No abstract

Agave plants are important crassulacean acid metabolism (CAM) plants with multiple agricultural uses, such as being used in tequila and fiber production. Agave hybrid H11648 ((A. amaniensis Trel. and Nowell × A. angustifolia Haw.) × A. amaniensis) is the main cultivated Agave species for fiber production in large tropical areas around the world. In this study, we conducted a transcriptome analysis of A. H11648. About 49.25 million clean reads were obtained by Illumina paired-end sequencing. De novo assembly produced 148,046 unigenes with more than 40% annotated in public databases, or matched homologs in model plants. More homologous gene pairs were found in Asparagus genome than in Arabidopsis or rice, which indicated a close evolutionary relationship between Asparagus and A. H11648. CAM-related gene families were also characterized as previously reported in A. americana. We further identified 12 cellulose synthase genes (CesA) in Asparagus genome and 38 CesA sequences from A. H11648, A. americana, A. deserti and A. tequilana. The full-length CesA genes were used as references for the cloning and assembly of their homologs in other Agave species. As a result, we obtained CesA1/3/4/5/7 genes with full-length coding region in the four Agave species. Phylogenetic and expression analysis revealed a conserved evolutionary pattern, which could not explain the distinct fiber traits in different Agave species. We inferred that transcriptional regulation might be responsible for Agave fiber development. This study represents the transcriptome of A. H11648, which would expand the number of Agave genes and benefit relevant studies of Agave fiber development.

Background and study aims: Tandem colonoscopy studies have found that about one in five adenomas are missed at colonoscopy. It is still debatable whether the combination of a computer-aided detection (CADe) system for colorectal polyp detection with a computer-aided quality improvement (CAQ) system for real-time withdrawal speed monitoring may result in additional benefits in the task of adenoma detection or if the synergetic effect may be harmed due to excessive visual burden resulting from the information overload. This study aims to evaluate the interaction effect on improving the adenoma detection rate (ADR). Patients and methods: This is a single-center, randomized, four-group parallel controlled study, performed in Renmin Hospital of Wuhan University. Between July 1, 2020 and Oct 15, 2020, 1076 participants were randomly allocated into four treatment groups [control: 271, CADe: 268, CAQ: 269 and CADe plus CAQ (COMBO): 268]. The primary outcome was the ADR. Results: The average ADR in the control, CADe, CAQ and COMBO groups was 14.76% (95% C.I. 10.54-18.98), 21.27% (95% C.I. 16.37-26.17), 24.54% (95% C.I. 19.39-29.68) and 30.6% (95% C.I. 25.08-36.11), respectively. The ADR was higher in the COMBO group compared with the CADe group but not compared with the CAQ group (21.27% VS 30.6%, P=0.024, OR 1.284, 95%C.I. 1.033-1.596; 24.54%vs. 30.6%, P = 0.213, OR = 1.309, 95% C.I. 0.857-2, respectively). Conclusions: CAQ significantly improved the efficacy of CADe in a four-group parallel controlled study. No significant difference in the ADR or PDR was found between the CAQ and COMBO groups.

Agave species are an important family of crassulacean acid metabolism (CAM) plants with remarkable tolerance to heat and drought stresses (Agave deserti) in arid regions and multiple agricultural applications, such as spirit (Agave tequilana) and fiber (Agave sisalana) production. The agave genomes are commonly too large to sequence, which has significantly restricted our understanding to the molecular basis of stress tolerance and economic traits in agaves. In this study, we collected three transcriptome databases for comparison to reveal the phylogenic relationships and evolution patterns of the three agave species. The results indicated the close but distinctly domesticated relations between A. tequilana and A. sisalana. Natural abiotic and biotic selections are very important factors that have contributed to distinct economic traits in agave domestication together with artificial selection. Besides, a series of candidate unigenes regulating fructan, fiber, and stress response-related traits were identified in A. tequilana, A. sisalana, and A. deserti, respectively. This study represents the first transcriptome comparison within domesticated and wild agaves, which would serve as a guidance for further studies on agave evolution, environmental adaptation, and improvement of economically important traits.