Characterization of a rice pollen-specific gene and its expression

Pollen development requires a large number of genes expressed in both sporophytic and gametophytic tissues. We have isolated a pollen-specific gene, PS1, from rice. PS1 is a unique gene in the rice genome and encodes a 164 amino acid long protein. RNA blot analysis shows that PS1 mRNAs accumulate specifically in rice anthers. When introduced into rice tissues by microprojectile bombardment, the PS1 promoter drives expression of a marker gene, β-glucuronidase, specifically in rice pollen. The PS1 gene and the deduced amino acid sequence of the PS1 protein share significant levels of homology with another monocot pollen-specific gene—the maize Zm-13 gene and its deduced protein, respectively. PS1 also shows some homology with the dicot tomato anther-specific gene LAT-52. Interestingly, the structure of the PS1 gene is more similar to that of the LAT-52 gene than to Zm-13. The coding regions of both PS1 and LAT-52 are interrupted by a single intron, and the positions of the introns are conserved in these genes. Moreover, there is considerable sequence homology in the introns of the PS1 and LAT-52 genes in regions immediately upstream of the 3' splice sites. The upstream regulatory sequences of the PS1 gene show several regions of homology with other pollen- or anther-specific genes from a number of plant species. The conservation of coding sequences of PS1 from rice, Zm-I3 from maize, and LAT-52 from tomato suggests a functional conservation of their gene products. Similarities in the regulatory regions of PS1 and other anther- or pollen-specific genes among monocotyledonous and dicotyledonous species indicate that at least some regulatory features controlling gene expression in male reproductive tissues are conserved. This is supported by the preservation of pollen-specific expression from the rice PS1 promoter when it is introduced into tobacco plants by Agrobacterium Ti plasmid-mediated transformation.     

Patchy distributions of Spirogyra arcta do not affect growth of the submerged macrophyte Ceratophyllum demersum

Spatial heterogeneity is common in aquatic conditions, but few studies have examined the effects of heterogeneous distributions of biological factors on aquatic plants. Spirogyra (Spirogyra arcta) coexists with many submerged macrophytes, such as Ceratophyllum demersum, but no study has examined the effects of heterogeneous distributions of spirogyra on the growth of submerged plants. We grew the submerged plant C. demersum in three homogeneous, aquatic conditions (0, 50 and 100% of the water surface in the container was evenly covered by spirogyra, referred to as ‘control’, ‘50%’ and ‘100%’, respectively) and two patchy conditions (the left half of the water surface in the container was not covered by spirogyra and 50% and 100% of the water surface in the right half of the container was evenly covered by spirogyra, referred to as ‘50%‐patchy’ and ‘100%‐patchy’, respectively). Compared with the control, the 100% treatment greatly decreased the biomass and number of ramets of C. demersum, but the 50% treatment did not. Growth of C. demersum in the left half of the container did not differ significantly between the control and the two heterogeneous treatments (50%‐patchy and 100%‐patchy). In addition, growth of C. demersum in the right half of the container did not differ between the 100% and the 100%‐patchy treatment or between the 50% and the 50%‐patchy treatment. Our results suggest that C. demersum can tolerate shading by spirogyra to a certain extent and that heterogeneous distributions of spirogyra do not affect its growth.     

微生物学“六化”教学理念和管理模式的构建及实施

针对微生物教学中存在的问题进行一系列改革,总结出了"六化"教学理念和管理方式:教师团队层次化,兴趣引导文学化,微生物史纵横化,知识讲解形象化,实验选题生活化,考核方式多元化。教学改革涉及教学方法、教学内容以及考核方式等多方面,取得显著效果。学生不仅在专业知识的学习上取得进步,而且综合素质得到了全面提升。     

AMIGO2 attenuates innate cisplatin sensitivity by suppression of GSDME-conferred pyroptosis in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) accounts for approximately 85% of lung cancer. Cisplatin is commonly used in the treatment of many malignant tumours including NSCLC. The innate drug sensitivity greatly affects the clinical efficacy of cisplatin-based chemotherapy. As a plasma membrane adhesion molecule, amphoterin-induced gene and ORF-2 (AMIGO2) initially identified as a neurite outgrowth factor has been recently found to play a crucial role in cancer occurrence and progression. However, it is still unclear whether AMIGO2 is involved in innate cisplatin sensitivity. In the present study, we provided the in vitro and in vivo evidences indicating that the alteration of AMIGO2 expression triggered changes of innate cisplatin sensitivity as well as cisplatin-induced pyroptosis in NSCLC. Further results revealed that AMIGO2 might inhibit cisplatin-induced activation of (caspase-8 and caspase-9)/caspase-3 via stimulating PDK1/Akt (T308) signalling axis, resulting in suppression of GSDME cleavage and the subsequent cell pyroptosis, thereby decreasing the sensitivity of NSCLC cells to cisplatin treatment. The results provided a new insight that AMIGO2 regulated the innate cisplatin sensitivity of NSCLC through GSDME-mediated pyroptosis.