On Glycolysis in Trichomonas vaginalis

SYNOPSIS. The mechanism of carbohydrate dissimilation was studied in cell-free extracts prepared from mass cultures of the trichomonads. Evidence for the presence of all the enzymes associated with the Embden-Meyerhof glycolytic scheme was obtained. Several enzyme systems directly associated with the glycolytic pathway were examined. Two of these, alcohol dehydrogenase and phosphorylase, were not demonstrated in the T. vaginalis extract. The absence of phosphorylase in the presence of a very high glycogen concentration in the cell (20.8%) suggests the possibility of an alternate route. A very active TPN-linked "malic enzyme" was also demonstrated, although no functional citric acid cycle is known for this trichomonad. Based on the experimental evidence and collateral data, a functional Embden-Meyerhof system was suggested for T. vaginalis.     

The genus Troglophilus Krauss, 1879 (Orthoptera: Rhaphidophoridae) in the west Balkans

We present a revision of the genus Troglophilus in the western part of the Balkan Peninsula based on morphological and genetic analysis, and provide distribution data for the species. The results of these analyses reduced the number of the known taxa within the genus Troglophilus in this area to five valid species: Troglophilus cavicola ( Kollar, 1833 ), Troglophilus neglectus Krauss, 1879 , Troglophilus ovuliformis Karny, 1907 , Troglophilus brevicauda Chopard, 1934, and Troglophilus lazaropolensis Karaman, 1958. A new species Troglophilus zorae sp. nov. is described and Troglophilus neglectus serbicus Maran, 1958, Troglophilus neglectus vlasinensis Maran, 1958, Troglophilus bukoviki Karaman, 1968 and Troglophilus pretneri Us, 1970 are synonymized. The distribution pattern of the western Balkan species supports a general east?west migration route. We also determined the centres of origin and spreading directions of particular species according to the distribution of the taxa and the structure of the haplotypes. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 1035–1063.     

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.     

Phylogenetic analysis of the Silurian Retiolitidae

A cladistic, phylogenetic analysis of the Retiolitidae, using 18 genera and parataxa and 23 characters, reveals that two distinct clades can be recognized within this family, as well as a primitive stem-group that includes the genus Pseudoretiolites . One of the derived clades includes Pseudo-plegmatograptus, Stomatograptus and Retiolites , which are assigned to the revised subfamily Retiolitinae. The other derived clade, the early part of which shows a paraphyletic relationship, includes the remaining known genera Rotaretiofites s.l., Paraplectograptus s.l., Sokolovograptus, Plectograptus, Agastograptus, Spinograptus, Gothograptus, Eisenackograptus, Neogothograptus, Semiplectograptus, Plectodinemagraptus and Holoretiolites . These genera are all included within an expanded Plectograptinae. The biostratigraphic distribution of these taxa suggests that these two clades diverged from a Pseudoretiolites-like ancestor in mid-Aeronian time.     

Photoperiodic induction of diapause in the spider mite Tetranychus urticae: qualitative or quantitative time measurement?

Abstract. Insects and mites may measure photoperiods eitfier by classifying them as long or short relative to a critical value (qualitative time measurement) or by using the absolute value (quantitative time measurement). The spider mite Tetranychus urticae is thought to use a qualitative mechanism of time measurement. In this paper we present the results of experiments with an inbred line of the spider mite (to keep genetic variation in photoperiodic responses small), to test whether quantitative aspects also play a role. Differences in diapause incidence in different long-night photoperiods at different temperatures may be an indication of quantitative responses to photoperiod. The effect of temperature on the photoperiodic response curve was studied at 16^oC, 19^oC and 22^oC. The response curves appeared to be similar at 16^oC and 19^oC, with a critical nightlength between 10 and 11 h. At 22^oC, diapause induction was less than 100% in all long-night regimens and die critical nightlength had shifted to 12 h. Maximum diapause induction (93%) occurred in a light-dark cycle with a 16 h dark phase (LD 8:16 h). Diapause induction was lowest in long-night photoperiods with dark phases of 20 h and longer. The number of light-dark cycles needed for 50% diapause induction at 19^oC varied. between 12.1 and 14.7 for LD 6:18 h, between 10.9 and 12.5 for LD 8:16 h, between 10.6 and 11.6 for LD 10:14 h, and between 10.1 and 10.7 for LD 12:12 h. Independent of die light-dark regimen, diapause induction took place in some individuals after receiving 8 cycles and virtually all individuals entered diapause after 16 cycles. No effect was found of the photoperiodic treatment during prediapause development (LD 6:18 h, LD 8:16 h, LD 10:14 h, LD 12:12 h) on diapause duration. The average diapause duration at LD 10:14 h and 19^oC was 61 days over all four treatments. We explained the results by hypothesising that nightlengths are assessed qualitatively and mat the photoperiodic clock operates more accurately near the critical nightlength.     

Is the last glaciation the only relevant event for the present genetic population structure of the meadow brown butterfly Maniola jurtina (Lepidoptera: Nymphalidae)?

Phylogeographical studies are available for a considerable number of European species, but few analyses exist for temperate species with very large and fairly continuous populations that are also absent from Northern Europe. Therefore, we studied the butterfly Maniola jurtina as a model for this group. The species has two major genetic lineages (mean genetic distance between lineages: 0.033; F _CT: 0.052), most probably evolving in glacial differentiation centres in the western and eastern Mediterranean. The onset of this differentiation might have been the beginning of the last glacial stage maximum some 40 kyr bp . A hybrid zone between these two lineages exists in western Central Europe. No genetic substructures have been found within the two lineages ( F _SC: 0.017) and average genetic distances are very small. Therefore, it is highly probable that postglacial expansion was of the phalanx type. There is, at most, very limited differentiation at regional and local scales. However, the genetic diversity within populations is high (means: A : 2.68; H _E: 17.2%; P : 78%), as would be predicted for such a common species. Comparison of these results with a published allozyme analysis revealed a similar phylogeographical pattern, but lower genetic diversity in the latter. Morphological patterns of wings and genitalia show similar geographical patterns as allozyme data.   © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 85 , 419–431.     

Evolution in Monograptus priodon

Biometric analysis of the Silurian graptolite Monograptus priodon (Bronn) from Arctic Canada and the British Isles shows that the length of the sicula and the rhabdosome width at the level of theca 5 undergo a progressive increase from latest Llandoverian to late Wenlockian time. This change is attributed to sympatric evolution within the species. Monograptus flemingii (Salter) may have evolved elsewhere from priodon stock and migrated later into the two regions. Monograptus riccartonensis Lapworth probably ranges from latest Llandoverian through the Wenlockian, and may have been ancestral to the Ludlovian to Devonian Monograptus lineages.     

Biochemical and Ultrastructural Changes in Tetrahymena pyriformis During Starvation*

SYNOPSIS. Certain of the ultrastructural and biochemical changes occurring during the first 25 hr of starvation in Tetrahymena pyriformis were studied. Ultrastructurally, numerous profiles of degenerating mitochondria were seen in the early stages of starvation. The presence of oxidizable substrate such as glucose and acetate did not prevent this degeneration. Numerous large nucleoli were formed, many of which seemed to be passing into the cytoplasm as forming autophagic vacuoles. There was a transient increase in Oil Red O-positive bodies, presumably lipid (triglycerides). The extent and duration of this increase were pronounced in the presence of acetate. The lipid droplets appeared to arise within the cisternae of the endoplasmic reticulum. Lipid reserves were apparently utilized prior to carbohydrates, as the disappearance of lipid droplets preceded glycogen utilization, both in the presence of acetate and in the absence of exogenous substrate. A considerable loss of cellular protein also occurred. In cells from inorganic medium supplemented with glucose, glycogen occupied much of the cell, leaving only islands of cell organelles. Acid phosphatase was localized, ultrastructurally, mainly in autophagic vacuoles which contained mitochondria and other cell organelles, and in association with small, double-membraned structures which seemed to be sequestering small areas of cytoplasm. Such sequestered areas also appeared within larger autophagic vacuoles. Residual bodies containing concentric whorls of myelin-like membranes surrounding a more solid core accumulated during starvation. Acid phosphatase activity decreased in amount but not in specific activity. The specific activity of cathespin doubled or tripled, but there was little change in total enzyme.