Birds of a feather age together: telomere dynamics and social behavior predict life span in female Japanese quail (Coturnix japonica).

Social support is vital for mental and physical health and is linked to lower rates of disease and early mortality. Conversely, anti-social behavior can increase mortality risks, both for the initiator and target of the behavior. Chronic stress, which also can increase mortality, may serve as an important link between social behavior and healthy lifespan. There is a growing body of literature in both humans, and model organisms, that chronic social stress can result in more rapid telomere shortening, a measure of biological aging. Here we examine the role of anti-social behavior and social support on physiological markers of stress and aging in the social Japanese quail, Coturnix Japonica. Birds were maintained in groups for their entire lifespan, and longitudinal measures of antisocial behavior (aggressive agonistic behavior), social support (affiliative behavior), baseline corticosterone, change in telomere length, and lifespan were measured. We found quail in affiliative relationships both committed less and were the targets of less aggression compared to birds who were not in these relationships. In addition, birds displaying affiliative behavior had longer telomeres, and longer lifespans. Our work suggests a novel pathway by which social support may buffer against damage at the cellular level resulting in telomere protection and subsequent longer lifespans.

Polystyrene microplastics disrupted physical barriers, microbiota composition and immune responses in the cecum of developmental Japanese quails.

Microplastics, a new type of emerging pollutant, is ubiquitous in terrestrial and water environments. Microplastics have become a growing concern due to their impacts on the environment, animal, and human health. Birds also suffer from microplastics contamination. In this study, we examined the toxic effects of polystyrene microplastics (PS-MPs) exposure on physical barrier, microbial community, and immune function in the cecum of a model bird species-Japanese quail (Coturnix japonica). The one-week-old birds were fed on environmentally relevant concentrations of 20 µg/kg, 400 µg/kg, and 8 mg/kg PS-MPs in the diet for 5 weeks. The results showed that microplastics could cause microstructural damages characterized by lamina propria damage and epithelial cell vacuolation and ultrastructural injuries including microvilli breakage and disarrangement as well as mitochondrial vacuolation in the cecum of quails. In particular, blurry tight junctions, wider desmosomes spacing, and gene expression alteration indicated cecal tight junction malfunction. Moreover, mucous layer breakdown and mucin decrease indicated that chemical barrier was disturbed by PS-MPs. PS-MPs also changed cecal microbial diversity. In addition, structural deformation of cecal tonsils and increasing proinflammatory cytokines suggested cecal immune disorder and inflammation responses by PS-MPs exposure. Our results suggested that microplastics negatively affected digestive system and might pose great health risks to terrestrial birds.

Quail GHRL and LEAP2 gene cloning, polymorphism detection, phylogenetic analysis, tissue expression profiling and its association analysis with feed intake.

The GHRL, LEAP2, and GHSR system have recently been identified as important regulators of feed intake in mammals and chickens. However, the complete cloning of the quail GHRL (qGHRL) and quail LEAP2 (qLEAP2) genes, as well as their association with feed intake, remains unclear. This study cloned the entire qGHRL and qLEAP2 cDNA sequence in Chinese yellow quail (Coturnix japonica), including the 5' and 3' untranslated regions. Sanger sequencing analysis revealed no missense mutations in the coding region of qGHRL and qLEAP2. Subsequently, phylogenetic analysis and protein homology alignment were conducted on the qGHRL and qLEAP2 in major poultry species. The findings of this research indicated that the qGHRL and qLEAP2 sequences exhibit a high degree of similarity with those of chicken and turkey. Specifically, the N-terminal 6 amino acids of GHRL mature peptides and all the mature peptide sequence of LEAP2 exhibited consistent patterns across all species examined. The analysis of tissue gene expression profiles indicated that qGHRL was primarily expressed in the proventriculus and brain tissue, whereas qLEAP2 exhibited higher expression levels in the intestinal tissue, kidney, and liver tissue, differing slightly from previous studies conducted on chicken. It is necessary to investigate the significance of elevated expression of qGHRL in brain and qLEAP2 in kidney in the future. Further research has shown that the expression of qLEAP2 can quickly respond to changes in different energy states, whereas qGHRL does not exhibit the same capability. Overall, this study successfully cloned the complete cDNA sequences of qGHRL and qLEAP2, and conducted a comprehensive examination of their tissue expression profiles and gene expression levels in the main expressing organs across different energy states. Our current findings suggested that qLEAP2 is highly expressed in the liver, intestine, and kidney, and its expression level is regulated by feed intake.

Dietary restriction and life-history trade-offs: insights into mTOR pathway regulation and reproductive investment in Japanese quail.

Resources are needed for growth, reproduction and survival, and organisms must trade off limited resources among competing processes. Nutritional availability in organisms is sensed and monitored by nutrient-sensing pathways that can trigger physiological changes or alter gene expression. Previous studies have proposed that one such signalling pathway, the mechanistic target of rapamycin (mTOR), underpins a form of adaptive plasticity when individuals encounter constraints in their energy budget. Despite the fundamental importance of this process in evolutionary biology, how nutritional limitation is regulated through the expression of genes governing this pathway and its consequential effects on fitness remain understudied, particularly in birds. We used dietary restriction to simulate resource depletion and examined its effects on body mass, reproduction and gene expression in Japanese quails (Coturnix japonica). Quails were subjected to feeding at 20%, 30% and 40% restriction levels or ad libitum for 2 weeks. All restricted groups exhibited reduced body mass, whereas reductions in the number and mass of eggs were observed only under more severe restrictions. Additionally, dietary restriction led to decreased expression of mTOR and insulin-like growth factor 1 (IGF1), whereas the ribosomal protein S6 kinase 1 (RPS6K1) and autophagy-related genes (ATG9A and ATG5) were upregulated. The pattern in which mTOR responded to restriction was similar to that for body mass. Regardless of the treatment, proportionally higher reproductive investment was associated with individual variation in mTOR expression. These findings reveal the connection between dietary intake and the expression of mTOR and related genes in this pathway.

The potential of lemon peel powder as an additive in layer quails (Coturnix coturnix Japonica): An experimental study.

The current research intended to examine the impact of dietary lemon peel powder (LPP) on laying quail performance, egg quality criteria, and the antioxidant capacity of the yolk. A total of 120 female Japanese quails (272.6±9.3 g), aged 21 weeks, were allotted to 6 trial groups, each with 5 replicates of 4 quails. Additions of 0, 1, 2, 3, 4, or 5 g/kg of LPP to the basal diet were used to create the treatment groups. Quails were fed ad libitum for 70 days. Neither performance parameters nor egg production was affected by LPP. However, eggshell-breaking strength improved by adding 2 g/kg LPP to the diet, but worsened at 5 g/kg. Moreover, the relative weight of eggshell and yolk L* value decreased with the treatments. Dietary LPP enhanced oxidative stability, reducing malondialdehyde (MDA) and increasing 1,1-diphenyl-2-picrylhydrazyl (DPPH) yolk values. The current study demonstrated that LPP, a safe and easily accessible agricultural by-product, enhanced eggshell quality when it was included in the diet of laying quails at doses of 2 g/kg. In contrast, improvement of yolk antioxidant capacity required increased amounts of LPP (4 g/kg). LPP could be advantageous to animal nutrition as an adequate substitute to reduce waste by-products.

Evaluation of biological selenium nanoparticles on growth performance, histopathology of vital organs and genotoxicity in Japanese quails (coturnix coturnix japonica).

Research on the effects of selenium nanoparticles (Se-NPs), particularly in Japanese quails, is lacking, especially regarding the potential for DNA damage. Therefore, this study aimed to investigate the impact of administering 0.2 and 0.4 mg/kg of Se-NPs on the growth performance, DNA integrity, and histopathological alterations of the liver, lung, kidney, and heart in quails. A total of 480 one-day-old Japanese quails were divided into three experimental groups as follows: Group 1 served as the control and received only basic feed, while Group 2 and 3 received 0.2 mg/kg and 0.4 mg/kg of Se-NPs via oral gavage. Our results suggested that, birds fed with Se-NPs at both levels significantly (p < .01) reduced feed intake, however, weight gain was significantly (p < .01) increased in quails supplemented with 0.2 mg/kg. Similarly, feed conversion ratio (FCR) was significantly (p < .01) reduced in group supplemented with 0.2 mg/kg Se-NPs. White blood cells increased significantly (P0.01) in 0.4 mg/kg while haemoglobin and red cell distribution width decreased (p < .01) in the same group. Both treatment regimens resulted in DNA damage and histopathological alterations; however, the adverse effects were more prominent in the group receiving the higher dose of 0.4 mg/kg. These findings indicate that the lower dose of 0.2 mg/kg may have beneficial effects on growth. However, the higher dose of 0.4 mg/kg not only negatively impacts growth but also leads to histopathological alterations in major organs of the body and DNA damage as well.

Expression of mRNAs Encoding Hypothalamic Small Proteins, Neurosecretory Protein GL and Neurosecretory Protein GM, in the Japanese Quail, Coturnix japonica.

Neurosecretory protein GL (NPGL) and neurosecretory protein GM (NPGM) are novel neuropeptides that have been discovered in the hypothalamic infundibulum of chickens. NPGL and NPGM play important roles in lipid metabolism in juvenile chickens. The physiological functions of NPGL and NPGM in sexually mature birds remain unknown. The Japanese quail (Coturnix japonica) seems to be an appropriate model for analyzing NPGL and NPGM during sexual maturity. However, studies on NPGL or NPGM have yet to be reported in the Japanese quail. In the present study, we identified cDNAs encoding precursor proteins of NPGL and NPGM in the quail hypothalamus. In situ hybridization revealed that NPGL mRNA-expressing cells in the hypothalamus were localized in the infundibular nucleus and median eminence, and NPGM mRNA-expressing cells were only found in the mammillary nucleus. Immunohistochemistry revealed that NPGM-like immunoreactive cells were distributed in the mammillary nucleus, whereas NPGL-like immunoreactive cells were not detected in the hypothalamus. Real-time PCR analysis indicated that the expression of NPGL mRNA was higher in the hypothalamus of females than in that of males, and NPGM mRNA expression showed no sex differences. NPGL and NPGM mRNA expression in males was upregulated after 24 h of food deprivation. In females, only NPGM mRNA expression was increased by fasting. These results suggest that the physiological functions of NPGL and NPGM are different in quail, and these factors are involved in sex differences in energy metabolism.

Dietary restriction reveals sex-specific expression of the mTOR pathway genes in Japanese quails.

Limited resources affect an organism's physiology through the conserved metabolic pathway, the mechanistic target of rapamycin (mTOR). Males and females often react differently to nutritional limitation, but whether it leads to differential mTOR pathway expression remains unknown. Recently, we found that dietary restriction (DR) induced significant changes in the expression of mTOR pathway genes in female Japanese quails (Coturnix japonica). We simultaneously exposed 32 male and female Japanese quails to either 20%, 30%, 40% restriction or ad libitum feeding for 14 days and determined the expression of six key genes of the mTOR pathway in the liver to investigate sex differences in the expression patterns. We found that DR significantly reduced body mass, albeit the effect was milder in males compared to females. We observed sex-specific liver gene expression. DR downregulated mTOR expression more in females than in males. Under moderate DR, ATG9A and RPS6K1 expressions were increased more in males than in females. Like females, body mass in males was correlated positively with mTOR and IGF1, but negatively with ATG9A and RS6K1 expressions. Our findings highlight that sexes may cope with nutritional deficits differently and emphasise the importance of considering sexual differences in studies of dietary restriction.

Age-related changes in testicular histological structure, testosterone level, libido and semen traits in male Coturnix quail.

To investigate the effect of age in male quail on testicular weight and histology, sexual libido and semen characteristics, a study was performed on 100 quails at 10, 16, 22, 28 and 34 weeks of age. The body and testicular weights were significantly (p < .05) higher at 16 and 22 than at 28 weeks of age. The circumference and diameter of the seminiferous tubules were significantly (p < .05) higher at 28 and 34 than at 10 and 16 weeks of age. Histological evaluation of testicular slices revealed advanced and effective seminiferous tubes as early as 10 weeks, while spermatogenic activity peaked at 16 weeks of age. The highest semen volume, sperm motility and sperm concentration were observed at weeks of age and then decreased gradually with age. At the same time, the testosterone level and libido were significantly (p < .05) higher at 22 than at 10 weeks of age. Furthermore, the age was positive (p < .05), correlated to seminiferous tubule circumference and diameter, and negative (p < .05), correlated to sperm concentration. In conclusion, the age of quail markedly affected the testicular histological structure, libido, testosterone level and semen characteristics.

Genome-Wide Association Study Revealed Putative SNPs and Candidate Genes Associated with Growth and Meat Traits in Japanese Quail.

The search for SNPs and candidate genes that determine the manifestation of major selected traits is one crucial objective for genomic selection aimed at increasing poultry production efficiency. Here, we report a genome-wide association study (GWAS) for traits characterizing meat performance in the domestic quail. A total of 146 males from an F2 reference population resulting from crossing a fast (Japanese) and a slow (Texas White) growing breed were examined. Using the genotyping-by-sequencing technique, genomic data were obtained for 115,743 SNPs (92,618 SNPs after quality control) that were employed in this GWAS. The results identified significant SNPs associated with the following traits at 8 weeks of age: body weight (nine SNPs), daily body weight gain (eight SNPs), dressed weight (33 SNPs), and weights of breast (18 SNPs), thigh (eight SNPs), and drumstick (three SNPs). Also, 12 SNPs and five candidate genes (GNAL, DNAJC6, LEPR, SPAG9, and SLC27A4) shared associations with three or more traits. These findings are consistent with the understanding of the genetic complexity of body weight-related traits in quail. The identified SNPs and genes can be used in effective quail breeding as molecular genetic markers for growth and meat characteristics for the purpose of genetic improvement.

Long-term fasting induced basal thermogenesis flexibility in female Japanese quails.

Male Japanese quails (Coturnix japonica) have been found to exhibit a three-phase metabolic change when subjected to prolonged fasting, during which basal thermogenesis is significantly reduced. A study had shown that there is a significant difference in the body temperature between male and female Japanese quails. However, whether female Japanese quails also show the same characteristic three-phase metabolic change during prolonged fasting and the underlying thermogenesis mechanisms associated with such changes are still unclear. In this study, female Japanese quails were subjected to prolonged starvation, and the body mass, basal metabolic rate (BMR), body temperature, mass of tissues and organs, body fat content, the state-4 respiration (S4R) and cytochrome c oxidase (CCO) activity in the muscle and liver of these birds were measured to determine the status of metabolic changes triggered by the starvation. In addition, the levels of glucose, triglyceride (TG) and uric acid, and thyroid hormones (T3 and T4) in the serum and the mRNA levels of myostatin (MSTN) and avian uncoupling protein (av-UCP) in the muscle were also measured. The results revealed the existence of a three-phase stage similar to that found in male Japanese quails undergoing prolonged starvation. Fasting resulted in significantly lower body mass, BMR, body temperature, tissues masses and most organs masses, as well as S4R and CCO activity in the muscle and liver. The mRNA level of av-UCP decreased during fasting, while that of MSTN increased but only during Phase I and II and decreased significantly during Phase III. Fasting also significantly lowered the T3 level and the ratio of T3/T4 in the serum. These results indicated that female Japanese quails showed an adaptive response in basal thermogenesis at multiple hierarchical levels, from organismal to biochemical, enzyme and cellular level, gene and endocrine levels and this integrated adjustment could be a part of the adaptation used by female quails to survive long-term fasting.

Signaling pathways and regulatory networks in quail skeletal muscle development: insights from whole transcriptome sequencing.

Quail, as an advantageous avian model organism due to its compact size and short reproductive cycle, holds substantial potential for enhancing our understanding of skeletal muscle development. The quantity of skeletal muscle represents a vital economic trait in poultry production. Unraveling the molecular mechanisms governing quail skeletal muscle development is of paramount importance for optimizing meat and egg yield through selective breeding programs. However, a comprehensive characterization of the regulatory dynamics and molecular control underpinning quail skeletal muscle development remains elusive. In this study, through the application of HE staining on quail leg muscle sections, coupled with preceding fluorescence quantification PCR of markers indicative of skeletal muscle differentiation, we have delineated embryonic day 9 (E9) and embryonic day 14 (E14) as the start and ending points, respectively, of quail skeletal muscle differentiation. Then, we employed whole transcriptome sequencing to investigate the temporal expression profiles of leg muscles in quail embryos at the initiation of differentiation (E9) and upon completion of differentiation (E14). Our analysis revealed the expression patterns of 12,012 genes, 625 lncRNAs, 14,457 circRNAs, and 969 miRNAs in quail skeletal muscle samples. Differential expression analysis between the E14 and E9 groups uncovered 3,479 differentially expressed mRNAs, 124 lncRNAs, 292 circRNAs, and 154 miRNAs. Furthermore, enrichment analysis highlighted the heightened activity of signaling pathways related to skeletal muscle metabolism and intermuscular fat formation, such as the ECM-receptor interaction, focal adhesion, and PPAR signaling pathway during E14 skeletal muscle development. Conversely, the E9 stage exhibited a prevalence of pathways associated with myoblast proliferation, exemplified by cell cycle processes. Additionally, we constructed regulatory networks encompassing lncRNA‒mRNA, miRNA‒mRNA, lncRNA‒miRNA-mRNA, and circRNA-miRNA‒mRNA interactions, thus shedding light on their putative roles within quail skeletal muscle. Collectively, our findings illuminate the gene and non-coding RNA expression characteristics during quail skeletal muscle development, serving as a foundation for future investigations into the regulatory mechanisms governing non-coding RNA and quail skeletal muscle development in poultry production.

Dietary supplementation with Dunaliella salina microalga promotes quail growth by altering lipid profile and immunity.

The goals of the current research are to ascertain the impacts of Dunaliella salina (DS) on quail growth, carcass criteria, liver and kidney functions, lipid profile, and immune response. Two hundred and forty 7-day-old quail chicks were divided equally into 4 separate groups with 6 replicates with 10 birds each. The groups were as follows: 1) control diet (the basal feed without DS), 2) control diet enriched with 0.25 g DS/kg, 3) control diet enriched with 0.50 g DS/kg, and 4) control diet enriched with 1.00 g DS/kg. Results elucidated that the birds which consumed 0.5 and 1 g DS/kg diet performed better than other birds in terms of live body weight (LBW), body weight gain (BWG), and feed conversion ratio (FCR). There were no significant changes in feed intake (FI) and carcass characteristics due to different dietary DS levels. Compared to the control group, DS-treated groups had better lipid profile (low total cholesterol and LDL values and high HDL values) and immune response (complement 3 values). The quails consumed feeds with different levels of DS had greater (P < 0.038) C3 compared to control. Adding 0.5 and 1 g DS/kg lowered blood concentrations of triglycerides and total protein (TP) values. The high level of DS (1 g/kg) had higher albumin values and lower AST values than other groups (P < 0.05). The creatinine values were at the lowest levels in the group consumed 0.50 g DS/kg feed. No changes (P > 0.05) were demonstrated among experimental groups in the ALT, urea, and lysozyme values. In conclusion, adding D. salina to growing quail diets enhanced growth, immune system, blood lipid profile, and kidney and liver function.

Effects of the algae derivatives on performance, intestinal histomorphology, ileal microflora, and egg yolk biochemistry of laying Japanese quail.

We examined the effect of the Persian Gulf algae derivates, phycocyanin (PC) and fucoidan (FUC), on production performance, egg quality, intestinal histomorphology, ileal microflora, and egg yolk biochemistry of laying Japanese quail. A total of 250 six-wk-old Japanese quails with an average body weight of 215 ± 10 g were allocated to 5 treatments, 5 replicates and 10 birds in each replicate in a completely randomized design. The treatment groups received PC (from Spirulina platensis) and FUC (from brown seaweed) in their drinking water while control groups did not. Treatment groups received PC and FUC at 20 or 40 mg/L levels (denoted as PC20, PC40, FUC20, and FUC40, respectively). All birds were fed the same diet. All treatments significantly improved the percentage of hen day egg production (HDEP) (P = 0.002), egg mass (P = 0.002), and feed conversion ratio (FCR) (P = 0.022) but no difference was noted in egg weight (EW) and feed intake (FI). Different levels of PC and FUC significantly increased the thickness of eggshells (P = 0.022); however, the weight of the digestive tract (liver, spleen, proventriculus, gizzard, and pancreas) and oviduct was not affected. Algal derivates improved the villus height (P = 0.007) and crypt depth (P = 0.007) of the duodenum, as well as, the villus height (P = 0.005) and crypt depth (P = 0.026) of the jejunum. Both algal derivates positively affected the intestinal microflora (populations of Lactobacillus (P = 0.017), Coliform (P = 0.005), and Clostridium (P = 0.000)) whereas aerobic bacteria were unaffected. Yolk cholesterol P = 0.012) and yolk malondialdehyde P = 0.050) content were significantly reduced in experimental treatments compared to the control group. In conclusion, our results showed that the treatment of laying Japanese quails with algal derivates positively affects quail performance, intestinal morphology, intestinal microflora, and yolk cholesterol and malondialdehyde. Additional studies exploring optimal dosages and mechanisms of action is warranted to fully understand the scope of the algae derivates in poultry production.

The incorporation of sumac seed powder (Rhus coriaria L.) into the diet of quail breeders as a novel feed additive.

A total of 150 adult quails, aged 8 wk, were divided into 5 groups to study the effect of sumac seed powder on reproductive and productive parameters, egg quality, digestive enzymes, and quail breeders' blood profiles. Dietary supplements containing sumac powder were formulated as follows: group 1 (G1) (control, only basal diet); group 2 (G2) (basal diet + 1 g sumac powder/kg diet); group 3 (G3) (basal diet + 2 g sumac powder/kg diet); group 4 (G4) (basal diet + 3 g sumac powder/kg diet); and group 5 (G5) (basal diet + 4 g sumac powder/kg diet). The feed conversion ratio was significantly higher at all levels of sumac powder (P < 0.05) compared to the control group (G1). Overall, during the study (8-16 wk), quail-fed 3 g sumac powder/kg diet (G4) showed no significant increase (P > 0.05) in the feed intake compared to the control group. Sumac powder supplementation significantly (P < 0.05) increased egg number, egg weight, egg mass, fertility, and hatchability. While supplementing with sumac powder did not impact other egg quality parameters, it did significantly (P < 0.05) increase yolk percentage, Haugh unit, and unit surface shell weight. Furthermore, when compared to the control group (G1), birds given 2, 3, or 4 g of sumac powder/kg diet showed a significant improvement (P < 0.05) in hematological parameters such as red blood cells, white blood cells, and hemoglobin, as well as a decrease in glucose levels. Feeding quail with a 3 g sumac powder/kg diet (G4) resulted in significantly (P < 0.05) higher globulin levels and improved albumin/globulin ratio compared to other treatments and control (G1). Sumac powder intake significantly (P < 0.05) reduced plasma lipid profile, liver enzymes (aspartate aminotransferase, and alanine aminotransferase), and kidney functions (creatinine, and urea). Furthermore, the supplementation of sumac powder resulted in a substantial increase (P < 0.05) in the levels of amylase, lipase, and protease. Sumac powder administration also significantly (P < 0.05) improves immunity by boosting IgM, IgG, IgA, and lysozyme levels in quail breeders' plasma. Supplementing with sumac powder, on the other hand, increased levels of reduced glutathione, total antioxidant capacity, catalase, and superoxide dismutase. The results of the current study indicated that the addition of 1, 2, 3, and 4 g of sumac powder to the diet of Japanese quail breeders led to improvements in egg quality, digestive enzymes, reproductive and productive performances, and most blood hematological and biochemical parameters.

Ethynylestradiol feminizes gene expression partly in testis developing as ovotestis and disrupts asymmetric Müllerian duct development by eliminating asymmetric gene expression in Japanese quail embryos.

In avian embryos, xenoestrogens induce abnormalities in reproductive organs, particularly the testes and Müllerian ducts (MDs). However, the molecular mechanisms remain poorly understood. We investigated the effects of ethynylestradiol (EE2) exposure on gene expression associated with reproductive organ development in Japanese quail embryos. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis revealed that the left testis containing ovary-like tissues following EE2 exposure highly expressed the genes for steroidogenic enzymes (P450scc, P45017α, lyase, and 3ß-HSD) and estrogen receptor-ß, compared to the right testis. No asymmetry was found in these gene expression without EE2. EE2 induced hypertrophy in female MDs and suppressed atrophy in male MDs on both sides. RNA sequencing analysis of female MDs showed 1,366 differentially expressed genes between developing left MD and atrophied right MD in the absence of EE2, and these genes were enriched in Gene Ontology terms related to organogenesis, including cell proliferation, migration and differentiation, and angiogenesis. However, EE2 reduced asymmetrically expressed genes to 21. RT-qPCR analysis indicated that genes promoting cell cycle progression and oncogenesis were more highly expressed in the left MD than in the right MD, but EE2 eliminated such asymmetric gene expression by increasing levels on the right side. EE2-exposed males showed overexpression of these genes in both MDs. This study reveals part of the molecular basis of xenoestrogen-induced abnormalities in avian reproductive organs, where EE2 may partly feminize gene expression in the left testis, developing as the ovotestis, and induce bilateral MD malformation by canceling asymmetric gene expression underlying MD development.

Embryonic methionine triggers post-natal developmental programming in Japanese quail.

Embryonic development is one of the most sensitive and critical stages when maternal effects may influence the offspring's phenotype. In birds and other oviparous species, embryonic development is confined to the eggs, therefore females must deposit resources into the eggs to prepare the offspring for the prevailing post-natal conditions. However, the mechanisms of such phenotypic adjustments remain poorly understood. We simulated a maternal nutritional transfer by injecting 1 mg of L-methionine solution into Japanese quail eggs before the onset of incubation. The increase in early methionine concentration in eggs activated the insulin/insulin-like signalling and mechanistic target of rapamycin (IIS/mTOR) signalling pathways and affected post-natal developmental trajectories. Chicks from methionine-supplemented eggs had higher expression of liver IGF1 and mTOR genes at hatching but were similar in size, and the phenotypic effects of increased growth became apparent only a week later and remained up to three weeks. Circulating levels of insulin-like growth factor-1 (IGF-1) and expression of ribosomal protein serine 6 kinase 1 (RPS6K1), the mTOR downstream effector, were elevated only three weeks after hatching. These results show that specific nutritional cues may have phenotypic programming effects by sequentially activating specific nutrient-sensing pathways and achieving transgenerational phenotypic plasticity.

The developmental architecture of the crop of quail embryos (Coturnix coturnix): Morphometric, light and scanning electron microscopy.

The present study focused on the histogenesis of the crop in quail embryos. The developmental sequence was recorded from day 10 of incubation to the hatching day (17th day) by gross anatomy, morphometric analysis and by using light and scanning electron microscope (SEM). Grossly, the crop was distinguished as an enlarged pouch of the cervical oesophagus on the 12th day of incubation. Histologically, the development of the crop began on the 10th day of incubation. The muscularis mucosae was observed as a small, thin layer of myoblast cells on the 10th day, then it appeared as longitudinally arranged smooth muscle fibres with progression of the developmental age till hatching day. The submucosal layer was also observed on the 10th day, while the lamina propria, muscular layer (inner circular and outer longitudinal layers of smooth muscle fibre) and glandular primordia were detected on the 12th day. The epithelial cells of crop revealed affinity for PAS stain and AB-PAS on the 10th day of incubation till the 17th day, while the affinity for AB stain appeared on the 14th day of incubation. Additionally, the glandular cells showed the positive for AB, PAS and AB-PAS on the 12th day of incubation. SEM sections showed variable sizes of the openings of the oesophageal glands. In conclusion, the present study provided a detailed overview of the histogenesis of the crop in quail embryos.

A set of cross-correlated relaxation experiments to probe the correlation time of two different and complementary spin pairs.

Intrinsically disordered proteins (IDPs) defy the conventional structure-function paradigm by lacking a well-defined tertiary structure and exhibiting inherent flexibility. This flexibility leads to distinctive spin relaxation modes, reflecting isolated and specific motions within individual peptide planes. In this work, we propose a new pulse sequence to measure the longitudinal 13C' CSA-13C'-13Cα DD CCR rate [Formula: see text] and present a novel 3D version of the transverse [Formula: see text] CCR rate, adopting the symmetrical reconversion approach. We combined these rates with the analogous ΓxyN/NH and ΓzN/NH CCR rates to derive residue-specific correlation times for both spin-pairs within the same peptide plane. The presented approach offers a straightforward and intuitive way to compare the correlation times of two different and complementary spin vectors, anticipated to be a valuable aid to determine IDPs backbone dihedral angles distributions. We performed the proposed experiments on two systems: a folded protein ubiquitin and Coturnix japonica osteopontin, a prototypical IDP. Comparative analyses of the results show that the correlation times of different residues vary more for IDPs than globular proteins, indicating that the dynamics of IDPs is largely heterogeneous and dominated by local fluctuations.

Determining the hierarchical order by which intestinal tract, administered diet, and individual relay can shape the gut microbiome of fattening quails.

A bacterial metabarcoding approach was used to compare the microbiome composition of caecal and faecal samples from fattening Japanese quails (Coturnix coturnix japonica) fed three different diet regimes. The tested feedstuffs included (1) a commercial diet for fattening quails, (2) a commercial diet containing 12% full-fat silkworm (Bombyx mori) pupae meal, and (3) a commercial diet containing 12% defatted silkworm pupae meal. The aim of the experiment was to verify the relative effect of three variables (diet type, gut tract comparing caecum to rectum, and individual animal) in determining the level of bacterial community dissimilarity to rank the relevance of each of the three factors in affecting and shaping community composition. To infer such ranking, the communities resulting from the high-throughput sequencing from each sample were used to calculate the Bray-Curtis distances in all the pairwise combinations, whereby identical communities would score 0 and totally different ones would yield the maximum distance, equal to 1. The results indicated that the main driver of divergence was the gut tract, as distances between caecal and faecal samples were higher on average, irrespective of diet composition, which scored second in rank, and of whether they had been sampled from the same individual, which was the least effective factor. Simpson's species diversity indexes was not significantly different when comparing tracts or diets, while community evenness was reduced in full-fat silkworm diet-fed animals. The identities of the differentially displayed taxa that were statistically significant as a function of gut tract and diet regimen are discussed in light of their known physiological and functional traits.