Evolution of bitter receptor genes and ontogenetic dietary shift in a frog.

Vertebrate Tas2r taste receptors detect bitter compounds that are potentially poisonous. Previous studies found substantial variation in the number of Tas2r genes across vertebrates, with some frog species carrying the largest number. Peculiar among vertebrates, frogs undergo metamorphosis, often associated with a dietary shift between tadpoles and adults. A possible explanation for the large size of frog Tas2r families could be that distinct sets of Tas2r genes are required for tadpoles and adults, suggesting differential expression of Tas2r genes between tadpoles and adults. To test this hypothesis, we first examined 20 amphibian genomes and found that amphibians generally possess more Tas2r genes than do other vertebrate clades. We next focused on the American bullfrog (Lithobates catesbeianus) to examine the expression of its Tas2r genes in herbivorous tadpoles and insectivorous adult frogs. We report that close to one fifth of its 180 Tas2r genes are differentially expressed (22 genes enriched in adults and 11 in tadpoles). Tuning properties were determined for a subset of differentially expressed genes by a cell-based functional assay, with the adult-enriched Tas2r gene set covering a larger range of ligands compared to the tadpole-enriched subset. These results suggest a role of Tas2r genes in the ontogenetic dietary shift of frogs and potentially initiate a new avenue of ontogenetic analysis of diet-related genes in the animal kingdom.

Pulse Compression Shape-Based ADC/DAC Chain Synchronization Measurement Algorithm with Sub-Sampling Resolution.

In this article, we address the problem of synchronizing multiple analog-to-digital converter (ADC) and digital-to-analog converter (DAC) chains in a multi-channel system, which is constrained by the sampling frequency and inconsistencies among the components during system integration. To evaluate and compensate for the synchronization differences, we propose a pulse compression shape-based algorithm to measure the entire delay parameter of the ADC/DAC chain, which achieves sub-sampling resolution by mapping the shape of the discrete pulse compression peak to the signal propagation delay. Moreover, owing to the matched filtering in the pulse compression process, the algorithm exhibits good noise performance and is suitable for wireless scenarios. Experiments verified that the algorithm can achieve precise measurements with sub-sampling resolution in scenarios where the signal-to-noise ratio (SNR) is greater than -10 dB.

Characterization of complete mitochondrial genome of the common tiger, Danaus genutia (Lepidoptera: Nymphalidae: Danainae) and phylogenetic implications within the subfamily Danainae.

Nymphalidae is the most diverse butterfly family worldwide, with more than 6000 species, whereas the mitogenomic data of nymphalid species, especially the subfamily Danainae, is still lacking for more comprehensive systematic studies. To this contribution, the complete mitogenome of Danaus genutia (Lepidoptera: Nymphalidae: Danainae) was determined via sequencing and annotating. The mitogenome in total consists of 15,255 base pairs (bp), containing 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a 440-bp noncoding A+T-rich region. Furthermore, phylogeny of the subfamily Danainae was reconstructed applying maximum likelihood and Bayesian inference on the basis of the mitogenomic data sets. Combined with our analysis and previous studies, the genus-level phylogenetic relationships within the subfamily Danainae are ((Tirumala + Danaus) + ((Idea + Euploea) + (Ideopsis + Parantica))). This study offers molecular information and provides a new perspective for phylogenetic research within the subfamily Danainae.

A maternal high-fat/low-fiber diet impairs glucose tolerance and induces the formation of glycolytic muscle fibers in neonatal offspring.

PURPOSE: In our previous study, the maternal high-fat/low-fiber (HF-LF) diet was suggested to induce metabolic disorders and placental dysfunction of the dam, but the effects of this diet on glucose metabolism of neonatal offspring remain largely unknown. Here, a neonatal pig model was used to evaluate the effects of maternal HF-LF diet during pregnancy on glucose tolerance, transition of skeletal muscle fiber types, and mitochondrial function in offspring. METHODS: A total of 66 pregnant gilts (Guangdong Small-ear Spotted pig) at day 60 of gestation were randomly divided into two groups: control group (CON group; 2.86% crude fat, 9.37% crude fiber), and high-fat/low-fiber diet group (HF-LF group; 5.99% crude fat, 4.13% crude fiber). RESULTS: The maternal HF-LF diet was shown to impair the glucose tolerance of neonatal offspring, downregulate the protein level of slow-twitch fiber myosin heavy chain I (MyHC I), and upregulate the protein levels of fast-twitch fiber myosin heavy chain IIb (MyHC IIb) and IIx (MyHC IIx) in soleus muscle. Additionally, compared with the CON group, the HF-LF offspring showed inhibition of insulin signaling pathway and decrease in mitochondrial function in liver and soleus muscle. CONCLUSION: Maternal HF-LF diet during pregnancy impairs glucose tolerance, induces the formation of glycolytic muscle fibers, and decreases the hepatic and muscular mitochondrial function in neonatal piglets.

Role of mitochondrial reactive oxygen species in chemically-induced ferroptosis.

Ferroptosis is a form of iron-dependent regulated cell death which is different from apoptosis. Chemically-induced ferroptosis is characterized by an accumulation of lipid reactive oxygen species (ROS) in the cells. A number of earlier studies have suggested the involvement of mitochondrial ROS in ferroptosis, and the present study seeks to further investigate the role of mitochondrial ROS in the induction of chemically-induced ferroptotic cell death. We find that during erastin-induced, glutathione depletion-associated ferroptosis, mitochondrial ROS accumulation is an important late event, which likely is involved in the final execution of ferroptotic cell death. The mitochondrion-originated ROS is found to accumulate in large quantities inside the nuclei during the late phases of erastin-induced ferroptosis. Completion of the late-phase accumulation of mitochondrion-produced ROS inside the nucleus of a cell likely marks an irreversible point in the cell death process. Similarly, accumulation of large amounts of mitochondrion-produced ROS inside the nucleus is also observed in the late phases of RSL3-induced ferroptosis. The results of this study indicate that the mitochondrial ROS play an important role in the final steps of both erastin- and RSL3-induced ferroptotic cell death.

A molecular phylogeny for all 21 families within Chiroptera (bats).

Bats, members of the Chiroptera order, rank as the second most diverse group among mammals. Recent molecular systematic studies on bats have successfully classified 21 families within two suborders: Yinpterochiroptera and Yangochiroptera. Nevertheless, the phylogeny within these 21 families has remained a subject of controversy. In this study, we have employed a balanced approach to establish a robust family-level phylogenetic hypothesis for bats, utilizing a more comprehensive molecular dataset. This dataset includes representative species from all 21 bat families, resulting in a reduced level of missing genetic information. The resulting phylogenetic tree comprises 21 lineages that are strongly supported, each corresponding to one of the bat families. Our findings support to place the Emballonuroidea superfamily as the basal lineage of Yangochiroptera, and that Myzopodidae should be situated as a basal lineage of Emballonuroidea, forming a sister relationship with the clade consisting of Nycteridae and Emballonuridae. Finally, we have conducted dating analyses on this newly resolved phylogenetic tree, providing divergence times for each bat family. Collectively, our study has employed a relatively comprehensive molecular dataset to establish a more robust phylogeny encompassing all 21 bat families. This improved phylogenetic framework will significantly contribute to our understanding of evolutionary processes, ecological roles, disease dynamics, and biodiversity conservation in the realm of bats.

Dietary adenosine supplementation improves placental angiogenesis in IUGR piglets by up-regulating adenosine A2a receptor.

Abnormal placental angiogenesis is associated with the occurrence of intrauterine growth restriction (IUGR) in piglets, and effective treatment strategies against this occurrence remain to be explored. Adenosine has been reported to play an important role in angiogenesis, but its role in placental angiogenesis is still unknown. Here, we investigated the effect of dietary adenosine supplementation on IUGR occurrence in piglets by analyzing the role of adenosine in placental angiogenesis for Normal and IUGR piglets. Specifically, 88 sows were allotted to 2 treatments (n = 44) and fed a basal diet supplemented with 0% or 0.1% of adenosine from day 65 of gestation until farrowing, followed by collecting the placental samples of Normal and IUGR piglets, and recording their characteristics. The results showed that adenosine supplementation increased the mean birth weight of piglets (P < 0.05) and placental efficiency (P < 0.05), while decreasing the IUGR piglet rate (P < 0.05). Expectedly, the placenta for IUGR neonates showed a down-regulated vascular density (P < 0.05) and angiogenesis as evidenced by the expression level of vascular cell adhesion molecule-1 (VCAM1) (P < 0.05). Notably, dietary adenosine supplementation promoted angiogenesis (P < 0.05) both in the Normal and IUGR placenta. More importantly, the expression level of adenosine A2a receptor (ADORA2A) was lower (P < 0.05) in the IUGR placenta than in Normal placenta, whereas adenosine treatment could significantly increase ADORA2A expression, and also had an interaction effect between factors IUGR and Ado. Collectively, placentae for IUGR piglets showed impaired angiogenesis and down-regulated expression level of ADORA2A, while dietary adenosine supplementation could activate ADORA2A expression, improve the placental angiogenesis, and ultimately decrease the occurrence of IUGR in piglets.

Dietary fiber supplementation during the last 50 days of gestation improves the farrowing performance of gilts by modulating insulin sensitivity, gut microbiota, and placental function.

Our previous study found dietary konjac flour (KF) supplementation could improve insulin sensitivity and reproductive performance of sows, but its high price limits its application in actual production. This study aimed to investigate the effects of supplementation of a cheaper combined dietary fiber (CDF, using bamboo shoots fiber and alginate fiber to partially replace KF) from the last 50 days of gestation to parturition on farrowing performance, insulin sensitivity, gut microbiota, and placental function of gilts. Specifically, a total of 135 pregnant gilts with a similar farrowing time were blocked by backfat thickness and body weight on day 65 of gestation (G65d) and assigned to 1 of the 3 dietary treatment groups (n = 45 per group): basal diet (CON), basal diet supplemented with 2% KF or 2% CDF (CDF containing 15% KF, 60% bamboo shoots fiber, and 25% alginate fiber), respectively. The litter performance, insulin sensitivity and glucose tolerance parameters, placental vessel density, and short-chain fatty acids (SCFAs) levels in feces were assessed. The gut microbiota population in gilts during gestation was also assessed by 16S rDNA gene sequencing. Compared with CON, both KF and CDF treatments not only increased the piglet birth weight (P < 0.05) and piglet vitality (P < 0.01) but also decreased the proportion of piglets with birth weight ≤ 1.2 kg (P < 0.01) and increased the proportion of piglets with birth weight ≥ 1.5 kg (P < 0.01). In addition, KF or CDF supplementation reduced fasting blood insulin level (P < 0.05), homeostasis model assessment-insulin resistance (P < 0.05), serum hemoglobin A1c (P < 0.05), and the level of advanced glycation end products (P < 0.05) at G110d, and increased the placental vascular density (P < 0.05) at farrowing. Meanwhile, KF or CDF supplementation increased microbial diversity (P < 0.05) and SCFAs levels (P < 0.05) in feces at G110d. Notably, the production cost per live-born piglet was lower in CDF group (¥ 36.1) than KF group (¥ 41.3). Overall, KF or CDF supplementation from G65d to farrowing could improve the farrowing performance of gilts possibly by improving insulin sensitivity, regulating gut microbiota and metabolites, and increasing placental vascular density, with higher economic benefits and a similar effect for CDF vs. KF, suggesting the potential of CDF as a cheaper alternative to KF in actual production.

Dietary konjac flour (KF) supplementation could improve insulin sensitivity and reproductive performance of sows, but its high price limits its application in actual production. This study investigated the impact of 2% konjac flour (KF) and 2% combined dietary fiber (CDF, containing 15% KF, 60% bamboo shoots fiber, and 25% alginate fiber) supplementation from the last 50 days of gestation to farrowing on farrowing performance, placental function, insulin sensitivity, and gut microbiota of gilts. Results indicated that KF or CDF supplementation during this time could improve the farrowing performance of gilts possibly by improving insulin sensitivity and gut microbiota, and increasing placental vascular density. Meanwhile, CDF could lower the production cost per live-born piglet and have a similar effect to KF, thus a cheaper alternative to KF in actual production. This study facilitates understanding the beneficial effects of KF and non-conventional dietary fiber sources on the reproductive performance of gilts.

Effects of dietary supplementation of gestating sows with adenosine 5'-monophosphate or adenosine on placental angiogenesis and vitality of their offspring.

Our previous study found that dietary nucleotide supplementation, including adenosine 5'-monophosphate (AMP), could increase AMP content in sow milk and promote piglet growth, but its effects on placental efficiency and piglet vitality remain unknown. This experiment aimed to investigate the effects of dietary AMP or its metabolite adenosine (ADO) supplementation on sow reproductive performance and placental angiogenesis. A total of 135 sows with a similar farrowing time were blocked by backfat and body weight (BW) at day 65 of gestation and assigned to one of three dietary treatment groups (n = 45 per treatment): basal diet, basal diet supplemented with 0.1% AMP or 0.1% ADO, respectively. Placental analysis and the characteristics of sows and piglets unveiled that compared with control (CON) group, AMP or ADO supplementation could improve sow placental efficiency (P < 0.05) and newborn piglet vitality (P < 0.05), increase piglet birth weight (P < 0.05), and reduce stillbirth rate (P < 0.05). More importantly, AMP or ADO supplementation could increase the contents of AMP, ADO, and their metabolites in placentae (P < 0.05). Meanwhile, AMP or ADO supplementation could also increase placental vascular density (P < 0.05) and the expression of vascular endothelial growth factor A (P < 0.05), as well as promote the migration and tube formation of porcine iliac artery endothelial cells (P < 0.05). Overall, maternal dietary AMP or ADO supplementation could increase their contents in the placenta, thereby improving placental angiogenesis and neonatal piglet vitality.

Placental angiogenesis regulates piglet growth and development. Adenosine 5ʹ-monophosphate (AMP), a breakdown product of adenosine triphosphate, can be further converted to adenosine with various biological activities. However, little is known about whether AMP supplementation favors piglet growth and development as well as placental angiogenesis. This study facilitates the understanding of the promoting effects of AMP supplementation on placental angiogenesis and farrowing performance.

Mitogenomes of Nine Asian Skipper Genera and Their Phylogenetic Position (Lepidoptera: Hesperiidae: Pyrginae).

In this study, complete mitochondrial genomes of nine species representing three tribes in the subfamily Pyrginae sensu lato were newly sequenced. The mitogenomes are closed double-stranded circular molecules, with the length ranging from 15,232 bp to 15,559 bp, which all encode 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a control region. The orientation and gene order of these nine mitogenomes are identical to the inferred ancestral arrangement of insects. All PCGs exhibit the typical start codon ATN except for cox1 (using CGA) and cox2 (using TTG) in Mooreana trichoneura. Most of the PCGs terminate with a TAA stop codon, while cox1, cox2, nad4, and nad5 end with the incomplete codon single T. For the different datasets, we found that the one comprising all 37 genes of the mitogenome produced the highest nodal support, indicating that the inclusion of RNAs improves the phylogenetic signal. This study re-confirmed the status of Capila, Pseudocoladenia, and Sarangesa; namely, Capila belongs to the tribe Tagiadini, and Pseudocoladenia and Sarangesa to the tribe Celaenorrhini. Diagnostic characters distinguishing the two tribes, the length of the forewing cell and labial palpi, are no longer significant. Two populations of Pseudocoladenia dan fabia from China and Myanmar and P. dan dhyana from Thailand are confirmed as conspecific.

Dietary fibers with low hydration properties exacerbate diarrhea and impair intestinal health and nutrient digestibility in weaned piglets.

BACKGROUND: This study aimed to investigate the hydration properties of different-source fibrous materials by comparing their water-binding capacity (WBC), water swelling capacity (WSC), viscosity, and in vivo effects of selected samples on growth performance, nutrient digestibility, diarrhea, and intestinal health in weaned piglets. METHODS: A total of 13 commercially available fibrous materials were first compared in chemical composition and in vitro hydration property. Subsequently, 40 weaned piglets were randomized to five experimental dietary groups (8 piglets per group): control diet (a basal diet without dietary fiber, CON), basal diet supplemented with 5% microcrystalline cellulose (MCC), 5% wheat bran (WB), 5% Moringa oleifera leaf powder (MOLP), or 5% sugar beet pulp (SBP), followed by analyzing their growth performance and diarrhea rate in a 28-d experiment. After the feeding experiment, anaesthetized piglets were killed, and their intestinal and colon content or plasma samples were analyzed in nutrient digestibility, intestinal morphology, intestinal barrier, short-chain fatty acids (SCFAs), and bacterial population. RESULTS: In vitro studies showed low hydration properties for WB and MCC, while medium hydration properties for MOLP and SBP. In vivo studies indicated that compared with medium hydration property groups, low hydration property groups showed (1) exacerbated diarrhea, impaired intestinal health, and reduced apparent fecal digestibility of dry matter, gross energy, acid detergent fiber, and neutral detergent fiber; (2) decreased SCFAs concentration and relative levels of Lactobacillus and Bifidobacterium, but increased levels of Escherichia coli and Brachyspira hyodysenteriae in colon contents. Additionally, SBP showed optimal performance in reducing diarrhea and increasing SCFAs production. Correlation analysis revealed a positive correlation of fiber hydration properties with in vitro SCFAs production, and diarrhea index and nutrient digestibility were negatively and positively correlated with SCFAs levels in the colon contents of weaned piglets, respectively. CONCLUSIONS: Different-source dietary fibers varied in their hydration properties and impacts on diarrhea, microbial composition and SCFAs production in weaned piglets. WB and MCC could exacerbate diarrhea and impair nutrient digestibility, probably because their low hydration properties were detrimental to gut microbial homeostasis and fermentation. Our findings provide new ideas for rational use of fiber resources in weaned piglets.

Unique Duplication of trnN in Odontoptilum angulatum (Lepidoptera: Pyrginae) and Phylogeny within Hesperiidae.

To explore the variation and relationship between gene rearrangement and phylogenetic effectiveness of mitogenomes among lineages of the diversification of the tribe Tagiadini in the subfamily Pyrginae, we sequenced the complete mitogenome of Odontoptilum angulatum. The genome is 15,361 bp with the typical 37 genes, a large AT-rich region and an additional trnN (trnN2), which is completely identical to trnN (sequence similarity: 100%). The gene order differs from the typical Lepidoptera-specific arrangement and is unique to Hesperiidae. The presence of a "pseudo-trnS1" in the non-coding region between trnN1 and trnN2 supports the hypothesis that the presence of an extra trnN can be explained by the tandem duplication-random loss (TDRL) model. Regarding the phylogenetic analyses, we found that the dataset comprising all 37 genes produced the highest node support, as well as a monophyly of Pyrginae, indicating that the inclusion of RNAs improves the phylogenetic signal. Relationships among the subfamilies in Hesperiidae were also in general agreement with the results of previous studies. The monophyly of Tagiadini is strongly supported. Our study provides a new orientation for application of compositional and mutational biases of mitogenomes in phylogenetic analysis of Tagiadini and even all Hesperiidae based on larger taxon sampling in the future.

Complete mitochondrial genomes of three skippers in the tribe Aeromachini (Lepidoptera: Hesperiidae: Hesperiinae) and their phylogenetic implications.

The mitochondrial genome is now widely used in the study of phylogenetics and molecular evolution due to its maternal inheritance, fast evolutionary rate, and highly conserved gene content. To explore the phylogenetic relationships of the tribe Aeromachini within the subfamily Hesperiinae at the mitochondrial genomic level, we sequenced and annotated the complete mitogenomes of 3 skippers: Ampittia virgata, Halpe nephele, and Onryza maga (new mitogenomes for 2 genera) with a total length of 15,333 bp, 15,291 bp, and 15,381 bp, respectively. The mitogenomes all contain 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs), and a noncoding A + T-rich region and are consistent with other lepidopterans in gene order and type. In addition, we reconstructed the phylogenetic trees of Hesperiinae using maximum likelihood (ML) and Bayesian inference (BI) methods based on mitogenomic data. Results show that the tribe Aeromachini in this study robustly constitute a monophyletic group in the subfamily Hesperiinae, with the relationships Coeliadinae + (Euschemoninae + (Pyrginae + ((Eudaminae + Tagiadinae) + (Heteropterinae + ((Trapezitinae + Barcinae) + Hesperiinae))))). Moreover, our study supports the view that Apostictopterus fuliginosus and Barca bicolor should be placed out of the subfamily Hesperiinae.

Complete mitochondrial genome of the Small-Branded Swift: Pelopidas mathias (Lepidoptera, Hesperiidae).

We report the complete mitochondrial genome of the Small-Branded Swift: Pelopidas mathias, which is an important pest of rice. The total length of the circular double-stranded mitogenome is 15,524 bp, containing 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs) and a non-coding AT-rich region with the nucleotide base composition of 40.07% A, 40.83% T, 11.59% C, and 7.51% G, showing a relatively strong AT bias. The gene order and organization are consistent with typical Lepidoptera species. This work will provide molecular data support for the study of the phylogeny and evolution in the family Hesperiidae.

Characterization of complete mitochondrial genome of Polyura narcaeus (Lepidoptera: Nymphalidae: Charaxinae).

The complete mitochondrial genome of Polyura narcaeus (Hewitson, 1854) (Lepidoptera: Nymphalidae: Charaxinae) was sequenced in the study. The circular genome is 15,319 bp in size and includes 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and a non-coding AT-rich region. The base composition of the whole mitogenome is 39.15% A, 42.08% T, 11.18% C and 7.59% G, showing a strong AT bias. The characteristics of encoding PCGs, rRNAs and tRNAs, as well as the non-coding intergenic spacers and overlapping sequences are nearly the same with other known butterflies. The AT-rich region also contains several features characteristic of the typical butterflies. Phylogenetic analysis distinctly showed that the family Nymphalidae was a monophyletic group, and that the newly determined Polyura narcaeus of this study was firstly sister to Polyura nepenthes, then they were clustered with Polyura arja.

Comparative Mitogenomic Analysis of Five Awl Skippers (Lepidoptera: Hesperiidae: Coeliadinae) and Their Phylogenetic Implications.

To determine the significance of mitochondrial genome characteristics in revealing phylogenetic relationships and to shed light on the molecular evolution of the Coeliadinae species, the complete mitochondrial genomes (mitogenomes) of five Coeliadinae species were newly sequenced and analyzed, including Hasora schoenherr, Burara miracula, B. oedipodea, B. harisa, and Badamia exclamationis. The results show that all five mitogenomes are double-strand circular DNA molecules, with lengths of 15,340 bp, 15,295 bp, 15,304 bp, 15,295 bp, and 15,289 bp, respectively, and contain the typical 37 genes and a control region. Most protein-coding genes (PCGs) begin with ATN, with 3 types of stop codons including TAA, TAG, and an incomplete codon T-; most of the genes terminate with TAA. All of the transfer RNA genes (tRNAs) present the typical cloverleaf secondary structure except for the trnS1. Several conserved structural elements are found in the AT-rich region. Phylogenetic analyses based on three datasets (PCGs, PRT, and 12PRT) and using maximum likelihood (ML) and Bayesian inference (BI) methods show strong support for the monophyly of Coeliadinae, and the relationships of the five species are (B. exclamationis + ((B. harisa + (B. oedipodea + B. miracula)) + H. schoenherr)).

Maternal supply of cysteamine alleviates oxidative stress and enhances angiogenesis in porcine placenta.

BACKGROUND: Oxidative stress in placenta is associated with the occurrence of adverse pregnancy outcomes in sow, but there are few satisfactory treatment strategies for these conditions. This study investigated the potential of cysteamine (CS) as an antioxidant protectant for regulating the reproductive performance, redox status, and placental angiogenesis of sows. METHODS: The placental oxidative stress status and vascular density of piglets with different birth weights: < 1.0 kg (low birth weight, LBW) and 1.4-1.6 kg (normal birth weight, NBW) were evaluated, followed by allotting 84 sows to four treatments (n = 21) and feeding them with a basal diet supplemented with 0, 100, 300, or 500 mg/kg of CS from d 85 of gestation to d 21 of lactation, respectively. Placenta, serum, and colostrum samples of sows or piglets were collected, and the characteristics of sows and piglets were recorded. Furthermore, the in vivo results were validated using porcine vascular endothelial cells (PVECs). RESULTS: Compared with the NBW placentae, the LBW placentae showed increased oxidative damage and were vulnerable to angiogenesis impairment. Particularly, H2O2-induced oxidative stress prompted intracellular reactive oxygen species generation and inhibited the tube formation and migration of PVECs as well as the expression of vascular endothelial growth factor-A (VEGF-A) in vitro. However, dietary CS supplementation can alleviate oxidative stress and improve the reproductive performance of sows. Specifically, compared with the control group, dietary 100 mg/kg CS could (1) decrease the stillbirth and invalid rates, and increase both the piglet birth weight in the low yield sows and the placental efficiency; (2) increase glutathione and reduce malondialdehyde in both the serum and the colostrum of sows; (3) increase the levels of total antioxidant capacity and glutathione in LBW placentae; (4) increase the vascular density, the mRNA level of VEGF-A, and the immune-staining intensity of platelet endothelial cell adhesion molecule-1 in the LBW placentae. Furthermore, the in vitro experiment indicated that CS pre-treatment could significantly reverse the NADPH oxidase 2-ROS-mediated inactivation of signal transducer and activator of transcription-3 (Stat3) signaling pathway induced by H2O2 inhibition of the proliferation, tube formation, and migration of PVECs. Meanwhile, inhibition of Stat3 significantly decreased the cell viability, tube formation and the VEGF-A protein level in CS pretreated with H2O2-cultured PVECs. CONCLUSIONS: The results indicated that oxidative stress and impaired angiogenesis might contribute to the occurrence of LBW piglets during pregnancy, but CS supplementation at 100 mg/kg during late gestation and lactation of sows could alleviate oxidative stress and enhance angiogenesis in placenta, thereby increasing birth weight in low yield sows and reducing stillbirth rate. The in vitro data showed that the underlying mechanism for the positive effects of CS might be related to the activation of Stat3 in PVECs.

Inclusion of wheat aleurone in gestation diets improves postprandial satiety, stress status and stillbirth rate of sows.

This study investigated the effects of different amounts of wheat aleurone (WA) (0, 15%, 30%) inclusion in gestation diets on the reproductive performance, postprandial satiety, stress status and stereotypic behaviors of sows. A total of 84 Landrace × Yorkshire sows (parity 4.87 ± 1.32) at breeding were randomly allotted to one of the three isoenergetic and isonitrogenous dietary treatments based on parity and body weight. The results showed that, compared with the control (0), sows fed the WA diet had a higher serum concentration of peptide YY (PYY) (P < 0.05) and glucagon like peptide-1 (GLP-1) (P < 0.05) and a lower concentration of saliva cortisol (P < 0.01). Importantly, compared with the control group, only the 15% WA group had a higher concentration of the total antioxidant capacity (T-AOC) (P < 0.05), lower proportions of sitting (P = 0.05) and stillbirth rates (P < 0.01). Accordingly, the production cost per piglet born alive ($ 6.9 vs. $ 7.6) or per piglet born healthy ($ 7.4 vs. $ 7.9) declined in the 15% WA group versus the control group. Overall, 15% WA inclusion in gestation diets contributed to enhancing postprandial satiety, alleviating stress status and decreasing stillbirth rate of sows. This study provides a reference for the application of WA as a partial substitute for conventional feed ingredients to improve sows' reproductive performance.

Nox2 impairs VEGF-A-induced angiogenesis in placenta via mitochondrial ROS-STAT3 pathway.

Aberrant placental angiogenesis is associated with fetal intrauterine growth restriction (IUGR), but the mechanism underlying abnormal placental angiogenesis remains largely unknown. Here, lower vessel density and higher expression of NADPH oxidases 2 (Nox2) were observed in the placentae for low birth weight (LBW) fetuses versus normal birth weight (NBW) fetuses, with a negative correlation between Nox2 and placental vessel density. Moreover, it was revealed for the first time that Nox2 deficiency facilitates angiogenesis in vitro and in vivo, and vascular endothelial growth factor-A (VEGF-A) has an essential role in Nox2-controlled inhibition of angiogenesis in porcine vascular endothelial cells (PVECs). Mechanistically, Nox2 inhibited phospho-signal transducer and activator of transcription 3 (p-STAT3) in the nucleus by inducing the production of mitochondrial reactive oxygen species (ROS). Dual-luciferase assay confirmed that knockdown of Nox2 reduces the expression of VEGF-A in an STAT3 dependent manner. Our results indicate that Nox2 is a potential target for therapy by increasing VEGF-A expression to promote angiogenesis and serves as a prognostic indicator for fetus with IUGR.

Effects of Dietary Fiber Sources during Gestation on Stress Status, Abnormal Behaviors and Reproductive Performance of Sows.

Inclusion of fiber in gestation diets is a method for enhancing satiety and reducing abnormal behaviors in restricted feeding sows without providing excess energy. The purpose of this study was to use an in vitro-in vivo method to appraise the effects of two available unconventional dietary fiber resources during gestation on sows' physio-chemical properties of diets, postprandial satiety, performance, abnormal behaviors, stress status and lactation feed intake under three different dietary treatments: control diet (CON diet), 5% resistant starch diet (RS diet), and 5% fermented soybean fiber diet (FSF diet) with a total of 78 (average parity 5) Landrace × Yorkshire sows. Results showed that swelling capacity was higher in the RS diet than in the CON or FSF diet. Meanwhile, the 48 h cumulative gas production and the final asymptotic gas volume after in vitro fermentation of gestation diets showed an increased trend (p = 0.07, p = 0.09, respectively) in the RS diet versus the CON or FSF diets. While the sows' litter size, body weight, backfat or weaning-to-estrus interval were not affected (p > 0.05) by the three treatments during gestation, the RS group showed a decline in stillbirth number (p < 0.05) and stillbirth rate (p < 0.01) relative to the other two groups. Meanwhile, the proportion of standing was lower while the sow's serum concentrations of PYY (peptide YY) and GLP-1 (glucagon-like peptide-1) were higher (p < 0.05) on day 70 of gestation in the RS group than in the CON or FSF group. Compared with the CON group, the RS group showed a downward tendency (p = 0.07) in the sows' plasma cortisol concentration on day 70 of gestation. A comparison of oxidative and antioxidative indicators revealed an increase in the sows' serum FRAP (ferric ion reducing antioxidant power) (p < 0.05) and a decrease of protein carbonyl (p < 0.05) on day 109 of gestation in the RS or FSF group versus the CON group. Overall, inclusion of 5% RS with greater swelling capacity in the gestation diet contributed to enhancing the postprandial satiety, alleviating the stress status, reducing the abnormal behaviors and thus lowering the stillbirth rate of sows.