European checkerspots (Melitaeini: Lepidoptera,Nymphalidae) are not aposematic – the point of view of great tits (Parus major)

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Polymorphism and differentiation of multilocus DNA markers in natural populations of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis>

Using multilocus (RAPD) markers, variation and divergence of genomic DNA was examined in two Drosophila melanogaster populations from Russia and three populations from Ukraine. The populations were found to exhibit high polymorphism at RAPD markers. Estimation of genetic distances between the populations showed low differentiation of geographically distant populations of D. melanogaster. Significant gene flow between the D. melanogaster populations was found, which depended on the geographical distance between them.     

ONTOGENETIC NICHE SHIFT IN THE BRACHIOPOD TEREBRATALIA TRANSVERSA: RELATIONSHIP BETWEEN THE LOSS OF ROTATION ABILITY AND ALLOMETRIC GROWTH

Abstract: Many articulated brachiopods experience marked life habit variations during ontogeny because they experience their fluid environment at successively higher Reynolds numbers, and they can change the configuration of their inhalant and exhalant flows as body size increases. We show that the extant brachiopod Terebratalia transversa undergoes a substantial ontogenetic change in reorientation governed by rotation around the pedicle. T. transversa′s reorientation angle (maximum ability to rotate on the pedicle) decreases during ontogeny, from 180 degrees in juveniles to 10–20 degrees in individuals exceeding 5 mm, to complete cessation of rotation in individuals larger than 10 mm. Rotation ability is substantially reduced after T. transversa achieves the adult lophophore configuration and preferred orientation with respect to ambient water currents at a length of 2.5–5 mm. We hypothesize that the rotation angle of T. transversa is determined mainly by the position of ventral and dorsal points of attachment of dorsal pedicle muscles relative to the pedicle. T. transversa shows a close correlation between the ontogenetic change in reorientation angle and ontogeny of morphological traits that are related to points of attachment of dorsal pedicle muscles, although other morphological features can also limit rotation in the adult stage. The major morphological change in cardinalia shape and the observed reduction of rotation affect individuals 2.5–10 mm in length. The position of ventral insertions of dorsal pedicle muscles remains constant, but contraction of dorsal pedicle muscles is functionally handicapped because dorsal insertions shift away from the valve midline, rise above the dorsal valve floor, and become limited by a wide cardinal process early in ontogeny (<5 mm). The rate of increase of cardinal process width and of distance between dorsal pedicle muscle scars substantially decreases in the subadult stage (5–10 mm), and most of the cardinalia shell traits grow nearly isometrically in the adult stage (>10 mm). T. transversa attains smaller shell length in crevices than on exposed substrates. The proportion of small‐sized individuals and population density is lower on exposed substrates than in crevices, indicating higher juvenile mortality on substrates prone to grazing and physical disturbance. The loss of reorientation ability can be a consequence of morphological changes that strengthen substrate attachment and maximize protection against biotic or physical disturbance (1) by minimizing torques around the pedicle axis and/or (2) by shifting energy investments into attachment strength at the expense of the cost involved in reorientation.     

Changes in fatty acids contents and growth characteristics in transformed oilseed rape (Brassica napus)

Spring oilseed rapeBrassica napus L. ssp.oleifera cv. HM-81 was transformed with T_L-DNA of the Ri plasmid of the agropine strainAgrobacterium rhizogenes 15834. Selfed progenies (R₂ and R₃ generations) were studied for changes in values of growth characteristics and fatty acids contents. Transformants are ‘homozygous’ for T_L-DNA. Both generations of transformants differed significantly from the nontransformed control plants in reduced length, lower number of pods per plant, lower total mass of seeds and the higher number of branches. The contents of palmitic, linoleic and linolenic acids were significantly higher in transformants when compared with the control. On the contrary, the contents of both stearic and oleic acids were in most of transformants significantly lower. Only traces of erucic acid (less than 0.05 % ) were found, both in transformed and nontransformed plants.     

Diversity and ecology of algae from the Nahal Qishon river,northern Israel

In 59 samples of periphyton and phytoplankton collected in 2002 - 2003 from the Nahal Qishon (Qishon River), northern Israel, we found 178 species from seven divisions of algae and cyanoprocaryotes. Diatoms, clorophytes, and cyanoprocaryotes prevail. Nitzschia and Navicula (Bacillariophyta) are the most abundant. Most of the species are cosmopolitan or widespread, except Lagynion janei (Chrysophyta), which is endemic for the Mediterranean Realm. About 17% of species (26) are new for Israel and five of them represent the first recorded genera: Crinalium endophyticum Crow, Actinocyclus normanii (Gregory) Hustedt, Rhizoclonium hieroglyphicum (Agardh) Kütz (Chlorophyta), Lagynion janei Bourelly, and Stylococcus aureus Chodat. Most of them come from a rare riverine assemblage with red alga Audouinella pygmea, as well as from the estuarine assemblage. Alkaliphiles predominate among the indicators of acidity, with few acidophiles confined to the communities under the impact of industrial wastes. Among the indicators of salinity, most numerous are the oligohalobien-indifferents and species adapted to a moderate salinity level. The relative species richness of ecological groups and the indices of saprobity are correlated with changes in conductivity, pH, and N-nitrate concentration. Indicators of organic pollution fall in the range of betameso- to alfamesosaprobic self-purification grades. Our studies show ecological significance of the Nahal Qishon as a model for a strongly disturbed aquatic ecosystem in the coastal zone of eastern Mediterranean.     

Temporal dynamics and variation of multilocus ISSR-PCR DNA markers in the Uman' population of Drosophila melanogaster over two decades (1984-2004)

The temporal dynamics of genomic variation in the Uman' (Ukraine) population of Drosophila melanogaster over the period 1984-2004 was studied using multilocus ISSR markers. Considerable polymorphism of the genomic DNA fragments corresponding to ISSR markers was found in the D. melanogaster population studied: the values of average heterozygosity varied from 0.085 to 0.127 depending on the year. Significant differences in the frequencies of dominant alleles between the samples of different years were recorded for 12 of the 30 DNA fractions detected. These changes are nondirectional and random. The pattern of detected variation suggests the determining influence of gene drift and migration process on the variation of noncoding DNA sequences in the Uman' population of D. melanogaster.     

Temporal dynamics and variation of multilocus ISSR-PCR DNA markers in the Uman’ population of <Emphasis Type="Italic">Drosophila melanogaster</Emphasis> over two decades (1984–2004)

The temporal dynamics of genomic variation in the Uman’ (Ukraine) population of Drosophila melanogaster over the period 1984–2004 was studied using multilocus ISSR markers. Considerable polymorphism of the genomic DNA fragments corresponding to ISSR markers was found in the D. melanogaster population studied: the values of average heterozygosity varied from 0.085 to 0.127 depending on the year. Significant differences in the frequencies of dominant alleles between the samples of different years were recorded for 12 of the 30 DNA fractions detected. These changes are nondirectional and random. The pattern of detected variation suggests the determining influence of gene drift and migration process on the variation of noncoding DNA sequences in the Uman’ population of D. melanogaster.     

Dynamics of Malaria Mosquito Species Composition in Siberian Populations Detected by Restriction Analysis

The peculiarities of the dynamics of malaria mosquito species proportions were studied in natural populations. Twenty-one collections from five larval habitats of the Anopheles maculipennis complex malaria mosquitoes were taken in the vicinity of Novosibirsk (Russia). It was detected that the Anopheles messeae and An. daciae are dominant species in the collected samples. Three An. beklemishevi individuals were also detected. The dynamics of the species proportions within the reproduction seasons for a number of years and also the differences between localities in the species composition were studied. It was revealed that the An. daciae proportion is maximal in July and falls in August. The species proportions can change sharply from year to year. For example, the An. messeae species prevailed in localities on the left bank of Novosibirsk Reservoir in 2013 and 2014 with the frequency of 54–68%, while An. daciae began to prevail on this territory in 2016 with the frequency of 73–85%. Our data on the proportions of species in different reservoirs were compared with data of other authors for the collections of malaria mosquitoes of the Anopheles maculipennis complex in Russia (Tomsk oblast) and in Germany. A high correspondence of models provided by these authors for the territory that we studied was demonstrated. Thus, the ecological peculiarities of the An. messeae and An. daciae species are highly stable even in geographically and climatically distant localities. An increase in the portion of relatively anthropophilic An. daciae in the middle of summer can be a risk factor relative to malaria transmission in this period of time.     

Concentrations and ecological risks of metals in surface sediments of some coastal creeks in the Niger Delta,Nigeria

The concentrations of nine metals were measured by atomic absorption spectrophotometry in surface sediments of three coastal creeks, namely, the Ifie, Egbokodo and Ubeji creeks, in the Niger Delta of Nigeria, from August 2012 to January 2013. The aim of the study was to provide information on the spatial and seasonal distribution patterns, degree of contamination, and ecological risks of metals in these sediments. The mean concentrations of the nine metals in these creek sediments ranged from 0.30 to 3.20?mg kg^?1 Cd; 10.7 to 24.7?mg kg^?1 Pb, 125 to 466?mg kg^?1 Cr; 3.1.10 to 14.9?mg kg^?1 Cu; 4.7 to 14.3?mg kg^?1 Co; 61.1 to 115?mg kg^?1 Ni; 106 to 183?mg kg^?1 Mn; 52.0 to 170?mg kg^?1 Zn and 5 469 to 20 639?mg kg^?1 Fe. In general, the metal concentrations were higher in the dry season than the wet season, except for Cr. The concentrations of Cd, Cr, Ni and Zn were above their regulatory control limits in sediment as specified by the Nigerian Regulatory Authority and Cd was identified as the main ecological risk factor. The enrichment factors for the studied metals followed the order: Cd > Cr > Ni > Zn > Pb > Co > Mn > Cu. The average multiple pollution index values indicated that these sediments were severely polluted with significant inputs from Cd, Ni and Cr.