TITLE:
Expression of B Locus Beta 2 (BLB2) Gene at Cytolytic and Latent Immune Response Stages of Immunocompetence in Nigerian Indigenous Chickens
AUTHORS:
Abdulraheem Adedeji Bello-Ibiyemi, Adeyemi Sunday Adenaike, Micheal Irewole Takeet, Akpan Ubong, Christian Obiora Ndubuisi Ikeobi
KEYWORDS:
Nigerian Indigenous Chickens, BLB2 Gene Expression, Sheep Red Blood Cells
JOURNAL NAME:
Open Journal of Animal Sciences,
Vol.11 No.2,
April
8,
2021
ABSTRACT: An economically-important trait in poultry for which gene identification continues to be a challenge is immune response. The
objective of the study was to quantitate the expression of major histocompatibility
complex (MHC) class II BLB2 gene at cytolytic and latent immune response stages in Nigerian indigenous chickens. A total of 108 Nigerian indigenous chickens
(NIC) were sourced across the South-western states in Nigeria. The birds were inoculated
with sheep red blood cells (SRBC), after which blood samples were obtained (5 days
post-inoculation) and antibody haemagglutination test was carried out to place the
birds into groups of high and low antibody titre levels. The categorisation of the birds resulted in six groups of normal feather high,
normal feather low, naked neck high, naked neck low, frizzle feather high and frizzle
feather low antibody groups. A total of
48 chicks were selected from the progeny for gene expression
studies. Surgical excision of thymus and spleen was carried out
for the detection of cytolytic and latent responses of the birds. β-actin was used
as the endogenous control and the critical threshold method (2–ΔΔCт)
was carried out for the determination of fold change. The fold change of spleen
tissue expression at cytolytic immune response of the birds was 30,362.44 compared
to latent response 294.07; and the fold change of thymus expression at cytolytic
immune response of the birds was 51.98 compared to latent response 5.24. At both cytolytic and latent stages of
immune response to SRBC antigen, BLB2 expression in the spleen was comparatively higher than in the thymus and the height
of transcriptional activity was associated with the cytolytic stage. The birds of high titre at both the cytolytic
and the latent responses had higher mRNA expression. This study concluded that BLB2 gene expression in the Nigerian
indigenous chicken was induced at the cytolytic stage and repressed at the latent
stage. During avian infections, the category of high immune response birds would
perform better than the low immune response counterpart; and the protective response
that BLB2 gene offers will be
repressed from one time point to the other.