Effects of chitosan‐oligosaccharides on growth performance,digestive enzyme and intestinal bacterial flora of tiger puffer (Takifugu rubripes Temminck et Schlegel, 1850)

The present study was conducted to evaluate the effects of different dietary chitosan oligosaccharide (COS) levels on digestive enzyme activity, intestinal bacteria flora, and growth performance of the tiger puffer (Takifugu rubripes). Some 600 fish (initial body weight 129.2 ± 3.1 g) were randomly allocated into twelve 2,000‐L blue cylinder aquaria with 1,500‐L of sea water and divided into four groups (n = 3 aquaria/diet). The fish were fed experimental diets supplemented with different levels of COS (0% [control, L1], 0.05% [LC1], 0.1% [LC2], and 0.2% [LC3]) for 8 weeks. During the experiment, the water temperature was 18 ± 1°C, salinity 28 ± 0.1, pH 8.0 ± 0.1 (mean ± SD, n = 672); airstones were positioned at the bottom of the tank, dissolved oxygen content was above 7.0 mg/L, with a photoperiod of 12 hr light: 12 hr dark. The results showed that dietary COS significantly increased growth performance, intestinal‐somatic index (ISI), and intestinal protease as well as lipase activity (p < .05). However, dietary COS did not have a significant effect on the condition factor (CF), hepatosomatic index (HSI), viscerosomatic index (VSI), survival, or muscle proximate composition of tiger puffers (p > .05). High‐throughput sequencing analysis showed that COS affected the richness and diversity of intestinal microbial species. The Shannon index of intestinal bacterial flora was significantly higher in the control group than in other groups (p < .05). However, dietary COS supplementation did not alter the phyla species of intestinal bacterial flora. There were significantly more Aliivibrio and Bacillus in LC3 than in other groups, and there were significantly fewer Faecalibacterium, Escherichia, and Bacteroides than in other groups at the genus level (p < .05). It can be concluded that dietary COS can improve the growth performance and intestinal digestive enzyme activity and alter the intestinal bacterial flora in the tiger puffer, Takifugu rubripes.     

Length–weight relationships for two marine fish species from the Gulf of Oman: Uranoscopus guttatus Cuvier, 1829 and Lagocephalus inermis (Temminck & Schlegel, 1850)

This study presents the first report of length–weight relationships (LWRs) for Uranoscopus guttatus and Lagocephalus inermis from the Iranian coast on the Gulf of Oman. A wide range of body lengths and weights were obtained using samples from non‐selective trawling surveys. The LWRs obtained were W = 41.408L^3.519 and W = 16.525L^2.847 for U. guttatus and L. inermis, respectively.     

Relationship among acidophilic bacteria from diverse environments as determined by randomly amplified polymorphic DNA analysis (RAPD)

Summary Random amplification of polymorphic DNA (RAPD), a PCR-based technique was applied to evaluate genomic diversity among three strains of Acidithiobacillus thiooxidans, five strains of Acidithiobacillus ferrooxidans and one acidophilic moderate thermophile strain, using 45 random primers of five different series. More than 2200 bands were observed, with an average of 45 bands per primer. Primer OPC-3 produced the maximum number of fragments whereas minimum numbers of fragments were produced with primer OPA-5. A dendrogram was generated using cluster analysis by the unweighted pair group method of arithmetic means (UPGMA). The dendrogram showed three groups with similarity ranging from 29 to 85%. The maximum similarity (85%) was observed between the strains T.t₁ and T.t₂ of Acidithiobacillus thiooxidans.     

Cell-to-cell communication of equine uterine tube (oviduct) cells as determined by anchored cell analysis in culture

Cell culture systems using uterine tube (oviduct) epithelial cells (UTEC) have been described in several species; however, the presence and relative degrees of cell coupling occurring between these cells is unknown. This study was done to evaluate the cell-to-cell communication of cultured equine UTEC obtained from mares in the follicular phase. Monolayers of cells were grown from either primary explants or from passaged and frozen-thawed UTEC. Cell-to-cell communication via gap junctions was measured by an anchored cell analysis and sorting computerized workstation. The UTEC were labeled with carboxyfluorescein diacetate. Specific cells located in cell aggregates were photobleached, then the percentage of fluorescence recovery through gap junction mediated dye diffusion from neighboring cells was determined. Levels of cell communication and changes in intracellular calcium were also measured for UTEC before and after the addition of stallion sperm cells to the cell aggregates. The UTEC of both primary and passaged frozen-thawed cells showed cell coupling in vitro, with almost all cells having some fluorescence recovery. There was no difference in the percentage of fluorescence recovery seen between primary or passaged frozen-thawed UTEC cell groups (P = 0.24). The addition of sperm cells to the monolayer cells increased intracellular UTEC calcium levels (P < 0.001). There was also a tendency (P = 0.07) for UTEC coupling to increase in sperm cell co-culture. However, UTEC contraction and movement of the monolayer cells after co-culture with sperm cells made it difficult to accurately follow individual cells with a fluorescence-based anchored cell analysis and sorting workstation. This study indicates that equine UTEC display gap junction mediated cell communication in culture.     

Mechanism of soybean trypsin inhibitor induced polyspermy as determined by an analysis of refertilized sea urchin (Arbacia punctulata) eggs

The decreased growth rate observed in older muscle cultures has been attributed to the withdrawal of cells from the proliferative pool by fusion. The possibility was examined that this decrease reflects changes in the cell cycle as well. Before fusion, the cycle is relatively short and uniform (10.0 ± 2.7 hr) becoming greatly extended and more variable (19.2 ± 8.5 hr) in cultures undergoing fusion. Most of the increase in generation time is introduced by a long, variable G₁ phase, that phase to which fusion is restricted. These stage-specific cycle characterstics are a function of changes occurring in the medium, rather than of time in culture. Older cultures, refed fresh medium acquire the cell cycle characteristics of younger cultures, and conversely, early cultures fed medium collected from older cultures exhibit cycle measurements typical of older cultures.Although the mean G₁ time almost doubles at the time of fusion, there is no evidence that cells actually withdraw from the cycle prior to fusion. Continuous labeling before and after the initiation of fusion indicate that at all stages virtually 100% of the mononucleated cells incorporate ³H-TdR. Since fusion occurs in G₁, it seems reasonable to assume that some preparation for fusion occurs during this phase and the probability of fusion increases with protraction of G₁.     

Genetic structure within and among populations of the endangered razorback sucker (Xyrauchen texanus) as determined by analysis of microsatellites

Razorback sucker (Xyrauchen texanus) was once common and widely distributed throughout the Colorado River drainage of western North America. Water development and predation by non-native species led to significant decrease in the species’ range, and dramatic reduction in size of remaining populations. Previous analyses of mtDNA variation determined that most variation was found within locations and that haplotypes were randomly distributed relative to geography, indicating these samples represent remnants of a single, basin-wide population. In addition, both diversity and number of haplotypes declined progressively down- to upstream, consistent with geologically-recent expansion into the northern portions of the basin. Analyses of variation at 13 microsatellite loci also identified a decrease in genetic variation from down- to upstream, also consistent with the hypothesis of recent expansion. Analyses of population structure identified three distinct groups, but the majority of microsatellite variation was found within populations. Most individuals from the upper Colorado River were identified as a discrete unit. These individuals exhibited high levels of relatedness, indicating this represented an isolated group of closely related individuals. There also were significant differences between populations above and below the Grand Canyon; however, estimates of Θ were relatively low. Given nothing is known of local adaptation in this species, populations above and below the canyon should be managed as independent units; however, if numbers become too low it will be possible to translocate individuals from southern populations northward to increase levels of genetic variability and decrease relatedness within units. These results also illustrate the need for careful consideration of all available information when using molecular data in identifying units for management.     

The Q(y) absorption spectrum of the light-harvesting complex II as determined by structure-based analysis of chlorophyll macrocycle deformations

The absorption spectrum of the main antenna complex of photosystem II, LHCII, has been modeled using, as starting points, the chlorophyll (chl) atomic coordinates as obtained by the LHCII crystal analysis [Liu, Z., Yan, H., Wang, K., Kuang, T., Zhang, J., Gui, L., An, X., and Chang, W. (2004) Nature 428, 287-292] of three different trimers. The chl site Q(y) transition energies have been obtained in terms of the chl macrocycle deformations influencing the energy level of the chl frontier orbitals. Using these chl site transition energy values and the entire set of interaction energies, calculated in the ideal dipole approximation, the complete Hamiltonians for the three LHCII trimers have been written and the full set of 42 eigenstates of each LHCII trimer have been calculated. With the 42 transition energies and transition dipole strengths, either unperturbed or associated to the eigenstates, the LHCII Q(y) absorption spectrum has been calculated using a chl absorption band shape. These calculations have been performed both in vacuo and in the presence of a medium. Despite the number of approximations, a good correlation with the measured absorption spectrum of a LHCII preparation is obtained. This analysis shows that, although a substantial C3 symmetry of the LHCII trimer in terms of both chl-chl distances and interaction energies is present, a marked variation among monomer subsets of site transition energies is estimated. This leads to a C3 symmetry breaking in the unperturbed chl site transition energies set and, consequently, in the trimer eigenstates. It is also concluded that interactions among chlorophylls do not significantly modify the light absorption role of LHCII in plant leaves.     

Murine B cell leukemia (BCL1): organ distribution and kinetics of growth as determined by fluorescence analysis with an anti-idiotypic antibody.

The life history of a transplantable B cell leukemia (BCL1) that arose spontaneously in a BALB/c mouse is described. Animals bearing this tumor live from 2 to 4 months in apparently good health despite massive splenomegaly and leukemia. Antibody to the idiotype or gamma light chain of the tumor IgM was used in conjunction with the fluorescence-activated cell sorter to identify tumor cells in the BCL1-bearing mice. The results suggest that these cells multiply and differentiate in the spleen and subsequently emigrate to the blood. Tumor cells do not recirculate as evidenced by their failure to enter the thoracic duct or to infiltrate lymph nodes to a significant extent. During tumor growth, a population of T cell blasts appears that may be involved with an immune response against the tumor.     

Diversity and composition of the bacterial community of Poyang Lake (China) as determined by 16S rRNA gene sequence analysis

Poyang Lake is the largest fresh water lake in China. In this study, the objective was to examine the diversity of bacterial community in this environment. The phylogenetic composition of bacterioplankton communities from two sites and two dates (northern and southern sub-basins in October 2006 and in May 2007, respectively) in the water column of Poyang Lake were investigated by partially sequencing cloned 16SrRNA genes. Moreover, restriction fragment length polymorphism (RFLP) was applied in the 16SrRNA gene clones. In total, four clone libraries were constructed and 347 clones were screened by RFLP, yielding 153 operational taxonomic units, which mainly belonged to the proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Verrucomicrobia and Planctomycetes. Our results showed that Beta-proteobacteria was the most significant lineage, with dominant numbers of operational taxonomic units in the northern October 2006, southern October 2006 and May 2007 libraries. The highest bacterial diversity occurred in the library from the southern sub-basin in May 2007 and the lowest in the library from the northern sub-basin in May 2007. Horizontal and temporal differences associated with the concentration of total phosphorus, water temperature and pH suggested that the trophic state and the physicochemical properties of lake play key roles in sustaining bacterial community composition structure.     

The annual diet of the Roe deer (Capreolus capreolus) in the New Forest, Hampshire, as determined by rumen content analysis

By analysing rumen content samples from 105 dead specimens, the annual diet of the Roe deer ( Capreolus capreolus ) in the New Forest, Hampshire, was determined over the period from November 1970 to March 1973. Bramble and rose formed the bulk of the diet throughout the year, comprising the largest food fraction in all months except January and April. In January to March, foliage from felled conifers, Calluna , and ivy were major foods, plus lesser amounts of grasses, herbs and fungi. From May until early winter, herbs and grasses were important. New, tender, spring and summer growth from broadleaved deciduous trees, bilberry and holly was eaten in appreciable quantities. Acorns were a characteristic autumnal food. Abundant potential foods which Roe deer seldom selected included rushes, sedges, mosses, bark and dead hardwood leaves. Widespread species that Roe rarely consumed were Corsican pine, Erica tetralix, E. cinerea , gorses, bog myrtle and the grasses Agrostis setacea, Brachypodium sylvaticum, Deschampsia caespitosa and Molinia caerulea .     

The annual diet of the Fallow deer (Dama dama) in the New Forest, Hampshire, as determined by rumen content analysis

The diet of Fallow deer ( Dama dama L.) in the New Forest, Hampshire, was determined for the period November 1970 to March 1973 by analysing the rumen contents of 325 dead animals. Three main phases to the annual diet were recognized. From about March until September, grasses formed the principal food with herbs and broadleaf browse also of some importance. Acorns and mast were the characteristic food from September until about Christmas. Major winter foods included bramble, bilberry, grasses, Calluna , holly, ivy and browse from felled conifers. Fallow deer fed selectively; plants abundant in the New Forest which were seldom consumed included Erica tetralix, E. cinerea, Myricagale, Rhododendron ponticum, Ulex europea, Agrostis setacea, Deschampsia caespitosa, Motinia caerulea , most Juncaceae, Cyperaceae and Pteridium aquilinum.