No abstract

Inhibition of gene transcription is brought about by several mechanisms. The least understood mechanism is probably silencing, the analogue to transcriptional enhancing. We provide evidence that the silencing function of the oncogene product v‐ERBA or the cellular counterpart, the thyroid hormone receptor (TR, c‐erbA) is located in the C‐terminal part and is transferable to a heterologous DNA binding domain. Deletion analyses suggest an important role for a basic and hydrophilic amino acid stretch on both ends of the domain. In addition we show that the related retinoic acid receptor (RAR) also contains a functional silencing domain similar in size and amino acid sequence. However, the activity of this domain can be neutralized by an additional domain in the C‐terminus which functions cell specifically.

No abstract

The synthetic chickpea kairomone composed of pentan-1 -01, (+)-A-3-carene, D,L-a-pinene and m crene, was tested with Hehothis armigera moths under long distance and short range conditions in a iight tunnel. Under both conditions it is attractive to mated, egg laying moths, more with all its four components than with pentan-1-01 or with the terpenes only, both of which induce the same attractivity. Upwind orientation of the moths is demonstrated near the source by an increased turning and by zigzag flights under downwind situations. Unmated females poorly react on the kairomone and the males are unaffected. Field experiments almost exclusively resulted in female catches and as such are confirmatory for the laboratory data.

Simple repetitive DNA sequences have been regarded as mere "junk" present in all eukaryotic genomes. In fact, mixed simple repeat (gt)n(ga)m sequences are present in major histocompatibility complex MHC-DRB genes for long evolutionary times, including such distant animals as artiodactyla and man. We describe herein an unsophisticated method which reveals that at least certain simple repetitive (gt)n(ga)m sequences bind nuclear proteins and show characteristics of a specific DNA-protein interaction via gel retardation.