Chromosomal aberrancy and the level of fluctuating asymmetry in black-striped mouse (Apodemus agrarius): effects of disturbed environment

Analysis of chromosomal aberrations in bone marrow cells and determination of the level of fluctuating asymmetry (FA) for eight bilateral cranial traits were used to estimate effects of disturbed environment on natural populations of small mammals. During the spring and fall of 1994-2000 (except in 1999) black-striped mice (Apodemus agrarius) were collected from a polluted industrial area (Pancevo) and from an unpolluted reference site (Cer) in Serbia and Montenegro. Mice from the polluted area had significantly higher mean number of aberrant cells per individual than those in the reference site (p<0.01). Both sexes had the greater number of lesions in the polluted site than in the reference one. Also, there were no significant differences between sexes, neither within the same site/season nor between sites/seasons. Chi-square analysis of the difference between lesions per individual and aberrant cells per individual among sites showed that no site deviated from the expected difference (p=1.000). Developmental stability, assessed as FA, was reduced in the polluted area for two traits (width of lower jaw and length of the diastema lower jaw). Juvenile animals from the polluted area had significantly higher levels of FA compared to those from the reference site for three traits (length of the foramina incisiva, distance between incisor and the third upper molar, and length of the upper molars row). Juvenile animals from the polluted area had significantly higher levels of FA for three traits (length of the foramina incisiva, length of the lower molars row and width of lower jaw) compared to adult ones. In the polluted area seasonal differences were detected for two traits (length of the foramina incisiva and length of the upper molars row). Finally, Apodemus agrarius may be an important species for environmental quality evaluation studies based on an assay using a combination of end-points.     

Differentiation of mitochondrial DNA and Y chromosomes in Russian populations

The genetic composition of the Russian population was investigated by analyzing both mitochondrial DNA (mtDNA) and Y-chromosome loci polymorphisms that allow for the different components of a population gene pool to be studied, depending on the mode of DNA marker inheritance. mtDNA sequence variation was examined by using hypervariable segment I (HVSI) sequencing and restriction analysis of the haplogroup-specific sites in 325 individuals representing 5 Russian populations from the European part of Russia. The Y-chromosome variation was investigated in 338 individuals from 8 Russian populations (including 5 populations analyzed for mtDNA variation) using 12 binary markers. For both uniparental systems most of the observed haplogroups fell into major West Eurasian haplogroups (97.9% and 99.7% for mtDNA and Y-chromosome haplogroups, respectively). Multidimensional scaling analysis based on pairwise F(ST) values between mtDNA HVSI sequences in Russians compared to other European populations revealed a considerable heterogeneity of Russian populations; populations from the southern and western parts of Russia are separated from eastern and northern populations. Meanwhile, the multidimensional scaling analysis based on Y-chromosome haplogroup F(ST) values demonstrates that the Russian gene pool is close to central-eastern European populations, with a much higher similarity to the Baltic and Finno-Ugric male pools from northern European Russia. This discrepancy in the depth of penetration of mtDNA and Y-chromosome lineages characteristic for the most southwestern Russian populations into the east and north of eastern Europe appears to indicate that Russian colonization of the northeastern territories might have been accomplished mainly by males rather than by females.     

Tannenmischwälder und Schuttwälder im Tal der mittleren Lužnice und oberen Moldau in Südböhmen,Tschechoslowakei

Die vorliegende Arbeit befasst sich mit den phytozönologischen Verhältnissen und der Ökologie der Tannen- und Schuttwälder in den Durchbruchstälern der mittleren Lu?nice und oberen Moldau in Südböhmen. Die Schuttwälder werden durch die Ass.Querco robori-Aceretum repräsentiert, die vorwiegend im Tale der Lu?nice in zwei Subassoziationen u. zw.typicum undlunarietosum verbreitet ist. In den Gesellschaften der Tannenhangwälder auf nichtvernässten Böden wurden zwei Assoziationen unterschieden: krautreiche Linden-Tannenwälder repräsentiert die Ass.Tilio-Abietetum mit Subass.typicum, stellarietosum undlumarietosum, die zum VerbandTilio-Acerion Klika 1955 gehört, azidophile Tannenwälder die Ass.Deschampsio flexuosae-Abietetum, die in den VerbandLuzulo-Fagion Lohm. etTüxen 1954 inTüxen 1954 eingereiht wird.     

Azidophile Eichenwälder auf Quarziten im Tribeč-Gebirge,Slowakei

Die azidophilen Ginster-Traubeneichenwälder, die als Dauerstadien der Sukzession auf Quarziten im Tribe?-Gebirge in der Westslowakei verbreitet sind, gehören systematisch zur AssoziationGenisto pilosae-Quercetum petraeae Zólyomi, Jakucs, Fekete inZólyomi etJakucs 1957. Diese Assoziation zerfällt in zwei Subassoziationen, die sich durchphytozönologische Zusammensetzung und durch verschiedene Ökologie interscheiden: Subass.Quercetosum und Subass.fagetosum. Die beschriebene Assoziation ist auf flachgründigen, stark saueren Böden verbreitet, die bodentypologisch zu oligotrophen Rankern oder Ranker-Braunerden gehören.     

Studium autopathischer und allelopathischer Eigenschaften von Kulturpflanzen durch Folgekulturen-Methode

V práci byl sledován vliv p?edplodin lnu, ?ita, máku a ho??ice na následné plodiny tého? nebo jiného druhu p?i bezprost?edním vysévání po sobě a p?i vysévání v r?zně dlouhých ?asových intervalech s odstupňovanou délkou odpo?ívání zeminy. Pokusy byly prováděny v nádobách naplněných kompostovou zeminou, které byly umístěny na pokusné zahradě. Byl hodnocen r?st p?edplodiny a následné plodiny stanovením su?iny nadzemních ?ástí a ko?en?. Během r?stu následných rostlin byly odebírány vzorky zemin, v nich? byl stanoven obsah fyziologicky p?istupného dusíku, fostoru a draslíku. V?echny ?ty?i pou?ité p?edplodiny p?sobily pr?kazné změny v r?stu následných rostlin. Len a mák pěstované jako p?edplodiny p?sobily na následné rostliny lnu a cukrovky prost?ednictvím p?dních autopatických ?i allelopatických faktor?. Ú?inek ?ita jako p?edplodiny na ?ito a ho??ice na je?men byl méně výrazný. Z výsledk? se nedá v posledních dvou p?ípadech p?ímo usuzovat na p?ítomnost autopatických nebo allelopatických faktor?. P?i bezprost?ední kultivaci následných rostlin v zemině po p?edplodině bez odpo?ívání byla zji?těna jen inhibice r?stu. Pokusy s odstupňovanou délkou odpo?ívání zeminy dávají mo?nost zachytit celou ?kálu r?stových změn následných rostlin od inhibice ke stimulaci. Ú?inek p?edplodiny na následnou plodinu se zna?ně měnil s délkou odpo?ívání zeminy po p?edplodině. Změny r?stu následných rostlin nekorelovaly—kromě pokusu s ?item a ?áste?ně s ho??icí—se změnami v obsahu sledovaných ?ivin, ani s mno?stvím narostlé p?edplodiny.     

Physiological significance of isoprenoids and phenylpropanoids in drought response of Arundinoideae species with contrasting habitats and metabolism

Physiological, biochemical and morpho‐anatomical traits that determine the phenotypic plasticity of plants under drought were tested in two Arundinoideae with contrasting habitats, growth traits and metabolism: the fast‐growing Arundo donax, which also is a strong isoprene emitter, and the slow‐growing Hakonechloa macra that does not invest on isoprene biosynthesis. In control conditions, A. donax displayed not only higher photosynthesis but also higher concentration of carotenoids and lower phenylpropanoid content than H. macra. In drought‐stressed plants, photosynthesis was similarly inhibited in both species, but substantially recovered only in A. donax after rewatering. Decline of photochemical and biochemical parameters, increased concentration of CO₂ inside leaves, and impairment of chloroplast ultrastructure were only observed in H. macra indicating damage of photosynthetic machinery under drought. It is suggested that volatile and non‐volatile isoprenoids produced by A. donax efficiently preserve the chloroplasts from transient drought damage, while H. macra invests on phenylpropanoids that are less efficient in preserving photosynthesis but likely offer better antioxidant protection under prolonged stress.     

Effects of diet and temperature on Morimus funereus larval hemolymph cation concentrations

The effects of diet and different constant temperatures on hemolymph cation concentrations (Na⁺, K⁺, Mg²⁺, Ca²⁺) have been studied in Morimus funereus larvae collected from natural habitat, fed natural (oak or beech bark) or artificial diet, as well as in larvae reared from hatching on an artificial diet. In the hemolymph of larvae maintained under natural conditions Mg²⁺ was dominant, whereas Na⁺ concentration was very low. In their natural diets concentrations of Na⁺ and K⁺ were very low, while those of Ca²⁺ and Mg²⁺ were high. In larvae continuously reared on an artificial diet, hemolymph Mg²⁺ concentration was significantly decreased and Na⁺ concentration increased more than fourfold compared to the results obtained in oak-fed larvae. Na⁺ and K⁺ are the dominant cations in the artificial diet. The concentrations of K⁺ and Ca²⁺ in the hemolymph of larvae fed natural or artificial diet are nearly identical, suggesting the existence of an internal regulatory mechanism in this insect for these cations. The hemolymph cation concentrations of M. funereus larvae are predominantly dependent upon the diet consumed, much less upon the environmental temperatures. The most stable concentrations of cations were observed in larvae continuously fed an artificial diet and exposed to different constant temperatures. There was much less stability in the hemolymph cation concentration in oak larvae fed either natural or artificial food after their transfer to constant temperatures. With respect to the response to the external factors studied, the most sensitive are the Na⁺ concentrations, the most stable seems to be K⁺. © 1992 Wiley-Liss, Inc.     

Removing Contamination-Induced Reconstruction Artifacts from Cryo-electron Tomograms

Imaging of fully hydrated, vitrified biological samples by electron tomography yields structural information about cellular protein complexes in situ. Here we present a computational procedure that removes artifacts of three-dimensional reconstruction caused by contamination present in samples during imaging by electron microscopy. Applying the procedure to phantom data and electron tomograms of cellular samples significantly improved the resolution and the interpretability of tomograms. Artifacts caused by surface contamination associated with thinning by focused ion beam, as well as those arising from gold fiducial markers and from common, lower contrast contamination, could be removed. Our procedure is widely applicable and is especially suited for applications that strive to reach a higher resolution and involve the use of recently developed, state-of-the-art instrumentation.     

Structural basis for VIPP1 oligomerization and maintenance of thylakoid membrane integrity

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Meiotic studies in two infertile males with autosomal translocations

Summary Meiotic studies were performed in two infertile male carriers of balanced reciprocal translocations between chromosomes 3;5 and 6;10. The first patient had severe oligozoospermia with all stages of meiosis present. The other patient was azzospermic with meiotic breakdown after the first meiotic division. A ring quadrivalent configuration was found in diakinesis in both cases.