Genetic polymorphisms at candidate genes affecting fat content and fatty acid composition in Modicana cows: effects on milk production traits in different feeding systems.

Feeding greatly affects milk yield and composition. The research is highlighting the potential of genetic polymorphism at some loci to affect milk yield and quality traits. These loci can be up/down regulated depending on the production environment; therefore, we hypothesized that milk yield and composition could differ when cows with different genotype at SCD, DGAT1 and ABCG2 loci are reared in different feeding systems. The polymorphisms of SCD, DGAT1 and ABCG2 genes were investigated in Modicana breed. In all, three polymorphic sites, responsible for the genetic variation of quantitative trait loci and therefore defined quantitative trait nucleotides, were genotyped: the transition g.10329Cgt;T in 5th exon determines a substitution p.A293V in the SCD, the dinucleotide mutation g.10433-10434AAgt;GC in 8th exon responsible for p.K232A substitution in the DGAT1 and the transition g.62569Agt;C in the 14th exon responsible for p.Y581S substitution in the ABCG2 gene. In the sample of 165 Modicana cows, SCD and DGAT1 genes resulted polymorphic; the alleles g.10329T and g.10433-10434GC were the most frequent in SCD and DGAT1 (0.73 and 0.91) respectively, whereas ABCG2 locus was monomorphic for allele A (p.581Y). Sequencing analysis was carried out on 14 samples with different genotypes to confirm the results of the PCR-RFLP protocols. Based on the genotypes at SCD locus, 47 Modicana cows were selected for the nutritional trial: 24 cows in a semi-intensive farm, with 2 h/day grazing on natural pasture, and 23 cows in an extensive farm, with 8 h/day grazing on natural pasture. Monthly, milk yield and composition were evaluated and individual milk samples were analyzed for fatty acids composition by gas chromatography. No differences in milk yield, fat, protein, lactose, casein and urea were associated to SCD genotype. Feeding systems affected milk yield and composition. No significant genotype×feeding system interaction was observed for milk yield and composition. Fatty acids composition was significantly affected only by the feeding system. Significant interactions were found between SCD genotype and feeding system for six fatty acids: 4:0, 6:0, 8:0, 10:0, 12:0 and t11 18:1. We concluded that the feeding system was the factor that mostly affected milk production and composition; moreover, our results do not confirm what reported in literature as regard the effect of the SCD polymorphism on milk fatty acid composition. The high amount of pasture seemed to have resized the SCD polymorphism effects because of the different fatty acids composition of the diet

Preliminary genetic evidence of two different populations of Opisthorchis viverrini in Lao PDR

Opisthorchis viverrini is a major public health concern in Southeast Asia. Various reports have suggested that this parasite may represent a species complex, with genetic structure in the region perhaps being dictated by geographical factors and different species of intermediate hosts. We used four microsatellite loci to analyze O. viverrini adult worms originating from six species of cyprinid fish in Thailand and Lao PDR. Two distinct O. viverrini populations were observed. In Ban Phai, Thailand, only one subgroup occurred, hosted by two different fish species. Both subgroups occurred in fish from That Luang, Lao PDR, but were represented to very different degrees among the fish hosts there. Our data suggest that, although geographical separation is more important than fish host specificity in influencing genetic structure, it is possible that two species of Opisthorchis, with little interbreeding, are present near Vientiane in Lao PDR

Variation of serum hyaluronan with activity in individuals with knee osteoarthritis

PURPOSE: Serum hyaluronan (HA) was evaluated for diurnal variation in participants with osteoarthritis (OA) of the knee. METHODS: Twenty participants with radiographic OA of at least one knee were admitted overnight to the General Clinical Research Center for serial serum sampling. Serum was obtained between 6:00 p.m. and 8:00 p.m. on Day 1 (T3) after a day of normal activity. During the night of bed rest, participants remained supine for a minimum of 5 h between the hours of 3:00 a.m. and 8:00 a.m. Blood was drawn prior to arising from bed (T0), and 1h (T1) and 4 h (T2) after arising and performing usual morning activities, including eating breakfast. During the morning, participants were encouraged to remain physically active and were not permitted to sit for more than 30 min at a time. Serum HA was measured by enzyme-linked immunosorbent assay. Results were analyzed using non-parametric Freidman's test with Dunn's post-hoc Multiple Comparison test. RESULTS: Serum levels of HA increased significantly from T0 to T1 (P < 0.01). There were no other significant changes in serum HA levels observed between any of the other time points. CONCLUSIONS: Although a rise in serum HA with activity and eating has been demonstrated previously in individuals with rheumatoid arthritis, this is the first study to demonstrate a similar rise in individuals with OA. These results suggest that serum sampling for HA in OA clinical trials should be performed more than 1h after arising in the morning and at least 1h after breaking an overnight fast

The intestinal expulsion of the roundworm Ascaris suum is associated with eosinophils, intra-epithelial T cells and decreased intestinal transit time

Ascaris lumbricoides remains the most common endoparasite in humans, yet there is still very little information available about the immunological principles of protection, especially those directed against larval stages. Due to the natural host-parasite relationship, pigs infected with A. suum make an excellent model to study the mechanisms of protection against this nematode. In pigs, a self-cure reaction eliminates most larvae from the small intestine between 14 and 21 days post infection. In this study, we investigated the mucosal immune response leading to the expulsion of A. suum and the contribution of the hepato-tracheal migration. Self-cure was independent of previous passage through the liver or lungs, as infection with lung stage larvae did not impair self-cure. When animals were infected with 14-day-old intestinal larvae, the larvae were being driven distally in the small intestine around 7 days post infection but by 18 days post infection they re-inhabited the proximal part of the small intestine, indicating that more developed larvae can counter the expulsion mechanism. Self-cure was consistently associated with eosinophilia and intra-epithelial T cells in the jejunum. Furthermore, we identified increased gut movement as a possible mechanism of self-cure as the small intestinal transit time was markedly decreased at the time of expulsion of the worms. Taken together, these results shed new light on the mechanisms of self-cure that occur during A. suum infections

Hybridization in parasites: consequences for adaptive evolution, pathogenesis and public health in a changing world

[No abstract available

Molecular approaches to trematode systematics: 'best practice' and implications for future study

To date, morphological analysis has been the cornerstone to trematode systematics. However, since the late-1980s we have seen an increased integration of genetic data to overcome problems encountered when morphological data are considered in isolation. Here, we provide advice regarding the ‘best molecular practice’ for trematode taxonomy and systematic studies, in an attempt to help unify the field and provide a solid foundation to underpin future work. Emphasis is placed on defining the study goals and recommendations are made regarding sample preservation, extraction methods, and the submission of molecular vouchers. We advocate generating sequence data from all parasite species/host species/geographic location combinations and stress the importance of selecting two independently evolving loci (one ribosomal and one mitochondrial marker). We recommend that loci should be chosen to provide genetic variation suitable to address the question at hand and for which sufficient ‘useful’ comparative sequence data already exist. Quality control of the molecular data via using proof-reading Taq polymerase, sequencing PCR amplicons using both forward and reverse primers, ensuring that a minimum of 85% overlap exists when constructing consensus sequences, and checking electropherograms by eye is stressed. We advise that all genetic results are best interpreted using a holistic biological approach, which considers morphology, host identity, collection locality, and ecology. Finally, we consider what advances next-generation sequencing holds for trematode taxonomy and systematics

A Digenean Metacercaria (Apophallus sp.) and a Myxozoan (Myxobolus sp.) Associated with Vertebral Deformities in Cyprinid Fishes from the Willamette River, Oregon

A high prevalence of vertebral deformities has been observed in various fishes, especially cyprinids, from certain regions of the Willamette River for many years. One proposed source of these deformities is exposure to toxicants. Histological evaluation of affected chiselmouth Acrocheilus alutaceus revealed that all lesions associated with vertebrae were associated with metacercariae of digenean trematodes. Approximately half of the northern pikeminnow Ptychocheilus oregonensis had infections in which metacercariae were associated with these lesions. Metacercariae were also associated with vertebral lesions in three of four affected peamouth Mylocheilus caurinus. Many metacercariae that were present within the vertebral bodies were associated with bony dysplasia and bony proliferation in all three species. We also evaluated the association of the metacercariae with the vertebral deformities, using intact fish that had been cleared with trypsin. Fish from the affected regions had a much higher prevalence of metacercariae and deformities and a greater abundance of metacercariae than those in the reference site. Chiselmouths had more deformities and metacercariae than northern pikeminnow. In all fish species, 77% of deformities were directly associated with metacercariae; in chiselmouths, about 95% of the deformities exhibited this relationship. Two types of metacercariae were identified in affected fish: Apophallus sp. (Heterophyidae) and a neascus type (Strigeidida). The Apophallus sp. appeared to be more closely associated with the skeleton deformities. A Myxobolus sp. morphologically similar to M. cyprini was also associated with the vertebral lesions in about 50% of the northern pikeminnow and 5% of the chiselmouths. Intact plasmodia were found in somatic muscle, and lesions containing free spores were often located at bone surfaces. This survey demonstrates that metacercariae (probably Apophallus sp.) and a Myxobolus sp. are major causes of the vertebral deformities seen in cyprinid fishes from certain regions of the Willamette River.This is the publisher’s final pdf. The published article is copyrighted by the American Fisheries Society and can be found at: http://www.tandfonline.com/toc/uahh20/current#.UgvTRHfAF8F

Sex-Biased Expression of MicroRNAs in Schistosoma mansoni

Schistosomiasis is an important neglected tropical disease caused by digenean helminth parasites of the genus Schistosoma. Schistosomes are unusual in that they are dioecious and the adult worms live in the blood system. MicroRNAs play crucial roles during gene regulation and are likely to be important in sex differentiation in dioecious species. Here we characterize 112 microRNAs from adult Schistosoma mansoni individuals, including 84 novel microRNA families, and investigate the expression pattern in different sexes. By deep sequencing, we measured the relative expression levels of conserved and newly identified microRNAs between male and female samples. We observed that 13 microRNAs exhibited sex-biased expression, 10 of which are more abundant in females than in males. Sex chromosomes showed a paucity of female-biased genes, as predicted by theoretical evolutionary models. We propose that the recent emergence of separate sexes in Schistosoma had an effect on the chromosomal distribution and evolution of microRNAs, and that microRNAs are likely to participate in the sex differentiation/maintenance process