The diversity and role of the gut microbiota of insects is a rapidly growing field of entomology, primarily fueled by new metagenomic techniques. Whereas endosymbionts in the guts of xylophagous or herbivorous insects are well studied, the microbiomes in moss-eating (bryophagous) insects remain uncharacterized. Using the Illumina MiSeq platform, we determined the composition of microbiomes in the gut, abdomen and on the body surface of two bryophagous species: Simplocaria semistriata (Fabricius, 1794) and Curimopsis paleata (Erichson, 1846) (Coleoptera: Byrrhidae). Gut microbiomes differed substantially from abdominal microbiomes in the same individuals, which indicates the need to separate them during dissection. Microbiomes in the gut and abdomen differed markedly from surface microbial assemblages. Gut microbiomes in bryophages had the highest MOTU richness, diversity and relative rarity. The eudominant bacteria in the guts and abdomens of bryophages were Novosphingobium, Bradyrhizobium, Ralstonia and Caulobacter, which are responsible for the detoxification of secondary metabolites or nitrogen fixation. These are less common in the surface samples and, therefore, likely to be associated with the specific ability of bryophages to feed on mosses.
The objective of the current study is to present data on the
splitting of skeletal muscle fibers in C57BL/6NCrl mice. Skeletal
muscles (m. rectus femoris (m. quadriceps femoris)) from 500
(250 ♀ and 250 ♂) C57BL/6NCrl mice in the 16th week of life
were sampled during autopsy and afterwards standardly
histologically processed. Results show spontaneous skeletal
muscle fiber splitting which is followed by skeletal muscle fiber
regeneration. One solitary skeletal muscle fiber is split, or is in
contact with few localized splitting skeletal muscle fibers. Part of
the split skeletal muscular fiber is phagocytosed, but the
remaining skeletal muscular fiber splits are merged into one
regenerating skeletal muscle fiber. Nuclei move from the
periphery to the regenerating skeletal muscle fiber center during
this process. No differences were observed between female and
male mice and the morphometry results document <1 % skeletal
muscle fiber splitting. If skeletal muscular fibers splitting occurs
5 %> of all skeletal muscular fibers, it is suggested to describe
and calculate this in the final histopathological report.
A proper understanding of tissue and cell structure is of great importance for correct biological inferences, and particularly so in organisms used as research models. Nothobranchius spp. are short-lived freshwater fish species which are promising model organisms for toxicology, evolutionary ecology, aging and regeneration research. Nevertheless, studies examining Nothobranchius histology have focused exclusively on a few specific organs and associated functional impairments, and there is a lack of reference material on the natural state and appearance of tissue structure. Here we present a detailed histological map of the major body organ systems, which was built from 300 Nothobranchius spp. specimens. This overview offers baseline material for comparative histological studies and provides insights into functional and anatomical aspects of organs related to the unique life cycle of Nothobranchius spp.
During an ongoing systematic survey on species diversity of myxozoans parasitising allogynogenetic gibel carp Carassius auratus gibelio (Bloch) in China, plasmodia were detected in the fins, lip, jaw, gill chamber, gill arches, operculum and oral cavity of infected fish. Combining the morphological and molecular data, the present species was identified as Myxobolus turpisrotundus Zhang, Wang, Li et Gong, 2010. Histopathological examination revealed that despite infecting different organs, M. turpisrotundus always occurred in dermis, demonstrating its affinity to this tissue. Histopathological effect of M. turpisrotundus on the host is relatively mild except parasites in the gill arches producing compression of the adipose tissue and heavy adductor muscles deformation with lymphohistiocytic infiltrates. In addition, the plasmodia in different sites were with the same complex structure arrangement: cup-like cells with unknown derivation, a thin collagenous fibril layer, areolar connective tissue, basement membrane and host epithelial cell. Ultrastructural analysis showed that the parasite has monosporic pansporoblast and sporogenesis followed the usual pattern of most of the myxosporeans., Qingxiang Guo, Yanhua Zhai, Zemao Gu, Yang Liu., and Obsahuje bibliografii
In the parthenogenetic monogeneans of the genus Gyrodactylus Nordmann, 1832, the genetic diversity within or between hosts is determined by the relative roles of lateral transmission and clonal propagation. Clonality and limited transmission lead to high-amplitude metapopulation dynamics and strong genetic drift. In Baltic populations of the three-spined stickleback Gasterosteus aculeatus Linnaeus, the local mitochondrial diversity of Gyrodactylus arcuatus Bychowsky, 1933 is very high, and spatial differentiation weak. To understand the transmission dynamics in a single location, the transmission of the parasite from adults to next generation sticklebacks was investigated in a northern Baltic brackish water location. By sequencing 777 nt of cox1, as many as 38 separate mitochondrial haplotypes were identified. In August, the intensity of gyrodactylid infection on adult hosts was high, the haplotype diversity (h) was extreme and differentiation between fish was negligible (total h = 0.926, mean h = 0.938). In October, only 46% of the juvenile sticklebacks carried G. arcuatus. The number of parasites per young fish followed a Poisson distribution 0.92 ± 1.04 (mean ± SD) on October 2, and was clearly overdispersed 2.38 ± 5.00 on October 25. The total haplotype diversity of parasites on juveniles was nearly as high as in adults (h = 0.916), but the mean per fish was only h = 0.364 (FST = 0.60), due to low intensity of infection and rapid clonal propagation of early arrivals. The initial first come first served advantage of the first gyrodactylid colonisers will be lost during the host adulthood via continuous transmission. Nesting and polygamy are suggested as factors maintaining the high genetic diversity of the parasite population. The transmission dynamics and, consequently, the population structure of Baltic G. arcuatus is fundamentally different from that of G. salaris Malmberg, 1957, on the Baltic salmon Salmo salar Linnaeus., Jaakko Lumme, Marek S. Ziętara., and Obsahuje bibliografii
We deployed branch traps in an ash (Fraxinus) plantation to investigate how Agrilus planipennis behavior is associated with Fraxinus pennsylvanica condition and dispersal patterns. Data were collected from traps with or without the presence of beetle visual decoys, and from a yearly survey of exit holes. The traps were placed on trees that were either clearly declining, with most foliage arising from epicormic sprouting, or on apparently healthy trees, with little evidence of damage or decline. We calculated correlations of exit holes among neighboring tree rings and also between exit holes and male trap captures. The damaged trees the traps were hung upon had more cumulative exit holes observed than the corresponding healthy trees. However, there was otherwise no evidence that the experiment was biased by differences in exit hole patterns of the surrounding trees. Male captures were greater on decoy-baited traps than controls and this decoy effect was most clearly apparent late in the season when traps were placed on healthy trees. There were also patterns of correlations between male captures and exit hole numbers that may be indicative of short-range mate finding-and dispersal behaviors. Female captures were sparser, but were positively affected by decoys on healthy and declining trees early in the season. Thus, the results suggest that the placement of such traps on healthier trees will maximize detection, and the branch traps also show promise for further use in dispersal studies., Michael J. Domingue, Jennifer Berkebile, Kim Steiner, Loyal P. Hall, Kevin R. Cloonan, David Lance, Thomas C. Baker., and Obsahuje bibliografii
Aphis fabae and Myzus persicae (Hemiptera: Aphididae) are insect pests that damage sugar beet and bean crops. Both are responsible for losses in yield and transmission of viral diseases, and may be present on the same host at the same time. Three parasitoid species, Aphidius colemani, Lysiphlebus testaceipes and Lysiphlebus fabarum (Hymenoptera: Braconidae: Aphidiinae) have the potential to be used as biological control agents against at least one of these species of aphids. As a first step prior to the implementation of a biological control program, our aim was to understand the host selection behaviour of the parasitoids, particularly when both aphids are present. We recorded the host acceptance (number of insertions of the ovipositor / number of antennal contacts), suitability (number of mummies / the number of insertions of the ovipositor) and emergence (number of adults emerging from mummies) of these three aphid parasitoids when parasitizing the two aphids. We also analyzed the effect of the host plant on the host preference of the parasitoid. Females of each parasitoid species (n = 15) were exposed to 20 aphids of A. fabae or M. persicae, or a mixture of these two species of aphids, for 15 min, on a leaf disc of each of the two host plants, sugar beet and bean. Higher host acceptance and suitability were recorded for A. colemani attacking both species of aphid: A. fabae (43 and 46%) and M. persicae (43 and 46%) on beet and bean plants respectively, compared to L. testaceipes and L. fabarum. L. testaceipes and L. fabarum showed a clear preference for A. fabae. L. fabarum accepted M. persicae on both plants only when it was mixed with A. fabae, probably due to a confusion effect. We found that the host plant played a significant role in host acceptance, host suitability. We conclude that A. colemani is the better of the three parasitoids studied for the biological control in bean, and particularly, sugar beet crops. and Loulou Albittar, Mohannad Ismail, Claude Bragard, Thierry Hance.
The morphology, physiology, behaviour and ecology of spiralling whitefly, Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae) on different host plants differ greatly. The genetic differences between the A. dispersus populations on 17 host plants were evaluated in the current study. Microsatellite markers were used to identify the presence of host-related genetic variation among A. dispersus populations. Our research clearly shows that there is a significant amount of genetic divergence among the A. dispersus populations on 17 host plants in India. The spiralling whitefly on acalypha and calotropis were genetically more distinct than whiteflies on other host plants. Various population genetic parameters, like heterozygosity, Nei's genetic distance, fixation indices (FST), source of genetic variation in AMOVA, etc. indicate that populations of spiralling whiteflies differ greatly genetically, probably because the spiralling whitefly populations on the Indian sub-continent came from multiple sources. The results of this study have implications for the quarantine protection strategy against this invasive pest.
Myxobolus filamentum sp. n. was found infecting gill filaments of three of 39 Brycon orthotaenia Günther specimens examined (8%), which were taken from the river São Francisco in Minas Gerais state, Brazil. Plasmodia of the parasite were white and long, measuring 5 mm in lenght. Mature spores of M. filamentum sp. n. were oval from the frontal view and biconvex from the lateral view, measuring 7.5-9.7 µm (9.0 ± 0.3 µm) in length and 5.2-7.3 µm (6.2 ± 0.4 µm) in width. The polar capsules were elongated and equal in size, measuring 3.8-5.5 µm (4.7 ± 0.3 µm) in length and 1.3-2.2 µm (1.7 ± 0.1 µm) in width. The development of the parasite led to compression of the adjacent tissues and inflammatory infiltrate with granulocytic cells. Ultrastructural observation revealed that the plasmodia were delimited by two membranes, which had numerous and extensive pinocytotic channels extending into the wide ectoplasm zone. The plasmodial wall exhibited abundant villi-like projections and a thin layer of granular material prevented direct contact between the plasmodial wall and the host tissue. Phylogenetic analysis, based on 18S rDNA, showed M. filamentum sp. n. as a sister species of Myxobolus oliveirai Milanin, Eiras, Arana, Maia, Alves, Silva, Carriero, Ceccarelli et Adriano, 2010, a parasite of other fish species of the genus Brycon Müller et Troschel from South America., Juliana Naldoni, Suellen A. Zatti, Kassia R.H. Capodifoglio, Tiago Milanin, Antônio A.M. Maia, Marcia R.M. Silva, Edson A. Adriano., and Obsahuje bibliografii
Preferences of young caterpillars of three species of Pieris (P. rapae crucivora Boisduval, P. melete Ménétriès, and P. napi japonica Shirôzu) (Lepidoptera: Pieridae) for the upper and lower surfaces of the leaves of their host plants (Brassicaceae) were investigated in the laboratory. On horseradish Armoracia rusticana Gaertn. Mey. et Scherb., which was provided as a common food for three species, second and third instar larvae of the respective species preferred the lower to the upper surface of horizontally placed leaves, irrespective of whether they hatched on the upper or lower surface. First instar larvae seemed to remain on the surface on which they hatched. However, first instar larvae of P. melete on Rorippa indica (L.), a natural food of P. melete in the field, and first instar larvae of P. napi japonica on Arabis flagellosa Miq., a natural food of P. napi japonica, preferred the lower to the upper surface, just as second and third instar larvae did. To elucidate the effects of leaf-surface preference, the percentage parasitism of P. rapae crucivora on Arm. rusticana and Ara. flagellosa by the parasitoid Cotesia glomerata (L.) (Hymenoptera: Braconidae) was investigated. On Arm. rusticana, the percentage parasitism of the larvae on the upper surface was higher than that of larvae on the lower surface. On Ara. flagellosa, however, percentages parasitism were nearly equal on both surfaces. Leaf-surface preference by the larvae of Pieris is discussed in terms of avoidance of parasitism by the parasitoid C. glomerata.