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951.
952.
Kubota K Yamauchi N Matsumoto K Watanabe R Oozono S Aramaki S Wood C Soh T Hattori MA 《The Journal of reproduction and development》2008,54(5):340-345
Hedgehog (Hh) plays a pivotal role in various tissues during embryonic development, tissue homeostasis and tumorigenesis. In mammals, Hh exists in three homologs: Desert hedgehog (Dhh), Indian hedgehog (Ihh) and Sonic hedgehog (Shh). In this study, we cloned full-length cDNAs encoding Dhh and Ihh from the rat uterus. Their amino acid sequences have a high homology with those of the mouse and human. In addition, the changes of Hh gene expression in the rat uterus during early pregnancy were analyzed. The results showed that all three hedgehog mRNAs were detected in the rat uterus at the proestrus stage and during early pregnancy (1.5, 3.5, 5.5 and 7.5 days post coitus: dpc). Ihh mRNA expression varied and peaked at 3.5 dpc in the luminal and glandular epithelium. Expression was decreased on 5.5 dpc with the exception of sustained expression in the glandular epithelium. Despite such Ihh variability, the expressions of Dhh and Shh mRNA remained unchanged. This indicated that Ihh was mainly expressed in the rat uterus during early pregnancy. Moreover, the Hh target gene (glioma-associated oncogene homolog 1; Gli1) was also highly expressed at 3.5 dpc in the epithelium and periepithelial stroma in a manner similar to the temporal pattern of Ihh expression. This suggests that Ihh signaling axis play a role in the rat uterus during early pregnancy. In summary, our results elucidate that Ihh is a predominant Hh protein in the rat uterus during early pregnancy and that other Hhs have the potential to be expressed. This observation will help to elucidate the basic molecular mechanism of rat uterus during early pregnancy. 相似文献
953.
Josephine Pegg Chris F. Williams Julien Cucherousset J. Robert Britton 《Ecology of Freshwater Fish》2011,20(4):598-604
Abstract – Nonnative parasites have the potential to detrimentally affect naïve hosts, resulting in negative consequences for their growth, condition and energetics. Here, the effect of the introduced parasitic nematode Philometroides sanguineus on crucian carp Carassius carassius populations in England was investigated. Populations of C. carassius populations are increasingly spatially restricted in England and under increasing threat from habitat loss and hybridisation. Parasite prevalence across 6 infected populations was <27% and, generally, there was no significant relationship between levels of infection and fish length and age. Parasite abundance ranged between 1 and 8 nematodes and was not significantly related to fish length and age. Comparison of the growth, body weight and condition, and energy reserves between infected and noninfected C. carassius revealed infection did not incur significant detrimental impacts on these parameters. Whilst this suggests that infection had only minimal impacts on the examined host fish, this may have been a consequence of a low proportion of fish <100 mm in samples (i.e., size‐selective effects) and some tests did suffer from low statistical power because of, for example, unbalanced sample sizes. It does, however, suggest that P. sanguineus may not be a major threat to the status of these C. carassius populations and infection by introduced parasites may not always incur significant impacts in naïve fishes. 相似文献
954.
美国家禽业面临的机遇和挑战 总被引:1,自引:1,他引:0
Chris Harris 《中国家禽》2008,30(6):56-57
禽产品需求从全球趋势看是持续上涨的,但根据美国农业统计处研究分析,美国家禽业面临来自饲料原料价格、环境以及消费需求的压力和挑战.家禽业生产人类需要并且持续消费的产品.年复一年,从业者不断进行基因改良和生产改进,并获得了大量效益,这是其他行业不能做到的. 相似文献
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956.
Sabaz A. Khan Yury Tikunov Pierre‐Yves Chibon Chris Maliepaard Jules Beekwilder Evert Jacobsen Henk J. Schouten 《Plant Breeding》2014,133(2):281-290
We analysed metabolic diversity in apples from wild species, elite material and a F1 population, using liquid chromatography–mass spectrometry (LC‐QTOF‐MS). The evaluated elite material appeared to have strongly reduced levels of phenolic compounds, down to 1% of the concentrations in the investigated wild germplasm. In one quarter of the F1 population, the concentrations of phenolic compounds such as quercetin derivatives, procyanidin, catechin and epicatechin were further significantly reduced, due to accumulation of recessive alleles of putatively leucoanthocyanidin reductase, a structural gene that is located at the top of LG16. In another part of F1 progeny, putatively glycosylated forms of β‐glycols were up to 50 times more abundant compared to both parents. These metabolites were mapped with high logarithm of odds (LOD) scores at the top of LG8, and progeny that was homozygous recessive for the candidate gene showed the elevated levels. We hypothesize that this was caused by inheritance of non‐functional alleles of enoyl‐CoA hydratase gene. Both examples of transgressive segregation, where some progeny significantly deviated from both parents, were caused by accumulation of recessive alleles. 相似文献
957.
Miguel Costa Leal Marcela Carraro Melo Vaz João Puga Rui Jorge Miranda Rocha Chris Brown Rui Rosa Ricardo Calado 《Fish and Fisheries》2016,17(2):459-468
The marine ornamental fish trade (MOFT) is a worldwide industry that targets a remarkable quantity and diversity of reef fish species and provides an important source of revenue for exporting countries, particularly developing nations in Southeast Asia. Here we provide, for the first time, an economic assessment of the MOFT to the European Union (EU), one of the key players of the marine aquarium trade, along with the USA and Japan. Data from EUROSTAT (the European Statistical System) was analysed for the MOFT between 2000 and 2011. Results show that this industry was not affected by the economic crisis and accounted for a total of 135 million Euros during the study period. Both the UK and Indonesia have been reinforcing their importance as leading importer and exporter countries, respectively. The long‐term temporal pattern of the MOFT by EU and non‐EU countries is described, as well as its diversity and evenness between importing and exporting countries. The present economic assessment also identifies the key players of this industry, and ultimately contributes to management and conservation practices that may enhance the sustainable use of world's coral reefs. 相似文献
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960.
Chris de Bont Gert Jan Veldwisch Hans Charles Komakech Jeroen Vos 《Agriculture and Human Values》2016,33(3):641-654
This article contributes to the contemporary debate on land and water grabbing through a detailed, qualitative case study of horticultural agribusinesses which have settled in Tanzania, disrupting patterns of land and water use. In this paper we analyse how capitalist settler farms and their upstream and downstream peasant neighbours along the Nduruma river, Tanzania, expand and defend their water use. The paper is based on 3 months of qualitative field work in Tanzania. We use the echelons of rights analysis framework combined with the concept of institutional bricolage to show how this contestation takes place over the full spectrum of actual abstractions, governance and discourses. We emphasise the role different (inter)national development narratives play in shaping day-to-day contestations over water shares and rule-making. Ultimately, we emphasise that water grabbing is not a one-time event, but rather an on-going struggle over different water resources. In addition, we show how a perceived beneficial development of agribusinesses switching to groundwater allows them to avoid peasant-controlled institutions, avoiding further negotiation between the different actors and improving their image among neighbouring communities. This development illustrates how complex and obscured processes of water re-allocation can be without becoming illegal per se. 相似文献