Developmental changes in the activity and cellular localization of hepatic casein kinase II in the rat

Abstract The activity and cellular localization of hepatic casein kinase II(CKII) was examined during late fetal development in the rat. Cultured fetal hepatocytes displayed constitutive CKII activity which was not further activated by growth factor exposure. Similarly, fetal liver CKII showed approximately fivefold greater activity than adult liver. The fetal hepatic activity was, to a large degree, localized to a nuclear fraction. Postnuclear cytosol preparations from fetal and adult liver showed similar CKII activity. In all cases, FPLC ion exchange chromatography followed by Western immunoblotting showed that immunoreactive CKII coincided with kinase activity. However, Parallel determinations of CKII activity and immunoreactive CKII levels showed a higher(five-to sixfold) CKII specific activity in nuclear extracts compared to cytosol. In summary, fetal hepatic CKII demonstrates coincident nuclear localization and activation. We hypothesize that the regulation of hepatic CKII is relevant to the mitogen-independent proliferation displayed by fetal rat hepatocytes. © Wiley-Liss, Inc.     

Contribution of α- -galactopyranosyl end groups to attachment of highly and low metastatic murine fibrosarcoma cells to various substrates

There are much greater numbers of cell surface terminal, non-reducing α- -galactorpyranosyl groups in highly malignant (metastatic) cells than are found in low malignant cells derived from the same murine fibrosarcoma. We have examined the contribution of these residues to attachment of the cells to various collagens and to plastic. Removal of these carbohydrate groups with α-galactosidase or blocking them with lectins from Griffonia simplicifolia seeds or with anti-blood group B antiserum all dramatically inhibited the attachment of both the highly malignant and the low malignant cells. Following removal with the enzyme, the α- -galactopyranosyl end groups were rapidly resynthesized. This resynthesis was inhibited by tunicamycin, an inhibitor of de novo glycoprotein synthesis. This antibiotic also impaired cell attachment and, when used in addition to treatment with α-galactosidase, it inhibited cell attachment more than did treatment with the enzyme alone. The effects of all treatments on cell attachment were greater for the highly malignant than for the low malignant cells. With the latter cells, inhibition by lectin was seen only in the absence of serum, whereas the adhesion of highly malignant cells was affected in both the presence and the absence of serum. On their surface membrane the highly malignant cells express much more than do the low malignant cells of a glycoprotein that cross-reacts immunologically with laminin. The basement membrane glycoprotein laminin promotes cell attachment to collagen, and both glycoproteins contain terminal, non-reducing α- -galactopyranosyl groups. Attachment of cells is a requirement for the formation of a metastasis, and thus the laminin-like molecule and the α- -galactopyranosyl end groups (whether on the laminin-related moiety or on other cell surface molecules) may both be important for expression of the most malignant phenotype.     

Nucleotide sequence of the VP1 gene of the foot-and-mouth disease virus strain A Venceslau

The VP1 coat protein of FMDV strain A Venceslau (Aven) consists of 213 amino acid residues. Serum neutralization tests demonstrated that strain Aven is closely related to strain A Argentina/79 (A₇₉) but significantly different from strain A₂₄ Cruzeiro (A₂₄). There is a strong correlation between the amino acid sequences and the serological data. Nucleotide and amino acid sequence analyses of VP1 showed that serologically related viruses (Aven and A₇₉) differ less in this region of the genome than those of serologically distinct viruses (Aven vs. A₂₄). The most significant variation between Aven and A₂₄ occurs at amino acid positions 43 to 46, in which all four residues are different.     

ORGANIZATION AND ONTOGENY OF THE VASCULAR SYSTEM IN THE PETIOLE OF EASTERN COTTONWOOD

The topologic arrangement of petiolar bundles varies within the length of the cottonwood petiole. Each petiolar bundle is formed by the subdivision and aggregation of acropetally differentiating subsidiary bundles in a predictable pattern. The subsidiary bundles provide vascular continuity between the stem and specific portions of the leaf lamina. Spot-labeling of individual veins with ¹⁴CO₂, freeze substitution, and microautoradiography were used to establish the relation between the secondary veins of the lamina and the vasculature of the petiole. Within the petiole vasculature each subsidiary bundle was continuous with a specific portion of the lamina and seemed to have a separate function. Subsidiary bundles continuous with the central leaf trace were closely related functionally to the tip region of the lamina, while the subsidiary bundles continuous with the lateral leaf traces were functionally related to the middle and basal portions of the lamina.     

Caprine Arthritis-Encephalitis Virus Is Distinct from Visna and Progressive Pneumonia Viruses as Measured by Genome Sequence Homology

Competitive inhibition of hybridization between ¹²⁵I-labeled caprine arthritis-encephalitis viral RNA and homologous cDNA by heterologous viral RNA shows that the caprine retrovirus shares <20% genome sequence homology with visna and progressive pneumonia viruses. These viruses, however, are indistinguishable in immunodiffusion reactions involving the major structural protein (p28).     

Races of the emperor tamarin,Saguinus imperator Goeldi (Callitrichidae,Primates)

The two described subspecies of the emperor tamarin,Saguinus imperator imperator Goeldi andSaguinus imperator subgrisescens Lönnberg are defined and compared, the geographic range of each plotted.     

Elytrigia turcica sp. nova,an octoploid species of theE. elongata complex

Elytrigia turcica sp. nov., (Poaceae) (2n=8x=56), a member of the polyploid complex related toE. elongata (Host) Nevski, (2n=2x=14), is described and distinguished fromE. pontica (Podp.) Holub, (2n=10x=70), which it most resembles.