title: Expressed sequence tags from immature female sexual organ of a liverwort, Marchantia polymorpha.
abstract: A total of 970 expressed sequence tag (EST) clones were generated from immature female sexual organ of a liverwort, Marchantia polymorpha. The 376 ESTs resulted in 123 redundant groups, thus the total number of unique sequences in the EST set was 717. Database search by BLAST algorithm showed that 302 of the unique sequences shared significant similarities to known nucleotide or amino acid sequences. Six unique sequences showed significant similarities to genes that are involved in flower development and sexual reproduction, such as cynarase, fimbriata-associated protein and S-receptor kinase genes. The remaining unique 415 sequences have no significant similarity with any database-registered genes or proteins. The redundant 123 ESTs implied the presence of gene families and abundant transcripts of unknown identity. Analyses of the coding sequences of 61 unique sequences, which contained no ambiguous bases in the predicted coding regions, highly homologous to known sequences at the amino acid level with a similarity score greater than 400, and with stop codons at similar positions as their possible orthologues, indicated the presence of biased codon usage and higher GC content within the coding sequences (50.4%) than that within 3' flanking sequences (41.9%).
authors.affiliation: Laboratory of Plant Molecular Biology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Nagai
authors.forename: K T
authors.initials: KT
authors.lastname: Yamato
authors.forename: M
authors.initials: M
authors.lastname: Sakaida
authors.forename: H
authors.initials: H
authors.lastname: Yoda
authors.forename: H
authors.initials: H
authors.lastname: Fukuzawa
authors.forename: K
authors.initials: K
authors.lastname: Ohyama
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003062:Codon; D020451:Contig Mapping; D018076:DNA, Complementary / Q000235:genetics; D016208:Databases, Factual; D020224:Expressed Sequence Tags; D015723:Gene Library; D017343:Genes, Plant; D008969:Molecular Sequence Data; D005810:Multigene Family; D012333:RNA, Messenger / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D003062:Codon; D018076:DNA, Complementary; D012333:RNA, Messenger