Assignment of nucleoside phosphorylase gene to q2.1----q2.2 region of chromosome 7 in the pig, Sus scrofa domestica L.

Using in situ hybridization with a human probe, we have mapped the nucleoside phosphorylase gene on pig chromosome 7. These results are in agreement with those obtained by other groups, but give a more precise localization in the q2.1----q2.

Polyphthienoyl trehalose, glycolipids specific for virulent strains of the tubercle bacillus.

Phthienoic acids constitute a family of dextro-rotary odd-numbered unsaturated fatty acids isolated exclusively from virulent strains of human and bovine tubercle bacilli. In the bacterial cell they are not free and a search for their linked form in complex wall lipids of Mycobacterium tuberculosis (strain Canetti) showed that they esterified trehalose. Structural elucidation of the major phthienoyl trehalose showed the occurrence of five acyl residues located at 2, 2', 3', 4 and 6' positions of trehalose.

The high-resolution GTG-banding pattern of rabbit chromosomes.

A cell synchronization technique allowed the high-resolution GTG-banding pattern of rabbit chromosomes to be determined. A karyotype of the late-prophase 622-band stage is presented.

Chromosomal localization of leukocyte interferon gene in the pig (Sus scrofa domestica L.) by in situ hybridization.

Using as a probe pig genomic DNA, including the complete interferon alpha gene, we have mapped the leukocyte interferon gene on pig chromosome 1 by in situ hybridization. A total of 196 silver grains were noted on the 106 metaphases scored: 31% of the grains were observed on chromosome 1, and 67% of these were localized in the region 1q2.2----q2.

Assignment of the major histocompatibility complex to the p1.4----q1.2 region of chromosome 7 in the pig (Sus scrofa domestica L.) by in situ hybridization.

The pig major histocompatibility complex (SLA) was mapped by in situ hybridization. The probe used was a human cDNA containing most of the coding sequence for HLA-B7. The SLA complex was localized to the region p1.

Long-term multiplication of the Chinese hamster ovary (CHO) cell line in a serum-free medium.

A new synthetic medium (referred to as GC3) that supports the growth of the Chinese hamster ovary cell line has been developed. It is composed of a 1:1 mixture of Ham's F12 and modified Eagle's minimum essential (MEM.S) mediums supplemented with transferrin (10 micrograms/ml), insulin (80 mU/ml), and selenium (1 X 10(-7) M).

Lipid A monosaccharide analogues inhibiting oxidative phosphorylation.

Three acyl-glucosamine analogues of "lipid A" and an acyl-glucose analogue of "cord factor" were synthesized and their activity was tested on isolated rat liver mitochondria. The 4 glycolipids slightly inhibited succinate-supported active respiration and strongly inhibited glutamate-supported active respiration. The most potent inhibitors were the two diacylated compounds which are the most hydrophobic.

Localization of the alpha and beta casein genes to the q24 region of chromosome 12 in the rabbit (Oryctolagus cuniculus L.) by in situ hybridization.

The syntenic alpha and beta casein genes were localized in the rabbit by chromosomal in situ hybridization, using a mixture of two radioactive cDNA probes corresponding to these two genes. Highly significant labeling was observed on chromosome 12. A total of 175 silver grains was found on chromosomes in the 193 mitoses studied; 18% of the grains were on chromosome 12, and 42% of the grains on this chromosome were localized to the 12q24 region.

Dicorynomycoloyl trehalose activity: comparison of the activity of alpha,alpha'- and beta,beta'-trehalose derivatives on mitochondrial oxidative phosphorylation.

6,6'-Dicorynomycoloyl esters of alpha,alpha'- or beta;beta'-trehalose were synthesized and tested on isolated rat liver mitochondria. In contrast to the well known site-II-specific uncoupling effect of the alpha,alpha'-trehalose derivative, the beta,beta'-trehalose derivative exhibited only non-specific inhibition of active respiration in the presence of glutamate. It is proposed that this unexpected difference between the two isomers could arise from conformational differences in the carbohydrate moiety of the glycolipids, which would render the beta,beta' isomer unable to recognize targets specific to the alpha,alpha'-trehalose glycolipid.

[Gene mapping in the pig (Sus scrofa 1.). I. Study of two syntenic groups G6PD, PGK, HPRT and PKM2, MPI (author's transl)].

Thirteen pig-hamster and fifteen pig-mouse hybrid ceil lines were developed. These lines eliminate the pig chromosomes preferentially. The following syntenies were demonstrated: G6PD, PGK, HPRT, and PKM2, MPI.

Property and activity of mycoloyl esters of methyl glucoside and trehalose. Effect on mitochondrial oxidative phosphorylation related to organization of suspensions and to acyl-chain structures.

Methyl alpha-D-glucoside and alpha, alpha'-D-trehalose acylated on their primary hydroxyl group by alpha-alkyl-beta-hydroxy acids (mycolic acids) with 18, 32 and more than 80 carbon atoms were studied. These cord factors and analogues when dispersed in water gave hydrated and organized phases which bore resemblances and differences to phospholipid liposomes. Phase transition temperature was determined by fluorescence for the C32 derivatives and by differential scanning calorimetry for the C80 derivatives.

[A model of enzymatic kinetics].

In this Note, we study a system of differential equations representing the kinetics of an enzymatic reaction. For a closed system, and in the domain where it has a biological significance, it is shown that: (i) there exists a unique equilibrium point, which is an asymptotically stable point; (ii) if several enzymes act on the same substrates, the equilibrium values of the substrates concentrations take their values within the range of the equilibrium values achieved with each of these enzymes, (iii) the kinetics of the reaction can be approached by a single first-order differential equation, which may be seen as a generalization of the Michaelis equation.

Identity coefficients in finite populations. I. Evolution of identity coefficients in a random mating diploid dioecious population.

Properties of identity relation between genes are discussed, and a derivation of recurrent equations of identity coefficients in a random mating, diploid dioecious population is presented. Computations are run by repeated matrix multiplication. Results show that for effective population size (Ne) larger than 16 and no mutation, a given identity coefficient at any time t can be expressed approximately as a function of (1--f), (1--f)3 and (1--f)6, where f is the mean inbreeding coefficient at time t.