The chemical characterization of favin, a lectin isolated from Vicia faba.

We have determined the subunit structure of the glucose- and mannose-binding lectin favin, from Vicia faba. The molecule is composed of two nonidentical polypeptide chains held together by noncovalent interactions. We have determined the complete amino acid sequence of the smaller alpha chain (Mr = 5,571) and shown that it is homologous to the alpha chain of the lectins from lentil and pea and to residues 72 to 120 of concanavalin A (Con A). The larger beta chain (Mr = 20,000) contains carbohydrate and is homologous to the beta chain of lentil, pea, soybean, peanut, and red kidney bean lectins and is homologous to a portion of the Con A molecule beginning at residue 122. Favin also contains a minor component, beta' (Mr = 18,700), that closely resembles the beta chain but lacks carbohydrate and may, on the basis of apparent molecular weight, lack some part of the COOH-terminal region of the polypeptide chain. Although favin is similar to Con A, it, like the lentil and pea lectins, appears to lack residues corresponding to positions 1 to 71 of Con A. Because these residues contribute significantly to the carbohydrate binding site of Con A, the lack of this region in the otherwise homologous lectin favin suggests that the carbohydrate binding site of favin differs from that of Con A or that the region represented by residues 1 to 71 of Con A is located in a different portion (i.e. in the beta chain) of the favin molecule.     

Communication between termites by biofields

Building of vertical galleries (runways) by termites of the species Heterotermes indicola (Wasmann) is suppressed in the interior area of arrangements of plastic containers with equal groups of termites and takes place preferably at the periphery. This reaction is not induced by chemical, vibrational or thermal influences. Shielding separation by plates of glass, plastic foam or various metals demonstrated, that the influence on activity and directional behaviour is caused by fields produced by the termites. They are most probably alternating electric fields. These biofields act together or, if the direction of the gradients differs, in competition with a weak alternating magnetic field in the air-conditioned experimental room. The centrifugal reaction of the termites to the biofields which do not influence the feeding activity, induces gallery building at the periphery of the nesting area.This paper was presented at the International Congress of Entomology in Washington (D.C.), USA, on August 23, 1976. —Experiments with support by the Deutsche Forschungsgemeinschaft     

Long-term survey data (1965-1972) on the occurrence of Anisakis larvae (Nematoda: Ascaridida) in herring, Clupea harengus L., from the North Sea

The occurrence of larval Anisakis in North Sea herring was examined during the period 1965-1972 using a sampling method which yielded comparable data for all eight years. Data on abundance of infestation in several herring stocks pointed to remarkable fluctuations over the study period with an increase in the period 1966-1968 followed by a decrease in the period 1968-1972. Of various hypotheses that may explain this situation, it is concluded that changes in the migration behaviour of the herring may be responsible. Other data and statistics are discussed with special reference to variations in infestation level in different samples and to the occurrence of adult nematodes in marine mammals.     

A model for intramolecular recombination of herpesvirus DNA leading to the formation of circular, circular-linear and fragmented genomes.

A model is presented for intramolecular recombination of herpesvirus DNA. It is proposed that the terminal repeat sequences of the viral DNA contain insertion sequences which may integrate with homologous repeat sequences between the long (L) and short (S) components. In class 2 herpes-virus DNA (as defined by Honess &; Watson, 1977) in which the repeat sequences flank the S component only, circular-linear DNA molecules can be formed as an intermediate step. Reorientation of the S component leads to the formation of two DNA isomers. In class 3 herpesvirus DNA in which repeat sequences flank both the L and S components, either circular-linear or 8-shaped DNA molecules are proposed as intermediates leading to the formation of four DNA isomers. Fragmentation of the S component could lead to the formation of small circular DNA molecules.     

Facilitation of parental behavior in ring doves by systemic or intracranial injections of prolactin

Systemic administration of ovine prolactin (PRL) has been previously reported to stimulate parental feeding behavior toward 7-day-old foster squabs by nonbreeding ring doves with previous breeding experience. The first of the present experiments reexamined this claim in experienced, nonbreeding birds given test squabs of different ages. Each visually isolated male and female dove was given twice-daily subcutaneous injections of ovine PRL or vehicle for 7 days and then tested for parental responses toward a single 1-3, 6-8, or 11- to 13-day-old foster squab. Prolactin significantly increased the incidence or frequency of parental regurgitation-feeding episodes in tests with all three squab age groups and, in addition, increased the incidence of parental feeding invitations (squab-oriented bill openings) in tests with 6- to 8-day-old squabs. A second study explored the degree to which PRL can act directly on the central nervous system to facilitate parental activity in the absence of peripheral cues generated from PRL-induced changes in other target organs, such as those associated with crop sac growth and distension. In this experiment, 6- to 8-day-old test squabs were used to determine if parental behavior is enhanced by twice-daily intracerebroventricular (ICV) injections of PRL in doses below those required to stimulate peripheral target organs. Injection schedules and behavior testing procedures were the same as those used in Experiment 1. However, half of the ICV PRL-treated and ICV vehicle-treated birds were food deprived for 16 hr before and during the test in order to control for PRL-induced hyperphagia and resulting crop sac distension, which could confound the results by generating peripheral stimuli conductive to the display of regurgitation-feeding behavior. Intracranial injections of prolactin significantly increased the incidence of feeding behavior, parental feeding invitations, and crouching or sitting in the nest in food-deprived doves but not in freely fed animals. Empty crop sac weights of freely fed and food-deprived PRL-treated birds were not increased above control values, thus indicating that ICV PRL treatment did not result in significant stimulation of peripheral target organs. These results demonstrate a facilitative action of PRL on regurgitation-feeding responses and associated parental behaviors that is not restricted to squabs of one particular age range. They also indicate that PRL is capable of acting directly on the brain to promote these activities in the absence of PRL-induced changes in the crop sac and other peripheral target organs.     

Co-localization of ecdysteroid receptors and c-fos-like protein in the brain of Manduca sexta larvae

Summary The presence of c-fos, a marker for cell activation, was investigated in cerebral neurons actively expressing ecdysteroid receptors during larval-pupal development in the tobacco hornworm, Manduca sexta. Colocalization was accomplished by ecdysteroid autoradiography using the tritiated high affinity 20-hydroxyecdysone agonist ponasterone A and immunocytochemistry with an antibody to a peptide sequence which is highly conserved in both human and murine c-fos. Immunoreactivity to a c-fos-like protein(s) was present in nuclei of many neurons of all the developmental stages examined. However, with the exception of the optic lobe, cells expressing nuclear ecdysteroid receptors were more immunoreactive than non-ecdysteroid-binding neurons. These data suggest that ecdysteroid-induced gene activation and translation may involve c-fos expression. Offprint requests to: H.-J. Bidmon     

Prevention of Dahl salt-induced hypertension by chronic dietary tryptophan

Four-week-old inbred Dahl salt-sensitive (DS/JR) and Dahl salt-resistant (DR/JR) rats were placed on an 8% salt diet with or without a supplemental 2.5% tryptophan (Trp). Blood pressures were monitored for the next 5 weeks. Urine volumes and ion concentrations were measured during the 6th week. Blood pressures of DS/JR rats on control diets elevated rapidly and markedly, whereas pressures of DS/JR rats on the Trp-supplemented diet were not significantly elevated over those of DR/JR rats. Pressures of DR/JR rats were unaffected by Trp supplementation. Urinary sodium was significantly greater in DR/JR rats compared with DS/JR rats and was unaffected by Trp supplementation. This suggests that the antihypertensive effect of Trp was not at the level of the kidney. We conclude that dietary Trp blocks the development of hypertension in DS/JR rats maintained on a high salt diet.     

Stimulation of the anaerobic growth ofSalmonella typhimurium by reduction ofl-carnitine,carnitine derivatives and structure-related trimethylammonium compounds

In view of the development of al-carnitine deficiency, the metabolism ofl-carnitine and structure-related trimethylammonium compounds was studied inSalmonella typhimurium LT₂ by means of thin-layer chromatography (TLC).l-Carnitine, crotonobetaine and acetyl-l-carnitine stimulated the anaerobic growth in a complex medium significantly. The stimulation depended on the formation of -butyrobetaine. The reduction ofl-carnitine proceeded in two steps: (1) Dehydration of thel-carnitine to crotonobetaine, (2) hydrogenation of crotonobetaine to -butyrobetaine. The reduction of crotonobetaine was responsible for the growth stimulation. Terminal electron acceptors of the anaerobic respiration such as nitrate and trimethylamine N-oxide, but not fumarate, suppressed the catabolism ofl-carnitine completely. Glucose fermentation, too, inhibited the reduction ofl-carnitine but optimal growth with a high carnitine catabolism was achieved byd-ribose. The esters of carnitine with medium- and long-chain fatty acids inhibited the growth considerably because of their detergent properties.Abbreviations TLC thin-layer chromatography