title: Identification of genes associated with male sterility in a mutant of white birch (Betula platyphylla Suk.).
abstract: White birch (Betula platyphylla Suk.) is a monoecious tree species with unisexual flowers. In this study, we used a spontaneous mutant genotype that produced normal-like male (NLM) inflorescences and mutant male (MM) inflorescences at different locations within the tree to investigate the genes necessary for pollen development. A cDNA-amplified fragment length polymorphism (cDNA-AFLP) analysis was used to identify genes differentially expressed between the two types of inflorescences. Of approximately 5000 transcript-derived fragments (TDFs) obtained, 323 were significantly differentially expressed, of which 141 were successfully sequenced. BLAST analyses revealed 51.8% of the sequenced TDFs showed significant homology with proteins of known or predicted functions, 10.6% showed significant homology with putative proteins without any known or predicted function, and the remaining 37.6% had no hits in the NCBI database. Further, in a functional categorization based on the BLAST analyses, the protein fate, metabolism, energy categories had in order the highest percentages of the proteins. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the known TDFs were mainly involved in metabolic (28.4%), signal transduction (23.5%) and folding, sorting and degradation (13.6%) pathways. Ten genes from the NLM and MM development stages in the mutant were analyzed by quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR). The information generated in this study can provide some useful clues to help understand male sterility in B. platyphylla.
authors.affiliation: Northeast Forestry University, Harbin 150040, PR China.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Liu
authors.affiliation: Forestry Investigation and Planning Institute of Liaoning Province, Shenyang 110122, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Northeast Forestry University, Harbin 150040, PR China.
authors.forename: Chuang
authors.initials: C
authors.lastname: Liu
authors.affiliation: Northeast Forestry University, Harbin 150040, PR China.
authors.forename: Minxiao
authors.initials: M
authors.lastname: Guan
authors.affiliation: State Key Laboratory of Forest Genetics and Tree Breeding, Northeast Forestry University, Harbin 150040, PR China. Electronic address: yangchuanpingedu@yahoo.com.
authors.forename: Chuanping
authors.initials: C
authors.lastname: Yang
mesh_terms: D000818:Animals; D001483:Base Sequence; D029662:Betula / Q000235:genetics*; D002470:Cell Survival / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D056130:Gametogenesis, Plant / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D011058:Pollen / Q000235:genetics* / Q000502:physiology; D054817:Pollination / Q000235:genetics*
chemical_list: D018076:DNA, Complementary
keywords: Birch; Differential expression; Male sterility; cDNA-AFLP