In the sea urchin there is a tandemly repeated U2 snRNA gene set that is expressed early in embryogenesis and inactivated after blastula stage. In addition, there is a constitutive gene set which is expressed in all cells. A tandemly repeated and a single copy U2 snRNA gene were isolated from the sea urchin L. variegatus. Upon microinjection into sea urchin zygotes, the genes showed temporal expression characteristic of an embryonic and a constitutive gene, respectively. Four cis-acting elements were identified within the promoter of each gene: the TATA box at $-$30, the PSE element at $-$60, an element at $-$100 and an upstream activating sequence. Other than the TATA box there is no sequence homology between the elements from the two genes. The TATA and the PSE element are necessary and sufficient for basal transcription and for selection of the transcription initiation site. Swapping of the embryonic gene PSE element into the constitutive gene promoter converts temporal expression of the constitutive gene into that of the embryonic gene, suggesting that the PSE sequence is responsible for developmental regulation. A protein complex binds to the PSE and TATA elements of the embryonic gene in vitro. In vitro binding correlates with activity of the promoter in vivo. The binding activity is present in blastula nuclei and absent from gastrula nuclei. An 82 kD protein was UV crosslinked to the embryonic gene PSE sequence. The protein has been purified by DNA affinity chromatography. Cloning of its cDNA is a future goal. It is likely that the 82 kD factor is a key factor for developmental regulation of the sea urchin embryonic U2 snRNA genes. / Source: Dissertation Abstracts International, Volume: 52-11, Section: B, page: 5678. / Major Professor: William F. Marzluff, Jr. / Thesis (Ph.D.)--The Florida State University, 1991.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_76553 |
| Contributors | Stefanovic, Branko., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 231 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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