The feeding behaviour, activity and trappability of wild female Glossina pallidipe in relation to their pregnancy cycle

Female Glossina pallidipes Austen trapped with baited NG2B traps were subjected both to detailed ovarian dissection and to nutritional analysis. Using a calibration curve derived from dissected wild-caught, laboratory-held flies, the field females were assigned by discriminant analysis to each day of the pregnancy cycle. Field females were most available to NG2B traps while carrying the first instar larva. The nutritional characteristics of trapped field females over the pregnancy cycle lead to the following main conclusions. (i) Fat levels increase most rapidly during the egg in utero stage, while CRDW increases significantly only during the larval stages, culminating in a 4 mg increase during the last day of the third larval instar. (ii) The haematin content of the flies indicates that females feed at approximately 3-day intervals and may feed on any day of the pregnancy cycle. (iii) The estimated time of feeding during the day corresponds with the observed time of peak activity, both of which are earlier in the day later in the pregnancy cycle. (iv) The rate of fat usage reveals significantly greater flight activity on day 5 of the cycle than on other days, agreeing with the high trappability on this day, and overall females appear to use fat at twice the rate of males. Reproductive data provide a much more accurate picture of the relative sampling efficiency than do nutritional data, although the latter reveal the general trends correctly.     

p103 and A60: novel proteins of the neuronal membrane-associated cytoskeleton.

Associated with the neuronal plasma membrane are cytoskeletal proteins which probably control the specialization of the membrane into axonal and dendritic domains. Specialized isoforms of the proteins spectrin and ankyrin are located in each region and provide molecular mechanisms for locating specific transmembrane proteins at required points. However, spectrin and ankyrin were defined by extensions of the model for the erythrocyte membrane, an analogy unlikely to provide a complete account of the neuronal membrane skeleton. We have defined two new proteins of the neuronal membrane skeleton, designated p103 and A60. p103 is enriched in post-synaptic densities and binds with high affinity to integral membrane proteins--we suggest that it may have a role in linking the cytoskeleton to synaptic glycoproteins. A60 is a 60 kDa axonal protein, which appears to form a lining to the axolemma. It is almost exclusively axonal, although some neurons (such as Purkinje cells) appear to contain it in the cell body and initial dendrite segment. A60 binds both ankyrin and neurofilaments, and may have a role in transmitting information critical to axonal morphology to the membrane.     

Comparison of the structures of operator DNA free and in complex with lambda repressor

The structures of operator DNA unbound and in complex with lambda repressor protein are compared. The conformation of the left 10 base pairs of a lambda right regulatory operator DNA sequence has been previously determined in solution using nuclear magnetic resonance techniques and the structure of a homologous left regulatory operator DNA bound to lambda repressor N-terminal domain had been previously solved using X-ray crystallography. The DNA adopts an overall linear B-form DNA both in the absence and presence of lambda repressor. Superimpositioning of the DNA structures reveals small differences between them that are due to the binding of protein and not to the different techniques used for their determination.     

Chromosome 11q localization of one of the three expected genes for the human alpha-3-fucosyltransferases, by somatic hybridization.

Seventy-one human x mouse hybrid cell lines were used to map the locus of a human alpha-3-fucosyltransferase to 11q. The enzyme transfers fucose onto H type 2 more efficiently than onto sialyl-N-acetyllactosamine, suggesting that it is the myeloid type of alpha-3-fucosyltransferase (Mollicone et al., 1990), which makes the 3-fucosyllactosamine epitope on polymorphonuclear cells and monocytes. This epitope is also known as CD15 (Tetteroo et al., 1987).     

The effects of Heterosigma akashiwo on juvenile Oncorhynchus tshawytscha and its implications for fish culture

The effects of natural blooms of Heterosigma akashiwo on freshwater-and saltwater-acclimated juvenile chinook salmon were assessed. Rates of fish mortality in the blooms were independent of acclimation of fish to seawater and the ambient oxygen levels, but were dependent on concentration of algae and ambient water temperatures. No pathological abnormality to gills or other internal organs in the fish were evident. Aeration or oxygenation of fish cages did not enhance or inhibit fish survival in a H. akashiwo bloom. Cause of death was considered to be due to a labile ichthyotoxic agent.     

Marek's disease virus (MDV) ICP4, pp38, and meq genes are involved in the maintenance of transformation of MDCC-MSB1 MDV-transformed lymphoblastoid cells.

An antisense strategy has been used to identify genes important for the maintenance of transformation of MDCC-MSB1 (MSB1) Marek's disease virus-transformed lymphoblastoid cells. Oligodeoxynucleotides antisense to the predicted translation initiation regions of ICP4 and pp38 mRNAs inhibited proliferation of MSB1 cells but not MDCC-CU91 (CU91) reticuloendotheliosis virus-transformed cells. Control oligodeoxynucleotides having the same base composition but a different sequence did not inhibit MSB1 cell proliferation. In addition, ICP4 and pp38 antisense oligodeoxynucleotides resulted in 77- and 100-fold reductions in colony formation by MSB1 cells in soft agar, respectively. To extend and corroborate these results, a novel system based on efficiently regulated expression of eukaryotic genes by a chimeric mammalian transactivator, LAP267 (S. B. Baim, M. A. Labow, A. J. Levine, and T. Shenk, Proc. Natl. Acad. Sci. USA 88:5072-5076, 1991), was used. MSB1-derived stably transfected cell lines in which RNA antisense to Marek's disease virus ICP4, pp38, or meq could be induced by treatment of the cells with isopropyl-beta-D-thiogalactopyranoside (IPTG) were constructed. Control cell lines in which expression of ICP4 sense or pUC19 sequences could be induced by IPTG were also constructed. Induction of the cell lines indicated that ICP4 antisense RNA, but not ICP4 sense RNA or pUC19 RNA, inhibited proliferation of MSB1 cells. Induction of ICP4, meq, or pp38 antisense RNAs, but not ICP4 sense or pUC19 RNAs, had a dramatic effect on relative colony formation by MSB1 cells in soft agar. These results indicate that ICP4, pp38, and Meq are all involved in the maintenance of transformation of MSB1 cells.