Genetic Mapping Of The Male Sterile Gene MA In Arabidopsis Thaliana And Genome-wide Analysis Of MtN3/saliva Protein Family In Arabidopsis Thaliana

Male-sterile mutants have been identified in many higher plants and the defective of anther and pollen development is one of the most important reasons of male sterility. Anther and pollen development is one of the important areas in plant development biology. It is an efficient strategy to investigate the molecular mechanisms of plant anther and pollen develop by cloning genes from male-sterile mutants followed by functional analysis. In this paper, we screened a mutant ma with T-DNA insertion of Arabidopsis thaliana, and found that mutant ma is a basically sterile mutant of Arabidopsis . Genetic analysis indicated that the mutant was controlled by a single recessive nuclear gene. In this study, cytological observation suggested that the microspores were abberant which resulted in the male sterile phenotype of mutant ma.Using map-based molecular cloning method due to the losing T-DNA insertion in mutant plants, gene MA was located in a region between 23283kb and 23360kb kb on the Chromosomeâ… . Recently, a male fertility related gene ACOS5 was reported in this region, and ma was demonstrated as an allelic mutant of acos5 in this work.This work sets a base for the MA cloning and its functional studies. MtN3/saliva protein family genes are found universally in eukaryotes, and the majority of these proteins usually contain two copies of MtN3/saliva domain. Very few of the MtN3/saliva proteins have been characterized.And the two copies of MtN3/saliva domain's function is unclear. In this study, eighteen genes of the MtN3/saliva family were identified in Arabidopsis thaliana, while most of them were functionally unknown, except RPG1 cloned recently. The MtN3/saliva family in Arabidopsis was extensively analyzed, including gene structure, gene localization in genome, protein motif organization, phylogenetic relationship of family members and gene expression pattern. The main results are as follows:1. By both TAIR and Pfam searches, we found 18 MtN3/saliva family proteins in Arabidopsis thaliana. According to Chromosome Map Tool we got Chromosome the distribution for MtN3/saliva genes.2. We got the genetic structure of the MtN3/saliva family genes by Gene Structure Display Server(http://gsds.cbi.pku.edu.cn/index.php).3. We got the suctures of MtN3/saliva proteins by using TMHMM Server v. 2.0(http://www.cbs.dtu.dk/services/TMHMM/).4. The phylogenetic trees of MtN3/saliva proteins were generated with the neighbor-joining method and the Maximum Likelihood method, by using Mega4.1.5. According to the expression data from the e-FP Browser and Genevestigater website, four MtN3/saliva family genes were highly expressed in anther and/or mature pollen grains, and their expression have been further verified by Real-time RT-PCR in our research.These results facilitate us to further understand the function of MtN3/saliva family in plant.