Structural and genetic studies on chicken 7S immunoglobulin allotypes. II. Distribution of allotypes on the 7S immunoglobulin of homozygous and heterozygous chickens.

We have previously reported that chicken 7S immunoglobulin (Ig) heavy (H) chain allotypes (CS-1 locus) segregate as phenogroups in F2 progeny. Specificity CS-1.1 formed a phenogroup with CS-1.4 in inbred chicken line UCD 2, and a second phenogroup with CS-1.3 in line UCD 3. To determine whether these phenogroups were formed by combinations of specificities on the same, or on separate subclasses of 7S Ig, their distribution on the 7S Ig molecules of birds homozygous for 7S Ig allotypes was analyzed by radioimmunoassay. Anti-CS-1.1 and anti-CS-1.3 alloantisera each bound more than 94% of line UCD 3 1252-7S Ig. Similar results were obtained with alloantisera to CS-1.1 and CS-1.4 WITH 125 I-7S Ig from line UCD 2. These results indicate that both phenogroups were formed by combinations of specificities present on the same H chain. Thus, each phenogroup described, probably is the product of a single structural gene which is responsible for more than 94% of the 7S Ig H chain constant regions. In F hybrids with the genotype CS-1.3, 1.3/CS-1.2, two populations of serum 7S Ig molecules were detected by direct and sequential binding analysis with specific alloantisera. One population of 7S Ig contained specificities CS-1.1 AND CS-1.3, but not CS-1.2; while the second population was exclusively the product of one parental allele. Consistent with a genetic regulatory mechanism involving allelic exclusion, no MS Ig containing allotypes produced by both alleles was detected.     

Structural and genetic analysis of four chicken 7S immunoglobulin allotypes

Four 7S immunoglobulin allotypic specificities in three inbred chicken lines were demonstrated in two immunoglobulin regions, probably associated with the heavy chains. Two specificities were associated with papain-produced Fab fragments, most likely the Fd fragment since they were not demonstrated on the 17S immunoglobulin. The other allotypes were detected only on intact 7S immunoglobulin and were undetectable on the Fab and Fc fragments; therefore, they probably were associated with a region of the heavy chain sensitive to papain digestion. Among F₂ hybrids, these specificities segregated in a manner statistically indistinguishable from that expected of three codominant alleles at an autosomal locus. This locus was not closely associated with any of five chicken blood group loci.     

Genetic nomenclature for chicken immunoglobulin allotypes: An extensive survey of inbred lines and antisera

Based on a survey of 36 inbred and 8 partially inbred chicken lines and outbred jungle fowl, and with 29 alloantisera generated in different laboratories, 13 7S Ig and 5 IgM allotypes were designated and a new system of nomenclature for chicken Ig polymorphisms was developed. The survey also revealed considerable genetic polymorphism in the structural gene(s) (G-1) responsible for the production of 7S Ig H chains. IgM H chains, encoded by theM-1 locus were less polymorphic. NineG-1 and fourM-1 gene alleles were delineated in highly inbred lines by the formation of unique combinations ofG-1 orM-1 specificities. Five additionalG-1 alleles were found in chicken lines and jungle fowl segregating for allotypes. Thirty-three percent of theG-1M-1 haplotypes theoretically expected, were detected in inbred lines.     

Proposed standard nomenclature for the alpha- and beta-globin gene families

The globin family of genes and proteins has been a recurrent object of study for many decades. This interest has generated a vast amount of knowledge. However it has also created an inconsistent and confusing nomenclature, due to the lack of a systematic approach to naming genes and failure to reflect the phylogenetic relationships among genes of the gene family. To alleviate the problems with the existing system, here we propose a standardized nomenclature for the alpha and beta globin family of genes, based on a phylogenetic analysis of vertebrate alpha and beta globins, and following the Guidelines for Human Gene Nomenclature.     

Sequence studies on the heavy chain of rabbit immunoglobulin A of different alpha-locus allotypes.

The amino acid sequence was determined of part of the variable region of heavy chain from rabbit immunoglobulin A of allotypes a1 and a3. Two corrections of the primary sequence of Aa1 gamma-chains are reported; most of the structural correlates of the alpha-locus allotypes are confirmed. The amino acid sequence of the N-terminal 20 residues of alpha-negative molecules was also determined and found to be homologous to the human VhIII subgroup. These molecules are present in a much higher proportion in the alpha-chain pool than in the gamma-chain.     

Rat kappa-chain allotypes. III. Serological and genetic analysis of RI-1b cross-reactivity in Australian Rattus

The presence of rat kappa-chain allotype specificities (RI-1a and b) has been studied in 13 subspecies of the seven native Australian species of Rattus. RI-1a reactivity was not detected among these rats. On the other hand, extensive cross-reactivity was seen with RI-1b, some sera cross-reacting totally (R. leucopus cooktownensis), some not at all (R. colletti), and the remainder showing at least two distinct levels of partial cross-reactivity, confirming the existence of multiple specificities for RI-1b. Three subspecies show polymorphism with respect to RI-1b cross-reactivity (R. sordidus, R. colletti, and R. l. leucopus) and in one case (leucopus) breeding studies have indicated that there is allelic inheritance of this trait. The segregation of RI-1b reactivity has been studied in crosses and backcrosses made between species differing in their RI-1b reactivity, and the results are consistent with the existence of codominant alleles at a single locus. The fact that these species differ extensively in their karyotype opens the door to possible chromosomal localization of this and other genetic traits.     

Structural and evolutionary comparisons of four alleles of the mouse immunoglobulin kappa chain gene,Igk-VSer

The mouseIgK-VSer gene encodes an immunoglobulin light chain variable region which gives rise to two phenotypic polymorphisms of mouse chains. The nucleotide sequences of coding and flanking regions of theIgk-VSer ^c andIgk-VSer ^d alleles found in recently inbred strains of wild mice are compared with those of theIgk-VSer ^a andIgk-VSer ^b alleles described previously. Results suggest that the gene is evolving randomly and that framework 2 and complentarity determining region 2 are preserved, presumably for overall light chain structure. Results indicate that all four allels have an octamer motif upstream of the gene which should be functional and allow prediction of whether or not the product of the germ line gene will be detectable as either the I_B-peptide or Ef1^a phenotypic polymorphism. Southern hybridization of genomic DNA using as probe a 1-kbXba I-Xba I fragment located approximately 4 kb upstream of the BALB/cIgk-VSer ^b coding region demonstrated the presence of homologous DNA in mice bearing theIgk-VSer ^a allele and absence from mice bearing theIgk-VSer ^c andIgk-VSer ^d alleles. Nucleotide sequence comparison of BALB/c and SK/CamRk (Igk-VSer ^d ) DNA in this region demonstrated that BALB/c contained an insertion 2.4 kb in length which was absent from SK/CamRk. Both strains contain DNA homologous to the reverse complement of the mouse Bam5 repetitive element at the point of the insertion, with BALB/c containing approximately 70 nucleotides more of the element than SK/CamRk. Surprisingly, the strains containing DNA related to theXba I-Xba I probe are not those determined to be the most similar by nucleotide sequence comparisons and by the Phylogenetic Analysis Using Parsimony program. The evolutionary relationship of the alleles and a possible basis for the inconsistency presented by theXba I-Xba I fragment-related DNA are discussed.     

Surface immunoglobulin on rabbit lymphoid cells. III. Double expression and separate endocytosis of surface immunoglobulin allotypes on heterozygous lymphocytes demonstrated by immunoelectron microscopic labeling.

The expression of immunoglobulin b locus (k chain) allotypes on the surface of rabbit peripheral blood lymphocytes (PBL's) is examined using an indirect double immunoelectron microscopic labeling technique. Ferritin and whelk hemocyanin individually conjugated to allotypically specific IgG are used as ultrastructurally identifiable molecular markers. These indicators are coupled to lymphocyte surface immunoglobulin (Ig) allotypic determinants by an antiallotype antibody linkage. Human red blood cells, conjugated with IgG of a specific allotype and used as test cells, demonstrate the absolute specificity and high efficiency of the ultrastructural labeling technique. Specific labeling on rabbit PBL's shows that 65–75% of the cells are positive for surface Ig. Lymphocytes from homozygous donors (b4b4 or b6b6) are labeled specifically with only the appropriate allotypic labeling system. Thirty-three percent of the PBL's from heterozygous donors (b4b6) express both allotypes (allelic inclusion) on the cell surface; the remaining proportion of Ig-bearing cells have only one detectable allotype present (allelic exclusion). We conclude that approximately 50% of the Ig-bearing PBL's demonstrate allelic inclusion for the b locus allotypes. On allelically included heterozygous lymphocytes, both allotypic determinants can undergo specific endocytosis. Endocytosis of one allotype on heterozygous cells can be induced by stimulation with antiallotypic serum without affecting the surface appearance of the other allelic marker (separate endocytosis).     

Isolation and characterization of two alleles of the chicken cytochrome c gene.

Analysis of total chicken DNA by genomic blot hybridization indicates that only one cytochrome c gene exists in the chicken genome. The two alleles of this single cytochrome c gene have been isolated from a Charon 4A-chicken genomic library. This isolation made use of the yeast CYC1 cytochrome c gene as a specific hybridization probe. The 2 chicken alleles, CC9 and CC10, have been sequenced. The amino acid sequence predicted by these 2 alleles is identical, and agrees with the published chicken cytochrome c protein sequence. The flanking regions of these 2 alleles exhibit approximately 1% divergence, indicating a very limited polymorphism. Comparative sequence analysis with the flanking regions of previously isolated cytochrome c genes (yeast and rat) indicate no significant regions of homology. The presence of only one cytochrome c-like sequence in the chicken genome is in striking contrast with mammalian genomes, which contain as many as 20-30 cytochrome c-like sequences.     

Monoclonal antibodies to the bovine immunoglobulin G2a allotypes A1 and A2.

Production of murine monoclonal antibodies (Mabs) to bovine IgG2a-A1 and A2 allotypes resulted in three Mabs being selected as anti-IgG2a-A1 and A2 reagents. Two Mabs recognize the A1 allotype and 1 recognizes the A2 allotype. Initial epitope mapping with the Mabs indicates that one of the A1 epitopes resides in the hinge region and the other epitope resides more toward the C-terminus of the immunoglobulin. The A2 epitope recognized by the A2 Mab does not appear to reside in the hinge region of the immunoglobulin but apparently resides more C-terminal.     

Structural studies on periodate-oxidized chicken ovomucoid. Spectral behaviour of the tyrosine residues.

About 50% of the carbohydrate moiety of ovomucoid was destroyed by periodate oxidation. The oxidation was carried out for 6 h or 24 h. The data obtained showed that in the carbohydrate chain 2-5 glucosamines and 1-2 neutral sugar residues were decomposed with the consumption of 16 mol and 29 mol of periodate respectively. Periodic oxidation slightly changed the inhibitory activity of the ovomucoid, but altered its spectral properties. An increase of the absorption maximum at 278 nm was noted, as well as a tendency for normalization of phenolic ionization and an increase of the relative fluorescence. The reactivity of tyrosine residues towards tetranitromethane is also changed. It was suggested that even in native ovomucoid the tyrosines could be regarded as 'dissolved' in the 'carbohydrate solvent'. This contact could be achieved by the hydrogen bonds in the formation of which the NHCOCH3 groups of the glucosamine residues play an essential role. Peroxidate oxidation seems to lead to an alteration of the nature of the 'sugar solvent' and disturbs the conformation of the sugar chain.     

Population genetic studies of the Philippine Negritos. II. gm and km allotypes of three population groups.

Serum samples of the three tribal Negrito populations in the Philippine Islands (127 from Zambales, 87 from Bataan, and 93 from Agusan) were tested for Glm(1,2,3 and 17), and G3m(5,6,11,13,14,15,16, and 21), and Km(1). The GMpatterm of the Negritos is characterized by three haplotypes, Gm1,17;21, Gm1,2,17;21, and Gm1,3;5,11,13,14, which is also characteristic of Mongoloid-related populations, especially with high incidence of the latter haplotype. They also have the haplotype, Gm1,17;5,13,14, prevalent in Africa, New Guinea, and northern Australia, suggesting an ancient link between the Negritos and the New Guinean-Australian group. Two unusual samples of G3m(15) positive without G3m(16) observed in Zambales Negritos suggest the presence of Gm1,17;5,11,13,14,15 haplotype in the population. This appears to be unique to Zambales Negritos and the first such samples to be found.     

Further studies on the genetic control of chicken plasma alkaline phosphatase isozyme.

The effects of neuraminidase treatment on the electrophoretic pattern of alkaline phosphatase (AP) isozymes and AP activity were investigated in chicken plasma. AP comprised three isozymes. The zymogram of an individual chicken plasma had two bands, either the faster (F) or the slower (S) moving band by isozyme types and the B band irrespective of isozyme types. Mobility of the S band and AP activity in chicken plasma were not affected by neuraminidase treatment. The treatment has a reduced migration rate of the F band equal to that of the S band and the B band of both types closer to the origin. The genetic control of these bands is discussed.     

Proposed genetic nomenclature rules for Tetrahymena thermophila,Paramecium primaurelia and Paramecium tetraurelia. The Seventh International Meeting on Ciliate Molecular Biology Genetics Nomenclature.

Ordered tetrad data yield information on chromatid interference, chiasma interference, and centromere locations. In this article, we show that the assumption of no chromatid interference imposes certain constraints on multilocus ordered tetrad probabilities. Assuming no chromatid interference, these constraints can be used to order markers under general chiasma processes. We also derive multilocus tetrad probabilities under a class of chiasma interference models, the chi-square models. Finally, we compare centromere map functions under the chi-square models with map functions proposed in the literature. Results in this article can be applied to order genetic markers and map centromeres using multilocus ordered tetrad data.