Exogenous spermidine effectively improves the quality of cryopreserved boar sperm

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Abstract

Boar sperm are less resistant to the dramatic environmental changes that occur during in vitro preservation. Spermidine has various physiological functions including the anti-oxidative effect. The main objective of this study was to clarify whether spermidine could protect boar sperm from the attack of reactive oxygen species under cryopreservation treatment. We set the concentrations of spermidine at 0, 2, 4, 6, and 8 mmol/L and evaluated the effects of spermidine on sperm motility, viability, malformation rates, kinetic parameters, membrane integrity, mitochondrial activity, DNA integrity, H2O2 content, malondialdehyde content, total antioxidant capacity, and antioxidant enzyme activity. Finally, the effects of spermidine on the sperm fertility were assessed by artificial insemination. The results showed that spermidine improved various physiological parameters of sperm in a dose-dependent manner. The quality and antioxidant capacity of sperm cryopreserved with 6 mmol/L spermidine were significantly less reduced (P < 0.05), and the contents of malformation rate, H2O2, and malondialdehyde content were significantly decreased (P < 0.05). The significant increase in the number of litters indicated the possibility that spermidine had important practical value in pig reproduction (P < 0.05). Therefore, the addition of appropriate concentrations of spermidine to cryopreservation extenders may effectively improve the quality of boar sperm for in vitro preservation.

Roles of circular RNAs in osteogenic/osteoclastogenic differentiation

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Roles of circular RNAs in osteogenic/osteoclastogenic differentiation

The present review provides a systematic overview of recent literature on the processes through which circRNAs regulate the dynamic balance between osteoblasts and osteoclasts that ultimately preserve bone homeostasis. It will also give insight that can shape current understanding of the pathogenesis of OP and other bone metabolic diseases to better guide diagnostic and treatment strategies for affected patients.


Abstract

The process of bone remodeling occurs and is regulated through interactions between osteoclasts, which resorb bone, and osteoblasts, which generate bone tissue. When the homeostatic balance between these two cell types is dysregulated, this can contribute to abnormal bone remodeling resulting in a loss of bone mass as is observed in osteoporosis (OP) and other forms of degenerative bone metabolic diseases. At present, details of molecular mechanism underlying the development of bone metabolic diseases such as OP remain to be elucidated. Circular RNAs (circRNAs) are small non-coding RNA molecules with a closed-loop structure that can regulate the differentiation of osteoclasts and osteoblasts. The present review provides a systematic overview of recent literature on the processes through which circRNAs regulate the dynamic balance between osteoblasts and osteoclasts that ultimately preserve bone homeostasis. It will also give insight that can shape current understanding of the pathogenesis of OP and other bone metabolic diseases to better guide diagnostic and treatment strategies for affected patients.

Standard metabolic rate differs between rainbow trout (Oncorhynchus mykiss) growth forms

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Canadian Journal of Zoology, Ahead of Print.
In variable environments, repeatable phenotypic differences between individuals provide the variation required for natural selection. The pace-of-life syndrome (POLS) provides a conceptual framework linking individual physiology and life histories to behaviour, where rapidly growing individuals demonstrate higher rates of resting or “standard” metabolic rate (SMR). If differences in SMR are consistent between fast- and slow-growing individuals, these differences may be important to capture in bioenergetic relationships used to describe their growth, energy acquisition, and allocation. We compared growth rates and SMR between a domesticated and wild strain of rainbow trout (Oncorhynchus mykiss (Walbaum, 1792)) using intermittent flow respirometry. Though mass-scaling exponents were similar between strains, mass-scaling coefficients of SMR for fast-growing rainbow trout were 1.25 times higher than those for slower growing fish. These observed differences in mass-scaling coefficients between fast- and slow-growing rainbow trout were consistent with data extracted from several other studies. Bioenergetic estimates of consumption for domestic strain fish increased as the difference in SMR and wild strain fish increased, and increased as activity level increased. Our results indicate patterns of SMR consistent with POLS, and suggest that strain-specific SMR equations may be important for applications to active populations (i.e., field observations).

Running overnight and struggling to find sea ice: long-distance movement by an Arctic fox (Vulpes lagopus) from Russia

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Canadian Journal of Zoology, Ahead of Print.
Given the scale, speed, and complexity of recent changes in the Arctic, our understanding of their multiple implications for Arctic biota is still limited. We detail for the first time in the vast Russian Arctic the long-distance movement of an Arctic fox (Vulpes lagopus (Linnaeus, 1758)) tracked with a GPS/iridium collar providing considerably high precision (several meters) and frequency of locations (every 4 h). Revealed diurnal activity patterns of the Arctic fox indicate that it ran greater distances in night hours and shortest in day hours during the most intense movement period. The movement records suggested several attempts to leave the land, as it seemed to encounter open water four times on different parts of Yamal peninsula. The Arctic fox crossed the Ob Bay towards the Gydan peninsula and satellite imagery of discontinuous ice during crossing suggested that it might have stayed on pieces of floating ice. Our observation may support evidence that a reduction in the duration and extent of sea ice could affect the ability of Arctic foxes to cover long distances and thus, in the long term, the connectivity between populations. Similar studies are needed aiming to understand movement ecology of the Arctic foxes in the changing Arctic.

Clinical utility of postablation liver tumor biopsy and possibility of gene mutation analysis

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Abstract

Aim

Radiofrequency ablation (RFA) is regarded as a first-line treatment for hepatocellular carcinoma (HCC) at an early stage. When treated with RFA, tumor biopsy may not be performed due to the risk of neoplastic seeding. We previously revealed that the risk of neoplastic seeding is significantly reduced by performing biopsies after RFA. In this study, we investigated the possibility of pathological evaluation and gene mutation analysis of post-RFA tumor specimens.

Methods

Radiofrequency ablation was undertaken on diethylnitrosamine-induced mouse liver tumor, and tumor samples with or without RFA were subjected to whole exome sequencing. Post-RFA human liver tumor specimens were used for detection of TERT promoter mutations and pathological assessment.

Results

The average somatic mutation rate, sites of mutation, and small indels and base transition patterns were comparable between the nontreated and post-RFA tumors. We identified 684 sites of nonsynonymous somatic substitutions in the nontreated tumor and 704 sites of nonsynonymous somatic substitutions in the post-RFA tumor, with approximately 85% in common. In the human post-RFA samples, the TERT promoter mutations were successfully detected in 40% of the cases. Pathological evaluation was possible with post-RFA specimens, and in one case, the diagnosis of adenocarcinoma was made.

Conclusion

Our findings suggest that post-RFA liver tumor biopsy is a useful and safe method for obtaining tumor samples that can be used for gene mutation analysis and for pathological assessment.

Rare sequence variants associated with the risk of non‐syndromic biliary atresia

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Rare sequence variants associated with the risk of non-syndromic biliary atresia

We conducted an optimal sequence kernel association test using exome data of 15 Japanese patients with non-syndromic type III biliary atresia and 509 control individuals. The results indicate that rare damaging variants in MFHAS1 may constitute a risk factor for non-syndromic biliary atresia; however, the overall contribution of monogenic variants to the disease predisposition is small.


Abstract

Aim

The etiology of non-syndromic biliary atresia (BA) remains largely unknown. In this study, we performed genome-wide screening of genes associated with the risk of non-syndromic BA.

Methods

We analyzed exome data of 15 Japanese patients with non-syndromic BA and 509 control individuals using an optimal sequence kernel association test (SKAT-O), a gene-based association study optimized for small-number subjects. Furthermore, we examined the frequencies of known BA-related single-nucleotide polymorphisms in the BA and control groups.

Results

SKAT-O showed that rare damaging variants of MFHAS1, a ubiquitously expressed gene encoding a Toll-like receptor-associated protein, were more common in the BA group than in the control group (Bonferroni corrected p-value = 0.0097). Specifically, p.Val106Gly and p.Arg556Cys significantly accumulated in the patient group. These variants resided within functionally important domains. SKAT-O excluded the presence of other genes significantly associated with the disease risk. Of 60 known BA-associated single-nucleotide polymorphisms, only eight were identified in the BA group. In particular, p.Ile3421Met of MYO15A and p.Ala421Thr of THOC2 were more common in the BA group than in the control group. However, the significance of these two variants is questionable, because MYO15A has been linked to deafness, but not to BA, and the p.Ala421Thr of THOC2 represents a relatively common single-nucleotide polymorphism in Asia.

Conclusions

The results of this study indicate that rare damaging variants in MFHAS1 may constitute a risk factor for non-syndromic BA, whereas the contribution of other monogenic variants to the disease predisposition is limited.

The short‐term feeding of low‐ and high‐histidine diets prior to market affects the muscle carnosine and anserine contents and meat quality of broilers

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Abstract

Functional dipeptides carnosine and anserine are abundant in muscle. We determined the effect of short-term dietary histidine (His) content on muscle carnosine and anserine contents and meat quality of broilers. Three groups of 28-day-old female broilers were fed diets with His contents of 67%, 100%, or 150% of requirement for 10 days before market (His contents 0.21%, 0.32%, and 0.48%, respectively). The carnosine and anserine contents of 0-h aged muscle significantly increased with dietary His content; in particular, the carnosine content was 162% higher in the His 0.48% group than in the His 0.32% group. The contents of both peptides also increased with dietary His content in 48-h aged muscle, but carnosine was not detected in 0- and 48-h aged muscle of the His 0.21% group. The drip loss, cooking loss, shear force, and pH of meat were not affected by the dietary His content. The 2-thiobarbituric acid-reactive substances contents of 24- and 48-h aged muscles were lower in the His 0.48% group than in the other groups, and the a* and b* values were lower in the His 0.21% group. These results suggest that short-term dietary His content affects imidazole dipeptide contents, antioxidative capacity, and color of broiler meat.

Nutritional quality and organic acid profile of rice bran fermented with lactic acid bacteria isolated from horse feces

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Abstract

The study aimed to determine the effect of Limosilactobacillus equigenerosi and Ligilactobacillus equi as inoculants for solid-state fermentation (SSF) in the proximate composition of nutrients and organic acid profile of rice bran (RB). The RB was treated with distilled water (DW) without inoculant (control), L. equigenerosi (T1), L. equi (T2), and L. equigenerosi and L. equi 1:1 (v:v) (T3). For the treatments, 90 mL of culture was pelleted and suspended with DW. Each treatment was replicated three times and incubated for 4, 7, and 10 days at 37°C. The crude protein, ether extract, crude ash, crude fiber, neutral detergent fiber, and acid detergent fiber were increased (P < 0.05) in fermented RB. The lactate and total organic acid produced were increased by the addition of lactic acid bacteria (LAB) (P < 0.01), and the highest concentrations were recorded in treatments containing L. equi (T2 and T3). Acetate production in T1 was highest than in control, T2, and T3 (P < 0.01). The results showed that LAB isolated from horse feces in combination with SSF can improve the quality of RB as an ingredient for animal feed based on the higher concentrations of protein, carbohydrates, minerals, and organic acids.