Biomaterial Database

Maternal and zygotic expression of mRNA for S-adenosylmethionine decarboxylase and its relevance to the unique polyamine composition in Xenopus oocytes and embryos. 1996

J Shinga, and K Kashiwagi, and K Tashiro, and K Igarashi, and K Shiokawa

Department of Biological Sciences, Graduate School of Science, University of Tokyo, Japan.

From Xenopus tailbud cDNA library, we isolated the cDNA for S-adenosylmethionine decarboxylase (SAMDC), an enzyme which provides putrescine and spermidine with the aminopropyl group to form spermidine and spermine, respectively. The cDNA coded for 335 amino acids whose sequence had high homology (ca. 83%) to other vertebrate SAMDCs, preserving the sequences reportedly essential for enzyme activity, proenzyme processing, and putrescine stimulation of the enzyme activity. Northern blot analysis showed one major mRNA signal of ca. 3.5 kb, with a minor signal of ca 2.0 kb which may probably be due to cross-hybridization. In oocytes the SAMDC mRNA occurred from stage I, and its amount peaked at stage II, then gradually decreased from stage III to VI. The decreased level of the mRNA was maintained during oocyte maturation, further decreased from the cleavage to early neurula stage, and then increased greatly due to the zygotic expression during late neurula stages (stage 21-25), reaching a plateau level at the late tailbud stage (stage 28). Enzyme assays showed that the changing level of the SAMDC mRNA was reflected in the level of the functional enzyme, suggesting strongly that the zygotic expression of the mRNA leads to a large increase in the amount of SAMDC, albeit in the pre-neurula embryo the amount of the enzyme is very small. We found that the relative composition of polyamines is the eukaryote-type (high-level spermine) at the beginning of oogenesis, but it changes to the prokaryote-type, or more appropriately Escherichia coli-type (high-level putrescine but background level spermine) during oocyte maturation, and remains E. coli-type throughout embryogenesis. We assume that the E. coli-type polyamine composition is a necessary factor for the normal embryogenic development in Xenopus and its maintenance, especially that in pre-neurula stages, can be explained by the low level of both SAMDC mRNA and SAMDC.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009865	Oocytes	Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).	Ovocytes,Oocyte,Ovocyte
D009866	Oogenesis	The process of germ cell development in the female from the primordial germ cells through OOGONIA to the mature haploid ova (OVUM).	Oogeneses
D011073	Polyamines	Amine compounds that consist of carbon chains or rings containing two or more primary amino groups.	Polyamine
D011374	Progesterone	The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.	Pregnenedione,Progesterone, (13 alpha,17 alpha)-(+-)-Isomer,Progesterone, (17 alpha)-Isomer,Progesterone, (9 beta,10 alpha)-Isomer
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D004625	Embryo, Nonmammalian	The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.	Embryonic Structures, Nonmammalian,Embryo, Non-Mammalian,Embryonic Structures, Non-Mammalian,Nonmammalian Embryo,Nonmammalian Embryo Structures,Nonmammalian Embryonic Structures,Embryo Structure, Nonmammalian,Embryo Structures, Nonmammalian,Embryo, Non Mammalian,Embryonic Structure, Non-Mammalian,Embryonic Structure, Nonmammalian,Embryonic Structures, Non Mammalian,Embryos, Non-Mammalian,Embryos, Nonmammalian,Non-Mammalian Embryo,Non-Mammalian Embryonic Structure,Non-Mammalian Embryonic Structures,Non-Mammalian Embryos,Nonmammalian Embryo Structure,Nonmammalian Embryonic Structure,Nonmammalian Embryos,Structure, Non-Mammalian Embryonic,Structure, Nonmammalian Embryo,Structure, Nonmammalian Embryonic,Structures, Non-Mammalian Embryonic,Structures, Nonmammalian Embryo,Structures, Nonmammalian Embryonic
D005260	Female		Females
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia