Sphinganine-Analog Mycotoxins (SAMs): Chemical Structures, Bioactivities, and Genetic Controls

Sphinganine-analog mycotoxins (SAMs) including fumonisins and A. alternata f. sp. Lycopersici (AAL) toxins are a group of related mycotoxins produced by plant pathogenic fungi in the Fusarium genus and in Alternaria alternata f. sp. Lycopersici, respectively. SAMs have shown diverse cytotoxicity and phytotoxicity, causing adverse impacts on plants, animals, and humans, and are a destructive force to crop production worldwide. This review summarizes the structural diversity of SAMs and encapsulates the relationships between their structures and biological activities. The toxicity of SAMs on plants and animals is mainly attributed to their inhibitory activity against the ceramide biosynthesis enzyme, influencing the sphingolipid metabolism and causing programmed cell death. We also reviewed the detoxification methods against SAMs and how plants develop resistance to SAMs. Genetic and evolutionary analyses revealed that the FUM (fumonisins biosynthetic) gene cluster was responsible for fumonisin biosynthesis in Fusarium spp. Sequence comparisons among species within the genus Fusarium suggested that mutations and multiple horizontal gene transfers involving the FUM gene cluster were responsible for the interspecific difference in fumonisin synthesis. We finish by describing methods for monitoring and quantifying SAMs in food and agricultural products.

Interspecific Difference in Seed Dispersal Characteristics between Japanese Macaques (Macaca fuscata) and Sympatric Japanese Martens (Martes melampus)

We compared the characteristics of seeds within faeces between semi-terrestrial Japanese macaques (<i>Macaca fuscata</i>) and sympatric arboreal Japanese martens (<i>Martes melampus</i>) in Shiga Heights, central Japan. We collected faecal samples of the two mammalian species for 1 year (<i>n</i> = 229 for macaques and <i>n</i> = 22 for martens). We then compared the proportion of seed occurrence, life-form composition, number of seeds and species richness within single faecal samples, and the seed intact ratio between the two mammalian species. We detected seeds from 20 and 7 species from macaque and marten faeces, respectively. Macaque faeces contained seeds of multiple strata, while marten faeces contained no herbaceous plant seeds. Seed sizes within faeces showed no interspecific difference. For macaques, seeds were found within faecal samples collected in late spring to late fall, while for martens, seeds were found between summer and winter. The proportion of seed occurrence was greater in summer (both species) and fall (macaques), which implied that the seed dispersal roles of macaques and martens was greater in these seasons. The mean seed number (across species), intact ratio of seeds (high for both species) and seed species richness within single faecal samples of macaques and martens showed no significant differences, but for several species, martens defecated more seeds than macaques and showed higher intact ratio. Our study indicates that sympatric mammals in the temperate regions of Japan contribute differently to seed dispersal in forest ecosystems.

PSXIII-4 Species feature of morphometric parameters in poultry semen

The aim of the research was to study the specific features of morphometric parameters in rooster and guinea fowl spermatozoa. Thirty ejaculate samples from each species were investigated. A macroscopic assessment of the ejaculates obtained was carried out by volume, color and consistency. Microscopic parameters were studied using computerized sperm quality analysis systems. Diff-Quick set was used for staining sperm. Visualization of fixed preparations was performed using a Nikon Eclipse Ni-U microscope and a Nikon DS-Qi2 camera. Measurement of morphometric parameters was carried out in the program NIS-Elements BR 4.30. Evaluation of sperm morphometry was carried out according to the following indicators: total length of spermatozoa, length of head and tail, perimeter and area, head shape in indexes of ellipticity and elongation. The SPSS v.15.0 package was used for statistical analysis. To assess the statistical differences in the distributions of spermatozoa, the χ2-test was used. ANOVA was conducted to determine the effect of species. Roosters surpassed guinea fowls in ejaculate volume by 83.3% (P &lt; 0.001). Statistically significant differences were not established for sperm activity between species. The content of motile spermatozoa in the roosters ejaculate was 92.4 ± 5.3%, in guinea fowls - 88.7 ± 6.54%. The results of the morphometric parameters analysis showed that they have a specific feature. The total length of rooster spermatozoa was 90 ± 2.6 μm, which is 8 μm more than that in guinea fowl (P &lt; 0.05). The length of the sperm head in roosters was 2 μm longer than that in guinea fowls (P &lt; 0.05). The interspecific difference across the perimeters and width of the head was not statistically significant. Rooster ejaculates differed relative homogeneity compared to guinea fowl. The study results showed that morphometric parameters of poultry sperm have a specific feature. Supported by the RSF (16-16-04104).

Growth of Penaeus aztecus Ives, 1891 and Penaeus duorarum Burkenroad, 1931 in a hypersaline lagoon: relationships with environmental conditions and body size

Growth rates of the brown shrimp Penaeus aztecus Ives, 1891 and pink shrimp Penaeus duorarumBurkenroad, 1931 were estimated using length-frequency data in the hypersaline coastal lagoon, Laguna Madre of Tamaulipas, Mexico. The influence of environmental variables (salinity and temperature) and shrimp body size on the growth of both penaeid species were also evaluated. Shrimps were collected monthly from two fishing zones located at the central part of the lagoon throughout one year. A total of 4458 shrimps were analysed (69.3% P. aztecus and 30.7% P. duorarum) with total lengths (TL) ranging from 50.9 to 131.4 mm in P. aztecus and 59.7 to 134.5 mm in P. duorarum. Mean growth rate (±SD) of P. duorarum (3.10 ±1.78 mm TL per week) was slightly higher than that of P. aztecus (2.71 ±1.37 mm TL per week); however, the interspecific difference was not significant (p>0.05). Growth rates for both the penaeid shrimp species increased as water temperature increased. Additionally, a negative relationship between the growth rate and body length of shrimp was also detected suggesting that the positive effect of water temperature on the increase in shrimp length may be size-dependent.

Carbon-use strategies in stem radial growth of two oak species, one Temperate deciduous and one Mediterranean evergreen: what can be inferred from seasonal variations in the δ13C of the current year ring?

Tree ring synthesis is a key process in wood production; however, little is known of the origin and fate of the carbon involved. We used natural 13C abundance to investigate the carbon-use process for the ring development in a temperate deciduous (Quercus petraea (Matt.) Liebl.) and a Mediterranean evergreen (Quercus ilex L.) oak. The sapwood carbon reserves, phloem sucrose contents, stem respired CO2 efflux and their respective carbon isotope compositions (δ13C) were recorded over 1 year, in the native area of each species. The seasonal δ13C variation of the current year ring was determined in the total ring throughout the seasons, as well as in slices from the fully mature ring after the growth season (intra-ring pattern). Although the budburst dates of the two oaks were similar, the growth of Quercus ilex began 50 days later. Both species exhibited growth cessation during the hot and dry summer but only Q. ilex resumed in the autumn. In the deciduous oak, xylem starch storage showed clear variations during the radial growth. The intra-ring δ13C variations of the two species exhibited similar ranges, but contrasting patterns, with an early increase for Q. petraea. Comparison between δ13C of starch and total ring suggested that Q. petraea (but not Q. ilex) builds its rings using reserves during the first month of growth. Shifts in ring and soluble sugars δ13C suggested an interspecific difference in either the phloem unloading or the use of fresh assimilate inside the ring. A decrease in ring δ13C for both oaks between the end of the radial growth and the winter is attributed to a lignification of ring cell walls after stem increment. This study highlighted the differences in carbon-use during ring growth for evergreen and deciduous oaks, as well as the benefits of exploring the process using natural 13C abundance.

VERTICAL SEGREGATION IN PRISTIMANTIS SPECIES FROM A BAMBOO FOREST IN SOUTHEAST OF AMAZONIA, BRAZIL

In this work, the vertical stratification in Pristimantis species was studied in a remanescent forest dominated by bamboo in the southwest region of the Amazon. The field work was carried out between December 2012 and May 2013. The differences in height of the perch were analyzed interspecifically, and intraspecific in relation to the structure of the vegetation. A total of four species were recorded, Pristimantis fenestratus being the most abundant and occurring in all sampling units. There was significant interspecific difference in perch height, as well as between adults and juveniles. For P. fenestratus, there was no differentiation of segregation between sampling units. The structure of the vegetation did not explain the preference of heights; however, leaf litter depth influenced its vertical stratification. More data and occurrences are needed in all sampling units to infer better explanations.

A comparison of tarsal morphology and traction force in the two burying beetles Nicrophorus nepalensis and Nicrophorus vespilloides (Coleoptera, Silphidae)

Our aim was to compare friction and traction forces between two burying beetle species of the genus Nicrophorus exhibiting different attachment abilities during climbing. Specifically, the interaction of adhesive hairs and claws during attachment with respect to various surface properties was investigated by using a 2 × 3 experimental design. Traction force was measured for two different surface energies (hydrophilic vs hydrophobic) varying in roughness from smooth to micro-rough to rough. Nanotribometric tests on single legs were also performed. The external morphology of the attachment devices investigated by scanning electron microscopy suggested higher intra-specific (intersexual) than inter-specific differences. Whereas differences between the two species in traction force were high on smooth surfaces, no differences could be detected between males and females within each species. With claws intact, both species showed the highest forces on rough surfaces, although N. nepalensis with clipped claws performed best on a smooth surface. However, N. nepalensis beetles outperformed N. vespilloides, which showed no differences between smooth and rough surfaces with clipped claws. Both species demonstrated poor traction forces on micro-rough surfaces. Results concerning the impact of surface polarity were inconclusive, whereas roughness more strongly affected the attachment performance in both species. Nanotribometric analyses of the fore tarsi performed on micro-rough and rough surfaces revealed higher friction in the proximal (pull) direction compared with the distal (push) direction. In these experiments, we detected neither differences in friction performance between the two species, nor clear trends concerning the influence of surface polarity. We conclude that the investigated morphological traits are not critical for the observed interspecific difference in attachment ability on smooth surfaces. Furthermore, interspecific differences in performance are only clear on smooth surfaces and vanish on micro-rough and rough surfaces. Our results suggest that even subtle differences in the adhesion-mediating secretion in closely related species might result in qualitative performance shifts.