Differentially expressed genes in a flock of Chinese local-breed chickens infected with a subgroup J avian leukosis virus using suppression subtractive hybridization

Abstract

Avian leukosis virus subgroup J (ALV-J) is a new type of virus that mainly induces myeloid leukosis (ML) in chickens. To further elucidate the pathogenesis of ALV-J infection and tumor development, expression profiles from the bone marrow tissue of 15 infected and 18 non-infected birds from a local-breed poultry-farm under naturally infected conditions, were analyzed by suppression-subtractive hybridization. The birds were diagnosed as ML+ (or ML-) by specific ALV-J detection methods, involving serological tests for antigens and antibodies, and RT-PCR to detect viral RNA. A total of 59 partial gene sequences were revealed by differential screening of 496 forward and 384 reverse subtracted cDNA clones. Of these, 22 identified genes, including 8 up-regulated and 14 down-regulated, were related to immune functions, these genes being, MHC B-G antigen, translationally-controlled tumor protein (TPT1/TPTC), transferrin and ferritin, hemoglobin and Carbonic anhydrase. Four of the down-regulated genes were selected for further analysis, in view of their predicted roles in infection and immunity by real-time qRT-PCR, using RNA collected from the same birds as those used for SSH. The four genes were expressed at significantly lower levels (p < 0.001) in ALV-J infected birds than in non-infected ones.

Transcriptional response of Atlantic salmon families to Piscirickettsia salmonis infection highlights the relevance of the iron-deprivation defence system

“…Moreover, decreased relative abundance of transcripts encoding for proteins involved in intracellular non-hemic iron binding (ferritin middle and heavy subunits) and in hemic binding (hemopexin) suggest that P. salmonis infection induces changes in iron metabolism in Atlantic salmon. These changes may affect the expression of genes directly involved in the synthesis of hemoglobin, as has been reported for other pathogens [ 36 ]. Finally, Selenoprotein P, an extracellular protein that transports most plasma selenium [ 37 ], was consistently down-regulated following infection.…”

Analysis of differentially expressed gene fragments in the head kidney of lipopolysaccharide-stimulated Malabar grouper (Epinephelus malabaricus)

“…They were cloned in the SSH library of chickens infected with an avian leukosis virus subgroup (Zhao et al 2010). Moreover, Parish et al (2001) proved that haemoglobin (the intact tetramer of α-chain or/and β-chain) had the roles of oxygen transportation and was an important multi-defense agent against a wide range of microorganisms in snake, alligator, horse and human.…”

Selection of reference genes for quantitative real-time PCR analysis in chicken embryo fibroblasts infected with avian leukosis virus subgroup J

“…Disease severity of ALV-J is linked to an increase incidence of tumor formation, immunosuppression, with ensuing high mortality rates [1]. To elucidate the molecular pathogenesis of ALV-J infection and tumor development, many studies have focused on analyzing host gene expression profiles following ALV-J infection [2][3][4]. Assessment of mRNA expression levels via real-time PCR has been a standard approach with high accuracy, sensitivity and reproducibility, and thus it has been widely used to infer host gene expression in response to virus infection [5].…”