Embryogenesis in plants, as in animals, requires the regulated expression of sets of genes involved in developmental processes. To gain insight into the processes regulating gene expression during embryogenesis differential screening was used to identify embryo-specific sequences in a cDNA library constructed from Zea mays embryo RNA. Four embryo-specific sequences and one constitutive sequence were characterized further by RNA blot hybridization and DNA sequence determination. The constitutive sequence and two of the embryo-specific sequences were found to encode parts of the previously-reported chloroplast 23S rRNA, Oleosin KD-18, and RAB-17 genes. Two sequences, named Emb5 and Emb564, were found to encode novel maize homologs of a gene expressed during late embryogenesis in a wide range of seed plants. These 5 genes exhibited differential temporal and spatial accumulation during development. Moreover, analysis of RNA from cultured embryos suggested that 4 of these genes were regulated by abscisic acid. The ABA-responsive genes could be divided into 3 classes, based on their developmental expression, tissue-specificity, and sensitivity to ABA. Antibodies raised against a $ beta$-galactosidase:EMB564 fusion protein were used to analyze the accumulation of the EMB564 and/or EMB5 proteins. These polyclonal antibodies detected one or several polypeptides with a molecular weight less than 14 kD which exhibited patterns of developmental accumulation and regulation similar to Emb5 and Emb564 transcripts.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.41786 |
| Date | January 1993 |
| Creators | Williams, Bruce |
| Contributors | Tsang, Adrian (advisor), Brown, Greg (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Biology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001395986, proquestno: NN94722, Theses scanned by UMI/ProQuest. |
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