Chromosome duplications and deletions and their mechanisms of origin.

Duplications and deletions of the same gene loci or chromosome regions are known to produce different clinical manifestations and are significant factors in human morbidity and mortality. Extensive cytogenetic and molecular cytogenetic studies with cosmid and YAC probes in two patients with unique mosaicism for reciprocal duplication-deletion allowed us to further understand the origin of these abnormalities. The first patient's mosaic karyotype was 46,XX, inv dup(11) (q23q13)/46,XX,del(11)(q13q23). The second patient had a 46,XY,dup(7)(p11.2p13)/46,XY,del(7)(p11.2p13)/46,XY karyotype. Fluorescence in situ hybridization studies on the first patient placed the two breakpoints near the folate-sensitive fragile sites FRA11A and FRA11B. The presence of repeated sequences responsible for these fragile sites may have been involved in the patient's duplication-deletion. Our investigation leads us to conclude that, in addition to known mechanisms (such as unequal crossovers between homologs, unequal sister chromatid exchanges, excision of intrachromatid loops, and meiotic recombination within a single chromatid), duplication-deletion can also arise by the formation of an overlying loop followed by an uneven crossover at the level of the DNA strand.     

Der sibirische Zilpzalp (Phylloscopus collybita tristis): Gesang und Reaktion einer mitteleurop?ischen Population im Freilandversuch

Zusammenfassung Der Gesang des sibirischen ZilpzalpsPhylloscopus collybita tristis unterscheidet sich markant von jenem der beiden mittel- und ost-europäischen SubspeziesPh. c. collybita undPh. c. abietinus. Unterschiede betreffen Qualität und Quantität des Element-Repertoires, Syntax, Rhythmus innerhalb der Strophen und Frequenzumfang der Strophe.Tristis verfügt über den reicheren und vielfältigeren Gesang. Das wird als apomorphes Merkmal betrachtet. Eine mitteleuropäischecollybita-Population reagiert auftristis-Gesang im Feld-Experiment fast nicht. Nur solche Kunst-Strophen aus natürlichen Elementen vontristis werden vergleichsweise gut beantwortet, die Elementen entsprechen, über die auch mitteleuropäischecollybita verfügen. Die sibirische Gesangsform ist auf über 4000 km W-O-Erstreckung offensichtlich nahezu konstant. Der westliche Arealteil vonc. tristis, oft alsc. fulvescens bezeichnet (Ural bis Jenissei-Tal, 2000 km W-O) kann nicht als Hybrid-Population angesehen werden (abietinus xtristis), da sich in diesem Gebiet keine Merkmale desabietinus-Gesanges nachweisen lassen.

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Territorial song of the siberian chiffchaff (Phylloscopus collybita tristis) and playback experiments within a central european population (Ph. c. collybita)

Summary Territorial songs of Siberian ChiffchaffsPhylloscopus collybita tristis distinctly differ from songs of the Central and East European subspeziesPh. c. collybita andPh. c. abietinus (which do not differ from each other). Differences betweentristis andcollybita/abietinus concern quality and quantity of the notes within the song verses, syntax, rhythm within the song verses, and frequency range of the song verses.Tristis disposes of richer and more manifold song which is said to be an apomorphic character.Ph. c. collybita from Central Europe (Mainz area) using much more limited numbers of differing notes, displays nearly no territorial response totristis song in the field experiments. Only those artificial verses consisting of notes which are used also byc. collybita, were reacted on. The Siberian form of chiffchaff song is apparently more or less constant to about 4000 km in W-E extension. The Western part of thetristis range, often calledc. fulvescens (Ural to Yenisei river, 2000 km W-E), is not to be considered a hybrid population ofabietinus andtristis proper, for no characteristics ofabietinus song are taceable in thefulvescens area.

     

Ein neues captorhinomorphes reptil aus dem thüringischen rotliegend (Unter-Perm; Ost-Deutschland)

Thuringothyris mahlendorffae n.gen. n.sp. is described on the basis of the skull roof, palate, stapes and much of the postcranial skeleton from the Upper Rotliegend (Tambach-Schichten) of the Thuringian Forest in eastern Germany. The new taxon shows both protorothyridid and some captorhinid features. The interrelationships of the »Protorothyrididae«, primitive Captorhinidae, and earliest Diapsida are reviewd. The tetrapod material is used to reassess the biostratigraphic position of the fossil-bearing horizon.     

A method to calculate the cumulative energy demand (CED) of lignite extraction

For the utilisation of an energy carrier such as lignite, the whole life cycle including necessary energy supply processes have to be considered. Therefore using the ‘Cumulative Energy Demand’ (CED) is especially suited to determine and compare the energy intensity of processes. The goal of the CED is to calculate the total primary energy input for the generation of a product, taking into account the pertinent front-end process chains. So the CED is in many steps similar to the LCA, especially in the ‘inventory analysis step’. The statements of the CED for energy supply-systems are concerned with the (primary) energy-efficiency of the energy supply and pointing out the life cycle steps with high energy-resources demand. Due to the great environmental impacts of energy supply and use which have to be laboriously assessed in LCA, the CED provides a useful, additional, energy-related ‘screening-indicator’ to LCA. This case study analyses the extraction of lignite in an opencast mine in West-Germany as the first step of energy carrier provision. Our data for the inventory analysis arise from a measuring campaign about the period of one year. The results underline the great energy demand of lignite extraction in West-Germany. With reference to the energy contents of lignite, the fraction of primary energy demands for its’ mining amounts to about 6.2%. This accounts to 93.8 % of the lignite energy content being available as usable energy for further processes, which is obviously worse than other studies have shown.     

Sorting out “non‐canonical” autophagy

Canonically, LC3 lipidation has been associated with autophagy pathways but it becomes increasingly clear that this modification can also occur during autophagy‐unrelated processes. In this issue, Florey and colleagues find that the WD40 domain of ATG16L1 is dispensable for LC3 lipidation during starvation‐induced autophagy but required for its lipidation during several other membrane‐based processes that are different from autophagy. This finding opens the door for the analysis of the functions of LC3 lipidation in these pathways.     

Schriftenschau

Ohne Zusammenfassung     

The effects of heat and stannous chloride addition on the active distillation of acid volatile sulfide from pyrite-rich marine sediment samples

Iron monosulfides are important intermediates in pyrite formation, and are operationally defined as sulfides soluble in concentrated hydrochloric acid. A number of variations are currently employed in their isolation and quantification. In this study, the active distillation of acid volatile sulfide from sediment samples was studied to determine the effects of stannous chloride and heat. The addition of SnCl₂ caused recovery of sulfide to increase by 20% during distillations performed at room temperature. If distillations with SnCl₂ were then heated and boiled, recovery increased by up to 100%. Tests with 98% pure pyrite and elemental sulfur showed that these compounds were reduced to sulfide in solutions of 15% and 20% SnCI₂ in boiling 6N HCI, and that these reactions were grain size dependent. The compounds were not significantly reduced by solutions of SnCI₂ at room temperature, or by boiling 6N HCl not containing SnCl₂.