Mapping of nucleoside phosphorylase (Np-1) and esterase 10 (Es-10) on mouse chromosome 14

A method for detecting two alleles at Np-1 (nucleoside phosphorylase) and three alleles at Es-10 (esterase 10) from mouse blood by cellulose acetate electrophoresis is described. The allelic constitution at these loci for 44 inbred strains and stocks was determined. The location of Np-1 on chromosome 14 was established by backcross experiments in which alleles at Np-1 and Robertsonian translocations were segregating. Es-10 was shown to be linked to Np-1, and the following genetic map of Chr 14 was constructed: centromere-(8.9±4.0 cM)-[Np-1, Wc]-(10.2±1.9 cM)-Es-10-(15.5±3.7 cM)-s. The homologous human loci, NP and ES-D, are not linked.This work was supported by Contract E(11-1)-3267 with the Energy Research and Development Administration, by Contracts NO1-ES4-2156 and NO1-ES4-2159 with the National Institute of Environmental Health Sciences, and by Grants GM 19656 and GM 20919 from the National Institute of General Medical Sciences. D. A. K. was a participant in the 1975 Summer Program for College, Graduate, and Medical Students, which was supported, in part, by the Clark Foundation. The Jackson Laboratory is fully accredited by the American Association for Accreditation of Laboratory Animal Care.     

Comparison of storage proteins ofPhaseolus caracalla L. with the proteins of some other representatives of the genusPhaseolus

Storage proteins of the seeds (cotyledons) of the South-American speciesPhaseolus caracalla were compared by means of immunoelectrophoretic methods with other representatives of the genusPhaseolus. These proteins most resemble the proteins of the co-called tropical group (i.e. Ph. atropurpureus, Ph. geophilus, Ph. bracteatus, Ph. semierectus) and least the so-called American endemites (Ph. vulgaris, Ph. coccineus, Ph. acutifolius, Ph. lunatus), the main globulin of which is of a completely different specificity. The proteins ofPh. caracalla are less similar to the group of the so-called Asiatic species (Ph. aureus, Ph. calcaratus, Ph. angularis, Ph. aconitifolius, Ph. trilobus) including the analyzed representatives ofVigna sinensis; their main globulin is only partly similar to that ofPh. caracalla. Some considerations on the relationship ofPh. caracalla with the so-called tropical species is presented.     

Comparison of the protective ability of O and K immunity in mice after immunization withEscherichia coli

The protective abilities ofEscherichia coli O and K immunity against intraperitoneal infection was compared in CBA mice immunized with formalin-killed bacteria. The K13 immunity achieved seemed somewhat more effective than the O6 immunity. This was also reflected in a slightly more rapid clearance of a liveE. coli O6K13 bacteria in K13-immunized animals than in those immunized with O6. However, the protection achieved afterE. coli O6K2 and O2K1 immunization was related more to O immunity than to K immunity.     

Fetal cells in the maternal blood

Summary In an attempt to stimulate fetal cells in the maternal blood to mitotic division, peripheral blood lymphocytes were cultured from ten primiparous women and six multiparous women. In the case of the ten primiparous women, PWM was used to stimulate lymphocytes in 3- and 7-day cultures made at the 16th, 20th, 24th, and 28th week of gestation. Altogether, 10565 mitoses were analyzed after quinacrine staining of cells from five mothers who each subsequently gave birth to a male infant, and not a single XY mitosis was found.In the case of the multiparous women, lymphocyte cultures, with PHA or LPS as mitogen and MLC, were initiated between the 13th and 20th week of pregnancy. Four of the mothers were pregnant with a male child, and two with a female child. From cultures of each of the four mothers expecting a boy, a total of 9721 mitoses were analyzed after quinacrine staining, and not a single XY mitosis was found. However, one XY cell was found in the culture from one of the two women who delivered a girl. The XY mitosis probably originated from a pregnancy 8 months earlier which terminated in a male infant.In an attempt to culture and obtain good chromosome preparations from small numbers of cells, it was shown that a good mitotic response and good chromosome preparations could be obtained from as few as 6000 lymphocytes.     

Valine-sensitive acetohydroxy acid synthases in Escherichia coli K-12: unique regulation modulated by multiple genetic sites.

Summary Spontaneous mutants (146) of Escherichia coli K-12 were selected that were resistant to inhibition of growth by 1.2 mM L-valine (Val^r). The Val^r isolates, containing acetohydroxy acid synthase resistant to feedback inhibition by L-valine (AHAS^r), were classed according to cotransduction of the mutation with leu. Several mutations resulting in an AHAS^r phenotype were found to be cotransducible with glyA. However, no mutations causing a Val^r phenotype were linked to ilv. AHAS activity was more closely examined in representatives of three classes of mutants with Val^r linked to leu, labeled ilv-660, ilv-661, and ilv-662. The ilvE503 allele in E. coli K-12, known to cause a two- to three-fold derepression of AHAS, was found to affect regulation of synthesis of both valine-sensitive AHAS (AHAS^s) and AHAS^r in the mutants containing ilv-660 and ilv-661, whereas it affected repression of AHAS^s, only, in the mutant containing ilv-662. Further, both AHAS^s and AHAS^r in the ilv-661 mutant were repressed by valine, whereas valine did not repress AHAS^r synthesis in the strain carrying ilv-660 and only partially repressed AHAS^r in the strain carrying ilv-662. Unexpectedly, AHAS^r synthesis in strains carrying ilv-660 or ilv-662 was repressible by leucine. The ilv-660 locus appears to be similar in position to ilvH and encodes a product that confers valine-sensitivity upon AHAS activity in the wild-type E. coli K-12. The ilv-660 and ilv-662 loci may normally encode products that influence both the feedback sensitivity of AHAS and control of AHAS biosynthesis.     

Dihydroisocoumarins and phthalide from wood samples infested by fungi

Wood samples, infested by fungi during storage, were shown to contain, besides the known 5-methyl-mellein, additional (3R)-8-hydroxy-3-methyl-3,4-dihydroisocoumarins substituted by 7-methyl, 5-formyl, 5-carboxy, 5-hydroxy, 5-methoxy, 6-methoxy-5-methyl and 6,7-dimethoxy-5-methyl groups, as well as 6-formyl-7-hydroxy-5-methoxy-4-methylphthalide. Several 2-methylchromanones were synthesized in order to show that this class of compounds can be distinguished from 3-methyl-3,4-dihydroisocoumarins by MS.     

Purification and characterization of two isoenzymes of lipoxygenase from soybeans

A chromatographic procedure for the purification of two lipoxygenase isoenzymes (linoleate: O₂ oxidoreductase, EC 1.13.11.12.) from soybean is described. The procedure for the purification of isoenzyme L-1 includes optimalized extraction, ammonium sulfate fractionation, heat treatment and gradient elution from a CM-Sephadex C-50 column. The purification of L-2 includes ammonium sulfate fractionation, gelfiltration on Sephadex G-150 and gradient elution from a DEAE-cellulose column. Both isoenzymes L-1 and L-2 appear homogeneous after Disc-PAGE. The isoelectric points are 5.6 for L-1 and 5.8 for L-2. Molecular weights are estimated as 100,000 for L-1 as well as L-2 applying three different methods. Both isoenzymes contain 0.9 mol iron per mol protien. The estimated turn over numbers are 8,200 mol linoleate per mol enzyme and min for L-1 and 3,100 for L-2. Amino acid compositions determined after acid hydrolysis show marked differences between L-1 and L-2, particularly with respect to the amino acids Lys, Phe, Ser, Gly and Leu. L-1 posesses a total of 9 cysteine molecules, 6 of which are present as disulfide bonds. L-2 posesses a total of 8 cysteine molecules with only one disulfide bond.These results have been presented in part at the 13th ISF Congress in Marseille on 2nd September 1976     

Participation of splenic vessels in blood supply to the pancreas (experimental-mathematical study)]

In 60 objects the participation of splenic vessels in human pancreas blood supply was studied roentgeno-angiographically and by means of anatomical preparation. Morphometrical data obtained were treated by computers "Minsk-22" and "M-220-M" to calculate main statistic values and their correlations. Some recommendations of applied importance for pancreas surgery were suggested. Maximal and minimal dimensions of the pancreas segments, which can be used for grafting with the following blood supply restoration in the transplant at the expense of the splenic vessels only, were represented.     

Maximal activities of hexokinase, 6-phosphofructokinase,oxoglutarate dehydrogenase,and carnitine palmitoyltransferase in rat and avian muscles

The maximum activities of 6-phosphofructokinase and oxoglutarate dehydrogenase in muscle provide quantitative indices of the maximum capacities of anaerobic glycolysis and the Krebs cycle (i.e. the aerobic capacity) respectively. These activities were measured in red, white, and cardiac muscle of birds and the rat. The activities in the white pectoral muscle of the domestic fowl suggest that the Krebs cycle plus electron transfer could provide only about 1% of the rate of ATP production provided by anaerobic glycolysis whereas in pigeon pectoral muscle the predicted maximal rates from the two processes are similar. In contrast to domestic-fowl pectoral muscle, the white rat muscle, epitrochlearis, contains a significant activity of oxoglutarate dehydrogenase, which indicates that the Krebs cycle could provide about 12% of the maximum rate of ATP formation. This may be explained by a higher proportion of type-I and -IIA fibres in the rat muscle compared to the avian muscle. In the aerobic muscles of the rat the maximum activities of carnitine palmitoyl transferase indicate that fatty-acid oxidation could provide a high rate of ATP formation.     

Long-term changes in the phytoplankton of large lakes in response to changes in nutrient loading

In Sweden the recovery process of the four largest lakes (<500 km²) has been followed since the mid-1970's when the phosphorus loading was reduced by approximately 50%. A ten-year investigation period before that acts as a basis of comparison. The response of the dominating species in the phytoplankton communities in the eutrophic Lake Mälaren and the oligotrophic Lake Vättern is discussed also in relation to a pristine state of the lakes. The long-term investigations with monthly sampling make a natural phytoplankton biomass variation range possible to establish - a range that is mainly due to effects of weather fluctuations. In order to get a tool for water management where disturbing and highly disturbing total phytoplankton volumes can be anticipated from a certain phosphorus concentration, a model is suggested based on experiences from more than 50 Swedish lakes investigated during a series of years.