Die Anwendung von molekulargenetischen Techniken in der Neurochemie

Research in molecular neurobiology has recently entered a new phase of rapid development as a result of the application of the techniques of molecular genetics. This is illustrated by recent work on the electric ray (Torpedo marmorata and T. californica), whose electric organ is a rich source of cholinergic synapses. Other examples from recent literature of the application of the recombinant DNA technique to the mammalian central nervous system are given and possible future developments are discussed.     

Body condition and immune response in wild zebra finches: effects of capture, confinement and captive-rearing

Behavioural ecologists attempt to predict fitness in birds from estimates of body condition and immune capacity. We investigated how the stresses associated with capture, confinement and captive-rearing of wild zebra finches (Taeniopygia guttata) affected different elements of the immune system and body condition. Wild birds had higher heterophil:lymphocyte ratios and total leucocyte counts than aviary birds, presumably an outcome of mounting specific resistance to pathogens, but this response diminished significantly within 10 days of confinement. Wild birds had lower phytohaemagglutinin-A (PHA) responses than their aviary-bred counterparts possibly because energetic costs limited a general resistance response. Wild birds were heavier and had higher haematocrits than their aviary counterparts, but had less fat, although just 10 days of captivity significantly increased fat levels. Measures of body condition were of limited use for predicting immune responsiveness. We conclude that the different elements of the immune system and body condition respond independently, and often unpredictably, to many ecological and behavioural stressors.     

Prenatal diagnosis of mosaic 4p – in a fetus with trisomy 21

Mosaicism for the Wolf-Hirschhorn syndrome, del(4)(p16), is extremely rare and has not been reported in association with a numerical chromosome abnormality. We report the prenatal diagnosis of mosaic del(4)(p16) and non-mosaic trisomy 21 in a 16-week female fetus. The pregnancy ended in spontaneous abortion at 34 weeks secondary to fetal demise. The fetus had features of both 4p – and trisomy 21.     

Prenatal diagnosis of herlitz junctional epidermolysis bullosa by amniocentesis

Herlitz junctional epidermolysis bullosa (HJEB) is a severe blistering disorder which usually results in death during infancy. We have previously shown that the anchoring filament protein laminin-5 (kalinin/nicein), which mediates keratinocyte attachment and dermal–epidermal cohesion, is abnormally expressed in individuals with HJEB. Laminin-5 was detected by Western blot analysis in amniotic fluid from 44 consecutive normal secondtrimester control pregnancies, but was undetectable in second-trimester amniotic fluid from four pregnancies with fetuses affected by HJEB. In one case of severe non-Herlitz JEB, laminin-5 was detected in both amniotic fluid and skin. In human amniotic fluid, the laminin-5 a3 subunit was processed to a major 165 kD species and a minor 145 kD species and the β2 subunit was partially processed to 105 kD. Although laminin-5 was covalently associated with laminin-6 (K-laminin) in amniotic membrane, no covalent interaction was detected in amniotic fluid. Laminin-5 from amniotic fluid strongly supported keratinocyte attachment. These results suggest that Western blot analysis of second-trimester amniotic fluid is useful in determining the prenatal diagnosis of HJEB and that laminin-5 may serve a physiologically important function in amniotic fluid.