Interaction of genes controlling two allotypes in chickens.

This paper presents the results of the investigations of the newly detected antigen of chicken blood serum, called K2. It was established that the K2 antigen which was identified with isoimmune serum was a beta-globulin with the molecular weight over 200 000. The results of the genetic analysis based on sire-dam-offspring combinations seemed to indicate that the antigen under examination was controlled by a gene hypostatic to the gene controlling the previously described K1 allotype.     

Segregation of allotypes in a strain of chickens homozygous for theB locus

Sublines homozygous for alleles controlling IgM and IgG allotypes at two linked loci (M1 andG1) were established in the B14 strain of chickens, which is homozygous for theB locus controlling major histocompatibility antigens. Transfer of lymphoid cells resulted in a permanent donor-type IgG synthesis in irradiated 12-day-old recipients, but was followed by protracted rejection in chickens injected embryonally.     

Interaction between genes controlling a new group of glutenin subunits in bread wheat

Summary One-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of reduced total protein extracts from the endosperm of hexaploid wheat revealed a new set of faintly-stained bands, having slower electrophoretic mobility than the high-molecular-weight (HMW) glutenin subunits. These new bands have been termed the E group of glutenin subunits. Analysis of aneuploid stocks of Chinese Spring wheat has shown that three of the E bands, in order of increasing electrophoretic mobility, are controlled by genes on the short arms of chromosomes 1B, 1A and 1D, respectively. The E bands are expressed only in the presence of the long arm of chromosome 1B indicating an interaction between two or more genes involved in their production in wheat endosperm. The gene on the short arm of chromosome 1D controlling an E subunit recombined freely with Tri-D1 and the centromere but not at all with Gli-D1, indicating additional complexity at the Gli-DI locus in wheat.     

Water buffalo (Bubalus bubalus Arnee) allotypes: Identification of two specificities controlled by independent genes

Two water buffalo allotypes (Bl and CI) are described, which are located on distinct low molecular weight molecules. Bl is common to water buffalo and cattle. These two markers are inherited in a simple Mendelian manner and controlled by two independent genes.     

Immune response genes in chickens

The immunogenecity in chickens of the synthetic polypeptide TGAL is shown to be highly batch-dependent. Antibodies of at least two quite different specificities were formed: an MHC-linked anti-TG response, and a non-TG response (probably to poly-alanine) which is not linked to the MHC. Immunization with the random copolymer GT also gave rise to an anti-TG antibody response which showed a firm linkage to theB complex. It is concluded that GT may serve as a useful marker for an MHC-linked gene in chickens. Surprisingly, conjugation of GT to the immunogenic carrier MBSA did not convert low GT responder chickens to high responders. This finding raises the possibility that the low responder status may be the result of specific suppressor cells.     

Gm allotypes and racial admixture in two Brazilian populations

Summary The Gm types of 515 inhabitants of Belém and 395 inhabitants of Porto Alegre, Brazil were studied in an attempt to quantitatively estimate ethnic parental contributions. The people from Belém can be characterized as 24% black, 22% Indian, and 54% Caucasian. The Porto Alegre blacks seem to have inherited as much as 53% of their genes from Caucasian ancestors, while the whites living there have inherited 8% of their genes from African ancestors. The admixture values obtained for Belém are very similar if just the Gm system is considered or it plus seven other loci are considered, emphasizing the high efficiency of the Gm markers in such analyses.     

Preliminary studies on allotypes in cattle1

This paper presents evidence of five isoimmune sera, which identified five antigens of cattle blood serum. These antigens were examined by means of staining, immuno-electrophoresis and Sephadex G 200 column chromatography. It was established that the BA-2, BA-3, BA-4 and BA-4′ antigens were proteins, whilst the BA-1 antigen was a lipoprotein. The BA-3 antigen migrated in the γ-globulin position; the remaining four antigens migrated in the α-globulin region. The antigens under examination were already present in the blood serum during the first few days of life and appeared to be of a stable character. The results of genetic analysis suggest that these antigens were transmitted according to Mendelism.     

Interaction of distinct nuclear proteins with sequences controlling the expression of polyomavirus early genes.

The interaction between cellular factors and polyoma virus (Py) DNA was investigated by using a gel retention assay. Nuclear extracts from various cell lines (NIH 3T3, NIH 3T6, LTK-, F9) contained proteins that formed specific and distinct complexes with Py B enhancer fragments of either wild-type or F9-1 mutant origin. The presence of an excess amount of other well-characterized DNA sequences, including the Py A enhancer, the murine sarcoma virus enhancer, and the simian virus 40 enhancer-promoter region, did not interfere with this protein-DNA interaction. However, a fragment previously defined as containing the lymphotropic papovavirus enhancer shares the binding of some common factor. This observation, in combination with the results of retention gel assays at different Mg2+ concentrations, indicates the interaction of several nuclear factors and Py DNA. The assay systems that were used allowed a distinction between some factors on the basis of their different biochemical and sequence requirements. The contact sites of these complexes were mapped to the B enhancer region of Py with Bal 31-derived mutant restriction fragments and ExoIII nuclease and are compatible with the functional domains determined in vivo.     

Wheat chromosome 2D carries genes controlling the activity of two DNA-degrading enzymes

DNA-degrading enzymes of 24.0 kDa and 27.0 kDa were observed to have different activities in two common wheat (Triticum aestivum L.) cultivars, Wichita and Cheyenne. A substrate-based SDS-PAGE assay revealed that these two enzymes were much more active in Wichita than in Cheyenne. Genes controlling the activities of these two enzymes were localized on chromosome 2D by testing DNA-degrading activities in reciprocal chromosome substitution lines between Wichita and Cheyenne. While the allele on Wichita chromosome 2D stimulated the activities of the 24.0- and 27.0-kDa enzymes in Cheyenne, the allele on Cheyenne chromosome 2D did not reduce the activities of the 24-kDa and 27-kDa enzymes in Wichita. Whether these genes code for the DNA-degrading enzymes themselves or for factors that regulate the enzyme activities remains unknown.This work was supported in part by USDA-Competitive Research Grants Office grant No. 90-37140-5426 to P.S.B. Contribution from Agricultural Research Division, University of Nebraska. Journal Series Number 10304     

Characterization of two recessive genes controlling resistance to all races of bacterial spot in peppers

Bacterial spot, one of the most damaging diseases of pepper, is caused by Xanthomonas euvesicatoria. This pathogen has worldwide distribution and it is particularly devastating in tropical and sub-tropical regions where high temperatures and frequent precipitation provide ideal conditions for disease development. Three dominant resistance genes have been deployed singly and in combination in commercial cultivars, but have been rendered ineffectual by the high mutation rate or deletion of the corresponding cognate effector genes. These genes are missing in race P6, and their absence makes this race virulent on all commercial pepper cultivars. The breeding line ECW12346 is the only source of resistance to race P6 in Capsicum annuum, and displays a non-hypersensitive type of resistance. Characterization of this resistance has identified two recessive genes: bs5 and bs6. Individual analysis of these genes revealed that bs5 confers a greater level of resistance than bs6 at 25°C, but in combination they confer full resistance to P6 indicating at least additive gene action. Tests carried out at 30°C showed that both resistances are compromised to a significant extent, but in combination they provide almost full resistance to race P6 indicating a positive epistatic interaction at high temperatures. A scan of the pepper genome with restriction fragment length polymorphism and AFLP markers led to the identification of a set of AFLP markers for bs5. Allele-specific primers for a PCR-based bs5-marker have been developed to facilitate the genetic manipulation of this gene.     

An additional locus controlling liver esterases of chickens

Starch gel electrophoresis of liver extracts of chickens revealed six regions, designated I to VI, of esterase activity. Three phenotypes, A, B and AB, were found in esterases in region I. These phenotypes were shown to be controlled by a pair of codominant autosomal alleles, Es -5^A and Es -5^B.     

Identification and genetic control of two rabbit high-density lipoprotein allotypes

Rabbits were immunized with high-density lipoprotein (HDL) isolated from the serum of other rabbits by ultracentrifugation and gel filtration. Two different precipitating antibodies were elicited which distinguished two antigenically different genetic variants, i.e., allotypes, of HDL. The allotypes were identified as HDL based on the observation that on immunoelectrophoresis the antigen-antibody precipitate formed by the reaction of each of the antiallotype antisera with electrophoresed rabbit serum appeared electrophoretically in the α₁ region and reacted with Sudan black and with β-naphthyl acetate. In addition, the precipitin bands formed by the reaction of each antiallotype antiserum with a normal rabbit serum coalesced with the precipitin band formed by the reaction of goat anti-HDL with the same normal rabbit serum. The inheritance of the two allotypes is controlled by a pair of allelic genes, as shown by genetic studies of 312 progeny from 83 rabbit families. This HDL locus, designatedLhj, was shown not to be linked to theLpq locus of low-density lipoprotein nor to any of five other loci controlling allotypic specificities of different rabbit serum proteins. The use of these allotypes for studying the structure and biosynthesis of HDL is discussed. This study was supported by Research Grant PHS AI-07043 (Dr. S. Dray) and PHS AI-09241 from the National Institutes of Allergy and Infectious Diseases. One of us (K. L. K.) is the recipient of National Institutes of Health Career Development Award (AI-28687).     

Identification and genetic control of two rabbit low-density lipoprotein allotypes

Rabbits were immunized with a low-density lipoprotein (LDL) preparation isolated from rabbit serum by ultracentrifugation. This elicited precipitin isoantibodies which distinguished two antigenically different genetic variants, i.e., allotypes of serum LDL. Both allotypes were identified as LDL by the following criteria: (1) the precipitin lines stained intensely with the lipid stain Sudan black B; (2) the antigens were found in the low-density but not the high-density lipoprotein fraction; (3) the antigens migrated electrophoretically on Agarose in the ₂ to region. That the inheritance of these two allotypes is controlled by a pair of allelic genes at an autosomal locus is based on allotypes present in 323 progeny from six possible mating combinations. This LDL locus designated Lpqwas shown not to be linked to the light-chain or heavy-chain loci of immunoglobulins. This investigation was supported (in part) by NSF Grant GB-5536 and USPHS Grant AI07043-03.Supported by USPHS predoctoral fellowship (1-F1-GM-37, 211-01) from the National Institute of General Medical Sciences.