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Biomedical subjects

C M Warner

Publications and source records attributed to C M Warner.

At least 55 records · Page 3Linked to original sources
PubMed1991

Major histocompatibility complex antigen expression on lymphocytes from aging strain A mice.

Molecules encoded by the major histocompatibility complex (MHC) are crucial for the proper functioning of the immune response. In this study, the levels of class I and class II major histocompatibility antigens on lymphocytes from strain A mice were measured as a function of age. Class I protein levels increased significantly on both peripheral blood and spleen (T cells and B cells) lymphocytes with age. This increase in MHC class I protein levels was accompanied by an increase in class I mRNA levels. On the other hand, class II protein levels did not show a significant change with age. Moreover, while the percentage of class I-expressing spleen lymphocytes stayed at a steady-state level of 100% with age, the percentage of class II-expressing spleen lymphocytes decreased from 85% in young animals to 70% in old animals. This decrease was due to a decrease in the relative proportion of B cells compared to T cells in the spleen lymphocyte population of old mice. When class II mRNA levels were measured, it was found that these levels decreased markedly with age. Overall, it is clear that the regulation of MHC class I and class II expression changes with age in A strain mice. Since optimal levels of MHC expression are crucial for the proper functioning of cellular and humoral immune responses, it will be most interesting to understand how the control of MHC gene expression changes with age and whether MHC gene expression can be modulated in old individuals to restore better immune function.

Aging↗
PubMed1990

Changes in morphology, cell number, cell size and cellular estrogen content of individual littermate pig conceptuses on days 9 to 13 of gestation.

Days 9 to 12 of gestation in the pig are marked by a pronounced asynchrony among littermate embryos. Previously published studies have suggested that the most advanced embryos within a litter by d 12 synthesize greater amounts of estrogen. Embryonic estrogen secretion has been shown to advance endometrial secretions, which may adversely affect less-developed littermates. To date, however, no comprehensive study of the developmental pattern and synthetic activities of individual littermate embryos during this period has been conducted. Litters were collected from Yorkshire gilts on d 9 (n = 11), 11 (n = 10), 12 (n = 5) and 13 (n = 8). Size (greatest diameter), DNA content (cell number), protein:DNA ratio and estrone (E1) and estradiol-17 beta (E2) content were determined for each embryo. Embryo sizes (mm greatest diameter) were (x +/- SEM) 1 +/- .1, 5.6 +/- .7, 41.2 +/- 11.7 and 405.7 +/- 16.7 on d 9, 11, 12 and 13, respectively. The daily variation in embryo size, expressed as CV was 82% on d 9, 145% on d 11, 206% on d 12 and 46% on d 13. DNA per embryo increased progressively from d 9 to 13, whereas the protein:DNA ratio declined. Content of E1 and E2 per embryonic cell was greatest on d 11 and d 12 before declining markedly on d 13. Cell number and embryo size were correlated positively in embryos 1 to 7 mm (P less than .01) and embryos greater than 100 mm (P less than .01) but not in embryos 8 to 100 mm.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Analysis of restriction fragment length polymorphisms of the major histocompatibility complex of 15I5-B-congenic chicken lines.

Eight 15I5 B-congenic White Leghorn chicken lines, containing haplotypes B2, B5, B12, B13, B15, B19, and B21, were subjected to molecular genotyping with chicken B-F (Class I) and B-L (Class II) major histocompatibility complex (MHC) probes. Genomic DNA was digested with restriction enzymes, hybridized with a Class I or Class II probe, and analyzed for restriction fragment length polymorphisms. Digestion with HindIII or EcoRI yielded no B-L polymorphisms. Digestion with PvuII or BglII and hybridization with a B-L or B-F probe produced polymorphisms that were shared between several haplotypes, although the haplotypes with similar patterns were clustered differently between Class I and Class II probes. The genetic variation seen for B-L and B-F probe hybridization of PvuII digests was much less than that previously demonstrated for B-G probing of PvuII digests of the same lines. Description of MHC Class I and II restriction patterns of the well-characterized 15I5 B-congenic lines will aid in identification of genes important in disease resistance.

Animals↗
PubMed1989

Isolation and characterization of three class II MHC genomic clones from the chicken.

A genomic library was constructed from sperm DNA from an individual of the inbred chicken line G-B2, MHC haplotype B6. The library was screened with a chicken class II probe (beta 2 exon specific) and three MHC class II beta chain genomic clones were isolated. The restriction maps of the three clones showed that each of the three clones was unique. The position of the beta chain sequence was located in each of the three genomic clones by Southern blot hybridization. Subclones containing the beta chain gene were produced from each of the genomic clones and the orientation of the leader peptide, beta 1, beta 2, transmembrane, and cytoplasmic exons was determined by Southern blot hybridization and nucleotide sequencing. The complete nucleotide sequence of two of the three subclones was determined. Comparison of the nucleotide and predicted amino acid sequences of the two subclones with other class II beta chain sequences showed that the B6 chicken beta chain genes are evolutionarily related to the class II beta chain genes from chickens of other MHC haplotypes, and to class II beta chain genes from other species. Analysis of Southern blots of B6 chicken DNA, as well as the isolation of the three beta chain genes, suggests that chickens of the B6 haplotype possess at least three MHC class II beta chain genes.

Amino Acid Sequence↗
PubMed1989

Association of restriction fragment length polymorphisms of swine leucocyte antigen class I genes with production traits of Duroc and Hampshire boars.

Restriction fragment length polymorphism analyses of swine leucocyte antigen (SLA) class I genes were performed on 70 Duroc and 38 Hampshire boars from the 1986-87 national performance tests of each breed in the USA. Few boars were inbred. Southern blotting and hybridization procedures were performed on genomic DNA, isolated from white blood cells, using PvuII endonuclease and a swine major histocompatibility complex (MHC) class I probe. Durocs had an average of 11 restriction fragments, with the most common being in 63% of the boars and the least common appearing in only one boar. Hampshire boars had an average of 12 restriction fragments, with the most common appearing in 73% of the boars and the least common appearing in only one boar. Least squares procedures and stepwise regression methods were used to examine the association between DNA restriction fragments and the selection index (INDEX), average daily gain (ADG), average backfat thickness (BF), loin muscle area (LEA), and age at 104 kg (DAY104). In the Duroc breed one DNA restriction fragment was associated with decreased INDEX (P less than 0.05) and decreased ADG (P less than 0.05) whereas two other fragments were associated with increased BF (P less than 0.05). In the Hampshire breed two restriction fragments were associated with an increase in INDEX (P less than 0.05). Cluster analyses were used to group pigs of each breed on the basis of similar RFLP patterns. One cluster group in the Duroc breed was associated with lower average INDEX values (P less than 0.05), greater average DAY104 (P less than 0.05), and a larger mean LEA (P less than 0.05). In the Hampshire breed one cluster group was associated with lower INDEX (P less than 0.05). These results suggest there may be an association between swine MHC class I genes and performance traits in swine. The use of SLA class I restriction fragments, as genetic markers, may have potential in the future for improving pig performance.

Animal Husbandry↗
PubMed1989

Analysis of B-G and immune response genes in the Iowa State University S1 chicken line by hybridization of sperm deoxyribonucleic acid with a major histocompatibility complex class II probe.

Sperm DNA was isolated from chickens of the Iowa State University S1 line. Birds were from sublines selected for B-G antigen, humoral immune response to glutamic acid-alanine-tyrosine (IrGAT), and response to Rous sarcoma virus-induced (RSV) tumors. The DNA was digested with restriction enzymes and subjected to Southern blot analysis with a DNA probe specific for a class II gene of the chicken major histocompatibility complex (MHC). Restriction fragment length polymorphisms (RFLP) associated with B-G antigen type were found after digestion of DNA with three enzymes, PvuII, BglII, or Sau3A, out of a total of 15 tested. No RFLP were shown to be associated with IrGAT or RSV type. This study shows that RFLP analysis of DNA may be a useful addition to or alternative to serological evaluation of MHC haplotype in the chicken.

Animals↗
PubMed1989

Effects of H-2 haplotype and gender on the lifespan of A and C57BL/6 mice and their F1, F2, and backcross offspring.

The effects of H-2 type and gender on the lifespan of A and C57BL/6 mice and their F1, F2, and backcross offspring were studied. The proportion of mice remaining alive, percent survivors, was calculated at monthly intervals for each mating group. Statistical analyses of these survival data showed that, in agreement with studies from other laboratories, C57BL/6 (H-2b) mice lived significantly longer than A (H-2a) mice. When the survival curves for A and C57BL/6 backcross and F2 offspring were analyzed to test for the presence of an H-2 effect on mouse lifespan, no statistically significant association was detected, although a trend toward increased 10th decile survivorship among female H-2a mice was noted. The mice used in this study were also evaluated for the presence of an effect of gender on lifespan. Female mice of the A strain, and F1, F2, and backcross groups, but not the C57BL/6 mice, exhibited significantly longer lifespans when compared with their male counterparts. Thus these data show a significant gender effect, but only a trend towards an H-2 effect, on the lifespan of A and C57BL/6 mice and their F1, F2, and backcross offspring.

Animals↗
PubMed1988

Ped gene expression by embryos cultured in vitro.

The rate of cleavage division of preimplantation mouse embryos has been shown to be influenced by the Ped gene, a gene linked to the H-2 complex, the major histocompatibility complex of the mouse. There are two functional alleles of the Ped gene, slow and fast. To examine Ped gene expression outside of the maternal uterine environment, embryos from inbred and congenic mouse strains were cultured in vitro, in chemically defined medium, for various lengths of time. The results of these studies show that the difference in the rate of cleavage division between slow-developing strains (Ped slow) and fast-developing strains (Ped fast) is maintained in vitro. Thus, the Ped gene phenotype of developing embryos is an intrinsic property of the embryos themselves.

Alleles↗
PubMed1988

Influence of SLA haplotype on ovulation rate and litter size in miniature pigs.

Systemic blood was collected from and surgery performed on sows of 3 strains of miniature swine bred for specific SLA (swine MHC) haplotypes (a, c and d) from Day 2 to Day 6 after mating (first day of mating = Day 0). Ovulation rate was determined by counting corpora lutea and embryos were flushed from the uterus. Progesterone, oestradiol-17 beta and oestrone were quantitated in blood plasma and uterine flushings by RIA. SLAd/d females had a higher ovulation rate than SLAa/a or SLAc/c females (11.50 +/- 0.87 vs 9.11 +/- 0.68 and 8.17 +/- 0.83, respectively; P less than 0.01). Oestrone was higher than oestradiol-17 beta in systemic plasma (56.5 +/- 6.4 vs 33.0 +/- 4.7 pg/ml, P less than 0.01) while oestradiol-17 beta was higher than oestrone in uterine flushings (19.8 +/- 1.4 vs 14.9 +/- 1.5 pg/horn, P less than 0.10). Systemic progesterone concentration was correlated with day after mating (r = 0.93, P less than 0.01). There was no effect of haplotype on any of the hormone concentrations measured. Litter size was analysed from 99 matings amongst SLAa/a, SLAa/c, SLAa/d, SLAd/c and SLAd/d sires and dams. Litter size from -/d and d/d sows or from d/d boars were larger (P less than 0.05) than for all other matings. Although ovulation rate was higher in SLAd/d sows, the significant effect of sire SLA genotype on litter size suggests an additional effect of the d haplotype on embryonic survival.

Animals↗
PubMed1988

Influence of SLA haplotype on preimplantation embryonic cell number in miniature pigs.

Embryonic cell number in miniature pigs inbred for specific SLA haplotypes (a, c, and d) was determined on Day 6 by nuclear staining and, on Days 9 and 11, by DNA analyses (first day of oestrus = Day 0). Pigs exhibiting first behavioural oestrus at 08:00 h were hand-mated to an SLA homozygous boar 12 and 24 h later. Numbers of embryos flushed from uteri at 08:00-10:00 h on Days 6, 9 and 11 were greater (P less than 0.05) for SLAd females than for SLAa or SLAc females, which did not differ (8.2 vs 6.8 and 6.2, respectively). Recovery rates (embryos recovered/CL number) were similar, averaging 75.8% for all three SLA haplotypes. Embryos from SLAd dams contained fewer blastomeres (23 cells) on Day 6 than did embryos from SLAa (89 cells) or SLAc (79 cells) females. The reduced cell numbers of SLAd vs SLAa or SLAc embryos continued to Day 9 (28 vs 107 and 67 ng DNA/embryo) and Day 11 (167 vs 674 and 586 ng DNA/embryo). These results suggest an effect of the SLA complex on preimplantation embryonic development.

Animals↗
PubMed1988

Preparation and characterization of murine monoclonal antibodies to swine lymphocyte antigens.

A panel of monoclonal antibodies (mAb) was developed by the fusion of Sp2/0 myeloma cells and spleen cells from mice immunized with peripheral blood mononuclear cells (PMNC) or T cells from NIH swine leucocyte antigen (SLA) inbred miniature swine. Twenty stable hybridoma clones were isolated that secreted mAb that reacted with swine PMNC, as determined by an enzyme-linked immunosorbent assay (ELISA). The binding profile to swine PMNC and the ability to fix complement of these mAb were investigated by flow cytometric analyses. The molecular weights of the antigens recognized by six of the mAb were determined by immunoprecipitation of 125I surface-labelled PMNC, followed by SDS-PAGE under reducing conditions. The most interesting mAb, 7-34-1 (IgG2a), precipitated a putative MHC class I molecule composed of a 50,000 MW heavy chain and a 12,000 MW light chain (beta 2m). This is the third SLA class I-reactive monoclonal antibody to be described for swine. Properties of the mAb described in this paper, mAb 7-34-1, are different from the two other SLA class I-specific mAb that have been described elsewhere in the literature (mAb 74-11-10 and mAb PT85). Monoclonal antibody 7-34-1 recognized class I antigens of SLA haplotypes a, c and d in an equivalent manner. This mAb should be especially useful as a general anti-SLA class I reagent for experiments on NIH miniature swine.

Animals↗
PubMed1987

Mapping of C2, Bf, and C4 genes to the swine major histocompatibility complex (swine leukocyte antigen).

Three miniature swine lines, inbred for swine leukocyte antigen (SLA) haplotypes, a, c, and d, and a recombinant line, haplotype g, were analyzed for possible restriction fragment length polymorphisms (RFLP) by Southern blot hybridization with human C2, factor B (Bf), and C4 specific probes. The search for RFLP by using a human C2 probe failed to reveal any variants. However, a Taq I polymorphism was identified with the human Bf probe and Bam HI and Pvu II polymorphisms were identified with the human C4 probe. Overlapping restriction fragments were found with the C2 and Bf probes, which strongly suggests close linkage of C2 and Bf genes in swine. Segregation analyses of the Bf and C4 polymorphisms indicated that the polymorphic fragments followed a Mendelian pattern of inheritance. The recombinant haplotype g, which expresses class I genes of haplotype c and class II genes of haplotype d, was shown to produce an identical RFLP pattern, by using the Bf and C4 probes, as haplotype d, but different from that of haplotype c. This indicates that there is a close association of [C4-Bf-C2] and class II genes in miniature swine. Although these data do not show conclusively the location of the [C4-Bf-C2] genes, it is hypothesized that swine [C4-Bf-C2] genes are located between the class II and class I genes, as has been demonstrated in mouse and man.

Animals↗
PubMed1987

Killing of mouse blastocyst stage embryos by cytotoxic T lymphocytes directed to major histocompatibility complex antigens.

A new assay, mixed embryo leukocyte interaction assay, in which the ability of cytotoxic T lymphocytes (CTL) to kill preimplantation mouse embryos could be investigated, is described. CTL were generated both in vitro and in vivo to the H-2b and H-2d haplotypes. The specificity of the CTL was verified by using EL-4 (H-2b) and P815 (H-2d) target cells in a 51Cr-release assay. The cytolytic effect of the CTL on mouse blastocysts was measured by assessing blastocoel retention and inhibition of [3H]thymidine incorporation by the embryos. It was shown that CTL kill blastocyst stage embryos from C57BL/6J (H-2b) and B10.D2 (H-2d) mice with the zona pellucida removed, but not with the zona pellucida intact. These results demonstrate that the H-2 antigens present on mouse blastocysts can be recognized by CTL. It is suggested that one biologic role for the zona pellucida is the prevention of cell-mediated destruction of preimplantation embryos in utero.

Animals↗
PubMed1987

Linkage of the preimplantation-embryo-development (Ped) gene to the mouse major histocompatibility complex (MHC).

The preimplantation-embryo-development (Ped) gene influences the rate of cleavage division of preimplantation mouse embryos. The location of the Ped gene in the mouse major histocompatibility complex (MHC), the H-2 complex, has been inferred from the analysis of cleavage rates of embryos from mouse strains congenic at the H-2 complex. In this paper, formal genetic linkage studies were undertaken to evaluate linkage of the Ped gene to the H-2 complex. Co-segregation of Ped gene phenotype and H-2 haplotype was found in back-cross embryos. These data support the hypothesis that the Ped gene is linked to the H-2 complex.

Animals↗
PubMed1987

Analysis of Qa-2 antigen expression by preimplantation mouse embryos: possible relationship to the preimplantation-embryo-development (Ped) gene product.

The preimplantation-embryo-development (Ped) gene, a gene that controls the cleavage rate of preimplantation mouse embryos, maps to the Qa-2 subregion of the mouse major histocompatibility complex (MHC). A highly sensitive enzyme-linked immunosorbent assay (ELISA) procedure was used to detect Qa-2 antigens on mouse embryos. The use of a monoclonal antibody specific for Qa-2 antigens showed that Qa-2 antigens were present on oocytes, 2-cell, 8-cell, and blastocyst-stage embryos, with the greatest expression found on blastocysts. Expression of Qa-2 antigens by the embryos correlated completely with Ped gene phenotype. Those embryos expressing the fast Ped allele showed the presence of Qa-2 antigens (Qa-2a mice), whereas those embryos expressing the slow Ped allele showed the absence of Qa-2 antigens (Qa-2b mice). It is hypothesized that the Qa-2 antigen may be the Ped gene product.

Alleles↗
PubMed1987

Genetic control of immune responsiveness: a review of its use as a tool for selection for disease resistance.

Disease resistance and immune responsiveness have been traits generally ignored by animal breeders. Recent advances in immunology and molecular biology have opened new avenues towards our understanding of genetic control of these traits. The major histocompatibility gene complex (MHC) appears to play a central role in all immune functions and disease resistance. The need to understand the relationship between immune responsiveness, disease resistance and production traits is discussed in this review. Antagonistic relationships might prevent simultaneous improvement of all of these traits by conventional breeding methods. It is suggested that genetic engineering methods may allow the simultaneous improvement of disease resistance and production traits in domestic animals. Genes of the MHC will be especially good candidates for genetic engineering experiments to improve domestic species.

Animals↗