Stage-specific cuticular proteins of Ostertagia circumcincta and Ostertagia ostertagi

In this study we have shown that NHS-biotin and I¹²⁵-streptavidin can detect cuticular polypeptides of Ostertagia spp. The labelled polypeptide profile of intact nematodes is simple compared to the profile obtained by labelling homogenates. None of the major internal polypeptides are labelled and the subset of proteins labelled in intact nematodes appears to be mainly surface associated. The results presented here demonstrate that NHS-biotin may be used as a reagent for the analysis of surface polypeptides. The surface polypeptide profiles of the five major developmental stages (L1, L2, L3, L4 and adult) of Ostertagia circumcincta show a series of stage-specific molecules with no polypeptides common to all stages, indicating that the cuticle is a dynamic structure which changes throughout the life cycle. Similarity comparison of Ostertagia ostertagi L3 and L4 stage surface profiles showed that each stage is clearly distinct; comparison of these stages between the two species shows an overall similarity.     

AMONG- AND WITHIN-FLOWER COMPARISONS OF POLLEN TUBE GROWTH FOLLOWING SELF- AND CROSS-POLLINATIONS IN DIANTHUS CHINENSIS (CARYOPHYLLACEAE)

We compared the rate of pollen tube growth following self- and cross-pollinations both among and within flowers of two clones of Dianthus chinensis L. For among-flower comparisons, both styles of a flower were pollinated with either self- or cross-pollen. Within-flower comparisons were made between the two styles of the same flower, one of which was self-pollinated and the other cross-pollinated. Comparisons between flowers indicated that self-pollen grew slower than cross-pollen in both clones. However, differences in the growth rate of pollen tubes from self- and cross-pollinations were greater when comparisons were made between the two styles of the same flower than when pollinations were made in different flowers. These results suggest the existence of interstyle interactions in pollen tube growth.     

Occurrence,localization, and possible significance of an ornithine-containing lipid in Paracoccus denitrificans

A ninhydrin-positive, phosphorus-negative lipid from Paracoccus denitrificans ATCC 13543 has been isolated and purified by mild alkaline methanolysis followed by silicic acid column chromatography and preparative thin-layer chromatography. The lipid was identified as an ornithine-containing lipid. The major ester-linked fatty acid was cis vaccenic acid. Major amide-linked fatty acids were 3-OH-20:1 and 3-OH-18:0. Ornithine-containing lipid was a major lipid component of P. denitrificans. Phospholipids made up about 57% and ornithine-containing lipid about 14% of the weight of the total lipid of the organism. The ratios of lipid ornithine: lipid phosphorus were 0.23, 0.65 and 0.58 in cytoplasmic membrane, outer membrane, and an NaCl extract, which is thought to represent chiefly outer membrane, respectively. Thus ornithine-containing lipid appears to be present in larger amounts in outer membrane than cytoplasmic membrane. No substantial variations in lipid ornithine levels were noted in stationary phase versus exposnential phase organisms, organisms grown in complex medium versus organisms grown in minimal medium with and without amino acid supplements, or in organisms grown in low phosphate-containing medium.Non standard abbreviations TLC thin-layer chromatography - Tris-HCl tris(hydroxymethyl)aminomethane hydrochloride - TMS trimethylsilyl - TFA triluoroacetyl - NPPN ninhydrin-positive, phosphorus-negative - ECL equivalent chain length     

The rise and fall of pineal N-acetyltransferase in vitro: Neural regulation in the developing rat

In rats, the pineal gland has a rhythm in the activity of the enzyme, N-acetyltransferase (NAT), which is thought responsible for daily cycles of melatonin synthesis. Neonatal rat pineal glands, but not those of adult rats, have a single cycle that is observed in vitro during the first day of organ culture. The neural regulation of the cycle was investigated using neonatal rats with adult rats used for comparison. Prior treatment of rat pups with constant light did not abolish the cycle in vitro though it did abolish the in vivo rhythm. Removal of the superior cervical ganglia did not abolish the in vivo rhythm that was measured the first day after surgery, but ablation of the ganglia did abolish the rhythm if several days or more elapsed after surgery. Extirpation of the superior cervical ganglia abolished the in vitro NAT cycle in pup pineal glands as did the pharmacological equivalent, injection of 6-hydroxydopamine. Propranolol, a beta blocking agent, prevented the occurrence of the cycle in vitro.     

Intracerebral injection of gamma vinyl GABA: Method for measuring rates of GABA synthesis in specific brain regions invivo

In order to obtain an index of the rate of GABA synthesis in different rat brain regions, we examined the rate of accumulation of GABA after irreversible inhibition of GABA-transaminase. Gamma-vinyl-GABA (GVG), a catalytic inhibitor of GABA-transaminase, was microinjected directly into each of four brain areas: superior colliculus (SC), substantia nigra (SN), frontal cortex (CTX) and caudate-putamen (CP). The subsequent rate of GABA accumulation was linear for at least 90 min in all regions, and was found to be 2–3 times higher in the SC and SN than in the CTX and CP. The nerve terminal contribution to the initial rate of GABA accumulation after GVG was determined by comparing values obtained in the intact SN with those obtained in the SN in which the GABAergic afferent terminals had been destroyed. The initial rate of GABA accumulation in the denervated SN was less than one-half of that measured in the intact SN, indicating that, under normal conditions, both nerve-terminal and non-nerve-terminal (perikarya, glia) compartments contribute to the rate of GABA accumulation after GABA-transaminase inhibition. Our results indicate that the intracerebral injection of GVG is a sensitive and reliable method for studying $\text{in}\text{vivo}$ GABA synthesis in brain. Although the rate of GABA accumulation after GVG is sensitive to changes in the nerve terminal compartment, other GABA compartments may also influence these measurements.     

Intravascular and extracellular volumes in the diabetic rat

Simultaneously measured intravascular (IVV) and extracellular (ECV) volumes in diabetic rats have not been reported. We evaluated IVV and ECV in alloxan induced diabetic rats which were either untreated (DU) or received supplemental daily insulin (DI) for three months. Two separate groups of control rats were comparably weight matched to each experimental group. Radio-iodinated (125-I) human serum albumin (RISA) and 35-S sulfate were used to determine IVV and ECV respectively. In DU rats, values for IVV and ECV expressed as a percentage of body weight were 9.3±0.5% and 35±2% respectively; both are significantly larger than the volumes measured in control rats (IVV=6.6±0.2%, p^<0.001 and ECV=28±1%, p<0.01). DI rats had volumes (IVV=6.0±0.3% and ECV=24±3%) which were not significantly different than those of control rats (IVV=5.7±0.1% and ECV=22±1%). Thus, untreated diabetic rats had increased IVV and ECV while diabetic rats that received insulin were normovolemic despite the presence of hyperglycemia.     

Genetic analysis of X-linked mutagen-sensitive mutants of Drosophila melanogaster

Mutants at 2 new loci which control mutagen-sensitivity are described. Mutants at both loci are female-sterile and are hypersensitive to killing by MMS; neither increases the frequency of sex-linked recessive lethals. A screen of previously described female-sterile and meotic mutants has revealed that a number of these are also sensitive to mutagens. In addition, several new mutants have been identified on the basis of sensitivity to either HN2 or MMS. An anlysis of complementation data suggests that all of the X-linked genes controlling sensitivity to MMS may now have been identified. Among the new mei-41 alleles are mutants which show verly little meiotic nondisjunction or loss. Cytogenetic mapping of previously known mutants is also described. The mutants mus(1)104^D1 and mei-41^D5 are located in th eregion 14B13±?14D1,2 on the polytene chromosome map, and they map very close to each other genetically. Cytogenetically mus(1)101^D1 is between salivary chromosome bands 12A6,7 and 12D3, mus(1)103^D1 is between bands 12A1,2 and 12A6,7, and mus(1)-109^A1 is in section 8F3-9A2.     

Recognition of human minor alloantigen(s) by cytotoxic lymphocytes in vitro

Lymphocytes from an extensively transfused patient with aplastic anemia were induced to cytotoxicity against target cells from several HLA-matched siblings by in vitro stimulation with allogeneic cells. Effective stimulating cells shared HLA-B7 with the patient, but not all B7 individuals were effective. An additional factor, which was found to segregate in both the patient's and an unrelated sibship, was also necessary. Segregation of this minor alloantigen, W, was also revealed among the patient's HLA-matched sibs by differential susceptibility to lysis by effectors from the patient. The ratio of six positive to four negative siblings suggests that the antigen difference might be coded by a single locus. Lymphocytes from a normal sib, who like the patient is lacking the minor antigen, could not be induced to cytotoxicity against positive targets. Thus in vivo sensitization of the donor of the responding cells appears to be necessary for the demonstration of the cytotoxic response to the minor antigen in vitro. No correlation was observed between the segregation pattern of W and of known blood group antigens, and no cytotoxic antibody to W was detected in the patient's serum in several trials.Abbreviations used in this paper MHC major histocompatibility complex - Tc thymus dependent cells capable of mediating cytotoxicity in the absence of Immoral antibody - GVHD graft versus host disease - CML cell mediated lympholysis - MLC unidirectional mixed lymphocyte culture - ADCC antibody-dependent cell mediated cytotoxicity     

An allele (Pk-1 b ) from wild-caught mice that affects the activity and kinetics of erythrocyte and liver pyruvate kinase

A true breeding strain was made from a wild-caught mouse with low erythrocyte pyruvate kinase (E.C. 2.7.1.40) activity. This variation showed additive inheritance and segregated as an allele at a single locus (Pk-1 ^b). Mice homozygous for the reduced blood pyruvate kinase activity cosegregated for reduced liver activity. In both these tissues the variant enzyme had a lowered heat stability and reduced K _m values for ADP. An increased stimulation by FDP was also detected in the liver pyruvate kinase. No difference in the isoelectric point of the variant enzyme in either erythrocyte or liver was observed when compared with the enzyme from C57BL mice (Pk-1 ^a/Pk-1 ^a). It is concluded that Pk-1 is the structural gene for the erythrocyte and the major liver pyruvate kinase. No other tissue pyruvate kinase showed altered characteristics.This work was supported by a Medical Research Council grant.