Major contribution of epididymis to alpha-glucosidase content of ram seminal plasma

Acid alpha-glucosidase and L-carnitine (a well-known epididymal marker) were measured in rete testis and epididymal fluids of adult male rams. These fluids were collected by selective catheterization or by a micropuncture technique, respectively. Both parameters remained at a low and constant level in rete testis and all along caput and corpus epididymidis. Then they increased at equivalent rates in cauda epididymidis to much higher levels than those in seminal plasma (5 mU/mg protein and 10 mM, respectively). An optimum pH study of alpha-glucosidase activity in these fluids showed two well-separated peaks in rete testis and caput epididymal fluids around pH 4 and 7, respectively, but only a single peak at pH 4 in cauda epididymidis that was comparable to the one in seminal plasma. Sucrose density gradient fractions analyzed for their enzyme content in the absence or presence of sodium dodecyl sulfate (1% w/v), a selective inhibitor of acid alpha-glucosidase activity, allowed the demonstration of two enzyme forms at pH 6.8 in rete testis fluid sedimenting in the 7S and 4S regions of the gradient, while a unique 4S form was encountered in cauda epididymidis and in seminal plasma. Although the fate of the minor 7S component of the rete testis fluid in its epididymal transit is presently unknown, similarities between the enzyme in cauda epididymidis and seminal plasma are strong enough to support the hypothesis that epididymis contributes primarily to the acid alpha-glucosidase content of ram seminal plasma.     

Influence of aerial dispersal on persistence and spread of pesticide-resistant Metaseiulus occidentalis in California almond orchards

Aerial dispersal of the phytoseiid Metaseiulus occidentalis (Nesbitt) was evaluated as a component in managing pesticide-resistant populations established in California almond orchards. Peak dispersal occurred in late July and early August during 1982 and 1983. Most predators (and spider mites) left the orchards on the prevailing winds from the northwest. Within the orchard, the prevailing winds had less influence, and dispersal was usually random. Both spider mites and predators dispersed randomly with regard to height from the almond trees, but data obtained during one 24-h interval suggest they do not disperse randomly throughout the day. Most aerial movements occurred between 16–22 h when relative humidity and wind speeds increased and temperatures decreased. Spider mites and predators were trapped on panels located 200 m from the orchard. A survey of carbaryl resistance levels in M. occidentalis collected from almond orchards surrounding the release sites indicates that carbaryl-resistant M. occidentalis dispersed at least 800 m between 1981–83. However, growers wishing to use the resistant strains should release them in their orchards as natural dispersal appears to be too slow. Migration of native M. occidentalis into the release sites appeared to be sufficiently rare that dilution of carbaryl-resistant populations was minimal during a 2–4 year period.

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Résumé La dispersion aérienne du phytoseïdae, M. occidentalis (Nesbitt), a été estimée comme élément de la lutte contre les populations résistantes aux insecticides établies dans les vergers de Californie. La dispersion maximale s'est produite fin juillet et début a oût en 1982 et 1983. La plupart des prédateurs (et des acariens) quittent les vergers avec les vents dominants du nordouest. Dans le verger, les vents dominants sont moins importants et la dispersion est généralement au hasard. Tant les acariens que les prédateurs se dispersaient au hasard par rapport à la taille des amandiers, mais les relevés sur 24 heures laissent supposer qu'il n'y a pas une distribution aléatoire pendant la journée. La plupart des mouvements aériens se produisirent entre 16 et 22 heures quand HR et vitesse du vent augmentaient et température diminuait. Les acariens et prédateurs ont été piégés sur des panneaux à 200 m du verger.

     

Total biodegradation of 4-chlorobiphenyl (4 CB) by a two-membered bacterial culture

Summary Several bacterial strains that can oxidize mono- and dichlorinated biphenyls with one unsubstituted ring have already been described. The major route for this biodegradation leads ultimately to the corresponding chlorobenzoic acid, but several other minor chlorinated metabolites that might possibly be of concern for the environment have also been described previously. Since none of the bacterial strains that are able to oxidize these chlorinated biphenyls in pure culture are known to degrade chlorobenzoic acid, the oxidation of these substrates by axenic cultures always generates chlorobenzoates plus several other metabolites. In the present study, we have estimated the biodegradation of 4-chlorobiphenyl (4CB) by a two-membered bacterial culture containing one strain able to grow on 4CB and to transform it into 4-chlorobenzoate (4CBA) and one strain able to degrade 4CBA. The results were encouraging, since it was shown that the degradation of 4CB was more rapid and complete with the double bacterial culture.     

An immunocytochemical study of the optic ganglia of the crayfish Astacus leptodactylus (Nordmann 1842) with antisera against biologically active peptides of vertebrates and invertebrates

Summary The peptidergic system in the optic ganglia of Astacus leptodactylus is characterized by the immunocytochemical application of 15 antisera raised against biologically active peptides of vertebrates and invertebrates. Positive reactions were found with anti-FMRFamide, antiMSH, anti-vasotocin, anti-gastrin, anti-CCK, anti-oxytocin, anti-secretin, anti-glucagon and anti-GIP. Based on immunochemical reaction and localization it is possible to distinguish 30 cell groups. Only part of these cell groups is found in the known classical neurosecretory cell regions. This observation demonstrates a more extensive peptidergic system than formerly recognized. The morphology of this peptidergic system suggests that one part is neurohormonal and the other part neurotransmitter-like or neuromodulatory.     

Serological survey of T-lymphocyte differentiation antigens in wild mice

Allelic distributions of Thy-1, Ly-l, and Ly-2 antigens in wild mice are characteristic of each Mus musculus subspecies. Eastern mice (M.m.molossinus, M.mmusculus, M.m.castaneus, M.m.bactrianus) express the Thy-1.1 antigen, whereas Western mice (M.m. domesticus, M.m.brevirostris) express the Thy-1.2. All mice from wild populations examined in this survey express the Ly-1.2. The Ly-2.1 is distributed in Eastern mice and some Western mice, and the Ly-2.2 is found in the remaining Western mice. Allelic distributions of these antigens were also examined in two other species, Mus spretus and Mus spicilegus. Allelic constitutions of Thy-1 and Ly-1 in these species are similar to those of Eastern mice. Some M.spicilegus, however, express the Ly-1.1 antigen. This antigenic type is not found in M.musculus. Some Eastern mice related to M.m.castaneus react weakly to Ly-1.2-specific and Ly-2.1-specific monoclonal antibodies in both the complement-mediated cytotoxicity test and the absorption test. These results suggest that M.m.castaneus has unique alleles in the Ly-1 and Ly-2 loci.     

Ovarian and fat body protein concentrations in Ips sexdentatus (Coleoptera: Scolytidae) parasitized by nematodes

The protein concentrations of fat body and ovaries in Ips sexdentatus either uninfected or infected by Parasitaphelenchus sp., P. sexdentati, or Contortylenchus diplogaster were measured at various stages of insect development, from preswarming maturation to the first oviposition (24 hr after mating). Weight variations of the fat body and ovaries in insects infected by C. diplogaster show the same evolution as those observed in uninfected insects, but at a much lower level. Fat body proteins in uninfected insects reach their minimum level during swarming, but they remain fairly constant throughout the maturation of the first egg. After dropping shortly after swarming, the ovarian protein level in such insects increases in two stages during ovarian maturation. The first stage, which corresponds to a slow protein incorporation, takes place during the first 12 hr after mating. During the second stage, i.e., beyond 12 hr, a significant level of proteins is rapidly incorporated into the ovaries. In insects infected by Parasitaphelenchus fat body proteins are reduced and protein incorporation into the ovaries is reduced; Parasitaphelenchus would thus affect at least some proteins required for ovarian maturation in their host. Fat body protein levels are even more affected by C. diplogaster than by Parasitaphelenchus, while incorporation into ovaries seems to be less affected in spite of slower ovarian growth. C. diplogaster might thus essentially act both upon proteins which are not required for the ovarian maturation of their host and upon nonproteinaceous substances that are required for such maturation. Results are discussed in relation to the possible mode of action of parasitic nematodes.     

Characterization of newly isolated monoclonal antibodies against MHC of a Japanese wild mouse

We have already developed nine B10.MOL congenic strains carrying H-2 haplotypes derived from Japanese wild mice, Mus musculus molossinus, with the C57BL/10 genetic background. To obtain monoclonal antibodies against the H-2 antigen of the Japanese wild mouse, we carried out cell fusion using spleen cells from the animal immunized with one of the B10.MOL strains, B10.MOL-SGR (H-2 ^wm7). As a result, 19 hybridomas producing monoclonal antibodies were produced. Analysis with the intro-H-2 recombinants derived from B10.MOL-SGR indicated that 8 of them reacted with the class I and II with the class II molecule. The class I antibodies were tested for their cross -reactivities on wild mice and on the panels of standard inbred and B10.MOL strains. Most of the antibodies reacted with both the Japanese wild mice and the other subspecies, including standard inbred, while two antibodies highly specific for the donor H-2K region reacted with only three wild-derived mice, two M. m. molossinus from Anj o and Shizuoka, Japan, and one M. m. domesticus from Pigeon, Canada. In addition, all of the other four antibodies reactive with the K antigen of B10.MOL-SGR also reacted with the same three wild mice. The wild mice belonging to different subspecies might share very similar H-2K antigenic determinants in spite of their genetic and geographical remoteness.     

Interferon affects intracellular calmodulin levels

Interferon lowers calmodulin levels in two cell lines sensitive to its antiproliferative effect. Further, in synchronized cells, interferon strongly inhibits the increase in calmodulin observed when control cells enter the S phase, and concomitantly inhibits DNA synthesis. Calmodulin has been implicated in the control of cell proliferation and an increase in this protein seems to be necessary for the progression of cells into the S phase of the cell cycle. Therefore, the effect of interferon on calmodulin content might constitute part of the molecular mechanism by which interferon inhibits DNA synthesis.