The effect of chitooligosaccharide supplementation on intestinal morphology,selected microbial populations,volatile fatty acid concentrations and immune gene expression in the weaned pig

An experiment (complete randomised design) was conducted to investigate the effects of supplementing different molecular weights (MW) of chitooligosaccharide (COS) on intestinal morphology, selected microbial populations, volatile fatty acid (VFA) concentrations and the immune status of the weaned pig. A total of 28 piglets (24 days of age, 9.1 kg (± s.d. 0.80) live weight) were assigned to one of four dietary treatments for 8 days and then sacrificed. The treatments were (1) control diet (0 ppm COS), (2) control diet plus 5 to 10 kDa COS, (3) control diet plus 10 to 50 kDa COS and (4) control diet plus 50 to 100 kDa COS. The COS was included in dietary treatments at a rate of 250 mg/kg. Tissue samples were taken from the duodenum, jejunum and ileum for morphological measurements. Digesta samples were taken from the proximal colon to measure lactobacilli and Escherichia coli populations and digesta samples were taken from the caecum and proximal colon for VFA analysis. Gene expression levels for specific cytokines were investigated in colonic tissue of the pig. Supplementation of different MW of COS had no significant effect on pig performance during the post-weaning period (days 0 to 8; P > 0.05). The inclusion of COS at all MW in the diet significantly reduced faecal scores compared with the control treatment (P < 0.01). Pigs fed the 10 to 50 kDa COS had a higher villous height (P < 0.05) and villous height : crypt depth ratio (P < 0.05) in the duodenum and the jejunum compared with the control treatment. Pigs fed the 5 to 10 kDa COS had a lower lactobacilli population (P < 0.05) and E. coli population (P < 0.05) in the colon compared with the control group. Pigs offered the 5 to 10 kDa COS had significantly lower levels of acetic acid and valeric acid compared with the control group (P < 0.05). The inclusion of different MW of COS had no significant effect on the expression of the cytokines tumour necrosis factor-α, Interleukin (IL)-6, IL-8 and IL-10 in the gastro-intestinal tract of the weaned pig. The current results indicate that a lower MW of 5 to 10 kDa COS possessed an antibacterial activity, while the higher MW of 10 to 50 kDa was optimum for enhancing the intestinal structure.     

Unexpected role of lipocalin-type prostaglandin D synthase in brain: Regulation of glial cell migration and morphology

Lipocalin-type prostaglandin D synthase (L-PGDS) is one of the most abundant proteins in the cerebrospinal fluid. Nevertheless, its role in the central nervous system is far from clear. Here, we present evidence that L-PGDS induces glial cell migration and morphological changes in vitro and in vivo. We also identified myristoylated alanine-rich C-kinase substrate (MARCKS), heat shock proteins and actin as L-PGDS-binding proteins, demonstrating that MARCKS/Akt/Rho/Jnk pathways are involved in the L-PGDS actions in glia. We further show that the cell migration-promoting activity of L-PGDS is independent of PGD₂ production. The results suggest a novel non-enzymatic function of L-PGDS protein in brain inflammation, and may have an impact on glial cell biology and brain pathology related with reactive gliosis. L-PGDS is a potential drug target that can be exploited for therapeutic intervention of glia-driven neuroinflammation and related diseases.     

COLEOFASCICULUS GEN. NOV. (CYANOBACTERIA): MORPHOLOGICAL AND MOLECULAR CRITERIA FOR REVISION OF THE GENUS MICROCOLEUS GOMONT1

Species currently classified within the cyanobacterial genus Microcoleus were determined to fall into two distinct clades in a 16S rDNA phylogeny, one containing taxa within the Oscillatoriaceae, the other containing taxa within the Phormidiaceae. The two lineages were confirmed in an analysis of the 16S–23S internal transcribed spacer (ITS) region sequences and secondary structures. The type species for Microcoleus is M. vaginatus Gomont, and this taxon belongs in the Oscillatoriaceae. Consequently, Microcoleus taxa in the Phormidiaceae must be placed in separate genera, and we propose the new genus Coleofasciculus to contain marine taxa currently placed in Microcoleus. The type species for Coleofasciculus is the well‐studied and widespread marine mat‐forming species Microcoleus chthonoplastes (Mert.) Zanardini ex Gomont. Other characters separating the two families include type of cell division and thylakoid structure.     

MORPHOLOGY AND MOLECULAR PHYLOGENY OF A NEW MARINE SAND‐DWELLING PROROCENTRUM SPECIES,P. TSAWWASSENENSE (DINOPHYCEAE,PROROCENTRALES), FROM BRITISH COLUMBIA,CANADA1

A new marine benthic, sand‐dwelling Prorocentrum species from the temperate region of the Pacific coast of British Columbia, Canada, is described using LM and EM and molecular phylogenetic analyses. The cells have a broad oval shape, 40.0–55.0 μm long and 30.0–47.5 μm wide, and a wide U‐shaped periflagellar area on the right thecal plate. The left thecal plate consists of a straighter apical outline in the form of a raised ridge. Five to six delicate apical spines in the center of the periflagellar area are present. The nucleus is located in the posterior region of the cell, and a conspicuous pusule is located in the anterior region of the cell. The cells have golden‐brown chloroplasts with a compound, intrachloroplast pyrenoid that lacks a starch sheath. The thecal plates are smooth with round pores of two different sizes. The larger pores are arranged in a specific pattern of radial rows that are evenly spaced around the plate periphery and of irregular rows (or double rows) that form an incomplete “V” at the apical end of the plates. Large pores are absent in the center of the left and right thecal plates. The intercalary band is striated transversely and also has faint horizontal striations. Trichocysts and two types of mucocysts are present. The molecular phylogenetic position of Prorocentrum tsawwassenense sp. nov. was inferred using SSU rDNA sequences. This new species branched with high support in a Prorocentrum clade containing both benthic and planktonic species.     

Ejaculate traits in relation to male body size in the eastern mosquitofish Gambusia holbrooki

In the present study, the correlation between sperm number, sperm quality (speed, viability, longevity and length), sperm bundles quality (size and dissolving rate) and male body size has been tested in the eastern mosquitofish Gambusia holbrooki a poecilid species characterized by coercive mating tactics where males do not possess obvious ornaments, and the body size is the key determinant of pre‐copulatory male mating success. The results do not tally with theoretical predictions. Indeed, no correlation between male body size and either sperm or sperm‐bundle traits has been found, evidencing the lack of the theoretically expected trade‐off between the investment in characters involved in mate acquisition and the investment in ejaculate quality. An explanation for the observed pattern comes from the extremely dynamic mating system of G. holbrooki, characterized by variable size‐related male mating success and strong post‐copulatory selective pressure, with all males facing a similar high level of sperm competition. In this situation, a higher investment in growth and maintenance at the expense of ejaculate quality is not expected. These results underscore the necessity to comprehend detailed information on species’ reproductive biology and reproductive environment to understand both the evolution of ejaculate characteristics and possible deviations from theoretical predictions.     

Evolutionary Morphology in Belgium

In historical literature, Edouard van Beneden (1846–1910) is mostly remembered for his cytological discoveries. Less well known, however, is that he also introduced evolutionary morphology – and indeed evolutionary theory as such – in the Belgian academic world. The introduction of this research programme cannot be understood without taking both the international and the national context into account. It was clearly the German example of the Jena University that inspired van Beneden in his research interests. The actual launch of evolutionary morphology at his University of Liège was, however, also connected with the dynamic of Belgian university reforms and the local rationale of creating a research “school.” Thanks to his networks, his mastering of the rhetoric of the “new” biology, his low ideological profile and his capitalising on the new academic élan in late-19th century Belgium, van Beneden managed to turn his programme into a local success from the 1870s onwards. Two decades later, however, the conceptual underpinnings of evolutionary morphology came under attack and the “Van Beneden School” lost much of its vitality. Despite this, van Beneden’s evolutionary morphology was prototypical for the research that was to come. He was one of the first scientific heavyweights in Belgium to turn the university laboratory into a centre of scientific practice and the hub of a research school.     

Functional and ecological relevance of intraspecific variation in body size and shape in the lizard Podarcis melisellensis (Lacertidae)

Within populations, individual animals may vary considerably in morphology and ecology. The degree to which variation in morphology is related to ecological variation within a population remains largely unexplored. We investigated whether variation in body size and shape among sexes and age classes of the lizard Podarcis melisellensis translates in differential whole-animal performance (sprint speed, bite force), escape and prey attack behaviour in the field, microhabitat use and diet. Male and female adult lizards differed significantly in body size and head and limb proportions. These morphological differences were reflected in differences in bite strength, but not in sprint speed. Accordingly, field measurements of escape behaviour and prey attack speed did not differ between the sexes, but males ate larger, harder and faster prey than females. In addition to differences in body size, juveniles diverged from adults in relative limb and head dimensions. These shape differences may explain the relatively high sprint and bite capacities of juvenile lizards. Ontogenetic variation in morphology and performance is strongly reflected in the behaviour and ecology in the field, with juveniles differing from adults in aspects of their microhabitat use, escape behaviour and diet.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 251–264.     

Evolutionary changes in craniomandibular shape in the great cats (Neofelis Griffith and Panthera Oken)

Evolutionary shape changes in skull and mandibular anatomy was analysed in 223 specimens of pantherine felids (Neofelis nebulosa, Panthera leo, Panthera onca, Panthera pardus, Panthera tigris, Panthera uncia) compared to a small‐felid outgroup, consisting of 86 specimens of nine different species, using digital surface morphometry on 25 (skull) and 17 (mandible) landmarks. Shape evolution in the pantherine species is complex and nonlinear, and involves both large‐scale and small‐scale shape changes. Shape changes frequently differ among the ingroup species, but the four large Panthera species (leo, onca, pardus, tigris) bear some resemblance to each other. The leopard and jaguar bear the closest resemblance to each other, and several shape changes are common to the lion and tiger, but have probably evolved convergently as a result of large size. The lion has undergone the largest and most numerous shape changes from a small‐felid outgroup. Certain shape changes in the skull and, in some respects, the mandible of the clouded leopard bear resemblance to those in the four large Panthera species. The snow leopard is often regarded as the most primitive of the extant Panthera, and skull and mandibular shape changes often diverge markedly from those observed in the other five ingroup taxa; its overall skull shape is rather similar to the small‐felid outgroup. This indicates that the shape changes in the clouded leopard are convergent with those of the four large Panthera species. Landmark integration showed no significant correlation with molecular phylogeny, chiefly owing to the snow leopard being placed among the four large Panthera species. A traditional phylogenetic topology with the snow leopard as the basal‐most species of Panthera yielded a weak but nonsignificant phylogenetic signal. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 766–778.     

Morphological and mitochondrial DNA analyses indicate the presence of a hybrid zone between two species of leaf beetle (Coleoptera; Chrysomelidae) in Southern Spain

The present study reports a case where the survey of morphological and mitochondrial DNA variation among populations of a species complex of leaf beetle, the Gonioctena variabilis complex, has lead to the identification of a hybrid zone between two species of the complex in Southern Spain. The complex is divided into four species distributed around the western Mediterranean region. The four species, G. variabilis, Gonioctena aegrota, Gonioctena gobanzi, and Gonioctena pseudogobanzi, are traditionally determined by differences in the morphology of the male genitalia (aedeagus). To gain insight into the history of the speciation process within this species complex, we sampled populations in Portugal, Spain, Southern France, and Northern Italy. We sequenced a portion of the mitochondrial control region of each individual collected. A haplotype network of these sequences was found to comprise four distinct groups of sequence types, separated by a relatively large number of mutations. Moreover, in most of the samples for which morphological and molecular variation is available, there is a one‐to‐one correspondence between haplotype group, defined by mitochondrial sequence variation, and morphological groups defined on the basis of the aedeagus, showing evidence of four historically independent evolutionary units. This supports the use of the aedeagus morphology as a taxonomically informative trait in this species complex and a recent taxonomic revision upgrading four formerly subspecies, corresponding to the evolutionary units identified in the present study, to species status. However, some of the individuals from our samples in Southern Spain, morphologically identified as G. aegrota, were found to possess mitochondrial sequences typical of G. pseudogobanzi. The opposite case was also found. This suggests the presence of a zone of contact and hybridization between G. aegrota and G. pseudogobanzi. The location of this hybrid zone appears to be unusual. We identify historical scenarios that may explain our observations. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 94 , 105–114.     

The evolution of male genitalia: functional integration of genital sclerites in the dung beetle Onthophagus taurus

It is now widely recognized that sexual selection has been important in the rapid and divergent evolution of male genital morphology. However, distinguishing among putative mechanisms of sexual selection acting on male genital morphology represents a considerable challenge. Although there is growing evidence that variation in the size and/or shape of male genital structures can determine a male's success in gaining fertilizations, our knowledge of the functional morphology of male genitalia remains limited. Here we examine the functional morphology of genital sclerites that are known to influence paternity in the dung beetle Onthophagus taurus . We show that three of the sclerites form a functionally integrated unit that generates the tubular-shaped spermatophore and delivers its opening to the female's spermathecal duct. A fourth sclerite acts as a holdfast device during copulation. Our observations shed light on the mechanism by which these sclerites influence a male's paternity, and their patterns of phenotypic and genetic (co)variation.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 93 , 257–266.