{"doi":"10.17615/w953-2k27","title":"Cyclin D and cdk4 Are Required for Normal Development beyond the Blastula Stage in Sea Urchin Embryos","abstract":"cdk4 mRNA and protein are constitutively expressed in sea urchin eggs and throughout embryonic development. In contrast, cyclin D mRNA is barely detectable in eggs and early embryos, when the cell cycles consist of alternating S and M phases. Cyclin D mRNA increases dramatically in embryos at the early blastula stage and remains at a constant level throughout embryogenesis. An increase in cdk4 kinase activity occurs concomitantly with the increase in cyclin D mRNA. Ectopic expression of cyclin D mRNA in eggs arrests development before the 16-cell stage and causes eventual embryonic death, suggesting that activation of cyclin D/cdk4 in cleavage cell cycles is lethal to the embryo. In contrast, blocking cyclin D or cdk4 expression with morpholino antisense oligonucleotides results in normal development of early gastrula-stage embryos but abnormal, asymmetric larvae. These results suggest that in sea urchins, cyclin D and cdk4 are required for normal development and perhaps the patterning of the developing embryo, but may not be directly involved in regulating entry into the cell cycle.","journal":"UNC Libraries","year":2020,"id":116432,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9486,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":343565,"name":"G. M. Wessel","orcid":null,"position":1,"is_corresponding":false},{"id":545200,"name":"J. A. Nichols","orcid":null,"position":2,"is_corresponding":false},{"id":427058,"name":"W. F. Marzluff","orcid":null,"position":3,"is_corresponding":false},{"id":545201,"name":"J. L. Sumerel","orcid":null,"position":4,"is_corresponding":false},{"id":545202,"name":"A. Wikramanayake","orcid":null,"position":5,"is_corresponding":false},{"id":545203,"name":"J. C. Moore","orcid":null,"position":6,"is_corresponding":false},{"id":203099,"name":"Bradley J. Schnackenberg","orcid":null,"position":0,"is_corresponding":true}],"reference_count":0,"raw_metadata":null,"created_at":"2026-07-18T23:13:44.286758Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}