Sharp intense line in the bioluminescence emission of the firefly

Numerous investigations have been carried out on the spectral distribution of the light of different species of fireflies. Here we record the emission spectrum of the Indian species of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae) on a color film. Green and red color-sectors, with an intense yellow one in between, appear in this spectrum. Intensity profile of this spectrum reveals a hitherto undetected strong narrow yellow line, which lies within the full-width-at-half maximum (FWHM) of the intensity profile. The spectrum recorded in a high-resolution spectrometer confirms the presence of this sharp intense line. This finding lends support to an earlier drawn analogy between the in vivo emission of the firefly and laser light.     

Surface tension prey transport in shorebirds: how widespread is it?

Surface tension prey transport is a feeding mechanism employing the surface tension of water surrounding prey to transport prey from bill tip to mouth. Previously, it has been demonstrated only in the Red-necked Phalarope Phalaropus lobatus. On the basis of a model of the bill morphology necessary for this method of prey transport, I suggest that many species of shorebird should be capable of surface tension feeding. Laboratory investigations of the feeding mechanics of Wilson's Phalarope Phalaropus tricolor , Western Sandpiper Calidris mauri and Least Sandpiper Calidris minutilla demonstrated that all three use surface tension transport of prey when feeding in water. I examined interspecific variation in the performance of this feeding mechanism with a high-speed video system and a customized motion analysis system. Exploratory analyses indicated significant interspecific variation in distance the prey is transported per cycle of mandibular spreading, gape increase per unit transport, speed of transport, total number of cycles necessary to complete transport and total time to complete transport. The calidrid sandpipers also occasionally used other feeding mechanisms in conjunction with surface tension transport of prey. The discovery that these sandpipers, which normally obtain prey by probing, are capable of surface tension transport of prey implies that the capacity to employ this feeding mechanism may be widespread in the Scolopacidae and may have been a significant factor in the evolutionary radiation of phalaropes into aquatic environments.     

Functional and genetic plasticities of the poliovirus genome: quasi-infectious RNAs modified in the 5'-untranslated region yield a variety of pseudorevertants.

Poliovirus RNA species with nucleotides 564 to 571 deleted or with a secondary structure domain (positions 564 to 629) replaced by a shorter irregular oligonucleotide have been engineered previously; these RNAs have been considered quasi-infectious (yielding a single late revertant plaque) and dead, respectively (E. Pilipenko, A. Gmyl, Y. Svitkin, S. Maslova, A. Sinyakov, and V. Agol, Cell 68:119-131, 1992). By using large amounts of these RNAs for transfections, revertant clones with a great variety of genetic changes (point mutations, insertions of foreign sequences, short or extended deletions) were isolated. The pattern of these changes supported the notion that an appropriately spaced oligopyrimidine-AUG tandem is important for efficient poliovirus RNA translation. Structural features within and around this tandem modulated the initiation efficiency. The functional and genetic plasticities of the poliovirus genome are briefly discussed.     

Type I interferon genes in cattle: restriction fragment length polymorphisms,gene numbers and physical organization on bovine chromosome 8

Multiple, superimposed Type I interferon (IFN) restriction fragments were resolved following 72–92 h of horizontal electrophoresis. Restriction fragment length polymorphisms (RFLPs) for α IFN (IFNA), β IFN (IFNB), ωIFN (IFNW) and trophoblast IFN (IFNT) genes were identified in Hin dill, Eco RI and Taql digestions from 313 cattle. RFLPs with codominant segregation in cattle pedigrees were considered alleles, and 19 distinct polymorphic Type I IFN loci (5 IFNA, 4 IFNB, 8 IFNW and 2 IFNT) were identified. Allele frequencies and observed heterozygosity values were calculated for each locus and several loci were considered highly informative for linkage analysis. Bovine IFN gene numbers (10 IFNA, 6 IFNB, 20 IFNW and 6 IFNT) were estimated from the number of polymorphic loci plus additional monomorphic hybridizing bands present in Eco RI and Hindlll digestions. Physical linkage of the Type I IFN gene families on bovine chromosome 8 was demonstrated by pulsed field gel electrophoresis (PFGE). Hybridization of two or more IFN probes to similarly sized PFGE fragments suggested the tentative gene family order: IFNA/IFNW-IFNT-IFNB. These studies provide a basis for the development of more detailed genetic and physical maps of the bovine Type I IFNs.