A family of octamer-specific proteins present during mouse embryogenesis: evidence for germline-specific expression of an Oct factor.

in EMBO Journal (1989), 8(9), 2543-50

We have analysed various adult organs and different developmental stages of mouse embryos for the presence of octamer-binding proteins. A variety of new octamer-binding proteins were identified in ... [more ▼]

We have analysed various adult organs and different developmental stages of mouse embryos for the presence of octamer-binding proteins. A variety of new octamer-binding proteins were identified in addition to the previously described Oct1 and Oct2. Oct1 is ubiquitously present in murine tissues, in agreement with cell culture data. Although Oct2 has been described as a B-cell-specific protein, similar complexes were also found with extracts from brain, kidney, embryo and sperm. In embryo and brain at least two other proteins, Oct3 and Oct7, are present. A new microextraction procedure allowed the detection of two maternally expressed octamer-binding proteins, Oct4 and Oct5. Both proteins are present in unfertilized oocytes and embryonic stem cells, the latter containing an additional protein, Oct6. Whereas Oct4 was not found in sperm or testis, it is expressed in male and female primordial germ cells. Therefore Oct4 expression is specific for the female germline at later stages of germ cell development. Our results indicate that a family of octamer-binding proteins is present during mouse development and is differentially expressed during early embryogenesis. Protease clipping experiments of Oct4 and Oct1 suggest that both proteins contain similar DNA-binding domains. [less ▲]

Transcriptional activity of the octamer motif in embryonic stem cells and preimplantation embryos

in Hormones and Cell Regulation (1989), 198(14), 91-95

Structure, expression and chromosomal localization of Zfp-1, a murine zinc finger protein gene.

in Nucleic Acids Research (1989), 17(24), 10427-38

Zinc finger proteins (Zfp) are encoded by a large family of genes present in many organisms including yeast and human. Some of them are transcriptional activators and bind specifically to DNA by zinc ... [more ▼]

Zinc finger proteins (Zfp) are encoded by a large family of genes present in many organisms including yeast and human. Some of them are transcriptional activators and bind specifically to DNA by zinc mediated folded structures commonly known as zinc fingers. The Drosophila Kruppel (Kr) is a segmentation gene and encodes a zinc finger protein. Using a probe from the finger domain of Kr, we have isolated a structurally related gene Zfp-1 from the mouse. In this paper, we report the complete nucleotide sequence of two cDNA clones and the amino acid sequence deduced from them. The putative Zfp-1 protein contains in addition to 7 zinc fingers, two helix-turn-helix motifs. During murine embryogenesis, the Zfp-1 was found to express at a peak level in day 12 embryos. The ubiquitously expressed Zfp-1 gene is located in the 16q region on mouse chromosome 8, between the uvomorulin and the tyrosine amino transferase genes. [less ▲]

A mouse gene homologous to the Drosophila gene caudal is expressed in epithelial cells from the embryonic intestine.

in Genes and Development (1988), 2(12A), 1647-54

A mouse gene, Cdx-1, was isolated from an embryonic cDNA library using a Drosophila caudal gene probe. The deduced amino acid sequence of Cdx-1 contains conserved sequence domains along the entire gene ... [more ▼]

A mouse gene, Cdx-1, was isolated from an embryonic cDNA library using a Drosophila caudal gene probe. The deduced amino acid sequence of Cdx-1 contains conserved sequence domains along the entire gene, as well as a highly conserved caudal-type homeo box. A structural comparison suggests a common ancestral origin of mouse Cdx-1 and Drosophila caudal. The expression of Cdx-1 during embryogenesis was analyzed by Northern blotting and in situ hybridization. Cdx-1-specific transcripts are localized in the epithelial lining of the intestines beginning at 14 days' gestation. The expression of Cdx-1 in the intestine continues into adulthood, but cannot be detected in any other tissues. The Cdx-1 gene is the first homeo-box-containing gene expressed in cells derived from the embryonic endoderm. [less ▲]

Degree of methylation of transgenes is dependent on gamete of origin.

in Nature (1987), 328(6127), 251-4

Data derived from both pronuclear transplantation experiments and classical genetic experiments indicate that the maternal and paternal genetic contributions to the mammalian zygote nucleus do not ... [more ▼]

Data derived from both pronuclear transplantation experiments and classical genetic experiments indicate that the maternal and paternal genetic contributions to the mammalian zygote nucleus do not function equivalently during subsequent development. These observations have been interpreted as resulting from differential 'genome imprinting' during male and female gametogenesis. The molecular mechanism responsible for genome imprinting is unknown, but data gathered to date require that the mechanism fulfill at least four criteria: (1) the imprint must be physically linked to the pronucleus; (2) the imprint must persist through DNA replication and cell division; (3) the mechanism must be capable of affecting gene expression; and (4) the mechanism must be capable of switching the identity of the imprint from one sex to the other in successive generations. One molecular mechanism which could satisfy the first three criteria is differential DNA methylation during gametogenesis itself, or before formation of the zygote nucleus during embryogenesis. We present data indicating that the methylation patterns of exogenous DNA sequences in transgenic mice can be changed by switching their gamete of origin in successive generations. These data suggest that DNA methylation can also satisfy the fourth criterion for an imprinting mechanism. [less ▲]

Oxidative and conjugative metabolism of diethylstilbestrol by rabbit preimplantation embryos.

in Developmental Biology (1985), 109(2), 370-4

Five- and six-day-old rabbit preimplantation embryos were found to be capable of metabolizing [3H]diethylstilbestrol (DES) in vitro. Based on the analysis of the metabolites formed during a 24-hr ... [more ▼]

Five- and six-day-old rabbit preimplantation embryos were found to be capable of metabolizing [3H]diethylstilbestrol (DES) in vitro. Based on the analysis of the metabolites formed during a 24-hr incubation period we conclude that these early stage embryos do have active monooxygenase and conjugative activity. The monooxygenase seems to be specific to this early stage of embryonic development. [less ▲]

Asparagine and glutamine metabolism in chicks.

in Poultry Science (1984), 63(4), 717-29

In a series of four experiments, asparaginase and glutaminase activity was measured in liver and kidney tissue of 7- to 19-day-old male broiler chicks. In Experiment 1, chicks were fed purified amino acid ... [more ▼]

In a series of four experiments, asparaginase and glutaminase activity was measured in liver and kidney tissue of 7- to 19-day-old male broiler chicks. In Experiment 1, chicks were fed purified amino acid diets with 14.8 and 44.6% protein equivalents (PE) with 1, 3, or 5% added sodium bicarbonate. In Experiments 2, 3, and 4 the chicks were fed a 23% protein basal control diet, basal diet containing 5% ammonium chloride, and basal diet containing 5% ammonium chloride with 5 or 10% sodium bicarbonate, asparagine, or glutamine. In Experiments 2 and 4 the chicks were also fed 25, 50, or 75% protein-isolated soy-purified diets. The 44.6% PE diet increased liver and kidney asparaginase activity in chicks as compared to chicks fed a 14.8% PE diet. The addition of sodium bicarbonate to the 44.6% PE amino acid diet decreased the kidney asparaginase activity equivalent to kidney asparaginase activity of chicks fed the 14.8% PE diet. Asparaginase activity increased 4-fold in the kidneys of chicks fed the 23% protein basal diet containing 5% ammonium chloride and the pH of the urine from the chicks was 4.9. Chicks fed basal diets with 5% ammonium chloride plus 10% sodium bicarbonate or asparagine had the same kidney asparaginase activity and urine pH as chicks fed the 23% protein basal control diet. Glutamine added to chick diets containing 5% ammonium chloride did not decrease the kidney asparaginase activity or the urine acidity. Liver asparaginase activity was not increased in acidotic chicks fed diets with 5% ammonium chloride. The asparaginase activity of liver and kidney tissue were both significantly increased in chicks fed 75% protein-isolated soy purified diets and the pH of their urine was 5.6. The increase in liver asparaginase of chicks fed 75% protein or 44.5% PE diets was probably due to an endocrine gluconeogenic response producing increased catabolism of the majority of amino acids. The increase in kidney asparaginase of chicks fed 75% protein, 44.5% PE diets, and 23% protein basal diets with 5% ammonium chloride was primarily related to metabolic acidosis. Phosphate-dependent glutaminase (PDG) activity was localized in chick kidney mitochondria and was heat sensitive (55 C for 30 sec). The phosphate-independent glutaminase (PIG) activity was primarily localized in chick kidney mitochondria but was stable to a temperature of 55 C for 30 sec.(ABSTRACT TRUNCATED AT 400 WORDS) [less ▲]