Programmed cell death plays an important role in maintaining homeostasis during animal development, and has been conserved in animals as different as nematodes and humans. Recent studies of Drosophila have provided va...Programmed cell death plays an important role in maintaining homeostasis during animal development, and has been conserved in animals as different as nematodes and humans. Recent studies of Drosophila have provided valuable information toward our understanding of genetic regulation of death. Different signals trigger the novel death regulators rpr, hid, and grim, that utilize the evolutionarily conserved iap and ark genes to modulate caspase function. Subsequent removal of dying cells also appears to be accomplished by conserved mechanisms. The similarity between Drosophila and human in cell death signaling pathways illustrate the promise of fruit mes as a model system to elucidate the mechanisms underlying regulation of programmed cell death.展开更多
During anther development, the tapetum pro- vides materials and nutrients for pollen development. In Arabidopsis, several transcription factors have been iden- tified to form a genetic pathway （DYT1-TDF1-AMS- MS188-...During anther development, the tapetum pro- vides materials and nutrients for pollen development. In Arabidopsis, several transcription factors have been iden- tified to form a genetic pathway （DYT1-TDF1-AMS- MS188-MS1） for tapetal development and function. DEFECTIVE in TAPETAL DEVELOPMENT and FUNCTION1 （TDF1） is a member of the R2R3 MYB family and is essential for early tapetum development in Arabidopsis. Here, we characterized an ortholog of Ara- bidopsis TDF1 in rice, OsTDF1 （LOC_Os03g18480）. OsTDF1 shares 69 % amino acid sequence identity with AtTDF1 in the putative MYB domain near the N-terminal region. RT-PCR and in situ hybridization show that OsTDF1 is specifically expressed in tapetal cells of rice anthers. The expression of OsTDF1 in Arabidopsis tdfl mutant restores its fertility, suggesting that this homolog can fulfill the normal function of TDF1 in Arabidopsis. The ostdfl knockout mutant exhibits a male-sterile phenotype. Its tapetal cells exhibit a vacuolated and hypertrophic phenotype similar to that of Arabidopsis tdfl mutants. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays revealed OsTDF1 acts as an essential regulator for tapetum programmed cell death. The qRT-PCR analysis revealed that OsTDF1 acts downstream of UDT1 and upstream of TDR, EAT1, OsMYBI03 and PTCI in rice, suggesting that the genetic pathway for tapetum development is generally conserved between rice and Arabidopsis,展开更多
基金the Baehrecke laboratory for helpful discussions and comments on this manuscript. Work on this subject has been supported by NR
文摘Programmed cell death plays an important role in maintaining homeostasis during animal development, and has been conserved in animals as different as nematodes and humans. Recent studies of Drosophila have provided valuable information toward our understanding of genetic regulation of death. Different signals trigger the novel death regulators rpr, hid, and grim, that utilize the evolutionarily conserved iap and ark genes to modulate caspase function. Subsequent removal of dying cells also appears to be accomplished by conserved mechanisms. The similarity between Drosophila and human in cell death signaling pathways illustrate the promise of fruit mes as a model system to elucidate the mechanisms underlying regulation of programmed cell death.
基金This work was supported by the grants from the Ministry of Science and Technology of China （2013CB945100）, the National Natural Science Foundation of China （31100227）.
文摘During anther development, the tapetum pro- vides materials and nutrients for pollen development. In Arabidopsis, several transcription factors have been iden- tified to form a genetic pathway （DYT1-TDF1-AMS- MS188-MS1） for tapetal development and function. DEFECTIVE in TAPETAL DEVELOPMENT and FUNCTION1 （TDF1） is a member of the R2R3 MYB family and is essential for early tapetum development in Arabidopsis. Here, we characterized an ortholog of Ara- bidopsis TDF1 in rice, OsTDF1 （LOC_Os03g18480）. OsTDF1 shares 69 % amino acid sequence identity with AtTDF1 in the putative MYB domain near the N-terminal region. RT-PCR and in situ hybridization show that OsTDF1 is specifically expressed in tapetal cells of rice anthers. The expression of OsTDF1 in Arabidopsis tdfl mutant restores its fertility, suggesting that this homolog can fulfill the normal function of TDF1 in Arabidopsis. The ostdfl knockout mutant exhibits a male-sterile phenotype. Its tapetal cells exhibit a vacuolated and hypertrophic phenotype similar to that of Arabidopsis tdfl mutants. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays revealed OsTDF1 acts as an essential regulator for tapetum programmed cell death. The qRT-PCR analysis revealed that OsTDF1 acts downstream of UDT1 and upstream of TDR, EAT1, OsMYBI03 and PTCI in rice, suggesting that the genetic pathway for tapetum development is generally conserved between rice and Arabidopsis,
