NaturalMycoplasma arthritidis infection in mice

B6C3F₁ mice from a hybrid production colony frequently were serologically positive by enzyme-linked immunosorbent assay (ELISA) and consistently negative by culture forMycoplasma pulmonis. Subsequently, 162 mice were obtained and intensively studied using an expanded group of cultural procedures, ELISA, and histopathology. Lesions attributable to mycoplasma infection were not found, butMycoplasma arthritidis was isolated from 20 mice. TheM. pulmonis ELISA was positive (IgM, IgG, or both) in 113 mice. Selected sera were tested simultaneously in both theM. pulmonis ELISA and in an ELISA usingM. arthritidis antigen, and were found to be positive in both the IgM and IgG classes in both ELISAs. Thus, cross-reacting antibody was produced in mice naturally infected withM. arthritidis, confirming previous observations based on experimental infections. To our knowledge, this is the first report of naturalM. arthritidis infection in laboratory mice.     

Biological activity of 125iodine labelled globin mRNA in an Ehrlich ascites cell-free system

Globin mRNA was isolated from avian erythroblasts and labelled with ¹²⁵iodine to a specific activity of 4.5×10⁶ dpm μg^-1 mRNA. The labelling procedure was modified as compared to common techniques in order to protect the mRNA against degradation. When this RNA is translated in an Ehrlich ascites cell-free system globin chains are synthesized as is demonstrated by the analysis of the in vitro synthesized products. The biological activity of ¹²⁵iodine labelled mRNA has proven to be 30% of that of unlabelled mRNA.     

Dating the Northern African cercopithecid fossil record

The primitive cercopithecidProhylobates is known only from the (middle?) Orleanian sites of Moghara (Egypt) and Zelten (Libya). No cercopithecid is known from north Africa during the Astaracian and Vallesian periods.Macaca (or a closely allied form) appears in the (late?) Turolian of Sahabi (Libya) and Menacer (Algeria) where it is associated with colobines.Macaca persists into the Pliocene (Wadi Natrun, Egypt; Garaet Ichkeul; Ain Brimba) but apparently disappears before the end of this period, and is absent from north Africa until the middle Pleistocene (Ain Mefta).Theropithecus is known from a single tooth from the upper Pliocene of Ain Jourdel, and from several jaws from the middle Pleistocene of Ternifine (c. 0.7 m.y.) and Thomas Quarry III (c. 0.4 m.y.) in Algeria.     

Erythrocytic nicotinamide-adenine dinucleotide phosphate levels and the genetic regulation of erythrocytic glucose 6-phosphate dehydrogenase activity in the inbred mouse

NADP measurements in erythrocytes of eight inbred strains of mice showed a correlation between low NADP and low erythrocytic G6PD levels. In vitro heat inactivation tests indicated that the NADP differences found could explain the previously demonstrated lability of G6PD in the erythrocytes of the low G6PD activity strain, C57L/J. Breeding experiments suggested a common genetic control of erythrocytic NADP levels and G6PD activity in crosses between intermediate and low strains, but an effect of sex and other variables, as yet unidentified, precluded a strong demonstration of unitary genetic control.     

On the carrying behaviour of basic South American primates

InCallithrix, Saguinus, Aotus, andCallicebus other group members than the mother participate in infant care. Differences among these species are obvious in respect to the time of being off any caregiver, and in respect to the carrying position (Aotus andCallicebus). Alloparental care, a basic behaviour pattern in these species, has evolved from the parking behaviour of the prosimians. The infants are «parked» at other group members.     

Localization and phenotypic expression of a Tol marker in Citrobacter freundii

Among colicin-A-tolerant mutants of Citrobacter freundii we characterized some as Tol-2 mutants. The Tol-2 mutation results in insensitivity to bacteriocin S6 and an enhanced sensitivity to deoxycholate (DOC), ethylenediaminetetraacetic acid (EDTA) and to ampicillin. The Tol-2 mutation was mapped close near gal and the gene order pro-tol-gal was established in crosses between C. freundii Hfr tol ⁺ donor strains and C. freundii tol ^- acceptor strains. In these crosses a difference was observed in phenotypic expression of the pleiotropic properties of this tol ⁺ gene. Expression of resistance to DOC is substantially slower than the expression of EDTA-resistance. This phenomenon may play a disturbing role in those studies on cell envelope mutants, in which resistance to DOC is used as a selected marker. The differences in expression of DOC-and EDTA-resistance are discussed.