Multiple and integrated functions of floral C-class MADS-box genes in flower and fruit development of Physalis floridana

Plant Molecular Biology - This work reveals potentially multiple and integrated roles in flower and fruit development of floral C-class MADS-box genes in Physalis. The Physalis fruit features a...     

应用间接免疫荧光试验检测我国正常人和白血病病人血清中嗜T淋巴细胞Ⅲ型病毒抗体

法国巴斯德研究所,自获得性免疫缺损综合症(Aids)先兆症淋巴结病(LAS)分离到一种病毒,命名为淋巴结病相关病毒(LAV);美国Gallo自Aids患者分离出逆转录病毒。后来证明,两者是相同的,但与嗜T淋巴细胞病毒(HTLV)Ⅰ、Ⅱ型不同,称为HTLV-Ⅲ病毒,是Aids的致病因子。 Aids是1981年发现的一种高死亡率疾病。HTLV-Ⅲ病毒侵袭人的OK74或辅助T细胞而     

The euAP1 Protein MPF3 Represses MPF2 to Specify Floral Calyx Identity and Displays Crucial Roles in Chinese Lantern Development in Physalis

The Chinese lantern phenotype or inflated calyx syndrome (ICS) is a postfloral morphological novelty in Physalis. Its origin is associated with the heterotopic expression of the MADS box gene 2 from Physalis floridana (MPF2) in floral organs, yet the process underlying its identity remains elusive. Here, we show that MPF3, which is expressed specifically in floral tissues, encodes a core eudicot APETALA1-like (euAP1) MADS-domain protein. MPF3 was primarily localized to the nucleus, and it interacted with MPF2 and some floral MADS-domain proteins to selectively bind the CC-A-rich-GG (CArG) boxes in the MPF2 promoter. Downregulating MPF3 resulted in a dramatic elevation in MPF2 in the calyces and androecium, leading to enlarged and leaf-like floral calyces; however, the postfloral lantern was smaller and deformed. Starch accumulation in pollen was blocked. MPF3 MPF2 double knockdowns showed normal floral calyces and more mature pollen than those found in plants in which either MPF3 or MPF2 was downregulated. Therefore, MPF3 specifies calyx identity and regulates ICS formation and male fertility through interactions with MPF2/MPF2. Furthermore, both genes were found to activate Physalis floridana invertase gene 4 homolog, which encodes an invertase cleaving Suc, a putative key gene in sugar partitioning. The novel role of the MPF3-MPF2 regulatory circuit in male fertility is integral to the origin of ICS. Our results shed light on the evolution and development of ICS in Physalis and on the functional evolution of euAP1s in angiosperms.     

The origin and evolution of carpels and fruits from an evo-devo perspective

The flower is an evolutionary innovation in angiosperms that drives the evolution of biodiversity.The carpel is integral to a flower and develops into fruits after fertilization,while the perianth,consisting of the calyx and corolla,is decorative to facilitate pollination and protect the internal organs,including the carpels and stamens.Therefore,the nature of flower origin is carpel and stamen origin,which represents one of the greatest and fundamental unresolved issues in plant evolutionary bi...     

Slow Co-Evolution of the MAGO and Y14 Protein Families Is Required for the Maintenance of Their Obligate Heterodimerization Mode

The exon junction complex (EJC) plays important roles in RNA metabolisms and the development of eukaryotic organisms. MAGO (short form of MAGO NASHI) and Y14 (also Tsunagi or RBM8) are the EJC core components. Their biological roles have been well investigated in various species, but the evolutionary patterns of the two gene families and their protein-protein interactions are poorly known. Genome-wide survey suggested that the MAGO and Y14 two gene families originated in eukaryotic organisms with the maintenance of a low copy. We found that the two protein families evolved slowly; however, the MAGO family under stringent purifying selection evolved more slowly than the Y14 family that was under relative relaxed purifying selection. MAGO and Y14 were obliged to form heterodimer in a eukaryotic organism, and this obligate mode was plesiomorphic. Lack of binding of MAGO to Y14 as functional barrier was observed only among distantly species, suggesting that a slow co-evolution of the two protein families. Inter-protein co-evolutionary signal was further quantified in analyses of the Tol-MirroTree and co-evolution analysis using protein sequences. About 20% of the 41 significantly correlated mutation groups (involving 97 residues) predicted between the two families was clade-specific. Moreover, around half of the predicted co-evolved groups and nearly all clade-specific residues fell into the minimal interaction domains of the two protein families. The mutagenesis effects of the clade-specific residues strengthened that the co-evolution is required for obligate MAGO-Y14 heterodimerization mode. In turn, the obliged heterodimerization in an organism serves as a strong functional constraint for the co-evolution of the MAGO and Y14 families. Such a co-evolution allows maintaining the interaction between the proteins through large evolutionary time scales. Our work shed a light on functional evolution of the EJC genes in eukaryotes, and facilitates to understand the co-evolutionary processes among protein families.