Chicken erythrocytes are involved in immunity through binding of toll-like receptors (TLRs) with their ligands to activate downstream signaling and lead to cytokine production in erythrocytes. Some avian β-defensins (AvBDs) are constitutively expressed in tissues and some others can be induced by various bacteria and viruses. However, the expression of AvBDs in erythrocytes has not yet been studied extensively. The transcripts of eight AvBDs (AvBD1 to AvBD7, and AvBD9) and liver-expressed antimicrobial peptide-2 (LEAP-2) were found in normal chicken erythrocytes. The expression levels of AvBD2, 4 and 7 were significantly increased (P < 0.01), whereas the levels of AvBD1, 6 and 9 were significantly decreased (P < 0.01) after Marek’s disease virus (MDV) infection. The mRNA expression level of LEAP-2 was not significantly changed after MDV infection. Highest viral nucleic acid (VNA) of MDV in the feather tips among the tested time points was found at 14 days post-infection (d.p.i.). In addition, 35 MD5-related gene segments were detected in the erythrocytes at 14 d.p.i. by transcriptome sequencing. These results suggest that the AvBDs in chicken erythrocytes may participate in MDV-induced host immune responses.

Background: The Tibial dyschondroplasia (TD) in fast-growing chickens is mainly caused by improper blood circulation. The exact mechanism underlying angiogenesis and vascularization in tibial growth plate of broiler chickens remains unclear. Therefore, this research attempts to study genes involved in the regulation of angiogenesis in chicken red blood cells. Twenty-four broiler chickens were allotted into a control and thiram (Tetramethyl thiuram disulfide) group. Blood samples were collected on day 2, 6 (8- and 14-days old chickens) and 15 (23 days old chickens).Results: Histopathology and hematoxylin and eosin (H&E) results showed that angiogenesis decreased on the 6th day of the experiment but started to recover on the 15th day of the experiment. Immunohistochemistry (IHC) results confirmed the expressions of integrin alpha-v precursor (ITGAV) and clusterin precursor (CLU). Transcriptome sequencing analysis evaluated 293 differentially expressed genes (DEGs), of which 103 up-regulated genes and 190 down-regulated genes were enriched in the pathways of neuroactive ligand receptor interaction, mitogen-activated protein kinase (MAPK), ribosome, regulation of actin cytoskeleton, focal adhesion, natural killer cell mediated cytotoxicity and the notch signalling pathways. DEGs (n = 20) related to angiogenesis of chicken erythrocytes in the enriched pathways were thromboxane A2 receptor (TBXA2R),interleukin-1 receptor type 1 precursor (IL1R1),ribosomal protein L17 (RPL17),integrin beta-3 precursor (ITGB3), ITGAV,integrin beta-2 precursor (ITGB2),ras-related C3 botulinum toxin substrate 2 (RAC2),integrin alpha-2 (ITGA2),IQ motif containing GTPase activating protein 2 (IQGAP2),ARF GTPase-activating protein (GIT1),proto-oncogene vav (VAV1),integrin alpha-IIb-like (ITGA5),ras-related protein Rap-1b precursor (RAP1B),tyrosine protein kinase Fyn-like (FYN),tyrosine-protein phosphatase non-receptor type 11 (PTPN11),protein patched homolog 1 (PTCH1),nuclear receptor corepressor 2 (NCOR2) and mastermind like protein 3 (MAML3) selected for further confirmation with qPCR. However, commonly DEGs were sarcoplasmic/endoplasmic reticulum calcium ATPase 3 (ATP2A3), ubiquitin-conjugating enzyme E2 R2 (UBE2R2), centriole cilia and spindle-associated protein (CCSAP), coagulation factor XIII A chain protein (F13A1), shroom 2 isoform X6 (SHROOM2), ras GTPase-activating protein 3 (RASA3) andCLU.Conclusion: We have found potential therapeutic genes concerned to erythrocytes and blood regulation, which regulated the angiogenesis in thiram induced TD chickens. This study also revealed the potential functions of erythrocytes.Graphical 1. Tibial dyschondroplasia (TD) in chickens were more on day 6, which started recovering on day 15. 2. The enriched pathway observed in TD chickens on day 6 was ribosome pathway, on day 15 were regulation of actin cytoskeleton and focal adhesion pathway. 3. The genes involved in the ribosome pathways was ribosomal protein L17 (RPL17). regulation of actin cytoskeleton pathway were Ras-related C3 botulinum toxin substrate 2 (RAC2), Ras-related protein Rap-1b precursor (RAP1B), ARF GTPase-activating protein (GIT1), IQ motif containing GTPase activating protein 2 (IQGAP2), Integrin alpha-v precursor (ITGAV), Integrin alpha-2 (ITGA2), Integrin beta-2 precursor (ITGB2), Integrin beta-3 precursor (ITGB3), Integrin alpha-IIb-like (ITGA5). Focal adhesion Proto-oncogene vav (Vav-like), Tyrosine-protein kinase Fyn-like (FYN).

Immunomodulatory and Growth Promoting Effects of Basil (Ocimum basilicum) and Ascorbic Acid in Heat Stressed Broiler Chickens