonia, depending on molecular cues that have not been identified. We found that retinoic acid, produced by mesonephroi of both sexes, causes germ cells in the ovary to enter meiosis and initiate oogenesis. Meiosis is retarded in the fetal testis by the action of the retinoid-degrading enzyme CYP26B1, ultimately leading to spermatogenesis. In testes of Cyp26b1-knockout mouse embryos, germ cells enter meiosis precociously, as if in a normal ovary. Thus, precise regulation of retinoid levels during fetal gonad development provides the molecular control mechanism that specifies germ cell fate. 相似文献
992.
Hideaki Korai Nan Ling Hiroshi Saotome Takahiko Iida Tomoko Hamano Kensuke Kawarada 《Journal of Wood Science》2012,58(5):417-422
An air-injection press, which has holes punched in the heating plates, injects high-pressure air through the holes of one plate into particleboard and discharges the air through the other plate during press heating. The press can manufacture particleboard from high-moisture particles by controlling blowout of the boards. In this study, the optimum diameter and spacing of the air-injection holes and the effects of pre- and post-pressing were investigated. An optimum hole diameter was not found for the modulus of rupture and thickness swelling for a spacing of either 25 or 50 mm. In terms of internal bond strength, the optimum diameter of the holes arranged at a spacing of 25 mm was 1 mm, but the internal bond strength was not changed by the diameter of holes spaced 50 mm apart. Air injection under all hole conditions reduced the formaldehyde emission from the board. Pre-pressing was tested for further increase in the modulus of rupture and internal bond strength, but was found to have no effect. More efficient use of the air-injection press was achieved by injecting air from the early stages of pressing. 相似文献
993.
Hiroshi Saotome Hideaki Korai Takahiko Iida Tomoko Hamano Kensuke Kawarada Masaharu Ohmi 《Journal of Wood Science》2012,58(5):423-428
An air-injection press (AIP) was developed to prevent accidental blowouts of boards during production. In this study, the effects of the AIP on preventing blowouts were investigated by artificially creating a blowout-prone condition, and the press was shown to be effective in preventing blowouts. The modulus of rupture of the boards was almost constant irrespective of pressing time. Longer pressing time resulted in higher internal bond strength when pressed at 170 °C. The thickness swelling of the boards pressed at 170 or 190 °C was almost uniform irrespective of pressing time, and the manufactured boards showed performance similar to those manufactured with an ordinary press. The AIP prevented blowouts sufficiently even when the pressure of the injected air was reduced, and this reduction did not adversely decrease the performance of the boards. Air injection reduced formaldehyde emissions from the board. 相似文献
994.
Itoh N Ikegami H Takagi M Ito Y Kanai K Chikazawa S Hori Y Hoshi F Higuchi S 《Journal of Feline Medicine and Surgery》2012,14(6):436-439
The present study is the first national investigation of intestinal parasites in private-household cats in Japan. A total of 942 faecal samples were collected from private-household cats. Giardia species was assessed using an enzyme-linked immunosorbent assay kit and other intestinal parasites were identified microscopically. The overall prevalence of intestinal parasites was 10.1%; two protozoan parasites (Giardia species and Cystoisospora species) and five helminths (Toxocara cati, Toxascaris leonina, Ancylostoma tubaeforme, Taenia species and Spirometra erinacei) were detected. The total prevalence of intestinal parasite infection was significantly higher in cats aged ≤ 6 months old than in cats older than 6 months because of a significantly higher prevalence of Cystoisospora species and T cati. The total infection prevalence was higher among outdoor cats as a result of the significantly higher prevalence of T cati and S erinacei. Sex and faecal condition were not related to intestinal parasite infections. Regional differences were observed in Cystoisospora species and A tubaeforme. 相似文献
995.
Junichiro ISHII Hiroshi OMURA Tadao MITSUI Norichika EGUCHI Takashi UENO Hisaya GOTO Hiroshi ITO 《Animal Science Journal》2012,83(1):36-42
This study evaluated the effects of hinokitiol (a natural antibacterial compound extracted from Thujopsis dolabrata var. hondai) and an organic acid mixture (citrate content 50%) on ruminal fermentation. Antibacterial properties were examined by measuring minimal inhibitory concentration. Hinokitiol at 1.56 µg/mL or an organic acid mixture at 1600 µg/mL inhibited Streptococcus bovis growth. The combination of 0.78 µg/mL hinokitiol and 200 µg/mL of an organic acid mixture also inhibited S. bovis growth. Both hinokitiol and the hinokitiol and an organic acid mixture combination showed strong antibacterial properties on Gram‐positive bacteria such as S. bovis, but relatively weak antibacterial activities on Gram‐negative bacteria such as Megasphaera elsdenii. Three ruminally cannulated heifers were fed a bloat‐producing diet containing barley, pelleted alfalfa meal, soybean meal and salt without long‐cut roughage to investigate the ruminal characteristics in vivo. Feeding to heifers a bloat‐producing diet containing 7.8 mg/kg hinokitiol and 0.2% of an organic acid mixture significantly decreased the increase in stable ingesta volume. Hinokitiol or an organic acid mixture did not affect ruminal volatile fatty acids, protozoa and bacteria. These results suggest that a combination of hinokitiol and an organic acid mixture might reduce frothy bloat in cattle fed high‐grain diets. 相似文献
996.
Yoshinobu UEMOTO Takashi KIKUCHI Hikaru NAKANO Shuji SATO Tomoya SHIBATA Hiroshi KADOWAKI Kazuo KATOH Eiji KOBAYASHI Keiichi SUZUKI 《Animal Science Journal》2012,83(5):375-385
The leptin receptor (LEPR) gene is considered a candidate gene for fatness traits. It is located on SSC 6 in a region in which quantitative trait loci (QTLs) for backfat thickness (BF), fat area ratios, and serum leptin concentration (LEPC) have previously been detected in a Duroc purebred population. The objectives of the present study were to identify porcine LEPR polymorphisms and examine the effects of LEPR polymorphisms on fatness traits in this same population. The Duroc pigs (226 to 953 pigs) were evaluated for BF, fat area ratios using image analysis, and LEPC. A total of seven single nucleotide polymorphisms (SNPs) in the full‐length LEPR coding region were identified in pigs from the base population. Four non‐synonymous SNPs of the LEPR gene and 15 microsatellite markers on SSC 6 were then genotyped in all pigs. During candidate gene analysis, we detected significant effects of the non‐synonymous SNP c.2002C>T in exon 14 on all traits. In fine mapping analysis, significant QTLs for BF, fat area ratios, and LEPC were detected near the LEPR gene in the same region. These results indicated that the c.2002C>T SNP of LEPR has a strong effect on BF, fat area ratios and LEPC. 相似文献
997.
Konosuke OTOMARU Yuki NAOI Kei HAGA Tsutomu OMATSU Takehiko UTO Motoya KOIZUMI Tsuneyuki MASUDA Hiroshi YAMASATO Hikaru TAKAI Hiroshi AOKI Shinobu TSUCHIAKA Kaori SANO Sachiko OKAZAKI Yukie KATAYAMA Mami OBA Tetsuya FURUYA Junsuke SHIRAI Kazuhiko KATAYAMA Tetsuya MIZUTANI Makoto NAGAI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(2):321-324
During surveillance for bovine diarrhea of unknown causes in Japanese black cattle in Kagoshima Prefecture,
Japan, we found two types of novel kobu-like viruses in fecal samples of calves. Sequence analyses revealed
that they had L protein and 2A protein with H-box/NC sequence motif, which are present in kobuviruses.
Phylogenetic analysis revealed that they were related to kobuviruses; however, they clustered apart from other
kobuviruses. In the prevalence study of two types of novel kobu-like viruses, 16.9% and 10.4% prevalence of
these viruses were observed in the feces of diarrheal calves in this area. 相似文献
998.
Kohtaro Iseki Rusama Marubodee Hiroshi Ehara Norihiko Tomooka 《Plant Production Science》2017,20(1):144-148
A rapid quantification method for leaf sodium (Na+) and potassium (K+) concentrations was developed using a compact ion meter. Leaf ion concentrations were evaluated for species of Vigna vexillata (L.) A. Rich. after two weeks of treatment with 0–200 mM of sodium chloride. To compare the ion extraction efficiency, extraction solutions of distilled water and ammonium acetate were tested. The ion concentrations of extracts obtained by both solutions were measured using an ion meter, and the values were validated using ion chromatography. For both extraction solutions, the ion meter values were highly correlated with those of the ion chromatograph. However, correlations between ion meter and chromatograph values were largely different for Na+ and K+. The rapid quantification of ion concentrations using an ion meter developed in this study was successfully utilized for evaluating differences in leaf Na+ concentrations, K+ concentrations, and K+/Na+ ratio in species of V. vexillata. 相似文献
999.
Yuria UMEMURA Ryosuke MIYAMOTO Rie HASHIMOTO Kyoko KINOSHITA Takuya OMOTEHARA Daichi NAGAHARA Tetsushi HIRANO Naoto KUBOTA Kiichi MINAMI Shogo YANAI Natsumi MASUDA Hideto YUASA Youhei MANTANI Eiko MATSUO Toshifumi YOKOYAMA Hiroshi KITAGAWA Nobuhiko HOSHI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(12):1587-1598
Mammalian sexual fate is determined by the presence or absence of sex determining
region of the Y chromosome (Sry) in the “bipotential” gonads.
Recent studies have demonstrated that both male and female sexual development are induced
by distinct and active genetic pathways. Breeding the Y chromosome from Mus m.
domesticus poschiavinus (POS) strains into C57BL/6J (B6J) mice
(B6J-XYPOS) has been shown to induce sex reversal (75%: bilateral ovary, 25%:
true hermaphrodites). However, our B6N-XYPOS mice, which were generated by
backcrossing of B6J-XYPOS on an inbred B6N-XX, develop as males (36%: bilateral
testis with fertility as well as bilateral ovary (34%), and the remainder develop as true
hermaphrodites. Here, we investigated in detail the expressions of essential sex-related
genes and histological features in B6N-XYPOS mice from the fetal period to
adulthood. The onsets of both Sry and SRY-box 9 (Sox9) expressions as determined
spatiotemporally by whole-mount immunohistochemistry in the B6N-XYPOS gonads
occurred 2–3 tail somites later than those in B6N-XYB6 gonads, but earlier than
those in B6J-XYPOS, respectively. It is possible that such a small difference
in timing of the Sry expression underlies testicular development in our
B6N-XYPOS. Our study is the first to histologically show the expression and
ectopic localization of a female-related gene in the XYPOS testes and a
male-related gene in the XYPOS ovaries. The results from these and previous
experiments indicate that the interplay between genome variants, epigenetics and
developmental gene regulation is crucial for testis development. 相似文献
1000.
Ei-ichirou TAKAHARA Hideto YUASA Miho NISHIDA Youhei MANTANI Kankanam Gamage Sanath UDAYANGA Wang-Mei QI Takashi TAKEUCHI Toshifumi YOKOYAMA Nobuhiko HOSHI Hiroshi KITAGAWA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(4):387-393
A portion of the minute chylomicrons less than 75 nm in diameter are transcytosed from
the extravascular tissue into the subepithelial blood capillaries (sBC) in the villous
apices of the rat jejunum. However, the details of the transportation mechanism have not
been clarified. In this study, the endothelial receptor involved in the transportation of
minute chylomicrons into the sBC’s lumina was immunohistochemically and
histoplanimetrically examined in intestinal villi of the rat jejunum. Immunopositivity for
very low density lipoprotein (VLDL) receptor was detected on the luminal and basal
surfaces of the endothelial cells of sBC in approximately 68% of those apices of jejunal
villi that possessed numerous chylomicrons in the lamina propria, while VLDL receptor was
detected on the endothelial cells of sBC in only approximately 8% of intestinal villi that
possessed few or no chylomicrons in the lamina propria. No immunopositivity for LDL
receptor was detected in the sBC of all intestinal villi. These findings suggest that VLDL
receptor is expressed by the endothelial cells of the sBC in conjunction with the filling
of the lamina propria of jejunal villi with many chylomicrons produced by the villous
columnar epithelial cells and that the VLDL receptor mediates the transportation of minute
chylomicrons, maybe VLDL, into the subepithelial portal blood from the extravascular
tissue of the rat jejunal villi. 相似文献