Towards Tabula Gallus

The Tabula Gallus is a proposed project that aims to create a map of every cell type in the chicken body and chick embryos. Chickens (Gallus gallus) are one of the most recognized model animals that recapitulate the development and physiology of mammals. The Tabula Gallus will generate a compendium of single-cell transcriptome data from Gallus gallus, characterize each cell type, and provide tools for the study of the biology of this species, similar to other ongoing cell atlas projects (Tabula Muris and Tabula Sapiens/Human Cell Atlas for mice and humans, respectively). The Tabula Gallus will potentially become an international collaboration between many researchers. This project will be useful for the basic scientific study of Gallus gallus and other birds (e.g., cell biology, molecular biology, developmental biology, neuroscience, physiology, oncology, virology, behavior, ecology, and evolution). It will eventually be beneficial for a better understanding of human health and diseases.

Line Scan Spatial Speckle Contrast Imaging and Its Application in Blood Flow Imaging

Laser speckle imaging has been an indispensable tool for visualizing blood flow in biomedical applications. We proposed a novel design of the laser speckle imaging system, which combines confocal illumination and detection with various speckle analysis methods. The system can be operated by three imaging modes. One is surface illumination laser speckle contrast imaging (SI-LSCI) and the other two are line scan temporal speckle contrast imaging (LS-TSCI) and line scan spatial speckle contrast imaging (LS-SSCI). The experimental results of flow phantoms have validated the mixture model, which combines the Lorentzian and Gaussian models to describe the simultaneous existence of both Brownian motions and ordered flow. Our experimental results of in vivo chick embryos demonstrate that LS-SSCI maintains high temporal resolution and is less affected by motion artifacts. LS-SSCI can provide better image quality for in vivo imaging blood chick embryos than LS-TSCI. Furthermore, the experiential results present that LS-SSCI can detect and quantify the blood flow change during vascular clipping, and shows great potential in diagnosing vascular diseases, such as angiosclerosis, angiostenosis, or angiemphraxis.

TGFβ signaling is required for sclerotome resegmentation during development of the spinal column in Gallus gallus.

We previously showed the importance of TGFβ signaling in development of the mouse axial skeleton. Here, we provide the first direct evidence that TGFβ signaling is required for resegmentation of the sclerotome using chick embryos. Lipophilic fluorescent tracers, DiO and DiD, were microinjected into adjacent somites of embryos treated with or without TGFβR1 inhibitor, SB431542, at developmental day E2.5 (HH16). Lineage tracing of labeled cells was observed over the course of 4 days until the completion of resegmentation at E6.5 (HH32). Vertebrae were malformed and intervertebral discs were small and misshapen in SB431542 injected embryos. Inhibition of TGFβ signaling resulted in alterations in resegmentation that ranged between full, partial, and slanted shifts in distribution of DiO or DiD labeled cells within vertebrae. Patterning of rostro- caudal markers within sclerotome was disrupted at E3.5 after treatment with SB431542 with rostral domains expressing both rostral and caudal markers. Hypaxial myofibers were also increased in thickness after treatment with the inhibitor. We propose that TGFβ signaling regulates rostro-caudal polarity and subsequent resegmentation in sclerotome during spinal column development.

Development of the technology for preparation of enzymatic hydrolysate of waste chick embryos

The development of technologies for preparation of protein nutritional bases for microbiological nutrient media, from production waste of mainly readily available or non-food products, is a promising area in biotechnology. Researchers of Vyatka State Agrotechnological University assume that non-food secondary raw materials, such as waste chick embryos (WCEs) used in the production of anti-influenza products, could be used for these purposes, after removal of the virus-containing allantoic fluid. The aim of the study was to develop a technology for preparation of WCE enzymatic hydrolysate (WCEEH), and to evaluate growth properties of the hydrolysate-based solid nutrient medium, using Escherichia coli M-17 and Pseudomonas alcaligenes IP-1 test strains. Materials and methods: the authors offer methodological approaches to obtaining WCEEH and substantiate hydrolysis parameters. The obtained WCEEH was characterised in terms of physico-chemical properties: pH, amine nitrogen, total nitrogen, sodium chloride, degree of protein cleavage. The growth properties of the hydrolysate-based nutrient medium were studied using E. coli M-17 and Ps. alcaligenes IP-1 test strains. Results: the experiments demonstrated the feasibility of performing enzymatic hydrolysis of WCEs, and assessed physico-chemical properties of the prepared WCEEH batches. The study demonstrated the possibility of using the prepared hydrolysate as a component of solid nutrient media for growing the selected test strains. Conclusions: the study substantiated the optimal technological parameters for WCE enzymatic hydrolysis: pH (7.6 ± 0.3), duration (48 ± 2 h), temperature (49 ± 1) °C. The loading of hydrolysis components was optimised: mass fraction of the substrate—500 g/L, mass fraction of the hydrolysing agent—100 g/L. The physico-chemical properties of WCEEH make it suitable for preparation of microbiological media; the hydrolysate-based solid nutrient medium consistently ensures the growth of E. coli M-17 and Ps. alcaligenes IP-1 test strains with standard properties. The growth properties of the experimental medium are comparable to those of the meat-peptone broth-based nutrient medium.

The effect of vitamin K1 on VEGF levels in chick embryos with type 1 diabetes and Diabetic Retinopathy induced by streptozotocin

Objective: Hyperglycemia caused by Diabetes Mellitus (DM) is associated with long-term dysfunction such as diabetic retinopathy (DRP). The most effective growth factor in the development of DRP is the vascular endothelial growth factor (VEGF). Vitamin K1 reduces hyperglycemia and prevents the development of DM. In this study, we aimed to create streptozotocin (STZ) induced DM and DRP in chick embryos and to show whether vitamin K1 can prevent early-stage DRP by measuring VEGF levels. Material and Methods: The 140 specific pathogen-free (SPF) fertilized chicken eggs were used in this study. Three different STZ doses were administered to 120 SPF eggs for an induced DM model. Three different vitamin K1 doses were administered in each STZ dose group. On the 12th day and 18th day the remaining 20 SPF eggs were separated as control groups. On the 18th-day, blood glucose, blood insulin and VEGF levels were measured. Results: 0.45 mg/egg STZ dose (STZ3) was determined as the optimal/ideal dose for the DM model. When the group-administered STZ3 and vitamin K1 were evaluated among themselves; it was determined that there were significant changes in blood glucose, blood insulin, VEGF levels of the STZ3+K1-3 group compared to the STZ3+K1-1 and STZ3+K1-2 groups (p<0.05). Conclusion: Vitamin K1 increases blood insulin levels and decreases blood glucose levels. When hyperglycemia reduces, the VEGF levels reduce. Vitamin K1 protects from DRP by reducing VEGF levels.

Intra-Amniotic Administration of l-Glutamine Promotes Intestinal Maturation And Enteroendocrine Stimulation In Chick Embryos

Initial nutritional stimulation is a key driving force for small intestinal maturation, and is mediated by enteroendocrine L-cells signaling. In chick embryos, administration of specific nutrients into the amniotic fluid stimulates early development of the small intestine. In this study, we examined the effects of intra-amniotic administration of l-glutamine (Gln) on enterocyte morphological and functional maturation and L-cell signaling before and after hatch. Gln stimulation at embryonic day 17 caused an increase in enterocyte and microvilli dimensions by 10 and 20%, respectively, within 48h. Post-hatch, enterocytes and microvilli were 20% longer in Gln-treated chicks. Correspondingly, mRNA expression of brush border nutrient transporters PepT-1 and SGLT-1 and tight junction proteins TJP-1, TJP-2 and Occludin was significantly upregulated before and after hatch (P<0.05) in Gln-treated chicks. We then evaluated the effects of Gln stimulation on enteroendocrine signaling by locating L-cells in the developing jejunum and observed significant increases in mRNA expression of L-cell signaling components GLP-2R, IGF-1 and IGF-1R before and after hatch, in response to Gln stimulation (P<0.05). Our findings link primary nutrient stimulation of L-cells to enterocyte morphological and functional maturation and provide a model for investigating the effects of specific nutrients on enteroendocrine signaling in the developing small intestine.