Fine Mapping Of A Regulatory Gene Of Arabidopsis Anther Development, And Arabidopsis Phd-finger Family Of Proteins Genome Analysis

Anther and pollen development is the important process in plant life cycle. Studies on male sterile mutants and related genes in the model plant Arabidoopsis thaliana have provided insights into the molecular basis of anther and pollen development in plants. An Arabidopsis male-sterile mutant 1502 was isolated by enthyl methane sulfonate (EMS) treatment. Genetic analysis indicated that the mutant was controlled by a single recessive nuclear gene. Cytological analysis showed that the tapetum and the microspores were aberrant after Stage 7, which resulted in male sterile phenotype of 1502 mutant. Using map-based molecular cloning method, the gene was mapped to a region between 6703 kb and 6716 kb on the ChromosomeⅣ. Till now no genes involved in microspore formation were reported in this region, so we believed that 1502 gene could be a new gene controlling anther and pollen development in Arabidopsis. We selected At4g10940, At4g10950 and At4g10955 as candidate genes through phenotype and genotype analysis of SALK T-DNA lines of these genes in above region. The genetic complementation experiments of candidate genes are in process. Our work provides a basis for the gene cloning and its functional studies. PHD-finger proteins are found universally in eukaryotes and they are known as key players in regulating chromatin or transcription. In animals, many PHD-finger proteins have been studied deeply on structure and function. Compared to animals, only a few plant PHD-finger proteins have been characterized functionally.By both SMART and Pfam searches, all the PHD-finger proteins were identified in Arabidopsis thaliana. Most of the PHD-finger proteins in Arabidopsis thaliana are functionally unknown. Then we got the gene information of all the PHD-finger proteins. A complete overview of this gene family was presented, including the classification of subfamily, chromosome locations, the analysis of the tissue expression, the analysis of the functional domain, the prediction of the structure of PHD-finger domains. The main results are as follows:1. By both SMART and Pfam searches, we found 84 PHD-finger domains in 70 PHD-finger proteins in Arabidopsis thaliana.2. The phylogenetic trees of PHD-finger domains and proteins were generated with the neighbor-joining method and the Maximum Likelihood method. Based on the statistical support of each branch, we divided the Arabidopsis PHD-finger family into 17 subfamilies, designated A to Q.3. Based on the chromosomal location information on TAIR web, we localized the 70 PHD-finger genes of Arabidopsis in chromosomes. After analyzing the PHD-finger genes in duplicated segmental regions, we found the large-scale segmental duplication events seem to play a major role in the evolution of the PHD-finger gene family.4. We got the expression information of 70 PHD-finger genes of Arabidopsis using massively parallel signature sequencing (MPSS) and EST data. The results showed most genes expressed in all tissues, except some genes with tissue specific expression.5. We examined the domains of 70 PHD-finger proteins using MEME and SMART tools. The results show that many proteins in the same subfamily have the same domains, and a lot of PHD-finger proteins have the domains which are considered to bind histone proteins or DNA.6. We modelled the structure of some PHD-finger proteins of Arabidopsis using the Swiss-Model programs.These results lay solid foundation for the further structural and functional studies of PHD-finger proteins.