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Maize (Zea mays L.) is a monoecious grass plant in which mature male and female florets form the tassel and ear, respectively. Maize is often used as a model plant to study flower development. Several maize tassel seed mutants, such as the recessive mutants tasselseed1 (ts1) and tasselseed2 (ts2), exhibit a reversal in sex determination, which leads to the generation of seeds in tassels. The phenotype of the dominant mutant, Tasselseed5 (Ts5), is similar to that of ts2. Here, we positionally cloned the underlying gene of Ts5 and characterized its function. We show that the GRMZM2G177668 gene is overexpressed in Ts5. This gene encodes a cytochrome C oxidase, which catalyzes the transformation of jasmonoyl‐L‐isoleucine (JA‐Ile) to 12OH‐JA‐Ile during jasmonic acid catabolism. Consistent with this finding, no JA‐Ile peak was detected in Ts5 tassels during the sex determination period, unlike in the wild type. Transgenic maize plants overexpressing GRMZM2G177668 exhibited a tassel‐seed phenotype similar to that of Ts5. These results indicate that the JA‐Ile peak in tassels is critical for sex determination and that the Ts5 mutant phenotype results from the disruption of this peak in tassels during sex determination.  相似文献   
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Genome engineering for crop improvement and future agriculture   总被引:1,自引:0,他引:1  
Caixia Gao 《Cell》2021,184(6):1621-1635
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Background

With the establishment of minimally invasive surgery in society, the robot has been increasingly widely used in the urologic field, including in partial nephrectomy. This study aimed to comprehensively summarize the currently available evidence on the feasibility and safety of robotic partial nephrectomy for renal tumors of >4 cm.

Method and Findings

An electronic database search of PubMed, Scopus, Web of Science, and the Cochrane Library was performed. This systematic review and meta-analysis was based on all relevant studies that assessed robotic partial nephrectomy for renal tumors of >4 cm. Five studies were included. The meta-analysis involved 3 studies from 11 institutions including 154 patients, while the narrative review involved the remaining 2 studies from 5 institutions including 64 patients. In the meta-analysis, the mean ischemic time, operation time, and console time was 28, 319, and 189 minutes, respectively. The estimated blood loss and length of stay was 317 ml and 3.8 days, respectively. The rates of conversion, positive margins, intraoperative complications, postoperative complications, hilar clamping, and collecting system repair were 7.0%, 3.5%, 7.0%, 9.8%, 93.9%, and 47.5%, respectively. The narrative review showed results similar to those of the meta-analysis.

Conclusions

Robotic partial nephrectomy is feasible and safe for renal tumors of >4 cm with an acceptable warm ischemic time, positive margin rate, conversion rate, complication rate, operation time, estimated blood loss, and length of stay.  相似文献   
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Ardisia violacea (Myrsinaceae), one of China’s rare and endangered species, occurs only in Zhejiang and Taiwan provinces. We examined the population dynamics of this species to reveal details related to the development of populations. Assembling intensity indices were used, such as V/m, K, m*, PAI, CA and I. Age class structure and the time-specific life tables were analyzed by the contiguous grid quadrate method. The population structures and distribution patterns of A. violacea in different habitats, age classes and quadrat scales are discussed and the life parameters such as the survival curve, mortality curve and life expectancy were estimated. The results show the age class distribution of the entire population generally fits a reverse “J” type curve, suggesting a growing population. The population spatial distribution pattern was clumped in all three habitats, especially in the age classes I–III, and had a uniform distribution in the age classes VII and IX. The plants mainly occurred at microsites with generally adequate light, water, nutrients and air. Micro-environmental factors and human factors can also have a great impact. In the age class structure pattern, the individual percentage of the first three age classes accounted for 71.19% in H1 (habitat 1), 68.18% in H2 (habitat 2) and 88.24% in H3 (habitat 3), which indicated the number of individuals in the first three age classes were larger than any other age classes. The population size peaked in the age classes III and X and only 13.1% individuals survive age class III to enter class IV. As a result, fewer middle and advanced aged individuals were found. Age class IV had the highest life expectancy for A. violacea. The survival curve approached to Deevy-II. The spatial distribution pattern of A. violacea populations was decided mainly by the interaction of biological and ecological characteristics of its environment, habitat heterogeneities, microenvironments and human disturbance.  相似文献   
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We recently reported that epiblast stem cells (EpiSCs)-like cells could be derived from preimplantation embryos (named as AFSCs). Here, we established AFSCs from pre-implantation embryos of multiple mouse strains and showed that unlike EpiSCs, the derivation efficiency of AFSCs was affected by the genetic background. We then used AFSCs lines to dissect the roles of Activin A (Act A) and basic fibroblast growth factor and reported that Act A alone was capable of maintaining self-renewal but not developmental potential in vivo. Finally, we established a novel experimental system, in which AFSCs were efficiently converted to multipotent progenitor stem cells using Act A and bone morphogenetic protein 4 (named as ABSCs). Importantly, these ABSCs contributed to neural mesodermal progenitors and lateral plate mesoderm in postimplantation chimeras. Taken together, our study established a robust experimental system for the generation of specific multipotent progenitor stem cells that was self-renewable and capable of contributing to embryonic and extra-embryonic tissues.  相似文献   
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