Identification of a membrane glycoprotein overexpressed in murine lymphoma sublines resistant to cis-diamminedichloroplatinum(II)

A series of murine thymic lymphoma cell sublines was selected in vitro for resistance to cis-diamminedichloroplatinum(II) (CDDP). The level of CDDP resistance correlated with reduced drug accumulation in these cells. A rabbit antiserum was raised against the plasma membrane of a CDDP-resistant subline and used in Western blot analyses. Increased expression of a surface antigen of approximately 200 kDa was observed and found to correlate with the degree of resistance. Further biochemical and immunological studies demonstrated that this is a plasma membrane glycoprotein. However, it is different from the multidrug resistance-associated P-glycoprotein with a molecular weight of about 170,000. We have called this unique CDDP resistance-associated membrane protein CPR-200.     

Hybridization of a mouse T-cell lymphocyte line (HB1) with a polyoma virus-transformed mouse fibroblast line

The establishment of permanent T-lymphocyte cell lines by transformation with DNA viruses has not yet been achieved. This paper reports the successful transfer of polyoma virus genome into T-lymphocyte cells by somatic hybridization. A T-lymphocyte clone, HB₁, derived from (DBA/ 2J×AKR) spleen cells, isolated in vitro by cloning in semi-solid agar, was fused with a polyoma (Py) virus-transformed fibroblast C3HPy, clone 1. The authenticity of the hybrid C3H/HB was established by chromosome and histocompatibility antigen studies. This initial population and the various clones retained T-lymphocyte characteristics such as morphological appearance, growth properties (suspension culture) and differentiation antigen (Thy 1–2). The hybrid cell line and the various clones presented all the characteristics of Py transformation. Namely, they carried the Py genome originating from the fibroblastic parent and maintained Py virus tumour-associated antigens (TSTA, TSSA and T antigens). In most respects, this hybrid population resembled the C3HPy/C11 parent and exhibited the same tumorigenicity.     

Stochastic prey-predator relationships: A random evolution approach

The formalism and results of the theory of random evolutions are used to establish and investigate a model for two randomly interacting populations. The asymptotic stability of the expected solution is studied and contrasted to that of the associated deterministic system.     

Choline acetyl transferase activity in chick embryo neuroretinas during development in ovo and in monolayer cultures

The specific activity of the enzyme choline acetyl transferase (CAT) in chick neuroretinas was investigated during in ovo development and in monolayer cultures. The enzyme activity was barely detectable on the 6th day of incubation but increased markedly between the 7th and 11th days. The activity increased sharply between the 15th and 17th days and then slowly until hatching. When cell suspensions from 6- to 7-day neuroretinas were cultured as monolayers, CAT specific activity increased rapidly. After 4–5 days in culture, the activity of the enzyme was identical to that found in the neuroretina on the 11th day of incubation. Cells from 9-day neuroretinas also differentiate in monolayer cultures, but with a more irregular pattern. These data show that cholinergic neurons from chick embryo neuroretina differentiate in monolayer cultures without a lag and at the same rate as in vivo.     

Du probleme de l'origine des Dinosauriens d'apres les donneesde l'ichnologie du Trias

With the data of the osteological paleontology and these of the ichnology, the authors attempt to restore the biotopes where lived the trackmakers, biotopes which have favoured in the Triassic the evolution and the expansion of the Archosaurs, the specialized Reptiles in the easy and rapid locomotion. They pointed out that the chirotheroid footprints cannot be attributed at all events to the Pseudosuchians and they come to the conclusion that Dinosaurs and Pseudosuchians, as separated groups, are appeared as early as the lower Triassic.     

Capacités reproductrices et descendance de poulets ayant subi un transfert de cellules germinales primordiales durant la vie embryonnaire

Résumé Des cellules germinales primordiales de Dindon, transférées par injection intravasculaire à des embryons de Poulet préalablement stérilisés, peuvent subir une maturation complète dans les gonades de l'hôte et fournir des gamètes plus ou moins aptes à la fécondation.Les spermatozoïdes résultants ont fécondé des oeufs de poule avec une fréquence plus grande que les spermatozoïdes normaux de Dindon, mais sans permettre un développement embryonnaire plus important ou plus normal. Cependant, on n'est pas parvenu à leur faire féconder des oeufs de dinde.Les ufs résultants ont montré parfois un vitellus anormal et n'ont été pondus que durant 7 mois. Mis en présence de spermatozoïdes de coq, ils ont été quelquefois fécondés (ou peutêtre simplement activés), mais ils n'ont jamais fourni d'embryons. Fécondés par des spermatozoïdes de Dindon, ils ont fourni des embryons, parfois anormaux, qui ont atteint dans le meilleur cas le 15è jour d'incubation (stade 38 HH). Certainespraepennae de l'embryon qui a atteint ce stade montraient une pigmentation rouge brun qui ne peut pas être déterminée par le génotype du zygote (celui d'un Dindon de race blanche) et qui rappelle le phénotype de la mère nourricière (une poule rouge brun).A la suite de transferts intraspécifiques de cellules germinales primordiales, on a pu obtenir la maturation d'ovocytes de Rhode Island Red à l'intérieur d'un ovaire de Wyandotte Blanche (chez deux poules) et vice versa (chez une poule). La ponte a également été possible, mais à une fréquence souvent inférieure à la normale.Lorsqu'une poule Wyandotte Blanche, portant des ovocytes de Rhode Island Red a été accouplée à un coq Rhode Island Red normal, le duvet de leurs descendants s'est montré plus clair que celui des poussins Rhode Island Red dans un cas, mais il a été remplacé ensuite par un plumage rouge brun conforme au génotype.Lorsqu'une poule Rhode Island Red, portant des ovocytes de Wyandotte Blanche a été accouplée à un coq Wyandotte Blanche normal, le duvet de leurs descendants n'a jamais été conforme au génotype. Il présentait toujours du pigment noir plus ou moins étendu et, dans un cas, du pigment rouge brun, qui sont tous deux présents chez la mère nourricière. On ne connaît ni l'origine ni le mécanisme d'un tel transfert de pigments, qui ne représente peut-être qu'un effet transitoire affectant le duvet de la première génération. La crête, quant à elle, s'est toujours montrée conforme au génotype d'origine.

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Reproductive capacity and offspring of chickens submitted to a transfer of primordial germ cells during embryonic life

Summary Turkey primordial germ cells transfered by intravascular injection to previously sterilized chick embryos can undergo complete maturation inside the host's gonads and can give rise to gametes which are more or less suitable for fertilization.The resulting spermatozoa fertilized hen eggs at a higher frequency than normal turkey spermatozoa, but without allowing a longer or a more normal development. However, it was impossible to fertilize turkey eggs with them.The resulting eggs sometimes had an abnormal-looking yolk and were laid during the first 7 months only. Brought in contact with chicken spermatozoa, they were fertilized (or perhaps merely activated), but they never gave rise to embryos. Fertilized by turkey spermatozoa, they developed into embryos, sometimes abnormal, which in the best case reached the 15th day of incubation (stage 38 HH). Somepraepennae of the latter embryo showed a red-brown pigment which cannot be determined by the genotype of the zygote (a white turkey's) and which resembled the phenotype of the foster mother (a red-brown hen).After intraspecific transfer of primordial germ cells, maturation of Rhode Island Red oöcytes inside a Wyandotte White ovary (in two hens) and vice versa (in one hen) was achieved. Laying was also possible but often at a lower frequency than normal.When a Wyandotte White hen bearing Rhode Island Red oöcytes was mated with a normal Rhode Island cock, the down of their offspring looked brighter than Rhode Island Red chicken's in one case, but it was subsequently replaced by red-brown feathers according to the genotype.When a Rhode Island Red hen bearing Wyandotte White oöcytes was mated with a normal Wyandotte White cock, the down of their offspring was never in agreement with the genotype. It always showed a black pigment over more or less large areas and, in one case, a red-brown pigment, both of which were present in the foster mother. The origin and the mechanism of such a transfer of pigments are not understood. It might represent merely a temporary effect acting upon the down of the first generation. As far as the comb is concerned, it was always in agreement with the original genotype.