Among the ten local breeds of the Veneto region in Italy, Pepoi (PP) and Ermellinata di Rovigo (ER) hens start laying eggs earlier than the others. The egg laying rate (27-34 weeks of age) is higher (p < 0.01) in PP than in ER hens. Egg quality (at 33 weeks of age, 120 eggs/breed) was studied in fresh 1 day-old eggs and in preserved 21 day-old eggs according to breed and storage temperature (12 and 21 °C). Fresh ER eggs showed higher (p < 0.01) egg weights, yolk pH, Haugh units and yolk indices and lower (p < 0.01) eggshell lightness and thickness, surface area-to-volume ratios, and albumen pH than PP eggs, but the yolk-to-albumen ratio was similar between the breeds. After 21 days of storage, the egg traits showed the same trend for significant differences between breeds, with the exception of albumen pH and Haugh units, which were similar. Eggs stored at 21 °C showed lower (p < 0.01) Haugh units and yolk index values and higher (p < 0.01) albumen and yolk pH, albumen yellowness, and weight loss than eggs stored at 12 °C. Stored PP and ER eggs also differed in terms of observed changes in Haugh units, yolk pH and yolk index values with storage temperature: ER eggs showed higher (p < 0.01) yolk index values than PP eggs at both storage temperatures. Eleven weeks after the onset of laying, significant differences were observed in several traits of fresh and stored eggs from the studied breeds, particularly regarding the strength of the vitelline membrane. These preliminary results contribute to the characterization of the storage suitability of eggs from local breeds and to future crossbreeding programmes for enhancing chicken biodiversity.

Cryo-scanning electron microscopy (cryo-SEM) was used to examine intact frozen-fractured eggs from five avian species-quail, hen, duck, turkey, and goose-spanning two taxonomic orders (Galliformes and Anseriformes) and a wide range of egg sizes. Whole eggs were frozen in liquid nitrogen within 24 h of laying, fractured at cryogenic temperature, and observed in the frozen-hydrated state after vacuum sublimation and gold coating. Multiple structural regions were examined, including yolk spheres, the albumen body, the shell-shell membrane-albumen interface, and the yolk-vitelline membrane-albumen interface where suitable fracture surfaces were available. Yolk spheres displayed a conserved polyhedral close-packing geometry across species, with larger eggs generally showing larger yolk sphere dimensions. The frozen albumen displayed species-dependent ice crystal morphologies: an isotropic spongy network in quail, fine parallel lamellae in hen, coarser lamellae in turkey, a multi-domain columnar-dendritic pattern in duck, and coarse lamellae in goose. These morphological differences did not simply scale with egg size and suggest that species-dependent differences in albumen composition and freezing behavior may influence ice crystal growth during cryogenic fixation. Because freezing rate and egg geometry were not independently controlled, the observed structures should be interpreted as cryo-fixed freezing morphologies rather than direct representations of unfrozen albumen microstructure. To our knowledge, systematic cryo-SEM comparison of albumen freezing morphology within intact avian eggs has not previously been reported. This study provides a rare comparative cryo-SEM atlas of intact frozen-fractured avian eggs and a morphological basis for future controlled investigations of albumen composition, freezing behavior, and ice crystal growth.

BACKGROUND: Omphalocele with a concomitant patent vitelline duct is a rare presentation, with very few cases reported in the literature. Most reported cases present with visible bowel prolapse, meconium drainage or mucosal exposure at birth. Presentations without obvious intestinal herniation or mucosal exposure are extremely uncommon and pose diagnostic challenges. CASE PRESENTATION: A male neonate was born to a G3P2 mother at 38 + 6/7 weeks via spontaneous vaginal delivery after a pregnancy notable for a 20-week prenatal ultrasound concerning for omphalocele. Upon delivery, the omphalocele membrane was intact. Shortly after birth, the neonate developed persistent bilious emesis. Abdominal ultrasound demonstrated normal rotation, and abdominal X-ray was reassuring without evidence of obstruction or volvulus. No other congenital anomalies were demonstrated after VACTERL workup, including echocardiogram, abdominal and spinal ultrasounds. Genetic testing for Beckwith-Wiedmann syndrome was found to be normal. Surgical exploration revealed a patent vitelline duct fistula connecting the small bowel to the omphalocele sac. The fistula and adjacent small bowel were resected, followed by primary end-to-end anastomosis and primary fascial closure. The postoperative course was uncomplicated, and the neonate was thriving without any evidence of infection or obstruction at 2-month and 6-month follow-up visits. CONCLUSION: There have been very few cases of omphalocele with a patent vitelline duct reported in the literature, and those that have been described present with either visible mucosal prolapse or intestinal extrusion at birth. This case demonstrates that a vitelline duct anomaly may remain clinically occult and present only with obstructive symptoms such as bilious emesis. In neonates with omphalocele who develop gastrointestinal obstruction despite unrevealing imaging studies, clinicians may entertain the possibility of a concurrent vitelline duct remnant as a part of their differential diagnosis. Recognition of this association may guide operative planning and improve diagnostic awareness of this uncommon embryologic anomaly.

In externally fertilizing species such as ascidians, gametes are released into the surrounding seawater, which makes the fertilization process highly sensitive to environmental conditions. In the ascidian Phallusia philippinensis, the oviductal fluid has an acidic pH of 5.65 (Sensui et al., 2023), markedly lower than that of seawater (approximately 8.2). Consequently, eggs experience a rapid and substantial pH shift when released into the external environment. The vitelline coat (VC), an extracellular matrix surrounding the oocyte, serves both as a structural barrier and as a mediator of essential sperm-egg interactions during fertilization. In this study, we report for the first time a pH-dependent, pre-fertilization elevation of the VC in the ascidian P. philippinensis. The eggs of P. philippinensis exhibit rapid VC elevation that occurs independently of fertilization after release into seawater. This process appears to be driven by osmotic pressure and enzymatic structural loosening of the VC, rather than cortical granule exocytosis, which is well known to initiate the modification and hardening of the fertilization envelope in organisms such as sea urchins and mammals. Consistent with this, VC elevation occurs independently of fertilization and does not function as a polyspermy block in this species. These findings reveal a previously unrecognized pH-responsive property of the ascidian egg coat and provide new insights into a seawater pH-triggered mechanism regulating egg coat structure.

Litopenaeus vannamei is an economically important shrimp species that can survive in a variety of environments; however, low salinity compromises its reproduction. To investigate whether salinity affects ovarian development in L. vannamei, we reared female shrimp under optimal (30‰) and low (25‰, 20‰, 15‰) salinity conditions. On day 26 post-induction, the ovarian maturation rates were 67.7%, 58.3%, 56.7%, and 31.7% for the 30‰, 25‰, 20‰, and 15‰ salinity groups, indicating that low-salinity compromises ovarian maturation. To provide mechanistic insight, we performed comparative transcriptomic analysis of hepatopancreas, eyestalk, gill, and ovary tissues five days post-maturation induction. GO and KEGG enrichment analyses revealed that upregulated differentially expressed genes (DEGs) under low-salinity conditions (n = 2359 total) were primarily associated with immune response, apoptosis regulation, polysaccharide metabolism, and antioxidation pathways, reflecting stress adaptation to maintain cellular homeostasis. Downregulated DEGs (n = 2008 total) were significantly enriched in pathways related to energy metabolism, lipid metabolism, and estrogen signaling, indicating the inhibition of metabolic and reproductive pathways. Trend analysis identified the ovarian development-related gene, vitelline membrane outer layer protein 1 (VMO1), whose expression was verified to decrease significantly with declining salinity. These results provide practical guidance for L. vannamei breeding and a new perspective for understanding salinity-mediated reproductive regulation.

Embryonic hematopoiesis involves successive waves of progenitors from distinct anatomical sites, but the origins and contributions of early hematopoietic stem and progenitor cells (HSPCs) remain incompletely defined. Here we use genetic fate mapping in mice to temporally label hemogenic endothelium (HE) subsets and track their progeny. We show that a wave of fetal-restricted HSPCs arises from HE in the vitelline and umbilical arteries between embryonic days 8.5 and 9.5, preceding the emergence of definitive hematopoietic stem cells. Lineage tracing, single-cell transcriptomic analyses and functional assays revealed that these progenitors are transient and distinct from erythro-myeloid progenitors, contribute extensively to fetal lympho-myelopoiesis but decline postnatally. Our findings reveal a previously unrecognized early HE wave as a key source of fetal-restricted HSPCs, refining the spatial-temporal understanding of layered hematopoiesis and informing developmental origins of blood cell diversity.

The study aimed to analyze egg value, hatchability performance, gosling quality, and changes in extraembryonic structures, and nutrient utilization by embryos during incubation of eggs from White Kołuda® geese (WKG) and Biłgorajska geese (BG). The 620 hatching eggs were used, divided into two groups according to breed. In fresh eggs morphometric traits, eggshell and vitelline membrane strength, yolk color, pH, viscosity, and lysozyme activity were assessed. Incubation was carried out for 30 days. Egg weight loss, fertility, embryo mortality, and hatchability were monitored. During incubation (days 7, 14, and 21), changes in pH, viscosity, lysozyme activity, eggshell thickness, mineral composition, and content of mineral, vitamins, and the fatty acid profile in yolk and yolk sac were analyzed. Gosling quality was evaluated according to the Tona score. WKG eggs were characterized by higher weight and surface area, and higher fertility and hatchability compared with BG eggs. BG goslings received higher scores for quality despite lower hatchability performance. BG eggs had a stronger eggshell and higher yolk pigmentation. In both groups, changes in the pH of extraembryonic structures, a decrease in eggshell thickness, and intensive calcium utilization in the final stage of incubation were observed, with modifications of the fatty acid profile and a decline in vitamins A and E as embryonic development progressed. Lysozyme activity and the viscosity of albumen and amniotic fluid changed dynamically during incubation; however, WKG eggs showed higher lysozyme activity at critical stage (day 7) of embryonic development. Goose origin differentiates the quality of hatching eggs, the course of incubation, nutrient utilization, and hatchability performance, which is of practical relevance for breeding and the conservation of goose genetic resources.

Fish roe is consumed in different forms, e.g., caviar. The large and firm spherical roe from giant sea catfish (GSC, Arius thalassinus), which have a high price, are popular in some countries, like Thailand. However, the information on their nutrition and properties is scarce. Roe of different sizes from GSC, including medium (GSC-M), large (GSC-L), and extra-large (GSC-XL) sizes, were rich in protein (29.52-32.70%), fat (4.07-5.65%), and essential amino acids, particularly leucine and lysine. Vitelline was the major protein in GSC roe. Polyunsaturated fatty acids, including eicosapentaenoic acid and docosahexaenoic acid, were abundant, although GSC-M showed lower PUFA content (21.91%) than GSC-L and GSC-XL (25.56-25.94%). No significant differences in texture property were found between sizes, despite the microstructural and histological differences. Larger voids and strands were found with augmenting size, while GSC-L showed greater membrane thickness (133.55 µm). FTIR spectra confirmed the presence of peptide and ester bonds associated with proteins and triacylglycerols, respectively. GSC-L had the highest cholesterol content (651.2 mg/100 g), whereas GSC-M showed the highest α-tocopherol level (1.64 mg/kg). Phosphorus was the dominant mineral (3473-3894 mg/kg), followed by calcium and other minerals. Hence, the roe from GSC, regardless of size, possess high nutritive value and could be used as a wholesome marine food or functional ingredient.

Zeugodacus tau (Walker) is a globally significantly agricultural pest with severe economic and ecological impacts. Transcriptome sequencing-based data analysis has proven instrumental in identifying key functional genes in insects. However, the limited availability of transcriptome data has impeded the mining of functional genes in Z. tau. We conducted transcriptome sequencing on the midgut, Malpighian tubules, fat body, and ovary of 5-day old female Z. tau. Using a standard screening pipeline, we identified 2458 ovary-specific genes, which was much larger than that in other tissues. To verify the transcriptomic datasets, twelve randomly chosen ovary-specific genes were validated using quantitative real-time PCR (RT-qPCR), and their expression patterns were consistent with the RNA-seq data. Among these validated genes, we focused on a vitelline membrane protein (Vmp) gene, Vmp26Ab, which was involved in insect eggshell formation and maintaining the structural integrity of egg. Simultaneously, we identified two additional Vmp genes (Vmp26Aa and Vmp26Aa-like) by searching the transcriptome and genome of Z. tau. Amino acid sequences analysis revealed that all ZtVmps contained conserved proline-rich VM domains. RT-qPCR results showed that ZtVmps were highly expressed in the ovaries of 5-day-old and 9-day-old females Z. tau, and their expression levels were all upregulated under induction by 1 μg of 20-hydroxyecdysone (20E). RNA interference (RNAi) bioassay demonstrated that knockdown of Vmp26Ab facilitated embryonic water loss and reduced hatchability of eggs. These findings suggest that Vmp26Ab represents a potential target for developing RNA-based pesticides aimed at disrupting pest reproduction.

The hen egg vitelline membrane is a protein layer surrounding the egg yolk. The integrity of this membrane is important for both the shell egg and the egg products industries; however, its physical properties are altered during prolonged storage, depending on storage temperature. This study aimed to identify the structural and molecular changes of the hen egg vitelline membrane during a 28-day storage at +4 °C and +20 °C using a combination of physicochemical, ultrastructural and proteomic approaches. Our results demonstrated that the degradation of the vitelline membrane during storage at +20 °C was associated with a significant loss of dry matter, a decrease in the thickness of the outer vitelline membrane layer, and alterations in its proteome. Indeed, the abundance of two main components of the outer layer, namely ovomucin and VMO1, decreased during storage at room temperature. VMO1 actually dissociates from the vitelline membrane during egg storage and accumulates in the egg white. Taken together, these results contribute to a better understanding of the mechanisms of alterations of the vitelline membrane during the storage of eggs at room temperature, and provide evidence that VMO1 is a major biomarker of the integrity of the vitelline membrane.

During development cell deformations are spatially organized, however, how cellular mechanics is spatially controlled is unclear. Spatial control of cell identity often determines local cellular mechanics in a two-tiered mechanism. Theoretical studies also proposed that molecular gradients, so called "mechanogens", spatially control mechanics. We report evidence of a similar mechanism required for Drosophila gastrulation. We show that the GPCR ligand Fog, expressed in the posterior endoderm, diffuses and acts in a concentration-dependent manner to activate actomyosin contractility at a distance during a wave of tissue invagination. While Fog is uniformly distributed in the extracellular space, it forms a surface-bound gradient that recruits Myosin-II via receptor oligomerization. This activity gradient self-renews as the wave propagates and is shaped by both receptor endocytosis and modulation of GPCR signalling by integrins upon adhesion to the vitelline membrane. This exemplifies how chemical, mechanical and geometrical cues underly the emergence of a self-organized mechanogen activity gradient.

1. This study investigated whether the recessive ce gene, which causes the celadon shell colour in Japanese quail eggs and affects the shell structure and quality of both fresh eggs and eggs stored for 28 days at 4°C.2. Analyses were conducted on 54 fresh and 54 stored eggs from four quail groups, including those with typically wild-type shell pigmentation: Jumbo, Pharaoh and Texas, as well as Celadon laying eggs with reduced protoporphyrin (ce). Results included shell weight, ratio of shell to egg weight, shell strength with simultaneous acoustic measurement and shell microstructure using computed microtomography (both 2D and 3D). The quality of fresh and stored eggs was evaluated based on egg weight, yolk weight and proportion (%), yolk index, albumen quality, vitelline membrane strength and elasticity, pH and water activity of yolk and albumen and yolk viscosity. Egg weight (water) loss was measured in stored eggs.3. Celadon eggs had a higher number of shell pores, but the average pore area and its area-equivalent circle diameter were smaller. No differences in eggshell strength were found between Celadon and wild-type pigmented eggs, which was confirmed by acoustogram analysis. Celadon shells displayed a negative Euler number, which indicated strong connections between adjacent pores. This structural enhancement may be an adaptation to compensate for reduced protoporphyrin content.4. Celadon quail eggs were similar in quality to those of the other groups and could be stored with similar results. The greatest weight loss during storage was observed in Texas quail eggs, which exhibited the highest porosity (based on the number and surface area of pores) and the greater morphometric water vapour conductance.

Folliculogenesis is a process that requires accurate interpretation of female physiological cues and elaborate coordination between the growing oocyte and its surrounding follicle cells, each being capable of responding to external signals. Here, we investigate the role of insulin signaling in Drosophila follicle cells. Using a phase separation-based reporter system, we observe a surge of insulin receptor activity in follicle cells during vitellogenic stages, a surge that is disrupted by a maternal high-sucrose diet. Single-cell RNA-seq reveals a diet-sensitive subpopulation of stage-8 follicle cells, which exhibits a reduction in CrebA-mediated transcription of genes for yolk and vitelline membrane proteins. Our results suggest a critical role of CrebA in implementing the stage-specific effect of insulin signaling to boost the secretory capacity of follicle cells. Mechanistically, CrebA is directly repressed by nuclear FoxO that is subject to insulin control, a regulatory axis that we show is conserved in human granulosa cells. This study delineates a mechanism through which insulin and nutrient cues act on a developmental transition via modulating the biosynthetic and secretory functions of the ovary.

Sea urchin eggs are surrounded by a network of extracellular matrix, consisting of the jelly coat (JC) and vitelline layer (VL). While the voluminous JC evokes acrosomal reaction in the approaching sperm, the tight VL ensheathing the plasma membrane of the subjacent microvilli is known to be the subcellular site where 'sperm receptors' reside. In this study, we have examined the roles of JC and VL at fertilization in a combinatorial approach utilizing two different pretreatments of the eggs: (i) incubation with dithiothreitol (DTT) in alkaline seawater to remove JC and VL, (ii) masking the egg extracellular matrix with a carbohydrate-binding protein concanavalin A (Con A). Surprisingly, the results showed that the DTT-denuded eggs still engulfed sperm at fertilization, even more effectively than intact eggs, as multiple sperm entered. On the other hand, Con A appeared to interfere with sperm entry in a dose-dependent manner and to delay the onset of the Ca2+ wave in intact eggs after the cortical Ca2+ release, representing sperm-egg fusion. This prolonged time lag in triggering the Ca2+ wave at fertilization was associated with compromised dynamics of the subplasmalemmal actin filaments in Con A-pretreated eggs. By using Alexa Fluor 633 Con A and BPA-C8-Cy3, respectively, we also report unprecedented fluorescent labeling of the egg JC and the spontaneous 'acrosomal protrusion' on the head of Paracentrotus lividus sperm diluted in natural seawater. Combined with electron microscopy observations of intact and denuded eggs, our results suggest that the glycoconjugate on the egg surface contributes to the fertilization signal transduction, affecting the Ca2+ wave via actin cytoskeletal changes and sperm entry.