Effects of genomic selection for intramuscular fat content in breast muscle in Chinese local chickens

Improvements in living standards have resulted in consumers having higher expectations for chicken meat quality. This is particularly true in Asia, where there is high consumer preference for local breeds. Nothing is presently known about the effectiveness of using genomic selection (GS) strategies in chickens to genetically improve meat quality traits that cannot be measured in living potential parents. In this study, 724 Beijing-You chickens were used as a training population; all were genotyped using Illumina 60K SNP chips, and intramuscular fat content in breast muscle (IMFbr ) was measured. Birds in the GS line were selected based on genomic estimated breeding values, IMFbr being the sole trait. Genetic progress in one generation was compared to that from conventional family-based selection, and both were evaluated against random-bred controls. Results showed that relative to the random-bred controls, IMF percentage was improved 9.62% using GS, comparable to the 10.38% improvement using family-based selection. We quantified the effectiveness of GS when applied to a meat quality trait with low heritability in chickens. We plan to introduce custom SNP chips, appropriate for native chicken breeds in China, to assist in applying GS in local breeding and accelerate genetic gain.

[Three-dimensional finite element analysis of four-implants supported mandibular overdentures using two different attachments]

Objective: To compare the biomechanical characteristics of four-implants mandibular overdentures supported by Locator attachment or bar-clip attachment under different mechanical loads using three-dimensional finite element analysis method. Methods: Two different models of four-implants supported mandibular overdentures using Locator attachment and bar-clip attachment (hereinafter called Locator model and bar-clip model) were established. Each model was subjected to five different mechanical loading conditions: 100 N vertical loading in central incisor (vertical load of incisor), 100 N vertical loading or oblique loading in canine (vertical or oblique loads of canines), 100 N vertical or oblique loading in mandibular first molar (vertical or oblique loads of mandibular first molar). The stress distributions in implants, peri-implant bone and mucosa were recorded under the above five conditions to evaluate the effects of different attachments on the biomechanical properties of implant-supported mandibular overdentures. Results: Regardless of loading conditions and types of attachments, the stress concentration in implants were located at the neck of implants, and the stress concentration in peri-implant bone was located in the cortical bone. The stress values in mucosa were always much smaller than those in implants and cortical bone. Regardless of loading positions (on canine or on mandibular first molar), the maximum stress at the bone interface around the implant under lateral loading was much higher than that under vertical loading. Under various loading conditions, the stress in implants and cortical bone of the Locator model (the highest von Mise stress value was respectively 79.5 and 22.3 MPa) were lower than that of bar-clip model (the highest von Mise stress value was 110.3 and 28.7 MPa respectively) while the maximum compressive stress in mucosa (0.198 MPa) in Locator model was slightly higher than that in the bar-clip model (0.137 MPa). Conclusions: In clinical practice, the lateral force applied to the implant-retained overdenture should be minimized to avoid complications caused by pathological loads. Under the same loading condition, the stress distributions in overdenture using Locator attachment are more dispersed, which is more conducive to long-term stability of implants.

IgG1+ B-cell immunity predates IgE responses in epicutaneous sensitization to foods

BACKGROUND

The generation of IgE-mediated food allergy in humans is silent and only diagnosed upon manifestation of clinical symptoms. While experimental models have been used to investigate some mechanisms of allergic sensitization, the generation of humoral immunity and memory remains to be elucidated. Here, we defined the evolution of allergen-specific B-cell responses during epicutaneous sensitization to foods.

METHODS

Wild-type and genetic knockout animals, and drug or antibody strategies for cell depletion and immunoglobulin signaling blockade were used to investigate epicutaneous sensitization and disease progression; we analyzed allergen-specific germinal centers and IgG1⁺ memory B cells by flow cytometry, evaluated humoral responses, and determined clinical reactivity (anaphylaxis).

RESULTS

Epicutaneous sensitization caused microscopic skin damage, inflammation, and recruitment of activated dendritic cells to the draining lymph nodes. This process generated allergen-specific IgG1⁺ germinal center B cells, serum IgG1, and anaphylaxis that was mediated by the alternative pathway. Whether we used peanut and/or ovalbumin from the egg white for sensitization, the allergen-specific IgG1⁺ memory compartment predominantly exhibited an immature, pro-germinal center phenotype (PDL-2^- CD80^- CD35⁺ CD73⁺ ). Subsequent subclinical exposures to the allergen induced IgE⁺ germinal center B cells, serum IgE, and likely activated the classical pathway of anaphylaxis.

CONCLUSIONS

Our data demonstrate that IgG1⁺ B-cell immunity against food allergens in epicutaneous sensitization precedes the generation of IgE responses. Therefore, the assessment of allergen-specific cellular and humoral IgG1⁺ immunity may help to identify individuals at risk of developing IgE-mediated food allergy and hence provide a window for therapeutic interventions.

Dietary calcium requirements of Sheldrake ducklings from 1 to 21 days of age

An experiment was conducted to investigate the effect of dietary calcium (Ca) level on growth performance and bone characteristics to evaluate the Ca requirements for Sheldrake ducklings from 1 to 21 days of age. A total of 1080 day-old male Campbell Sheldrake ducklings were randomly allotted to one of six treatments with six replicate cages of 30 birds per cage with a completely randomised design. A basal diet with 0.40% non-phytate phosphorus was supplemented with Ca source (calcium carbonate) to achieve graded concentrations of Ca (0.45–1.20%) in diets with an increment of 0.15%. The bodyweight, average daily gain and average daily feed intake displayed quadratic responses to increasing concentrations of dietary Ca with maximal responses for ducklings fed the diets with 0.60 and 0.75% Ca. Serum Ca concentration, tibia ash percentage, Ca content in tibia ash and bone mineral density were increased linearly (P < 0.02) as dietary Ca concentrations increased. According to the non-linear regression analyses, the Ca requirements for maximal weight gain and bone mineralisation of Sheldrake ducklings from 1 to 21 days of age were estimated at 0.60% and 0.64–0.87% respectively.

Method using a co-culture system with high-purity intramuscular preadipocytes and satellite cells from chicken pectoralis major muscle

Intramuscular fat is important in improving meat quality; however, the lack of high-purity intramuscular preadipocyte (IMP) in vitro has severely limited the in-depth research on the mutual regulation of myocytes and adipocytes in chicken. In this study, we establish a new method by combining the mature adipocyte ceiling method and the transwell co-culture system. Mature intramuscular adipocyte (MIA) and muscle satellite cell (MSC) were obtained from digested pectoralis major, and MIAs were transformed into IMPs by dedifferentiation with ceiling culture. MSCs were then purified by differential adhesion for 2 h. The results by inverted-microscope observation, MTT assay, Oil Red O staining, and q-PCR revealed that the de-differentiated cells from MIA were identified as the IMPs, and had the same the cellular morphology, the capacity on differentiation, proliferation and passage with the abdominal fat preadipocytes (P > 0.05). The applicability of the obtained IMPs in co-cultured experiment with the MSC revealed that it could meet the requirements of the experimental study. Finally, a co-culture system of IMPs and MSCs was established using a transwell chamber. The co-cultured results indicated that MSCs in the proliferative stage tend to accelerate the differentiation of IMPs to induce more fat content in co-cultured IMPs than in single-culture IMPs (P < 0.05), in the non-proliferative stage, the results tend to show the opposite (P < 0.05). The mRNA levels of related genes significantly changed in accordance with the fat content in cells. The results strongly supported the view that the established co-culture system was effective and feasible. In summary, we successfully found a new method to explore the interaction between myocytes and adipocytes of chicken. Our findings can deepen research on the regulation of chicken myocytes and adipocytes.

Expression and effect of Calpain9 gene genetic polymorphism on slaughter indicators and intramuscular fat content in chickens

Calpain 9 (CAPN9) is expressed in the stomach and small intestine. CAPN9 has regulatory roles in hypertension, heart disease, gastric mucosal defense, and kidney disease. The involvement of CAPN9 has not been reported in the development of chickens. CAPN9 mRNA was found in adipose and muscle tissue in this study. Two linkage single nucleotide polymorphisms (SNP; G7518A and C7542G) in intron 4 were screened from 160 birds of the D2 chicken line. The 2 mutation sites were associated with carcass weight, evisceration weight, abdominal fat weight (AFW), abdominal fat percentage (AFP), and breast muscle percentage (all P < 0.05). Intramuscular fat (IMF) content was not significantly different in the 3 genotypes. But, the AA(7518)/GG(7542) genotype had the highest IMF content, highest breast muscle weight, and lower AFW and AFP. Moreover, the mRNA level of CAPN9 in abdominal fat tissue was significantly different (P < 0.05 or P < 0.01) between any 2 genotypes, consistent with AFW and AFP. In summary, the expression of CAPN9 in adipose and breast muscle tissue is reported for the first time. CAPN9 affected production performance of chickens. As a marker, the linkage G7518A and C7542G polymorphisms in intron 4 of CAPN9 could affect the production traits by regulating mRNA expression. The findings concerning the marker enrich the theoretical foundation for molecular breeding of high-quality broilers.

High calcium to phosphorus ratio impairs growth and bone mineralization in Pekin ducklings

Two experiments were conducted to investigate the effect of high dietary calcium (Ca) level on growth performance, Ca and phosphorus (P) metabolism, and nutrient utilization in ducklings subjected to normal and low P levels in diets. A completely randomized design was used with a factorial arrangement of 2 total dietary P levels [normal-P (0.60%) and low-P (0.45%) groups] × 4 dietary Ca levels [low-Ca (0.55%), normal-Ca (0.75%), medium-Ca (0.95%) and high-Ca (1.15%) groups)]. Compared to normal-P group, low-P group had lower (P < 0.05) final body weight (BW), average daily gain (ADG), and average daily feed intake (ADFI) and reduced (P < 0.05) serum Ca and P levels, bone Ca, P, and ash content, and bone mineral density in ducklings during the starter period. Under the low-P group, birds from high-Ca group had lower (P < 0.05) final BW, ADG, ADFI, bone ash content, bone mineral density, and the utilization of energy, Ca, and P than those from low-Ca, normal-Ca, and medium-Ca groups. Our results indicate that high-Ca diet induced greater growth suppression and bone mineralization loss in ducklings fed a low-P diet. The aggravated negative effect of high dietary Ca level with a low P level might be related to the elevated serum alkaline phosphatase activity and the reduced utilization of energy, Ca, and P.

Safety and efficacy of telbivudine in late pregnancy to prevent mother-to-child transmission of hepatitis B virus: A multicenter prospective cohort study

Infection of hepatitis B virus (HBV) occurs in ~10% of infants of HBV-infected mothers with positive hepatitis B e antigen (HBeAg) after immunoprophylaxis. We aimed to evaluate the safety and efficacy of telbivudine used during late pregnancy for preventing mother-to-child transmission of HBV. We conducted a multicenter prospective cohort study in 5 hospitals from 2012 to 2014, which enrolled HBV-infected singleton pregnant women with positive HBeAg. By their choice, women were divided into therapy (telbivudine 600 mg/day, from gestation 28-32 weeks to 3-4 weeks postpartum) and control (no antiviral agent) groups. Infants received passive-active immunoprophylaxis and follow-up at the age of 7-14 months. Totally, 328 pregnant women were included: 149 in the telbivudine group and 179 in the control group. Baseline HBV DNA levels were similar in the 2 groups (7.43 vs 7.37 log₁₀ IU/mL, P = .711). At delivery, HBV DNA levels in the telbivudine and control groups were 3.80 and 7.26 log₁₀ IU/mL, respectively (P < .0001). Of the infants, 128 (85.9%) in the telbivudine group and 156 (87.2%) in the control group were followed up. No infant in the telbivudine group had chronic infection, while 2 (1.28%) infants in the control group did (P = .503). Three (2.34%) infants in the telbivudine group, but none in the control group, had severe congenital or developmental abnormalities (P = .090). The data indicate that telbivudine may block perinatal HBV transmission. However, larger studies are required to clarify whether anti-HBV therapy in pregnancy is associated with severe adverse effects in the foetuses and infants.

Proteomics and microscopy tools for the study of antimicrobial resistance and germination mechanisms of bacterial spores

Bacterial spores are ubiquitous in nature and can withstand both chemical and physical stresses. Spores can survive food preservation processes and upon outgrowth cause food spoilage as well as safety risks. The heterogeneous germination and outgrowth behavior of isogenic spore populations exacerbates this risk. A major unknown factor of spores is likely to be the inherently heterogeneous spore protein composition. The proteomics methods discussed here help in broadening the knowledge about spore structure and identification of putative target proteins from spores of different spore formers. Approaches to synchronize Bacillus subtilis spore formation, and to analyze spore proteins as well as the physiology of spore germination and outgrowth are also discussed. Live-imaging and fluorescence microscopy techniques discussed here allow analysis, at single cell level, of the 'germinosome', the process of spore germination itself, spore outgrowth and the spore intracellular pH dynamics. For the latter, a recently published improved pHluorin (IpHluorin) under control of the ptsG promoter is applicable. While the data obtained from such tools offers novel insight in the mechanisms of bacterial spore awakening, it may also be used to probe candidate antimicrobial compounds for inhibitory effects on spore germination and strengthen microbial risk assessment.

[Prevalence and trend of overweight and obesity in children and adolescents in Guangdong province, 2002-2012]

Objective: To investigate the prevalence and trend of overweight and obesity in children and adolescents aged 6-17 years between 2002 and 2012 in Guangdong province. Methods: A total of 7 075 children and adolescents aged 6-17 years were selected in Guangdong for nutritional survey in 2002 and a total of 2 319 children and adolescents aged 6-17 years were selected in nine counties/districts of Guangdong for nutritional survey during 2009-2012 through multi-stage random cluster sampling. The body height and weight of all the children and adolescents were measured. Results: The result of 2009-2012 survey indicated the average prevalence of overweight and obesity in the children and adolescents surveyed were 7.3% and 4.5%, respectively. The prevalence of overweight and obesity were higher in boys (8.9% and 6.5%) than in girls (5.3% and 2.2%), in rural area (9.3% and 5.6%) than in urban area (4.7% and 3.2%). Children and adolescents aged 9-11 years had a higher overweight and obesity rates compared with other age groups. Compared with 2002, except for obesity rate in urban girls, the prevalence of overweight and obesity in children and adolescents obviously increased. The increase rate was higher in rural area than urban area and in boys than in girls. Conclusions: Compared with 2002, the prevalence of overweight and obesity in children and adolescents in Guangdong obviously increased. The prevalence was much higher in boys, those living in rural area and those aged 9-11 years, thus more attention should be paid to them.

Exome sequencing identifies a TCF4 mutation in a Chinese pedigree with symmetrical acral keratoderma

BACKGROUND

Symmetrical acral keratoderma (SAK) is a rare skin disorder and its pathogenesis and inheritability are unknown.

OBJECTIVES

To investigate the inheritance and pathogenesis of SAK.

METHODS

Four SAK cases occurred in a four-generation Chinese family. Exome sequencing identified SNPs with potential SAK-related mutations, and a potentially responsible gene transcription factor 4 (TCF4) was identified. TCF4 was then sequenced in all 11 family members, and pedigree analysis was performed. Histopathology and immunohistochemistry evaluated TCF4 expression in skin lesions. The gene mutation was investigated in human keratinocytes for keratin-related protein expression.

RESULTS

A novel heterozygous missense mutation, c.85C>A (p.Pro29Thr) was found in TCF4. The mutation showed autosomal dominant inheritance and perfectly cosegregated with the SAK phenotype in all family members. In skin lesions, TCF4 was present in the cytoplasm and membranes of the basal layer, the stratum spinosum and the stratum granulosum of the epidermis. The mutant TCF4 induced overexpression of differentiation markers including KRT1, KRT14, loricrin and involucrin.

CONCLUSIONS

A SAK-related gene mutation in TCF4 may function through transcriptional regulation of keratin.

Effects of caponization and ovariectomy on objective indices related to meat quality in chickens

Capons and ovariectomized chickens are birds that have been gonadectomized to improve the meat quality. This study investigated the effects of caponization and ovariectomy on physical, chemical, and fatty acid and amino acid profiles of meat from Beijing-You chickens (a Chinese local breed) at market age (17 wk). All birds (20 capons, 20 ovariectomized, and 40 controls) were reared under the same conditions. Breast muscle fiber diameter and area were significantly smaller and the fiber density was higher in capons and ovariectomized chickens than in controls (P < 0.05). Compared with controls, caponization and ovariectomy significantly decreased breast muscle shear values and redness (a*), as well as increased yellowness (b*), hue (H*), and chroma (C*) (P < 0.05). There was significantly more intramuscular fat (IMF) in capons than in controls (P < 0.05), and there was a tendency for more inosine-5΄-monophosphate (IMP) in capons than in controls (P = 0.10). The levels of IMF and IMP in ovariectomized chickens were significantly higher than those in controls (P < 0.05). Capons and ovariectomized chickens exhibited a significantly higher content of palmitic acid (C16:0), palmitoleic acid (C16:1) and oleic acid (C18:1), together with a lower content of stearic acid (C18:0), arachidonic acid (C20:4), and lignoceric acid (C24:0) compared to controls (P < 0.05). The total saturated, monounsaturated, and polyunsaturated fatty acids as well as amino acid composition were not affected by gonadectomy (P > 0.05). Overall, this study indicates that both caponization and ovariectomy likely improve the meat quality of the breast muscle based on the objective indices of IMF, appearance (color), texture, and minor change of the fatty acid profile; ovariectomy improves flavor-related indices.

Mechanical force-mediated pathological cartilage thinning is regulated by necroptosis and apoptosis

OBJECTIVE

This study aimed to identify the mechanisms underlying mandibular chondrocyte cell death and cartilage thinning in response to mechanical force.

MATERIAL AND METHODS

An in vivo model (compressive mechanical force) and an in vitro model (TNF-α+cycloheximide) were used to induce mandibular chondrocyte necroptosis. Hematoxylin and eosin staining and transmission electron microscopy were used to assess histological and subcellular changes in mandibular chondrocyte. Immunohistochemistry, western blotting, and real-time PCR were performed to evaluate changes in necroptotic protein markers. Cell activity, mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) were examined in vitro.

RESULTS

The expression of RIP1, RIP3 and Caspase-8 in mandibular chondrocytes significantly increased after 4 days of compressive mechanical force. Furthermore, the inhibition of necroptosis by Necrostatin-1 (Nec-1) or the inhibition of apoptosis by N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (Z-VAD) partially restored mechanical force-mediated mandibular cartilage thinning and chondrocyte death. Moreover, a synergistic effect on cell death inhibition and mandibular cartilage thickness restoration were found when treated with Nec-1+Z-VAD. The results of the in vitro model were in line with the in vivo ones, indicating that the changes in MMP and ROS generation contributed to mandibular chondrocyte apoptosis and necroptosis.

CONCLUSION

In addition to apoptosis, necroptosis also plays critical roles in pathological changes in mandibular cartilage after compressive mechanical force stimulation, implying RIP1, a master protein that mediates both necroptosis and apoptosis, as a potential therapeutic target in temporal mandibular osteoarthritis.

Phylogenetic and paleobotanical evidence for late Miocene diversification of the Tertiary subtropical lineage of ivies (Hedera L., Araliaceae)

BACKGROUND

Hedera (ivies) is one of the few temperate genera of the primarily tropical Asian Palmate group of the Araliaceae, which extends its range out of Asia to Europe and the Mediterranean basin. Phylogenetic and phylogeographic results suggested Asia as the center of origin and the western Mediterranean region as one of the secondary centers of diversification. The bird-dispersed fleshy fruits of ivies suggest frequent dispersal over long distances (e.g. Macaronesian archipelagos), although reducing the impact of geographic barriers to gene flow in mainland species. Genetic isolation associated with geographic barriers and independent polyploidization events have been postulated as the main driving forces of diversification. In this study we aim to evaluate past and present diversification patterns in Hedera within a geographic and temporal framework to clarify the biogeographic history of the genus.

RESULTS

Phylogenetic (biogeographic, time divergence and diversification) and phylogeographic (coalescence) analyses using four DNA regions (nrITS, trnH-psbA, trnT-trnL, rpl32) revealed a complex spatial pattern of lineage divergence. Scarce geographic limitation to gene flow and limited diversification are observed during the early-mid Miocene, followed by a diversification rate increase related to geographic divergence from the Tortonian/Messinian. Genetic and palaeobotanical evidence points the origin of the Hedera clade in Asia, followed by a gradual E-W Asian extinction and the progressive E-W Mediterranean colonization. The temporal framework for the E Asia - W Mediterranean westward colonization herein reported is congruent with the fossil record. Subsequent range expansion in Europe and back colonization to Asia is also inferred. Uneven diversification among geographic areas occurred from the Tortonian/Messinian onwards with limited diversification in the newly colonized European and Asian regions. Eastern and western Mediterranean regions acted as refugia for Miocene and post-Miocene lineages, with a similar role as consecutive centers of centrifugal dispersal (including islands) and speciation.

CONCLUSIONS

The Miocene Asian extinction and European survival of Hedera question the general pattern of Tertiary regional extinction of temperate angiosperms in Europe while they survived in Asia. The Tortonian/Messinian diversification increase of ivies in the Mediterranean challenges the idea that this aridity period was responsible for the extinction of the Mediterranean subtropical Tertiary flora. Differential responses of Hedera to geographic barriers throughout its evolutionary history, linked to spatial isolation related to historical geologic and climatic constraints may have shaped diversification of ivies in concert with recurrent polyploidy.

Effects of continuous low dose infusion of lipopolysaccharide on inflammatory responses, milk production and milk quality in dairy cows

The objective of this study was to evaluate the effects of continuous low dose infusion of lipopolysaccharide (LPS) on inflammatory responses and milk production and quality in lactating dairy cows. Eight Holstein cows were assigned to two treatments in a cross-over experimental design. Cows were infused intravenously either with saline solution or with saline solution containing LPS from Escherichia coli O111:B4 at a dose of 0.01 μg LPS/kg body weight for approximately 6 hr each day during a seven-day trial. The clinical symptoms and milk production performance were observed. Milk samples were analysed for conventional components, fatty acids and amino acids. And jugular vein and mammary vein plasma samples were analysed for concentrations of cytokines and acute phase proteins. LPS infusion decreased feed intake and milk yield. An increase in body temperature was observed after LPS infusion. LPS infusion also increased plasma concentrations of interleukin-1β, serum amyloid A, LPS-binding protein, C-reactive protein and haptoglobin. LPS infusion decreased the contents of some fatty acids, such as C17:1, C18:0, C18:1n9 (trans) and C18:2n6 (trans), and most amino acids except for methionine, threonine, histidine, cysteine, tyrosine and proline in the milk. The results indicated that a continued low dose infusion of LPS can induce an inflammatory response, decrease milk production and reduce milk quality.

Circulating myeloid-derived suppressor cells predict disease activity and treatment response in patients with immune thrombocytopenia

Immune thrombocytopenia (ITP) is a disease characterized by isolated thrombocytopenia. Abnormal effector T cell activation is an important mechanism in the pathogenesis of ITP. Regulatory T cells (Treg) have a strong immunosuppressive function for T cell activation and their importance in the pathophysiology and clinical treatment of ITP has been confirmed. Myeloid-derived suppressor cells (MDSCs) are other immunosuppressive cells, which can also suppress T cell activation by secreting arginase, iNOS and ROS, and are essential for Treg cells’ differentiation and maturation. Therefore, we speculate that MDSCs might also be involved in the immune-dysregulation mechanism of ITP. In this study, we tested MDSCs and Treg cells in peripheral blood samples of twenty-five ITP patients and ten healthy donors. We found that MDSCs and Treg cells decreased simultaneously in active ITP patients. Relapsed ITP patients showed lower MDSCs levels compared with new patients. All patients received immunosuppressive treatment including dexamethasone alone or in combination with intravenous immune globulin. We found that MDSCs’ level after treatment correlated with platelet recovery. Our study is the first that focused on MDSCs’ role in ITP. Based on our results, we concluded that circulating MDSCs could predict disease activity and treatment response in ITP patients. This preliminary conclusion indicates a substantial significance of MDSCs in the pathophysiology and clinical treatment of ITP, which deserves further investigation.