Development of a 19-plex short tandem repeat typing system for individual identification and parentage testing of horses (Equus caballus)

Individual identification of horses for pedigree verification and registration is important for the sustainable development of the horse industry. Horse individual identification and parentage tests commonly use the 17 short tandem repeats (STRs) recommended by the International Society for Animal Genetics (ISAG) and the locus LEX33. While many multiplex STR typing systems have been established for the horse, a sex determining marker is usually absent, and none of them can simultaneously detect all 17 ISAG recommended loci and the locus LEX33. Here, we present a 19-plex STR typing system that contains the 17 ISAG recommend loci, the locus LEX33 and amelogenin as sex determining loci. The results of our sensitivity, species specificity, stutter analysis and population data analysis, indicate that this system is a specific, sensitive, and robust tool for the identification of individuals, parentage testing and genetic research in the horse.

Clinical characteristics and prognosis of acral lentiginous melanoma: a single-center series of 211 cases in China

BACKGROUND

Acral lentiginous melanoma (ALM) is common in China with poor prognosis. However, there are only a few studies of ALM in the Asian population. We aimed to summarize and analyze the clinical characteristics, treatment strategy, treatment effect, and prognostic factors of ALM in a Chinese population.

METHODS

We included a total of 249 ALM patients (211 with follow-up data) from a single institution. Demographic, laboratory data, treatment strategy, and prognosis were analyzed.

RESULTS

The ratio of male and female was 1.3 ∶ 1.0. The median age was 58 years old. The majority of patients (70.3%) had lesions on the sole. Trauma history and irritation were associated with lesion size increase in some patients. The prognosis of patients in stage II-III undergoing standard operation was significantly better compared with those without surgical treatment. Patients who did not receive postoperative adjuvant treatment had shorter time to distant metastasis. In multivariable analysis, distant metastasis, duration of disease, LDH level, and Ki67 index were independently associated with survival.

CONCLUSIONS

Prognosis for ALM patients was poor in our study. Distant metastasis, duration of disease, LDH level, and Ki67 index were independently associated with prognosis.

Safety and efficacy of HX008: A humanized immunoglobulin G4 monoclonal antibody in patients with locally advanced or metastatic melanoma—A single-arm, multicenter, phase II study

9554

Background: HX008 is a new recombinant humanized anti-PD-1 monoclonal antibody, belonging to human IgG4 / kappa subtype, which can selectively block the binding of PD-1 with its ligands PD-L1 and PD-L2. Methods: In this single arm phase 2 trial, eligible patients (pts) were aged from18 to 75, who previously failed with conventional treatment for locally advanced or metastatic melanoma, with an ECOG performance status of 0 or 1 and had measurable lesions according to the RECIST criteria (V1.1). Ocular melanoma, brain metastasis or previous use of anti PD-1 ab were excluded. Pts received HX008 3mg/kg every 3 weeks, until disease progression, intolerable toxicity or treatment discontinuation for any other reasons. The primary endpoint was ORR according to RECIST criteria, and the secondary endpoints were OS, PFS, DCR and the toxicity. The iRECIST criteria would also be used in the evaluation of response and treatment discontinuation. Clinical trial information: NCT04749485. Results: From Oct 2018 to Jan 2021, 119 pts have been eligible and enrolled. Basic characteristics: median age 59 years; 57 males (42.9%) ; stage 22%, stage 78%; primary: acral 52.1%, mucosal 19.3%, cutaneous 18.5% and unknown 10.1%; Gene mutation status: Braf 10.9%, Nras 9.2%, cKit 4.2%; condition of previous treatments: 67.26%, 25.21%,7.56% pts had received 1st, 2nd and 3rd line or above treatments respectively (chemotherapy 69.7%, targeted therapy 15.1%, immunotherapy 43.7%). The ORR according to RECIST V1.1 and iRECIST was 18.49% (1CR, 21 PR, 95% CI 11.96-26.64) and 20.17% (1 iCR, 23 iPR,95% CI 13.37-28.50), respectively. For PD-L1 positive pts the ORR was 15.09% (95%CI 6.75-27.60) and 12% for negative (95%CI 10.98-32.83). For different subtypes, the ORR was 36.36% for cutaneous melanoma, 14.52% for acral primary, 8.7% for mucosal primary, and 25% for unknown primary. The DCR and iDCR was 44.54% and 47.06%, respectively. With a median follow up time of 13.2 months, the median PFS was 3.25 months (95% CI 2.0, 4.1) and the PFS rate at 1 year was 25.8% (95%CI 17.19,35.33). The median OS was 17.91 months (95% CI 13.08,NR) and the OS rates at 1 year was 63.9% (95% CI 53.02, 73.00). Median DOR has not reached and the DOR and iDOR rates at 1 year were 80.64% and 87.39%, respectively. TRAEs occurred in 89.9% of the pts, with grade 3/4 AEs 31.9%, the followings were those incidences ≥1%, hyperglycemia (2.5%), elevated aspartate aminotransferase (1.7%), elevated serum bilirubin (1.7%), elevated serum creatine phosphokinase (1.7%), elevated lipase (1.7%), hypoalbuminemia (1.7%), hypokalemia (1.7%) and diabetic ketoacidosis (1.7%). Conclusions: HX008 shows its efficacy and safety in locally advanced or metastatic melanoma pts in the treatments of 2nd line or above. Randomized controlled studies are now on pending. Clinical trial information: NCT04749485.

Nicotinamide improves NAD+ levels to protect against acetaminophen-induced acute liver injury in mice

Acetaminophen (APAP) overdose causes acute liver injury (ALI). Nicotinamide adenine dinucleotide (NAD) is an essential coenzyme, and NAD⁺ is oxidized type which synthesized from nicotinamide (NAM). The present study aimed to investigate the role of NAD⁺ in ALI and protective property of NAM. The mice were subjected to different doses APAP. After 8 hours, the serum activities of alaninetransaminase (ALT) and aspartate aminotransferase (AST), the hepatic NAD⁺ level and nicotinamide phosphoribosyltransferase (NAMPT) expression were determined. Then, the mice were pretreated with NAM (800 mg/kg), the hepatoprotective effects and the key antioxidative molecules were evaluated. Our findings indicated that APAP resulted in remarkable NAD⁺ depletion in a dose-dependent manner accompanied by NAMPT downregulation, and NAM pretreatment significantly elevated the NAD⁺ decline due to upregulation of NAMPT. Moreover, the downregulated Kelch-like ECH-associated protein-1 (Keap1), upregulated nuclear factor erythroid 2-related factor 2 (Nrf2) and its translocation activation after NAM administration were confirmed, which were in accordance with improved superoxide dismutase (SOD) and glutathione (GSH) levels. Finally, NAM dramatically exhibited hepatoprotective effects by reducing the liver index and necrotic area. This study has suggested that APAP impairs liver NAD⁺ level and NAM is able to improve hepatic NAD⁺ to activate antioxidant pathway against APAP-induced ALI.

A new procedure, free from human assessment, that automatically grades some facial skin signs in men from selfie pictures. Application to changes induced by a severe aerial chronic urban pollution

OBJECTIVE

These were two folds: at first, to develop an automatic grading system specifically dedicated to some facial signs of men, similar to the one previously validated on women of different ethnic ancestry and second, to assess its potential in detecting and grading the possible impacts of a severe aerial urban pollution on some facial signs of Chinese men.

METHODS

In both studies, selfie images were obtained from differently aged men. Nine facial signs were automatically graded through a specific A.I-based algorithm and clinically assessed by a panel of experts and dermatologists. Selfie pictures were taken from individual smartphones of variable optical properties. The first study, designed for developing an automatic grading system, involved three comparable cohorts of men from three different regional ancestries (African, Asian, Caucasian, 110 each) the selfie images of which were acquired under four different lighting conditions. As a second use case study, the facial signs of two cohorts of Chinese men (101 and 100, each), differently aged, regularly exposed to very different aerial urban pollution conditions (UP) were analysed by the same algorithm, selfies being taken under only one lighting condition.

RESULTS

-The new automatic grading system of facial signs suits well to men, showing comparable results than that the one dedicated to women and provides data in close agreement with experts' assessments. -In both cases (expert's or automatic methodology), the accuracy of the scores appeared ethnic-dependent. -The applied case confirmed previous results obtained clinically, that is, that many facial signs were found of an increased severity among men exposed to a severe urban pollution, as compared to those living in a less polluted city. -In both studies, statistical agreements between the automatic grading system and expert's assessments were reached. In some facial signs, the automatic grading system seems offering a slightly better accuracy than the assessments made by the experts.

CONCLUSION

Apart from some minor limitations, this A.I-based automatic grading system, free from human intervention, performed as well as the one previously developed in women, in close agreement with expert's assessments. In epidemiological studies, this system offers an easy, fast, affordable and confidential approach in the detection and quantification of male facial signs.

Effect of 0.01% atropine eye drops on choroidal thickness in myopic children

PURPOSE

To examine the effects of low-dose atropine on the choroidal thickness (CT) of young children in Shanghai, China, as well as the ocular biometrics of myopic patients.

METHODS

A total of 59 eyes of 35 myopic children had subfoveal CT and ocular biometry measurements taken before and after 2weeks, 4weeks, and 8weeks of treatment with 0.01% atropine. All eyes were measured using swept-source optical coherence tomography. CT and changes in it were also recorded.

RESULTS

The choroid exhibited significant and continuous thickening under the fovea after patients were treated with 0.01% atropine. The magnitude of change in CT varied with the location and with the duration of treatment. The greatest change was observed in the fovea. There was no significant relationship between changes in subfoveal CT and axial length.

CONCLUSIONS

Using 0.01% atropine eye drops significantly increased CT in eyes of young myopic children, by variable magnitude depending upon location.

HIF-1α Mediates Osteoclast-Induced Mandibular Condyle Growth via AMPK Signaling

During the mandibular condylar growth, the absorption of calcified cartilage matrix induced by osteoclasts is crucial for the continuous endochondral osteogenesis. Meanwhile, recent studies showed that subchondral bone resided within the low-oxygen microenvironment, and our previous study revealed that hypoxia-inducible transcription factor 1α (HIF-1α) promoted osteoclastogenesis under hypoxia. However, whether HIF-1α regulates the function of osteoclasts in the mandibular condyle cartilage remains elusive. Our study indicated that severe deformity of the mandibular condyle was displayed in 10-wk-old osteoclast-specific HIF-1α conditional knockout (CKO) mice, accompanied by shortened length of condylar process and disorganized fibrocartilage. In 1-, 2-, and 4-wk-old CKO mice, the size of the hypertrophic layer and chondrocytic layer was significantly thickened. In the chondrocytic layer, chondrocytes were atrophied, showing a form of apoptosis in 4-wk-old CKO mice. Furthermore, an increase in the thickness of the fibrous and proliferating layer was observed in 10-wk-old CKO mice, as well as a significant decrease in that of the chondrocytic and hypertrophic chondrocyte layers. Interestingly, the articular surface of the condylar process abnormally presented a horizontal concave shape, and a disk-like acellular connective tissue appeared. In addition, genetic ablation of HIF-1α blunted cartilage matrix loss by subchondral osteoclast deficiency, resulting in a high subchondral bone mass phenotype, accompanied with a decreased number of blood vessels, alkaline phosphatase staining, and vascular endothelial growth factor (VEGF) expression. Mechanistically, the number of osteoclasts in the center of the condyle in CKO mice was significantly reduced by attenuated expression of adenosine 5′-monophosphate-activated protein kinase (AMPK) signaling. These findings reveal a novel influence of HIF-1α function in osteoclasts on maintenance of osteoclast-induced resorption of calcified cartilage matrix via AMPK signaling, as well as subchondral bone formation through VEGF-dependent angiogenesis in bone marrow.

Significant Day-time Ionospheric Perturbation by Thunderstorms along the West African and Congo Sector of Equatorial Region

The equatorial Congo has been recognized as the most active lightning chimney region in the Globe. Although the perturbation of tropospheric thunderstorms on the lower ionosphere has been noticed in the middle latitudes through their transient lightning electric fields or convective gravity waves, the effects on equatorial ionosphere and the horizontal extent of this perturbation remains a mystery because of the difficulties in extracting the effects due to the sporadic nature of the equatorial ionosphere. Here we present observational results showing solid evidence of deviations in ionospheric total electron content (TEC) and its direction of propagation associated with thunderstorms using the method of polynomial filtering, by utilizing the TEC measured from equatorial Global Positioning System (GPS) Receiver stations along the West African region-Congo Basin. The TEC deviations due to the thunderstorms were found to be mostly propagated in a specific direction from the point of the event, with the highest absolute peak TEC at ~±1.5 TECUs. The internal dynamics of the equatorial ionosphere have been found to be suppressed by large thunderstorm effects during the daytime, with negligible impact at night.

[Efficacy of minimally invasive pulmonary surfactant administration in preterm infants with neonatal respiratory distress syndrome: a multicenter clinical trial]

Objective: To explore the feasibility and safety of minimally invasive surfactant administration (MISA) in preterm neonates with respiratory distress syndrome (NRDS). Methods: In this multicenter prospective randomized controlled trial, 92 preterm infants with gestation age ≤30 weeks and diagnosed with NRDS were enrolled in 8 level Ⅲ neonatal intensive care units (NICU) in Beijing-Tianjin-Hebei Region from 1(st) July 2017 to 31(st) December 2018. They were randomly assigned to minimally invasive surfactant administration (MISA) group or endotracheal intubation surfactant administration (EISA) group according to random number generated by computer. Infants in both groups received calf pulmonary surfactant preparation at a dose of 70-100 mg/kg. The data of demography, perinatal situation, medication administration, complications, clinical outcomes in the two groups were compared with Chi-square test, Student's t-test, Mann-Whitney U test or Fisher's exact test. Results: Among the 92 preterm infants, 53 were males, 39 were females; 47 were in the MISA group (25 males), and 45 were in the EISA group (28 males). The gestational age and birth weight were (29.5±1.2) weeks and (1 271±242) g in all patients, (29.5±1.4) weeks and (1 285±256) g in the MISA group, and (29.6±0.9) weeks and (1 255±227) g in the EISA group. The duration of surfactant infusion and the length of whole procedure in the MISA group were significantly longer than that in the EISA group (60 (18, 270) s vs. 50 (30, 60) s, Z=3.009, P=0.003; 90 (60, 300) s vs. 60 (44, 270) s, Z=3.365, P=0.001). For the outcomes, the incidence of hemodynamically significant patent ductus arteriosus (hsPDA) and bronchopulmonary dysplasia (BPD) were lower in the MISA group than in the EISA group (36% (17/47) vs. 67% (30/45), χ(2)=8.556, P=0.003; 26% (12/47) vs. 47% (21/45), χ(2)=4.464, P=0.035). Conclusions: Minimally invasive surfactant administration is applicable in preterm infants ≤30 weeks gestational age with NRDS. Although the length of whole procedure is longer than route endotracheal administration, the benefit of decreasing the incidences of hsPDA and BPD outweighs this demerit.

Genome-wide Identification of Foxf2 Target Genes in Palate Development

Cleft palate is among the most common structural birth defects in humans. Previous studies have shown that mutations in FOXF2 are associated with cleft palate in humans and mice and that Foxf2 acts in a Shh-Foxf-Fgf18-Shh molecular network controlling palatal shelf growth. In this study, we combined RNA-seq and ChIP-seq approaches to identify direct transcriptional target genes mediating Foxf2 function in palate development in mice. Of 155 genes that exhibited Foxf2-dependent expression in the developing palatal mesenchyme, 88 contained or were located next to Foxf2-binding sites. Through in situ hybridization analyses, we demonstrate that expression of many of these target genes, including multiple genes encoding transcription factors and several encoding extracellular matrix-modifying proteins, were specifically upregulated in the posterior region of palatal shelves in Foxf2^-/- mouse embryos. Foxf2 occupancy at many of these putative target loci, including Fgf18, in the developing palatal tissues was verified by ChIP-polymerase chain reaction analyses. One of the Foxf2 target genes, Chst2, encodes a carbohydrate sulfotransferase integral to glycosaminoglycan sulfation. Correlating with ectopic Chst2 expression, Foxf2^-/- embryos a exhibited region-specific increase in sulfated keratan sulfate and a concomitant reduction in chondroitin sulfate accumulation in the posterior palatal mesenchyme. However, expression of the core protein of versican, a major chondroitin sulfate proteoglycan important in palatal shelf morphogenesis, was increased, whereas expression of collagen I was reduced in the corresponding region of the palatal mesenchyme. These results indicate that, in addition to regulating palatal shelf growth through the Fgf18-Shh signaling network, Foxf2 controls palatal shelf morphogenesis through regulating expression of multiple transcription factors as well as through directly controlling the synthesis and processing of extracellular matrix components in the palatal mesenchyme. Our ChIP-seq and RNA-seq data sets provide an excellent resource for comprehensive understanding of the molecular network controlling palate development.

LINC01116 promotes the proliferation and inhibits the apoptosis of gastric cancer cells

OBJECTIVE

To detect the relative expression of long intergenic non-protein coding ribonucleic acid (LINC) 01116 in gastric cancer (GC) tissues and cells and analyze the correlations of LINC01116 expression with the clinicopathologic characteristics of patients and investigate the biological functions of LINC01116 via in vitro experiments.

PATIENTS AND METHODS

The quantitative Real Time Fluorescence-Polymerase Chain Reaction (qRT-PCR) was applied to detect the relative expression level of LINC01116 in 73 cases of tissues and cells in GC patients. The patients were divided into LINC01116 high expression group and LINC01116 low expression group, and the correlations of LINC01116 with patient's pathological characteristics were statistically analyzed. In vitro experiments [cell counting kit-8 (CCK-8) assay, colony formation assay, and flow cytometry] were adopted to investigate the influences of LINC01116 on the biological functions of GC cells.

RESULTS

According to the results of qRT-PCR, the expression of LINC01116 was upregulated in 54 out of 73 cases of tissues (fold change >1), and it was upregulated in GC cells compared with that in the normal gastric mucosal epithelial cells (GES-1). The statistical analysis manifested that the highly expressed LINC01116 was positively correlated with the tumor-node-metastasis (TNM) stage (p=0.008), lymph node metastasis (p=0.005), and depth of invasion (p=0.007) of the GC patients. The patients with high expression of LINC01116 in the GC tissues had a shorter survival time than those with low expression (p=0.017). After interference in the expression of LINC01116, it was shown in CCK-8 assay and colony formation assay that the proliferative capacity of the cells was decreased. The results of flow cytometry indicated that the cell cycle was arrested at the G1/G0 phase, and the apoptosis rate was increased.

CONCLUSIONS

LINC01116 is highly expressed in GC tissues and cells, and highly expressed LINC01116 indicates poor prognosis of the patients, promotes the proliferation, and inhibits the apoptosis of GC cells.

Rapid Identification of Four New Synthetic Cannabinoids in Whole Blood

Objective To establish accurate and rapid methods to identify four new synthetic cannabinoids （JWH-203, JWH-122, 5F-APINACA and AB-CHMINACA） in blood samples. Methods The whole blood samples were extracted by acetonitrile and methanol, screened by gas chromatography-mass spectrometry （GC-MS） then confirmed by liquid chromatography-tandem mass spectrometry （LC-MS/MS） method, and multiple reaction monitoring （MRM） mode was used for quantitative analysis. Results The GC-MS method needed 21 min to complete the analysis, while the LC-MS/MS method needed 5 min. The AB-CHMINACA, JWH-203, 5F-APINACA and JWH-122 all used quasi molecular ion peak as a parent ion. The precursor-product ion combinations were m/z 357.4→312.2, m/z 340.2→125.0, m/z 384.1→135.1 and m/z 356.4→169.2. The four synthetic cannabinoids in blood samples had good linearity in the 1-250 ng/mL mass concentration range （r>0.99）. The limits of detection （LODs） were in the range of 0.1-0.5 ng/mL, the recovery rate was 85.4%-95.2%, the RSD less than 10.0%, and the matrix effect was 80.3%-92.8%. Conclusion The GC-MS and LC-MS/MS chromatographic behaviors and mass spectrometry analysis information of four synthetic cannabinoids were obtained in this study, and the possible causes of differences in chromatographic behaviors were discussed preliminarily. Therefore this study has a suggestive effect on judging the development trend of synthetic cannabinoids. This method can be used for rapid identification of four synthetic cannabinoids in blood, which can provide reference for identification of new synthetic cannabinoids when they are proliferating at present.

Requirement of Hyaluronan Synthase-2 in Craniofacial and Palate Development

Cleft palate is a common major birth defect resulting from disruption of palatal shelf growth, elevation, or fusion during fetal palatogenesis. Whereas the molecular mechanism controlling palatal shelf elevation is not well understood, a prevailing hypothesis is that region-specific accumulation of hyaluronan, a predominant extracellular glycosaminoglycan in developing palatal mesenchyme, plays a major role in palatal shelf elevation. However, direct genetic evidence for a requirement of hyaluronan in palate development is still lacking. In this study, we show that Has2, 1 of 3 hyaluronan synthases in mammals, plays a major role in hyaluronan synthesis in the neural crest-derived craniofacial mesenchyme during palatogenesis in mice. We analyzed developmental defects caused by tissue-specific inactivation of Has2 throughout the cranial neural crest lineage or specifically in developing palatal or mandibular mesenchyme, respectively, using Wnt1-Cre, Osr2-Cre, and Hand2-Cre transgenic mice. Inactivation of Has2 either throughout the neural crest lineage or specifically in the developing palatal mesenchyme caused reduced palatal shelf size and increased palatal mesenchyme cell density prior to the time of normal palatal shelf elevation. Whereas both Has2f/f;Wnt1-Cre and Has2f/f;Osr2-Cre mutant mice exhibit cleft palate at complete penetrance, the Has2f/f; Wnt1-Cre fetuses showed dramatically reduced mandible size and complete failure of palatal shelf elevation, whereas Has2f/f;Osr2-Cre fetuses had normal mandibles and delayed palatal shelf elevation. All Has2f/f;Hand2-Cre pups showed reduced mandible size and about 50% of them had cleft palate with disruption of palatal shelf elevation. Results from explant culture assays indicate that disruption of palatal shelf elevation in Has2f/f;Hand2-Cre mutant fetuses resulted from physical obstruction by the malformed mandible and tongue. Together, these data indicate that hyaluronan plays a crucial intrinsic role in palatal shelf expansion and timely reorientation to the horizontal position above the tongue as well as an important role in mandibular morphogenesis that secondarily affects palatal shelf elevation.

P3623Integrating depression and acute coronary syndrome care in low-resource hospitals in china: primary results from the I-Care randomised clinical trial

Background

Depression and acute coronary syndromes (ACS) are significant public health challenges. Patients with ACS often experience depression, which adversely affects prognosis. Low-cost, sustainable, and effective service models that integrate depression care into the management of ACS patients to reduce depression and improve ACS outcomes are critically needed.

Purpose

I-CARE study is a multi-center, randomised clinical trial (RCT) to evaluate the efficacy of an 11-month integrated care (IC) intervention compared to usual care (UC) in the management of ACS patients.

Methods

The I-CARE RCT was conducted between October 2014 and March 2018 in 16 rural Chinese hospitals. A total of 4041 patients with ACS were consecutively enrolled and randomly assigned in a 1:1 ratio to an IC intervention consisting of nurse-led risk factor management, group-based counseling supplemented by individual problem solving therapy and antidepressant medications as needed, or UC. The primary outcome was change in Patient Health Questionnaire-9 (PHQ-9) scores from baseline to 6 and 12 months. Secondary outcomes included incidence of major adverse events (MAEs) after discharge, quality of life (EQ5D), and adherence to ACS secondary prevention medications. Data analysis used a multilevel mixed-effects model with hospital-level and subject-level random-effect intercepts and hospital-level random slope incorporated to adjust for clustering effect. Primary analyses followed the intent-to-treat principle.

Results

The mean age of the patients was 61±10 years and 63% were men; however, only 3.3% were classified as depressed based upon a cutoff of ≥10 on the PHQ-9, and 26.9% had PHQ-9 scores between 5 to 9 at the baseline. There were no significant differences in patients' clinical characteristics between IC and UC groups. Changes in PHQ-9 scores from baseline to 6- and 12-months did not differ between treatment groups (−1.47 in IC group vs −1.40 in UC group; adjusted mean difference, −0.04; 95% CI, −0.17 to 0.08 at 6-months; −1.62 in IC group vs −1.54 in UC group; adjusted mean difference, −0.06; 95% CI: −0.19 to 0.06 at 12-months).The risk of MAEs after discharge between IC and UC groups also did not differ significantly (42.1% vs 43.1%; p=0.307).

Conclusions

Results from the I-CARE trial showed that a nurse-coordinated ACS and depression IC intervention did not reduce depression or improve clinical outcomes among patients with ACS compared to usual care controls. The low prevalence of depression was unexpected and may have minimized the potential added benefits of the IC intervention on depression and clinical outcomes compared to UC.

Acknowledgement/Funding

This study is supported by a grant from the National Institute of Mental Health (R01MH100332).

A novel 86-bp indel of the motilin receptor gene is significantly associated with growth and carcass traits in Gushi-Anka F2 reciprocal cross chickens

1. A previous whole-genome association analysis has identified the motilin receptor gene (MLNR), which regulates gastrointestinal motility and gastric emptying, as a candidate gene related to chicken growth.2. MLNR mRNA was expressed in all tissues tested, and the expression level in digestive tissues was greater than in other tissues. Expression levels in the pancreas, duodenum and glandular stomach at day old and one, two and three weeks of age indicated a possible correlation with the digestive system. This suggested that the MLNR gene plays a central role in gastrointestinal tract function and affects the growth and development of chickens. Moreover, there was a significant difference in expression in the glandular stomach tissue between Ross 308 and Gushi chickens at six weeks of age.3. Re-sequencing revealed an 86-bp insertion/deletion polymorphism in the downstream region of the MLNR gene. The mutation locus was genotyped in 2,261 individuals from nine different chicken breeds. MLNR expression levels in the glandular stomach of chickens with DD genotypes were greater than those in chickens with the ID and II genotypes. The DD genotype was the most dominant genotype in commercial broiler's (Ross 308 and Arbor Acres broilers), and the D allele frequency in these breeds exceeded 91%. The deletion mutation tended towards fixation in commercial broilers.4. Association with growth and carcass traits analysed in a Gushi-Anka F₂ intercrossed population, showed that the DD genotype was significantly associated with the greatest growth and carcass trait values, whereas values associated with the II genotype were the lowest in the F₂ reciprocal cross chickens.5. The results suggest that the mutation is strongly associated with growth related traits and it is likely to be useful for marker-assisted selection of chickens.

Genetic parameters of the thick-to-thin albumen ratio and egg compositional traits in layer-type chickens

1. Generating a robust egg albumen is one of the major factors contributing to interior egg quality owing to its nutritive value and superior appearance. However, the genetic factors regulating the proportion of thick albumen are poorly understood. 2. In this study, 1330 eggs were collected from 450 Rhode Island White layers, aged 40 weeks, to measure egg compositional traits for three successive days. The restricted maximum likelihood method was applied to estimate genetic parameters for the thick-to-thin albumen ratio and other egg compositional traits. A univariate animal model was fitted to calculate heritability for each trait. 3. The heritabilities of egg weight, yolk weight, albumen height, Haugh units, percentages of yolk, thick albumen, thin albumen and the thick-to-thin albumen ratio were 0.32, 0.34, 0.28, 0.47, 0.61, 0.39, 0.31, and 0.45, respectively. The percentage of thick albumen was negatively correlated genetically with all traits, and percentage of thin albumen was negatively correlated genetically with all traits except for Haugh units. The thick-to-thin albumen ratio was positively correlated genetically with egg weight, albumen height and Haugh units, with correlations ranging from 0.21 to 0.54. 4. The results indicated that the percentage of thick albumen and the thick-to-thin albumen ratio were found to be moderately to highly heritable, and selection for the thick-to-thin albumen ratio could be conducive to the improvement of egg albumen quality.