Abstract: The invention relates to an apparatus (1) for removing and depositing micro-drops (2′) of solutions from/on a surface (2), in particular chemical or biological solutions. The inventive apparatus comprises at least one micropipette or deposit point (3) which is mounted on a head (4) that can move in at least one direction, at least between one or more removal sites (5) and one or more deposit sites (6). Said apparatus is characterised in that the micropipette(s) (3) are mounted in the body of said head (4) and they can be moved in translation in relation to said head, by means of a device for controlling and limiting the application force of the micropipette(s) (3) on the deposit surface (2). Said controlling and limiting device is connected to a device for guiding said micropipette(s) in translation in relation to the head (4), while they are in contact with said surface (2) or in order to bring them into contact with said surface (2).

Abstract: The present invention is based in part on the novel observation that two different types of nuclear receptors, retinoic acid receptors (RAR) and thyroid receptors (TR) dimerize with a RX receptor (RXR) to form a heterodimer which is capable of binding to retinoic acid response elements (RARE) or thyroid receptor response elements (TRE) at physiological conditions. In addition, the present invention discloses that RXR homodimers are capable of binding to RARE's. Based on this observation, the present invention provides novel dimeric proteins, methods of identifying agents capable of binding the dimers of the present invention, methods of identifying DNA sequences capable of being bound by the dimers and methods to identify RA metabolic enzymes and proteins which are required for the activation function of nuclear receptors.

Abstract: The present invention provides mice which are deficient in the normal expression of one or more members of the RAR or RXR class of receptors, to mice heterozygous for such deficiency, and to cell lines, preferably pluripotent or totipotent cell lines, which are heterozygous or homozygous for such deficiency. The present invention further provides the use of any of the above mice and cell lines in situations where the absence of at least one RAR or RXR receptors, or the normal expression thereof, is desirable.

Abstract: The present invention is directed to mice which are genetically altered to be deficient in the normal expression of RXR.gamma., to mice heterozygous for such deficiency, and to cell lines, preferably pluripotent or totipotent cell lines, which are heterozygous or homozygous for such deficiency. The invention further provides mice and cell lines which, in addition to being deficient in RXR.gamma., are genetically altered to be deficient in the expression of RXR.alpha. and/or RXR.beta.. The present invention further provides the use of any of the above mice and cell lines in situations where the absence of RXR.gamma., or the normal expression thereof, is desirable.

Abstract: The present invention provides mice which are deficient in the normal expression of one or more members of the RAR or RXR class of receptors, mice which are heterozygous for such deficiency, and to cell lines, preferably pluripotent or totipotent cell lines, which are heterozygous or homozygous for such deficiency. The present invention further provides the use of any of the above mice and cell lines in situations where the absence of at least one RAR or RXR receptor(s), or the normal expression thereof, is desirable.

Abstract: The present invention provides mice which are deficient in the normal expression of one or more members of the RAR or RXR class of receptors, to mice heterozygous for such deficiency, and to cell lines, preferably pluripotent or totipotent cell lines, which are heterozygous or homozygous for such deficiency. The present invention further provides the use of any of the above mice and cell lines in situations where the absence of at least one RAR or RXR receptors, or the normal expression thereof, is desirable.