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The transcript composition of egg cells changes significantly following fertilization in wheat ( Triticum aestivum L.)
Author(s) -
Sprunck Stefanie,
Baumann Ute,
Edwards Keith,
Langridge Peter,
Dresselhaus Thomas
Publication year - 2005
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2005.02332.x
Subject(s) - biology , gene , expressed sequence tag , complementary dna , gametophyte , embryo , cell division , human fertilization , egg cell , cdna library , microbiology and biotechnology , gene expression , genetics , cell , botany , pollen
Summary Here, we report the transcript profile of wheat egg cells and proembryos, just after the first cell division. Microdissected female gametophytes of wheat were used to isolate eggs and two‐celled proembryos to construct cell type‐specific cDNA libraries. In total, 1197 expressed sequence tags (ESTs) were generated. Analysis of these ESTs revealed numerous novel transcripts. In egg cells, 17.6% of the clustered ESTs represented novel transcripts, while 11.4% novel clusters were identified in the two‐celled proembryo. Functional classification of sequences with similarity to previously characterized proteins indicates that the unfertilized egg cell has a higher metabolic activity and protein turnover than previously thought. Transcript composition of two‐celled proembryos was significantly distinct from egg cells, reflecting DNA replication as well as high transcriptional and translational activity. Several novel transcripts of the egg cell are specific for this cell. In contrast, some fertilization induced novel mRNAs are abundant also in sporophytic tissues indicating a more general role in plant growth and development. The potential functions of genes based on similarity to known genes involved in developmental processes are discussed. Our analysis has identified numerous genes with potential roles in embryo sac function such as signaling, fertilization or induction of embryogenesis.