Spirorbinae (Polychaeta:Serpulidae) from the Red Sea, including descriptions of a new genus and four new species

A new genus, a new subgenus, four new species and four previously described species are recorded from the Red Sea. The new genus Anomalorbis has four and a half thoracic segments. Re-discovery of the sinistral variety of Janua (Dexiospira) steueri confirms Sterzinger's observation that this species may coil in either direction. Janua (Fauveldora) anticorrugata sp. nov. is also sinistral and a shallow water species. It therefore appears that the Red Sea may have been the centre of origin for sinistral mutants of the Janua complex. Other of the new forms live in fairly deep water. The assemblage encountered shows closest affinity with the Indo-Pacific, but suggests a high degree of endemism, which may be related to the high temperatures prevailing at all depths in the Red Sea.     

Analysis of Chlamydomonas reinhardtii Histones and Chromatin

Chromatin spreads made from isolated nuclei of the unicellular green alga Chlamydomonas reinhardtii show the beaded fibers typical of eukaryotic polynucleosomes. Micrococcal nuclease digestions confirmed the presence of nucleosomes with a repeat length of 189 base pairs, essentially the same as typical mammalian cells. Basic nuclear proteins extracted from isolated nuclei or chromatin with 1 M calcium chloride and 0.3 M hydrochloric acid are resolved into seven major components by electrophoresis in the presence of sodium dodecyl sulfate (SDS). These seven components were subjected to qualitative peptide mapping with V8 protease on SDS gels for comparison with the major histone components of calf thymus. Finally, the C. reinhardtii basic nuclear proteins were fractionated by reversed phase high performance liquid chromatography and their amino acid composition determined. From these studies, we conclude that C. reinhardtii has a full complement of the five histones with properties very similar to those of both higher animals and higher plants.     

Characterization of Rat CD4 T Cell Clones Specific for the Major Surface Glycoprotein of Pneumocystis carinii

ABSTRACT. Pneumocystis carinii are coated by abundant heterogenous major surface glycoproteins (MSGs), which facilitate interaction with the host. We have produced MSG-specific T-cell clones from the spleens of P. carinii -exposed Lewis rats and analyzed five for antigen specificity to native MSG and a recombinant form of MSG, cell surface markers, and cytokine profiles. All five of the clones were CD4+. All of the clones proliferated specifically to both the native MSG and the recombinant MSG only in the presence of antigen presenting cells demonstrating that the response is antigen/driven rather than mitogen/driven. All five of the clones secreted IL-2 and IFN-γ, although in differing amounts, implicating a Th l response. Only one of the clones produced any detectable IL-4. This is the first report of T cell clones responsive to a specific antigen of P. carinii , MSG. We conclude that the T cell clones will be helpful in mapping protective epitopes present in MSG and in functional studies of MSG.     

Calculations of population differentiation based on GST and D: forget GST but not all of statistics!

G _ST‐values and its relatives (F_ST) belong to the most used parameters to define genetic differences between populations. Originally, they were developed for allozymes with very low number of alleles. Using highly polymorphic microsatellite markers it was often puzzling that G_ST‐values were very low but statistically significant. In their papers, Jost (2008) and Hedrick (2005) explained that G_ST‐values do not show genetic differentiation, and Jost suggested calculating D‐values instead. Theoretical mathematical considerations are often difficult to follow; therefore, we chose an applied approach comparing two artificial populations with different number of alleles at equal frequencies and known genetic divergence. Our results show that even for more than one allele per population G_ST‐values do not calculate population differentiation correctly; in contrast, D‐values do reflect the genetic differentiation indicating that data based on G_ST‐values need to be re‐evaluated. In our approach, statistical evaluations remained similar. We provide information about the impact of different sample sizes on D‐values in relation to number of alleles and genetic divergence.     

Temporal variations of trace metals in aquatic insects

1. Temporal fluctuations were measured in the concentrations of the trace metals cadmium (Cd), copper (Cu) and zinc (Zn) in six insect taxa collected from the same sites in a temperate zone lake over a 14-month period. The consequences of temporal changes in insect contaminant concentrations for biomonitoring studies are assessed. 2. Significant temporal fluctuations in the concentrations of the three metals were measured in almost all of the insect taxa studied. In no case was there a greater than sixfold change in the concentration of a trace metal over the course of the year. The extent of the fluctuations was generally greater for CD, a non-essential metal, than for the essential micronutrients Cu or Zn. 3. Temporal fluctuations in CD concentrations appeared to follow a seasonal periodicity for most taxa. Minima were measured during the winter period in the megalopteran Sialis spp. and in the dipteran taxa Chaoborus punctipennis, Glyptotendipes sp., and Procladius spp., whereas a maximum was measured in the mayfly Hexagenia Hmbata during the same season. In general, temporal fluctuations in Cu and Zn concentrations were less seasonal in character than were those of Cd. 4. For some of the taxon—metal combinations studied, temporal fluctuations in metal concentrations could be ignored in biomonitoring studies, whereas in other cases a temporal window of minimum variability should be chosen for the collection of organisms from different sites.