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31.
Tsuyoshi SHIMMURA Yusuke EGUCHI Katsuji UETAKE Toshio TANAKA 《Animal Science Journal》2008,79(1):129-138
The objective of the present study was to evaluate the welfare level of hens in four molting methods by comparing their behavior, physical condition and performance. In total, 96 White Leghorn layers (72 weeks of age) were used. The four molting methods consisted of 10 days of feeding and the first 3 days of water withdrawal WFW); 10 day feed withdrawal (WF) followed by ad libitum access to a layer diet from day 11, 28 days of restricted feeding (RF) and 28 days without withdrawing their feed (NW). The RF and NW hens were fed a low energy diet. The WFW and WF hens showed two clear phases of behavior during the 10‐day fasting period. Explorative and stereotyped behavior increased for WFW and WF hens just after their fast. Standing‐resting then increased for WFW and WF hens while lying‐resting decreased. In contrast, RF and NW hens did not show clear behavioral changes during the 28‐day molt period. The weight loss of the NW hens was more gradual compared with the other three methods. No significant differences were seen in any productive trait among the four methods during the postmolt period. In conclusion, the welfare level of RF and NW, especially NW, was higher compared with WFW and WF. 相似文献
32.
To investigate the reproductive traits and diel activity ofMonochamus saltuarius, 14 pairs of the adults were reared and observed at each of 20°C and 25°C. Both sexes were more active at 25°C than at 20°C
irrespective of the presence or absence of light. A diel change in behavior during 24 h was found on 33% of a total of 48
observations of three age classes of both sexes. No significant difference was found in the mean longevity between sexes or
between the two temperature conditions. The time required for reproductive maturation showed no significant difference within
the same sex when reared at 20°C and 25°C. The mean oviposition period was significantly longer at 25°C (28.8 days) than at
20°C (12.2 days). The mean lifetime fecundity was significantly greater at 25°C than at 20°C. There was no significant difference
in the oviposition ratio (number of eggs deposited/number of oviposition wounds excavated), oviposition rate or hatchability
for females between the two temperature conditions. 相似文献
33.
Kenji Minami Hiroki Yasuma Naoki Tojo Shin-ichi Fukui Yusuke Ito Takahiro Nobetsu Kazushi Miyashita 《Fisheries Science》2010,76(5):729-736
Sustainable management of the kelp forests of the Shiretoko Peninsula, a World Natural Heritage site, is necessary due to
kelp’s ecological and economic importance. The objectives of this study were to estimate the area of kelp forests and to clarify
their spatial characteristics in coastal waters of the Shiretoko Peninsula. Data on the presence/absence and thickness of
kelp forests were collected via acoustic observation on transects over about 80 km using an echosounder at 200 kHz. Acoustic
data were geostatistically interpolated, and the areas covered by kelp forests were estimated. Differences in kelp distribution
between the eastern and western sides of the peninsula were compared. The total area of kelp forest was 3.88 km2 (eastern area: 3.49 km2; western area: 0.39 km2). The range of thickness of the kelp forests was 34–91 cm. Many kelp forests in the eastern area were thick (>78 cm) and
distributed continuously, while kelp forests in the western area were sparsely distributed. 相似文献
34.
Yoshiki HIRATA Yusuke KATSUKURA Yuka HENMI Ren OZAWA Sayaka SHIMAZAKI Akira KUROSAWA Yasushi TORII Hironori TAKAHASHI Hisataka IWATA Takehito KUWAYAMA Koumei SHIRASUNA 《The Journal of reproduction and development》2021,67(4):257
Advanced maternal age is a risk factor for female infertility, and placental dysfunction is considered one of the causes of pregnancy complications. We investigated the effects of advanced maternal aging on pregnancy outcomes and placental senescence. Female pregnant mice were separated into three groups: young (3 months old), middle (8–9 months old), and aged (11–13 months old). Although the body weights of young and middle dams gradually increased during pregnancy, the body weight of aged dams only increased slightly. The placental weight and resorption rate were significantly higher, and live fetal weights were reduced in a maternal age-dependent manner. Although mRNA expression of senescence regulatory factors (p16 and p21) increased in the spleen of aged dams, mRNA expression of p16 did not change and that of p21 was reduced in the placenta of aged dams. Using a cytokine array of proteins extracted from placental tissues, the expression of various types of senescence-associated secretory phenotype (SASP) factors was decreased in aged dams compared with young and middle dams. The aged maternal placenta showed reduced immune cell accumulation compared with the young placenta. Our present results suggest that models using pregnant mice older than 8 months are more suitable for verifying older human pregnancies. These findings suggest that general cellular senescence programs may not be included in the placenta and that placental functions, including SASP production and immune cell accumulation, gradually decrease in a maternal age-dependent manner, resulting in a higher rate of pregnancy complications. 相似文献
35.
Lin Zhang Yusuke Nakagomi Takashi Endo Mika Teranishi Jun Hidema Shusei Sato Atsushi Higashitani 《Rice》2018,11(1):63
Background
The rice blast resistance gene Pi54 was cloned from Oryza sativa ssp. indica cv. Tetep, which conferred broad-spectrum resistance against Magnaporthe oryzae. Pi54 allelic variants have been identified in not only domesticates but also wild rice species, but the majority of japonica and some indica cultivars lost the function.Results
We here found that Pi54 (Os11g0639100) and its homolog Os11g0640600 (named as #11) were closely located on a 25 kbp region in japonica cv. Sasanishiki compared to a 99 kbp region in japonica cv. Nipponbare. Sasanishiki lost at least six genes containing one other R-gene cluster (Os11g0639600, Os11g0640000, and Os11g0640300). Eight AA-genome species including five wild rice species were classified into either Nipponbare or Sasanishiki type. The BB-genome wild rice species O. punctata was Sasanishiki type. The FF-genome wild rice species O. brachyantha (the basal lineage of Oryza) was neither, because Pi54 was absent and the orientation of the R-gene cluster was reversed in comparison with Nipponbare-type species. The phylogenetic analysis showed that #11gene of O. brachyantha was on the root of both Pi54 and #11 alleles. All Nipponbare-type Pi54 alleles were specifically disrupted by 143 and 37/44?bp insertions compared to Tetep and Sasanishiki type. In addition, Pi54 of japonica cv. Sasanishiki lost nucleotide-binding site and leucine-rich repeat (NBS–LRR) domains owing to additional mutations.Conclusions
These results suggest that Pi54 might be derived from a tandem duplication of the ancestor #11 gene in progenitor FF-genome species. Two divergent structures of Pi54 locus caused by a mobile unit containing the nearby R-gene cluster could be developed before domestication. This study provides a potential genetic resource of rice breeding for blast resistance in modern cultivars sustainability.36.
37.
Yoji Igarashi Hiroyuki Doi Yusuke Yamanoue Shigeharu Kinoshita Toshiaki Ishibashi Hideki Ushio Shuichi Asakawa Mutsumi Nishida Shugo Watabe 《Fisheries Science》2013,79(2):243-250
Pufferfishes belonging to the genus Tetraodon form one of the largest groups in the family Tetraodontidae. This group consists of more than 20 species distributed across freshwater, as well as brackish and coastal waters, of Africa and Southeast Asia. However, their phylogenetic and evolutionary relationships are still ambiguous. In the present study, mitochondrial genes encoding 16S rRNA and cytochrome b were sequenced for 17 Tetraodon species collected from various areas mentioned above. Supermatrix analysis based on the complete sequences of the two genes from Tetraodon species was performed using a tree with 50 tetraodontid species (including 7 Tetraodon species) as a backbone. The obtained phylogenetic tree classified Tetraodon species into three groups, correlating well with their habitats, such as Asian freshwater, Asian brackish water, and African freshwater. We also showed that salinity tolerance of Asian freshwater species T. cochinchinensis was apparently lower than that of Asian brackish water species T. nigroviridis, suggesting that the speciation of Tetraodon species in the Asian freshwater group was caused by the molecular evolution associated with osmotic regulation. 相似文献
38.
To determine the viscoelasticity of wood three-dimensionally, a longitudinal tensile creep test was conducted on 12 species
of wood to examine the change in the rate of volume increase (ΔV/V) with time. Immediately after the beginning of creep, ΔV/V was positive, and during creep, ΔV/V decreased rapidly, then more gradually. The decrease in tangential strain was considered to mainly contribute to the decrease
in ΔV/V during creep. Immediately after the removal of the load, ΔV/V decreased to a negative value; thereafter, it decreased slowly and finally reached a certain value. The value of ΔV/V during creep tended to decrease with increasing density of wood. Also, there was a negative correlation between wood density
and the rate of increase in ΔV/V. 相似文献
39.
Kemmochi S Fujimoto H Woo GH Hirose M Nishikawa A Mitsumori K Shibutani M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(5):655-664
We have shown phosphoinositide 3-kinase (PI3K)/Akt signaling activation in thyroid capsular invasive carcinomas (CICs), which are highly induced by promotion with sulfadimethoxine (SDM) in a rat 2-stage thyroid carcinogenesis model. To examine the potency of calcitriol, a synthetic vitamin D3 analog, on the development or progression of CICs, male F344 rats were injected with calcitriol (0.1 μg/kg body weight) three times a week intraperitoneally, during an entire period of SDM-promotion for 13 weeks (Experiment 1) or during the last 2 weeks of a 15-week SDM-promotion (Experiment 2). Initiation with N-bis(2-hydroxypropyl)nitrosamine preceded all treatments. In Experiment 1, long-term calcitriol treatment reduced the multiplicity of CICs, while cell proliferation activity, estimated by Ki-67 cell index in the induced CICs, was unchanged with SDM-promotion alone. Considering the strong dependency of promotion with SDM during the early stages on thyroid-stimulating hormone, the reduced multiplicity in Experiment 1 may be due to the effect on an early stage of neoplastic proliferation. Although the magnitude was mild, cell proliferation activity was decreased in existing CICs after short-term calcitriol treatment in Experiment 2, which was associated with a mild decrease in cyclin-dependent kinase-2-positive cells, cytoplasmic immunolocalization of phosphorylated, inactive, Rb protein and a mild increase in nucleocytoplasmic expression of p27(kip1). Although the effect was mild at the late stage of SDM-promotion in this hypothyroidism-related thyroid carcinogenesis model, our results suggest that calcitriol targets cell proliferation via inhibition of a molecular cascade downstream of PI3K/Akt signaling, controlling G1/S transition. 相似文献
40.
Arai Y Ohgane J Yagi S Ito R Iwasaki Y Saito K Akutsu K Takatori S Ishii R Hayashi R Izumi S Sugino N Kondo F Horie M Nakazawa H Makino T Shiota K 《The Journal of reproduction and development》2011,57(4):507-517
Epigenetic alteration is an emerging paradigm underlying the long-term effects of chemicals on gene functions. Various chemicals, including organophosphate insecticides and heavy metals, have been detected in the human fetal environment. Epigenetics by DNA methylation and histone modifications, through dynamic chromatin remodeling, is a mechanism for genome stability and gene functions. To investigate whether such environmental chemicals may cause epigenetic alterations, we studied the effects of selected chemicals on morphological changes in heterochromatin and DNA methylation status in mouse ES cells (ESCs). Twenty-five chemicals, including organophosphate insecticides, heavy metals and their metabolites, were assessed for their effect on the epigenetic status of mouse ESCs by monitoring heterochromatin stained with 4¢,6-diamino-2-phenylindole (DAPI). The cells were surveyed after 48 or 96 h of exposure to the chemicals at the serum concentrations of cord blood. The candidates for epigenetic mutagens were examined for the effect on DNA methylation at genic regions. Of the 25 chemicals, five chemicals (diethyl phosphate (DEP), mercury (Hg), cotinine, selenium (Se) and octachlorodipropyl ether (S-421)) caused alterations in nuclear staining, suggesting that they affected heterochromatin conditions. Hg and Se caused aberrant DNA methylation at gene loci. Furthermore, DEP at 0.1 ppb caused irreversible heterochromatin changes in ESCs, and DEP-, Hg- and S-421-exposed cells also exhibited impaired formation of the embryoid body (EB), which is an in vitro model for early embryos. We established a system for assessment of epigenetic mutagens. We identified environmental chemicals that could have effects on the human fetus epigenetic status. 相似文献