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Ageing Belanger's croaker,Johnius belangerii (Cuvier, 1830), based on otolith shape analysis 下载免费PDF全文
Z. J. Ye C. Zhang S. K. Panhwar Z. G. Li R. Wan 《Zeitschrift fur angewandte Ichthyologie》2015,31(1):27-31
The use of morphological characters and otolith weight as predictors of fish age has proven to be an efficient, objective and precise method, but studies were heretofore focused primarily on fast‐growing fish species. In the present study, Belanger's croaker, Johnius belangerii (Cuvier, 1830), is presented as a model species for slow‐growing fish where it is hypothesized that age has a significant effect on the otolith shape, and that the otolith weight has the potential to predict individual fish age as an alternative and objective method. Discriminant function analysis (DFA) of shape variables and cross‐validation were applied to a total of 359 sagittal otoliths in the age groups 0, 1 and 2. The shape variables demonstrated 64.1% correct age classification, and a 93.5% correct age classification with the inclusion of otolith weight in the discriminant function. Results show that a combination of shape variables and otolith weight work well in age determination of Belanger's croaker, and demonstrate its application potential for sciaenids that are distributed throughout the coastal waters of China. 相似文献
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Yanwen Guo Jun Liu Sarah J. Elfenbein Yinghong Ma Mei Zhong Caihong Qiu Ye Ding Jun Lu 《Nucleic acids research》2015,43(4):2326-2341
Steady state cellular microRNA (miRNA) levels represent the balance between miRNA biogenesis and turnover. The kinetics and sequence determinants of mammalian miRNA turnover during and after miRNA maturation are not fully understood. Through a large-scale study on mammalian miRNA turnover, we report the co-existence of multiple cellular miRNA pools with distinct turnover kinetics and biogenesis properties and reveal previously unrecognized sequence features for fast turnover miRNAs. We measured miRNA turnover rates in eight mammalian cell types with a combination of expression profiling and deep sequencing. While most miRNAs are stable, a subset of miRNAs, mostly miRNA*s, turnovers quickly, many of which display a two-step turnover kinetics. Moreover, different sequence isoforms of the same miRNA can possess vastly different turnover rates. Fast turnover miRNA isoforms are enriched for 5′ nucleotide bias against Argonaute-(AGO)-loading, but also additional 3′ and central sequence features. Modeling based on two fast turnover miRNA*s miR-222-5p and miR-125b-1-3p, we unexpectedly found that while both miRNA*s are associated with AGO, they strongly differ in HSP90 association and sensitivity to HSP90 inhibition. Our data characterize the landscape of genome-wide miRNA turnover in cultured mammalian cells and reveal differential HSP90 requirements for different miRNA*s. Our findings also implicate rules for designing stable small RNAs, such as siRNAs. 相似文献
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Xin-Yan?Liao Lin-Tong?Yang Yi-Bin?Lu Xin?Ye Li-Song?ChenEmail author 《Acta Physiologiae Plantarum》2015,37(1):1743
Four scion-rootstock combination [i.e., X/X and X/SP, ‘Xuegan’ (Citrus sinensis) grafted on ‘Xugan’ and ‘Sour pummelo’ (Citrus grandis), respectively, and SP/X and SP/SP, ‘Sour pummelo’ grafted on ‘Xuegan’ and ‘Sour pummelo’, respectively] plants were treated for 18 weeks with 0 (?Al) or 1.2 mM AlCl3·6H2O (+Al). Thereafter, leaf, stem and root concentrations of phosphorus and aluminum (Al), leaf and root levels of organic acids (OAs), Al-induced release of OA anions (i.e., malate and citrate), photosynthesis and chlorophyll a fluorescence (OJIP) transients were measured. Al-induced decrease of photosynthesis and damage of photosynthetic electron transport chain were less pronounced in X/X and X/SP leaves than in SP/SP and SP/X leaves, which might be related with the higher Al-induced root efflux of OA anions and leaf P concentration. C. sinensis rootstock alleviated the influences of Al-toxicity on leaf photosynthetic electron transport chain by enhancing Al-induced release of root OA anions, hence lessening Al-induced photosynthesis inhibition in SP/X plants, while the reverse was the case for C. grandis rootstock in X/SP plants. In conclusion, the tolerance of grafted Citrus plants to Al depends on the scion as well as rootstock genotype, and the scion-rootstock interaction. 相似文献
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