ABSTRACT
Genetic reprogramming of differentiated cells is studied broadly in multicellular Viridiplantae as an adaptation to herbivory or damage; however, mechanisms underlying cell development and redifferentiation are largely unknown in red algae, their nearest multicellular relatives. Here we investgate cell reprogramming in the widely cultivated, edible seaweed Neopyropia yezoesis ("nori"), where vegetative cells in wounded blades differentiate and release as large numbers of asexual spores. Based upon physiological changes and transcriptomic dynamics after wound stress in N. yezoensis and its congener Neoporphyra haitanensis, another cultivar that does not differentiate spores after wounding, we propose a three-phase model of wound-induced spore development in N. yezoensis. In Phase I, propagation of ROS by RBOH and SOD elicites systematic transduction of the wound signal, while Ca2+ dependent signaling induces cell reprogramming. In Phase II, a TOR signaling pathway and regulation of cyclin and CDK genes result in cell divisions that spread inward from the wound edge. Once sporangia form, Phase III involves expression of proteins required for spore maturation and cell wall softening. Our analyses not only provide the first model for core molecular processes controlling cellular reprogramming in rhodophytes, but also have practical implications for achieving greater control over seeding in commercial nori farming.
ABSTRACT
Objective To investigate the relationship between underweight and pulmonary function in the general population. Methods A total of 2 350 patients who underwent a pulmonary function examination at Chongqing Three Gorges Central Hospital from January to June 2019 were selected as the study subjects. The subjects were divided into three groups based on their BMI value including underweight (2), normal weight (BMI between 18.5 kg/m2 and 25 kg/m2), and overweight and obese (≥25 kg/m2). Results Subjects in the overweight group had significantly worse biochemical indicators compared with underweight and normal weight subjects, but the frequency of strenuous exercise of the underweight subjects was significantly lower than that of the other two groups (P<0.001). Compared to the normal weight and overweight groups, the underweight group had lower level of forced expiratory volume in first second (FEV1), predicted FEV1(%), forced vital capacity (FVC), predicted FVC(%), and peak expiratory flow (PEF) (P<0.001), but higher level of FEV1/FVC, as well as predicted FEV1 (%)<80% and predicted FVC (%)<80%. Multivariate logistic regression model analysis showed that after adjusting for multiple confounding factors, the risk of reduced lung function in underweight group increased significantly, and the odd ratios were 2.10 (95%CI 1.98–2.21) and 4.90 (95%CI 4.62–5.18) for FEV1(%)<80% and FVC%<80%, respectively. Conclusion This study demonstrated that in the general population, the underweight was significantly associated with reduced lung function.
