PCR-RFLP Analysis of Single Nucleotide Polymorphism (SNP) C-2402T at the Promoter Region of Prolactin Gene and its Association with Positively Correlated Production Traits in White Leghorn Chicken

Background: The avian prolactin gene is highly conserved, located on chromosome number 2 and most sequence polymorphisms occurs in the 5’ flanking region, 3’ flanking region, and the coding region of signal peptide. The present study was aimed at the identification of SNP C-2402T of prolactin gene and its association with production traits in White Leghorn chicken. Methods: A total of 200 birds of White Leghorn were selected from All India Co-ordinated Research Project on Poultry improvement (AICRP) farm, Mannuthy. Genomic DNA was isolated from venous blood. Polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) analysis was done to identify the SNP C-2402T of prolactin gene. Result: All the birds were observed with the same genotype CC and the frequency of the C allele was one.

Comparative study on Pharmacokinetic Profiles of Chicken IgY to Horse IgG in Rabbits

Chicken IgY antibody has been extensively reported for various applications as an alternative to mammalian IgG. To evaluated the pharmacokinetics profile of chicken IgY in comparison with horse IgG. Chicken IgY antibody was prepared by immunizing the white leghorn chicken with tetanus toxoid (TT) and then extracted anti-TT-IgY from immune egg yolks by PEG-6000 extraction. The titer of anti-TT-IgY was determined by ELISA in order to select the hyper immune eggs for further extraction. Rabbits were injected with 300 μg/kg of Chicken IgY and horse IgG by intravenous (i.v.) and intramuscular (i.m.) administrations. Then, the concentrations of IgY and IgG in rabbit serum were determined using indirect ELISA. Pharmacokinetic parameters were estimated using non-compartmental analysis. IgY can reach higher concentration (Cmax= 4.54 mg/L after i.m. injection) within shorter time (Tmax= 0.12 h after i.m. injection) than IgG (Cmax= 3.99 ng/mL after i.m. injection; Tmax=0.11 h after i.m. injection), while the IgY lifespan (T1/2=26.98 h and 31.98 h after i.v. and i.m. administration, respectively) in the body was comparable with IgG (T1/2=27.94 h and 29.58 h after i.v. and i.m. administration, respectively). IgY might be a promising choice as an alternative to mammalian sourced antibodies.

Molecular and functional characterization of Toll-like receptor 5 (TLR5) in Aseel and White Leghorn chicken

Toll-like receptors (TLRs) are pattern recognition receptors (PRRs) which detect pathogen-associated molecular patterns (PAMPs) and initiate the innate as well as adaptive immune response. In the present study TLR5 gene from Aseel and White Leghorn was amplified and sequenced by primer walking method. The sequence analysis revealed that Aseel TLR5 shared 97-98% and 98-99% homology with other chicken breeds at nucleotide and amino acid levels, respectively. Further, the TLR5 mRNA expression levels were quantified in different tissues of day-old Aseel and WL chicks by real time PCR assay. TLR5 mRNA expressions were significantly higher in liver, spleen and intestine of Aseel than White Leghorn chicken (P less than 0.01). However, in bone marrow significantly higher expression was observed in WL than Aseel chicken (P less than 0.01) and no significant difference in transcript expression was found in muscle, bursa and heart tissue. In vitro stimulation of PBMCs of Aseel and WL with recombinant flagellin resulted in significantly higher levels of proinflammatory cytokine IL-1â gene expression in Aseel birds than WL. Polymorphisms in ligand binding region, higher transcript expression in tissues at the site of microbial entry and higher pro-inflammatory response to flagellin stimulation in Aseel chicken better immune competence in this native chicken breed.