Biomedical subjects

Z Uni

Publications and source records attributed to Z Uni.

41 records · Page 3Linked to original sources

PubMed1992

Immunological parameters in meat-type chicken lines divergently selected by antibody response to Escherichia coli vaccination.

Our group has established two lines of meat-type chickens divergently selected for early (HC line) and late (LC line) antibody responsiveness at 10 days of age to immunization with inactivated pathogenic Escherichia coli bacteria. The question addressed in the study presented here is whether this selection has changed other immunological responses, increasing the overall 'early' immunocompetence. Broilers of the third and fourth generations (S3 and S4) of the selected lines (HC and LC) and a control, unselected line (CT) were vaccinated at 10 days of age with E. coli vaccine, Newcastle virus vaccine (NDV), sheep erythrocytes (SRBC) or bovine serum albumin (BSA). Line-HC chicks exhibited higher antibody titers to E. coli, NDV and SRBC than CT or LC chicks. At 20 days of age HC chicks demonstrated a higher total protein and a higher beta- and gamma-globulin levels in their serum. At 21 days of age, HC chicks cleared carbon particles faster than LC chicks. Peripheral blood lymphocytes (PBL) from HC chicks vaccinated with E. coli vaccine, proliferated in vitro more actively in the presence of the stimulating antigen than the PBL of LC chicks. Peripheral blood lymphocytes (PBL) obtained from HC-line chicks exhibited a higher proliferative response to concanavalin A (Con A)-, phytohemagglutinin (PHA)- or pokeweed mitogen (PWM)-stimulation than LC PBL. These results demonstrate that the selection for high or low antibody response to E. coli at a young age resulted also in a significant change in the response of other parameters of the immune system. The high response to E. coli was found to be associated with a high antibody response to other antigens (NDV and SRBC), increased phagocytic activity and increased proliferative response to antigen or mitogens. The selection most probably affected early immunocompetence.

Aging↗

PubMed1992

Restriction fragment length polymorphism analysis of major histocompatibility complex class IV (B-G) genotypes in meat-type chickens.

Restriction fragment length polymorphism (RFLP) was used as a molecular genotyping approach to characterize differences in major histocompatibility complex class IV genes in meat-type chickens. A high level of polymorphism was observed following digestion with each of the two restriction endonucleases PvuII and BglII. Examination of DNA from 54 chickens revealed 23 polymorphic fragments. Application of RFLP techniques in the analysis of family groups should make possible the determination of B-G genotypes in the meat type chickens.

Animals↗

PubMed1992

Replicated divergent selection of broiler chickens for high or low early antibody response to Escherichia coli vaccination.

Four sublines of broiler chickens were selected from a base population for three generations for high or low antibody response to vaccination with Escherichia coli at 10 days of age. Two sublines were selected for a high response (HC) and two for a low response (LC). Realized heritability estimates over three generations of selection for each pair of replicated lines averaged .23 in HC lines and .32 in LC lines. No correlated response in the important production trait, body weight at marketing age, was observed. The ability to survive pathogenic E. coli challenge with or without prevaccination showed no differences between the lines in the unvaccinated chicks, although following vaccination there was higher mortality and morbidity in the LC lines. These data suggest that the use of antibody response in young chicks to E. coli vaccine may be a useful genetic indication of more general disease resistance.

Animals↗

PubMed1991

Serological evidence for major histocompatibility complex (B complex) antigens in broilers selected for humoral immune response.

Genetic selection for early humoral immune responsiveness against two simultaneous antigens, namely, heat-killed Escherichia coli and Newcastle disease virus vaccine (NDV), was performed in a heterogenic population of broiler chickens. The humoral immune response was measured prior to 24 days of age, depending on the vaccine. Chicks were divided into two populations according to their antibody response: a population of high responders to both antigens and a population of low responders. After four generations of selection, a significant difference was observed in the immune response of the two populations, and therefore, an attempt was made to identify possible differences in the segregation of major histocompatibility complex genes. Using alloantisera prepared in B-congenic White Leghorn, the high responders exhibited a high percentage of chickens having erythrocytes agglutinated with B5 antisera, and the low responders exhibited a high percentage of chicks with erythrocytes agglutinated with B15 and B19 antisera. The B13 antisera agglutinated cells of similar proportions of chickens in the two populations. A random commercial broiler flock was screened with the antisera, and correlation was high between B haplotype and antibody level to E. coli following vaccination. The present work indicated the possibility of a direct association between the genetic characteristics represented in the B complex and humoral antibody response in a broiler population.

Animals↗

PubMed1991

Peanut agglutinin as a marker of maturation and activation of chicken thymic-derived lymphocytes.

In mammals peanut agglutinin (PNA) is used for separation of lymphocytes into immature and mature T-cells. Lymphocytes that bind PNA are young and functionally immature, but the cells that do not bind PNA are considered mature. No conclusive information was published on PNA as a marker of lymphocytes maturation in chickens. The present results showed that T-lymphocytes that do not bind PNA (PNA-) responded significantly higher to Concanavalin A (Con-A) stimulation than PNA+ ones. During Con-A activation, a PNA receptor was revealed. Double staining of Con-A cultured lymphocytes revealed the presence of both I-associated antigen and PNA. Therefore, the PNA receptor, on chicken T-lymphocytes, was not indicative always of immaturity. During maturation, the receptor was covered and the cells were PNA-, but subsequent proliferation reverted PNA- cells to PNA+ cells.

Animals↗