New rhythmic changes in mitosis and growth in low differentiated green and red marine macroalgae

The cell division and vegetative growth of the thalli of simply differentiated macroalgae with a diffuse growth type—Ulva pseudocurvata (Chlorophyta) and Porphyra umbilicalis (Rhodophyta)-have been studied under natural and laboratory conditions. For this purpose the mitotic index and growth rate of algae were measured over 18 days. A diurnal rhythm of the mitotic index was revealed: the minimal mitotic index was registered in morning and daylight hours (for U. pseudocurvata 1–4%, for P. umbilicalis 0.5–2%), in the afternoon the index grew and reached its maximum 1 hour before dark (for U. pseudocurvata 12%, for P. umbilicalis 7%), then it slowly decreased during the night. In the studied algal species 2–3-and 6-day rhythms of mitotic index and growth rate were found for the first time both under natural and laboratory conditions. With constant white light these rhythms persisted for 9 days, this confirms the endogenous regulation of these rhythmic variations.     

Concerning the problem of carcinophilia of <Emphasis Type="Italic">Careproctus</Emphasis> species (Scorpaeniformes: Liparidae) in the North Kurils

Along the east coast of North Kurils, the egg deposits of Careproctus snailfishes (Scorpaeniformes: Liparidae) were revealed in the gill cavity of 9.9% of all golden king crabs, mostly in individuals with carapace of 61–80 mm width (61.6%). The number of Careproctus eggs in the gill cavity of crabs increased with the increase of the carapace width. In fact, 97.0% of the crabs had such egg deposits only at one side of their carapaces. Most of the egg deposits, apparently, belonged to C. cypsellurus and C. furcellus. The number of crabs with egg deposits was related to the number of post-molt individuals. Evidently, egg depositing by Careproctus snailfishes out of the gill cavity of crabs is a rather widespread phenomenon.     

Abundance,distribution, and territory areas of rock-dwelling Lake Tanganyika cichlid fish species

Lake Tanganyika, the second-oldest and second-deepest lake in the world, harbors an impressive cichlid fish fauna counting about 250 endemic species that are characterized by a great level of ecological, morphological, and behavioral specialization. This study describes and compares cichlid fish communities at two rocky shores with differential human impact in the south of Lake Tanganyika. Species inventories and depth-dependent abundances were elaborated. About 41 and 46 sympatric cichlid species were recorded in the two study sites, respectively. Variabilichromis moorii was the most abundant species (29–60% of total number of fishes), followed by Aulonocranus dewindti (3–19%), Tropheus moorii (12%), Ophthalmotilapia ventralis (4–10%), Eretmodus cyanostictus (6–11%), and Cyathopharynx furcifer (0.01–9%). All other species had abundances below 5%. It further emerged that large cichlids such as Petrochromis species, Cyathopharynx furcifer, and Lobochilotes labiatus were very rare at one location, with frequencies of 0.55% or less. Territorial sizes of three particularly abundant species, Variabilichromis moorii, Aulonocranus dewindti, and Tropheus moorii, were assessed by behavioral observations. We distinguished between territorial core areas and total defended area, yielding average core areas between 0.4 (V. moorii) and 1.6 m² (T. moorii), and total defended areas averaging for each species between 1.6 (V. moorii) and 5.0 m² (A. dewindti) with no significant differences between the two study sites. The data on individual densities are also relevant for evolutionary studies, in that they allow more accurate calculations of effective population sizes.     

Polymorphism of <Emphasis Type="Italic">yellow</Emphasis> locus in <Emphasis Type="Italic">Drosophila melanogaster</Emphasis> mutants from natural populations

We have studied the molecular characteristics of the yellow locus (y; 1–0.0), which determines the body color of phenotypically wild-type and mutant alleles isolated in different years from geographically distant populations of Drosophila melanogaster. According to the Southern blot, data restriction maps of the yellow locus of all examined strains differ from one another, as well as from Oregon stock. FISH analysis shows that, in the neighborhood of the yellow locus in the X chromosome, neither P nor hobo elements are found in y^1–775 stock, while only hobo is found in these region in y^1–859 and y^1–866 stocks, only the P element is found in y⁺sn⁸⁴⁹ stock, and both elements are found in y^1–719 stock. Thus, all yellow mutants studied are of independent origin. Locus yellow located on the end of X chromosome (region 1A5–8 on the cytologic map) carries significantly more transposon than retrotransposon induced mutations compared to the white locus (region 3C2). It is possible that, at the ends of Drosophila melanogaster chromosomes, transposons are more active than retrotransposons.     

Leaf spot disease on <Emphasis Type="Italic">Tilia cordata</Emphasis> caused by the fungus <Emphasis Type="Italic">Cercospora microsora</Emphasis>

Increased incidence of leaf spots on many tree species, up to the presence of peripheral importance only, including linden trees was noticed recently. First massive and continuous occurence of the fungus Cercospora microsora Sacc. [teleomorph Mycosphaerella millegrana (Cook.) Schröet., Mycosphaerella microsora Syd.], causal agent of anthracnose on linden trees (Tilia cordata Mill.) grown in urban plantings in Slovakia was reported. Along with this, certain of the important growth characteristics of this fungus were studied under laboratory conditions. To specify Cercospora biology mycelial growth of C. microsora in pure hyphal cultures was observed in relation to medium and locality. One-way ANOVA has confirmed a statistically significant influence of both factors, culture medium and locality on growth rate values of C. microsora. The effect of these factors has not proved unambiguously in all cases. In the case of one locality (Nitra), the significant influence of used media has not been proved (P > 0.05). PDAg showed generally as the most suitable medium, inducing the most intensive growth in three localities (41.06 mm/week on average). Comparing three localities, the effect of this factor is not so unambiguous. Growth rate values from the localities Bratislava and Pribeta indicate unsuitability of medium A for the fast radial growth. A Tukey test separately conducted for the factors medium and the locality revealed the significant combinations of means (P ≤ 0.05).     

Patterns of growth and oxidation of natural pyrites by the representatives of acidophilic chemolithotrophic microorganisms

The patterns of the growth and oxidation of different types of natural pyrites were studied for the three microbial species adapted to these substrates and belonging to phylogenetically remote groups: gram-negative bacterium Acidithiobacillus ferrooxidans, gram-positive bacterium Sulfobacillus thermotolerans, and the archaeon Ferroplasma acidiphilum. For both A. ferrooxidans strains, TFV-1 and TFBk, pyrite 4 appeared to be the most difficult to oxidize and grow; pyrite 5 was oxidized by both strains at an average rate, and pyrite 3 was the most readily oxidized. On each of the three pyrites, growth and oxidation by TFBk were more active than by TFV-1. The effectiveness of the adaptation of S. thermotolerans Kr1^T was low compared to the A. ferrooxidans strains; however, the adapted strain Kr1^T showed the highest growth rate on pyrite 3 among all the cultures studied. No adaptation of strain Kr1^T to pyrite 5 was observed; the rates of growth and pyrite oxidation in the third transfer were lower than in the first transfer. The strain F. acidiphilum Y^T was not adapted to pyrites 3 and 5; the rates of growth and pyrite oxidation were the same in the first five transfers. The strains of three species of the microorganisms studied, A. ferrooxidans, S. thermotolerans, and F. acidiphilum, grew on pyrite 3 (holetype (p) conductivity) and oxidized it better than pyrite 5 (mixed-type (n-p) conductivity). The most readily oxidized were the pyrites with a density of 5.6–5.7 g/cm³ and high resistance values (ln R = 8.8). The pyrite oxidation rate did not depend on the type of conductivity. Changes in the chromosomal DNA structure were revealed in strain TFBk on adaptation to pyrites 3 and 4 and in the TFV-1 plasmid profile on adaptation to pyrite 3. Correlation between genetic variability and adaptive capabilities was shown for A. ferrooxidans. No changes in the chromosomal DNA structure were found in S. thermotolerans Kr1^T and F. acidiphilum Y^T on adaptation to pyrites 3 and 5. Plasmids were absent in the cells of these cultures.     

Mutual effects of several fouling organisms of the White Sea (<Emphasis Type="Italic">Mytilus edulis,Styela rustica</Emphasis>, and <Emphasis Type="Italic">Hiatella arctica</Emphasis>) on their growth rate and survival

The mutual effects of several fouling species (the bivalves Mytilus edulis and Hiatella arctica and a solitary ascidian Styela rustica) on their growth rate and mortality were studied through field experiments. The interactions between S. rustica and H. arctica appeared to be the least antagonistic. In contrast, the mussel was the most “aggressive” species with regard to both competitors. It was observed that the ascidians died, because they were intensively braided and gummed up with the byssus threads of the mussels. However, in some cases the intraspecific competition was stronger than the interspecific one.     

Interactions of Algae within the Community of <Emphasis Type="Italic">Gracilaria gracilis</Emphasis> (Rhodophyta)

Interactions among the unattached red alga Gracilaria gracilis, the dominant species of an algal community, and associated algal species Chaetomorpha linum, Enteromorpha prolifera f. prolifera, and Polysiphonia sp. were studied during and after an algal bloom. It was shown that during their bloom the associated algae Enteromorpha and Polysiphonia sp. significantly decreased the photosynthetic rate of G. gracilis but did not affect its growth rate. It is suggested that the inhibition of Gracilaria gracilis photosynthesis is connected to the impact of extracellular metabolites excreted by Chaetomorpha linum, Enteromorpha prolifera f. prolifera, and Polysiphonia sp. In laboratory experiments, the photosynthetic rate of the associated species was enhanced in the presence of Gracilaria. However, no significant alterations were observed in the content of chlorophyll a, growth, and the dark respiration rates of associated algae when they were kept together with Gracilaria. It was suggested that allelopathic interactions observed among algal species during the formation of the monospecific Gracilaria community, as well as during algal blooms, are not determinative.     

Effect of excretory-secretory products of some fouling organisms on settling and metamorphosis of the larvae of <Emphasis Type="Italic">Styela rustica</Emphasis> (Ascidiae)

The effect of the excretory-secretory products of some fouling animals on the settling and metamorphosis of larvae of the solitary ascidian Styela rustica was assessed. The substances secreted by the sponge Halichondria panicea stimulated settling of larvae, but concurrently blocked their metamorphosis. The excretory-secretory products of the mussel Mytilus edulis and the ascidian Molgula citrine did not affect settling of the S. rustica larvae but impeded their subsequent development. Water conditioned by the bivalve Hiatella arctica, stimulated settling and, apparently, metamorphosis of the larvae of S. rustica. The chemical substances produced by adult individuals of S. rustica facilitated settling of conspecific larvae but slightly delayed their metamorphosis.     

Population structure and growth of the Japanese littleneck clam <Emphasis Type="Italic">Ruditapes philippinarum</Emphasis> in Amursky Bay,Sea of Japan

This paper deals with the size, age, and sex structure of population and growth of the Japanese littleneck clam Ruditapes philippinarum in Amursky Bay (Peter the Great Bay, Sea of Japan). One-year-olds and individuals with a shell length less than 19.8 mm were not found in the population under study. The population consisted mostly of 3-4-year-old clams (72.4%) with a shell length of 35–45 mm (67.8%). The maximum recorded age of R. philippinarum was 7 years, and maximum shell length was 52.7 mm. The male to female ratio was approximately 2: 1. Hermaphroditism (2.1%) and parasitic castration (1.4%) were observed. Linear growth rates of clams were found to increase until the age of three years old (11.6 ± 0.6 mm/year). Mollusks reach a commercial size of over 35 mm in shell length in the fourth year of life. The parameters of the von Bertalanffy equation describing group linear growth were L _∞ = 56.6 mm, k = 0.302 year^?1, and t ₀ = 0.468 year. The relationship between the shell length and the wet body weight is described by the equation W = 0.000253L^2.954.     

Association of the <Emphasis Type="Italic">POLG1</Emphasis> T(−365)C, <Emphasis Type="Italic">ANT1</Emphasis> G(−25)A,and <Emphasis Type="Italic">PEO1</Emphasis> G(−605)T polymorphisms with diabetic polyneuropathy in patients with Type 1 diabetes mellitus

This study is dedicated to a search for the association of the polymorphic markers T(?365)C of the POLG1 gene G(?25)A of the ANT1 gene and G(?605)T of the PEO1 gene with diabetic polyneuropathy (DPN) in Type 1 diabetes mellitus (DM1) patients. All patients were ethnic Russian Moscow residents, with DM1 records of no more than 5 years and DPN or DM1 records of more than 10 years but without DPN. We found that the polymorphic marker T(?365)C of POLG1 was associated with DPN in Russian patients with DM1. The carriers of the C allele and the CC genotype had a higher risk of DPN development (OR = 1.62; CI = 1.11–2.38; and OR = 1.76; CI = 0.99–3.13; respectively). In contrast, the T allele carrier status and the TT genotype were associated with a lower DPN risk (OR = 0.62, CI = 0.42–0.90; and OR = 0.61; CI = 0.35–1.07; respectively). We found no association of the polymorphic markers G(?25)A of ANT1 or G(?605)T of PEO1 with DPN in Russian DM1 patients living in Moscow.     

Above-ground biomass changes over an 11-year period in an Amazon monodominant forest and two other lowland forests

Tropical rain forest dominated by Peltogyne gracilipes (Fabaceae) occurs on Maracá Island, Roraima, Brazil, on a range of soil types. Three forest types were stratified for sampling, according to the occurrence of Peltogyne trees: (1) Peltogyne-rich forest (PRF), (2) Peltogyne-poor forest (PPF), and (3) forest without Peltogyne (FWP). Biomass increment and change in total stand biomass were calculated from mortality, recruitment, and growth data for trees in the three forest types. Data were derived from permanent plots established in 1991, where all trees (≥10 cm diameter at breast height), including palms and vines (lianas), were tagged and measured in three plots, each of 0.25 ha, in each of the three forest types. Field surveys were carried out in October 1991 and March 2003. Over a period of 11 years, the above-ground biomass in all forest types declined slightly (<5%), associated with the death of large trees, especially in the monodominant forests (PRF and PPF). Within the study period, the forest on Maracá experienced two heavy droughts, related to El Niño events (1997–1998 and 2002–2003) and most mortality and loss of biomass probably occurred during these events. Therefore, as the Maracá forests appear not be increasing in above-ground biomass overall, they may not be acting as a sink for atmospheric CO₂. The trees of the five most abundant species (Ecclinusa, Lecythis, Licania, Peltogyne, and Pradosia) accounted for about 55% of the total biomass in both FWP and PPF and for 74% in PRF. Peltogyne gracilipes had a stable, regenerating population in PRF, and is clearly a persistent dominant in a monodominant forest.     

A review of the Indo-Pacific bonefishes of the <Emphasis Type="Italic">Albula argentea</Emphasis> complex,with a description of a new species

In this statement about numbers of nominal and valid species, the bonefish Albula argentea (Forster in Bloch and Schneider 1801) of the western and South Pacific, previously regarded as an unavailable name, is a senior synonym of Albula forsteri Valenciennes (an unnecessary replacement name for A. argentea) and A. neoguinaica Valenciennes. It is easily distinguished from the wide-ranging A. glossodonta (Forsskål 1775) by its more pointed lower jaw and higher vertebral and lateral-line scale counts. It is most similar to the Indian Ocean A. oligolepis, described here as a new species, and the endemic Hawaiian A. virgata Jordan and Jordan, resurrected from synonymy. Albula argentea differs from its two related species by higher counts of pored lateral-line scales and vertebrae. It has 68–74 (mode 70) lateral-line scales vs. 61–65 (63) for A. oligolepis and 63–67 (65) for A. virgata, and 71–74 (73) vertebrae vs. 64–66 (65) for A. oligolepis and 65–68 (67) for A. virgata. Albula virgata differs further from A. oligolepis in having the pelvic fin tip reaching beyond the anus (vs. short of or just reaching anus) and higher numbers of scale rows above the lateral line 9–10 (9) vs. 7½–8 (8) for A. oligolepis.     

Pistil-function breakdown in a new <Emphasis Type="Italic">S</Emphasis>-allele of European pear, <Emphasis Type="Italic">S</Emphasis><Subscript><Emphasis Type="Italic">21</Emphasis></Subscript>°, confers self-compatibility

European pear exhibits RNase-based gametophytic self-incompatibility controlled by the polymorphic S-locus. S-allele diversity of cultivars has been extensively investigated; however, no mutant alleles conferring self-compatibility have been reported. In this study, two European pear cultivars, ‘Abugo’ and ‘Ceremeño’, were classified as self-compatible after fruit/seed setting and pollen tube growth examination. S-genotyping through S-PCR and sequencing identified a new S-RNase allele in the two cultivars, with identical deduced amino acid sequence as S ₂₁ , but differing at the nucleotide level. Test-pollinations and analysis of descendants suggested that the new allele is a self-compatible pistil-mutated variant of S ₂₁ , so it was named S ₂₁ °. S-genotypes assigned to ‘Abugo’ and ‘Ceremeño’ were S ₁₀ S ₂₁ ° and S ₂₁ °S ₂₅ respectively, of which S ₂₅ is a new functional S-allele of European pear. Reciprocal crosses between cultivars bearing S ₂₁ and S ₂₁ ° indicated that both alleles exhibit the same pollen function; however, cultivars bearing S ₂₁ ° had impaired pistil-S function as they failed to reject either S ₂₁ or S ₂₁ ° pollen. RT-PCR analysis showed absence of S ₂₁ °-RNase gene expression in styles of ‘Abugo’ and ‘Ceremeño’, suggesting a possible origin for S ₂₁ ° pistil dysfunction. Two polymorphisms found within the S-RNase genomic region (a retrotransposon insertion within the intron of S ₂₁ ° and indels at the 3′UTR) might explain the different pattern of expression between S ₂₁ and S ₂₁ °. Evaluation of cultivars with unknown S-genotype identified another cultivar ‘Azucar Verde’ bearing S ₂₁ °, and pollen tube growth examination confirmed self-compatibility for this cultivar as well. This is the first report of a mutated S-allele conferring self-compatibility in European pear.     

Long-term changes in forest composition and diversity following early logging (1919–1923) and the decline of American chestnut (<Emphasis Type="Italic">Castanea dentata</Emphasis>)

Chestnut blight fungus (Endothia parasitica [Murr.] P.J. And. &; H.W. And.)) is a classic example of an invasive species, which severely damaged populations of its host, Castanea dentata, and had widespread and long-term impacts on eastern North American forests. Concurrently, forests were further disturbed by lumbering, which was common across the region from the mid 1800s to the early 1900s. In 1926, local infestations of chestnut blight were reported in the Coweeta Basin, Southern Appalachian Mountains of North Carolina. We used permanent plot inventories of the Basin (first sampled in 1934 and twice afterward in 1969–72 and 1988–93) to describe the distribution of species along a complex environmental gradient. Specifically, we asked: How does vegetation change over approximately 60 years following logging and the demise of C. dentata? Does the association between vegetation and environment determine the pattern of species distributions through time? Which species replaced C. dentata across this complex environmental gradient? We used nonmetric multidimensional scaling ordination and multiresponse permutation procedure for the analyses of the inventory periods. In 1934, C. dentata was the most important species in the Coweeta Basin. It was present in 98% of the plots and contributed 22% of the total density and 36% of the total basal area. Diversity increased significantly over time and was attributed to an increase in evenness of species distribution. The canopy dominant, C. dentata, was replaced by more than one species across the environmental gradient. Importance values of Quercus prinus, Acer rubrum, Cornus florida, Tsuga canadensis, and Oxydendrum arboreum increased by 2–5% across the basin following the decline of C. dentata. Tsuga canadensis increased in abundance and distribution, especially near streams across elevations. Liriodendron tulipifera replaced C. dentata in moist coves, which have low terrain shape and high organic matter content. In contrast, Q. prinus and A. rubrum were ubiquitous, much like C. dentata before the chestnut blight becoming dominant or co-dominant species across all environmental conditions.     

Variation in mycorrhizal performance in the epiphytic orchid <Emphasis Type="Italic">Tolumnia variegata in vitro</Emphasis>: the potential for natural selection

Symbiotic seed germination is a critical stage in orchid life histories. Natural selection may act to favor plants that efficiently use mycorrhizal fungi. However, the necessary conditions for natural selection – variation, heritability, and differences in fitness – have not been demonstrated for either orchid or fungus. With the epiphytic orchid Tolumnia variegata as a model system, we ask the following questions: (1) Do seeds from different individuals in a population differ in germination and seedling development in the presence of the same fungi? (2) Do different mycorrhizal fungi (Ceratobasidium spp.) differ in ability to stimulate seed germination and growth in T. variegata? And (3) are the Ceratobasidium isolates that best induce seed germination and seedling development more closely related to each other than to isolates that are less effective? We performed symbiotic seed germination experiments in vitro. The experiments were done using mycorrhizal fungi isolated from T. variegata; relationships among the fungi were inferred from nuclear ribosomal ITS sequences. We found significant variation for both symbiotic germination and seedling growth among biparental seed crops obtained from a population of T. variegata plants. Differences among Ceratobasidium fungi in seed germination were significant. The fungi that induced highest seed germination and seedling development belonged to two of four clades of Ceratobasidium. The two experiments show that there is potential for natural selection to act on orchid–fungus relationships. Given that orchids vary in performance, and that mycorrhizal fungi are not geographically distributed homogeneously, mycorrhizae may affect population size, distribution and evolution of orchids.     

Biocontrol of a root rot of kale by <Emphasis Type="Italic">Muscodor albus</Emphasis> strain MFC2

Pythium ultimum is an oomycetous root rot pathogen that causes significant crop production losses on many crops including kale (Brassica oleracea), an economically important vegetable in Thailand. An endophytic fungus from Thailand designated Muscodor albus MFC2 controlled P. ultimum both in vitro and on kale seedlings grown under outdoor conditions via the production of volatile antibiotics. Ten-day old M. albus MFC2 PDA cultures killed P. ultimum in vitro. Thoroughly mixing three PDA plates of 10-day old M. albus MFC2 into a 500 g mixture of commercial soil and field soil did not adversely affect kale seed germination. The same amount of M. albus MFC2 could restore seedling emergence in P. ultimum inoculated soil to a level close to that of a non-infested control. In addition, M. albus MFC2 did not cause any disease symptoms, but rather seemed to promote the growth of kale in the presence or absence of P. ultimum for up to eight weeks after planting.