UDP-GalNAc : GalNAc-mucin α-N-acetylgalactosamine transferase activity in human intestinal cancerous tissues

GalNAc transferase activities of 6 human intestinal cancerous tissues were examined using bovine submaxillary gland mucin and its desialylated derivative, asialomucin, as acceptors. A Triton X-100 extract of these tissues was used as an enzyme source. All the tissues examined had GalNAc transferase that catalyzes the transfer of GalNAc from UDP-GalNAc to serine or threonine residues of the polypeptide chain. One of 6 specimens showed in addition UDP-GalNAc:GalNAc-mucin α-GalNAc transferase activity, synthesizing a disaccharide unit, GalNAcα→ GalNAc, when asialomucin was used as an acceptor. This carbohydrate structure was deduced on the basis of results of gel filtration, exoglycosidase digestion, and high-voltage paper electrophoresis.GalNAc transferaseHuman intestinal cancerous tissueBovine submaxillary gland mucin O-Glycosidically linked sugar chain     

Feeding ecology of mandrills (Mandrillus sphinx) in campo animal reserve,Cameroon

A field study on the ecology of mandrills (Mandrillus sphinx) was carried out for 28 months in Cameroon. Fresh food remnants and large quantities of fresh feces were collected by following the groups. Analyses of these products indicated that fruit (including seeds), monocotyledonous plant leaves and insects (especially ants and termites), were frequently eaten. Mandrills mostly ate the plant and animal foods in the lower forest stratum and on the ground. Fallen seeds and monocotyledonous plant leaves were eaten more frequently in the minor fruiting season than in the major fruiting season presumably to compensate for the shortage of fresh fruit during the former. Daily travel distances were shorter during the minor fruiting season than during the major fruiting season, because in the minor fruiting season mandrills forage for small food items, such as the new leaves and piths of monocotyledons and fallen seeds which are sparsely distributed on the ground, while in the major fruiting season they search for widely distributed food such as fruit. The daily pattern of group movement and a food intake experiment suggest that mandrills move and feed continuously throughout the day. Use of fallen seeds and monocotyledonous plant leaves appears to enable mandrills to maintain a terrestrial life in the tropical rain forest. The feeding and ranging characteristics of mandrills are basically similar to those of other baboon species in open land, though their environments differ extremely.     

Gland formation induced in the allantoic and small-intestinal endoderm by the proventricular mesenchyme is not coupled with pepsinogen expression

Abstract. Allantoic and small-intestinal endoderms of chick and quail embryos were associated with the proventricular mesenchyme of chick embryos and then cultivated on chorioallantoic membrane. This resulted in the induction of complex glands, but the recombinates never produced embryo-specific pepsinogens; also, glandular cells developed a brush border, expressed sucrase antigen on their apical surface, and sometimes differentiated into goblet cells, thus indicating that both endoderms have the tendency to differentiate into an intestinal epithelium. In the recombinates composed of allantoic endoderm and proventricular mesenchyme, acid-protease activity was detected, but biochemical analysis revealed that this activity was not due topepsinogens. These results indicate that the gland formation induced in allantoic and small-intestinal endoderms by the proventricular mesenchyme is not accompanied by the expression of pepsinogens, suggesting that independent mechanisms are responsible for the morphogenesis and cyto chemical differentiation of the endoderm.     

Total nitrogen and free amino acids in Morus alba stems from autumn through spring

During leaf senescence and abscission, total nitrogen in leaves of mulberry ( Morus alba L. ev. Shin-ichinose) declined substantially whereas total nitrogen in buds, bark and stem wood increased markedly, suggesting translocation of nitrogen from senescent leaves in the autumn. After leaf abscission the winter buds and stems remained almost unchanged with respect to fresh and dry weight and total nitrogen until bud break in spring. In burst buds these parameters then increased drastically during the new growth while they decreased markedly in stems. Free arginine in the stem bark accumulated in parallel with the accumulation of total nitrogen in buds and stems in the autumn. Accumulation of proline in the wood, bark and buds also started in October but continued even after leaf-fall, increasing until mid-January (wood), mid-February (bark) and the new growth (buds). Prior to and in the early stage of bud break, proline in bark and wood decreased significantly and arginine in stem bark decreased slightly. Simultaneously, proline and arginine in the dormancy-releasing buds and asparagine, aspartic acid and glutamic acid in the buds and stems increased appreciably, suggesting that this increase in free amino acids was mainly derived from free amino acids (proline and arginine) stored in stems. The resulting marked decrease in total nitrogen and the drastic increase in asparagine in the stems and sprouting buds/new shoots were primarily due to a breakdown of protein stored in stems.     

Models of Evolution of Reproductive Isolation

Mathematical models are presented for the evolution of postmating and premating reproductive isolation. In the case of postmating isolation it is assumed that hybrid sterility or inviability is caused by incompatibility of alleles at one or two loci, and evolution of reproductive isolation occurs by random fixation of different incompatibility alleles in different populations. Mutations are assumed to occur following either the stepwise mutation model or the infinite-allele model. Computer simulations by using It?'s stochastic differential equations have shown that in the model used the reproductive isolation mechanism evolves faster in small populations than in large populations when the mutation rate remains the same. In populations of a given size it evolves faster when the number of loci involved is large than when this is small. In general, however, evolution of isolation mechanisms is a very slow process, and it would take thousands to millions of generations if the mutation rate is of the order of 10(-5) per generation. Since gene substitution occurs as a stochastic process, the time required for the establishment of reproductive isolation has a large variance. Although the average time of evolution of isolation mechanisms is very long, substitution of incompatibility genes in a population occurs rather quickly once it starts. The intrapopulational fertility or viability is always very high. In the model of premating isolation it is assumed that mating preference or compatibility is determined by male- and female-limited characters, each of which is controlled by a single locus with multiple alleles, and mating occurs only when the male and female characters are compatible with each other. Computer simulations have shown that the dynamics of evolution of premating isolation mechanism is very similar to that of postmating isolation mechanism, and the mean and variance of the time required for establishment of premating isolation are very large. Theoretical predictions obtained from the present study about the speed of evolution of reproductive isolation are consistent with empirical data available from vertebrate organisms.     

Synthesis of derivatives of methyl β-sophoroside

Selective tritylation of methyl β-sophoroside (1) and subsequent acetylation gave the 3,4,2′,3′,4′-penta-O-acetyl-6,6′-di-O-trityl derivative, which was O-detritylated, and the product p-toluenesulfonylated, to give methyl 3,4,2′,3′,4′-penta-O-acetyl-6,6′-di-O-p-tolylsulfonyl-β-sophoroside (4) in 63% net yield. Compound 4 was also obtained in 69% yield by p-toluenesulfonylation of 1, followed by acetylation. Several, 6,6′-disubstituted derivatives of 1 were synthesized by displacement reactions of 4 with various nucleophiles. Treatment of 4 with sodium methoxide afforded methyl 3,6:3′,6′-dianhydro-β-sophoroside. Several 6- and 6′-monosubstituted derivatives of 1 were prepared, starting from the 4,6-O-benzylidene derivative of 1.     

Observations on the ultrastructure of nerve cells in the brain of the planarian,Dugesia gonocephala

Summary The submicroscopic structure of the nerve cells in the planarian brain was studied. Close similarities with neurons of other invertebrates were noted. In the cytoplasm of the planarian nerve cells there are at least three types of vesicular inclusions: 1) Clear vesicles (200–800 Å in epon embedded tissue) similar in morphological appearance to classical synaptic vesicles. These have generally some content of extremely low density but occasionally a dense core. 2) Dense vesicles (400–1,200 Å in epon embedded tissue) containing highly osmiophilic granules. Between the limiting membrane of the vesicle and the granule there is always a clear rim of variable width. These vesicles closely resemble synaptic vesicles described in vertebrate adrenergic endings. 3) Neurosecretory vesicles (600–1,300 Å in Vestopal embedded tissue) similar to elementary granules observed in neurosecretory systems in vertebrates and invertebrates. All three vesicle types have the same mode of origin from the Golgi membranes. All are present in the nerve cell processes of the neuropil as well as in the perikarya. Any given perikaryon or axon contains only one of the three vesicle types. All of these vesicles are considered to be discharged into the axons from their site of origin within the perikaryon.