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Results for “Locus Control Region”

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PubMed1977

Serum esterase genetics in rabbits. IV. The prealbumin and beta-globulin systems.

Discontinuous starch gel electrophoresis revealed a fourth allele of rabbit pre-albumin serum esterase at locus Est-2. This allele is designated Est-2f and appears to be silent. In addition to the prealbumin serum esterases, another serum esterase system was studied in rabbits. This system is localized in the beta-globulin region. Genetic analysis indicated that one locus with two codominant alleles controls the variation in this region. Linkage of this system with Est-1 and Est-2 of the prealbumin serum esterases was demonstrated. Comparison of the arrangement of these esterase loci on linkage group VI with the esterase loci on chromosome 8 of the mouse gives additional support for the theory of evolutionary conservation of chromosomal segments coding for mammalian esterases.

Alleles↗

PubMed1987

Effects of preoptic microinjections of alpha-MSH on fever and normal temperature control in rabbits.

alpha-MSH within the septal region of the brain has been implicated in fever control; this peptide and ACTH (1-24), which contains the alpha-MSH amino acid sequence, reduce fever when given intracerebroventricularly (ICV) or peripherally. These peptides also cause hypothermia when given in doses larger than those required to reduce fever. Both peptides occur naturally within the preoptic PO region of the brain, the CNS locus of primary temperature control. alpha-MSH (350 ng) injected bilaterally into the PO region via chronic cannulas reduced fever caused in six rabbits by IV injection of IL-1 (interleukin 1, endogenous or leukocyte pyrogen) but had no effect in afebrile animals. A larger dose (1.5 micrograms) not only reduced fever but caused hypothermia in 12 rabbits. In separate experiments PO injections of ACTH (1-24) (1 microgram) reduced normal temperature. In the same six rabbits alpha-MSH (1 microgram) caused slightly smaller hypothermia. alpha-MSH (1.5 micrograms) also had no effect in 8 afebrile rabbits when injected into the septum. The primary conclusion is that alpha-MSH receptors within the PO region can contribute to both the antipyretic and hypothermic actions that are observed after ICV and peripheral administration of the peptide.

Animals↗

PubMedDate not supplied

Health Locus of Control in Chukotka children.

Two groups of children in the cities of Anadyr and Pevek in the Chukotka Region of the Soviet Far East were administered a Russian translation of the Children's Health Locus of Control Scale in July, 1991. Results were analyzed to assess the similarities between response patterns among the Russian children and those found in American children. The analyses revealed a consistency in the data suggesting both face and theoretical validity of the Scale. It appears that the underlying mediating variable related to the children's perceived control over their health is operating in this Region of Russia in much the same way that it does in the United States.

Adolescent↗

PubMed1990

Conservation of the primary structure, organization, and function of the human and mouse beta-globin locus-activating regions.

DNA sequences located in a region 6-18 kilobases (kb) upstream from the human epsilon-globin gene are known as the locus-activating region (LAR) or dominant control region. This region is thought to play a key role in chromatin organization of the beta-like globin gene cluster during erythroid development. The beta-globin LAR activates linked globin genes in transiently or stably transfected erythroleukemia cells and in erythroid cells of transgenic mice. Since the human beta-globin LAR is functional in mice, we reasoned that critical LAR sequence elements might be conserved between mice and humans. We therefore cloned murine genomic sequences homologous to one portion of the human LAR (site II, positions -11,054 to -10,322 with respect to the human epsilon gene). We found that this murine DNA fragment (mouse LAR site II) and sequences homologous to human LAR sites I and III are located upstream from the mouse beta-like globin gene cluster and determined that their locations relative to the cluster are similar to that of their human counterparts. The homologous site II sequences are 70% identical between mice and humans over a stretch of approximately 800 base pairs. Multiple core sequences with greater than 80% identity were present within this region. Transient and stable transfection assays of K562 erythroleukemia cells demonstrated that both human and mouse LAR elements contain enhancer activity and confer hemin inducibility on a linked human gamma-globin promoter. These results suggest that primary structural elements--and the spatial organization of these elements--are important for function of the beta-globin LAR.

Animals↗

PubMed1976

Selective expression of H-2 (i-region) loci controlling determinants on helper and suppressor T lymphocytes.

Data presented here show that locidentify in the I-region of the H-2 gene complex are selectively expressed in different functional T-cell subpopulations. These loci are closely linked (or possibly identical) to loci that control immune responses. They control surface determinants which identify helper and suppressor T lymphocytes. Determinants described here on allotype suppressor T cells (Ts) are found on normal (nonsuppressed) lymphoid cells, but are not found on helper T cells (Th). These determinants are controlled by a locus mapping in the I region of the H-2 complex. In an accompanying publication we show that this locus (Ia-4) marks a new I subregion (I-J) and is expressed only on T cells. Thus Ia-4 determinants idenfity a T-cell subpopulation which includes Ts but not Th. Th also carry identifying surface determinants controlled by loci that map to the H-2 complex, probably within the I region. These determinants are not found on Ts. Data presented also establish that loci in the I region control determinants on Th, but do not conclusively demonstrate that these are the determinants that distinguish Th from Ts. The selective expression of H-2-controlled determinants on Ts and Th suggests that these determinants are directly involved in immunoregulation.

Animals↗

PubMed1979

Serum esterase genetics: identification and hormone induction of the Es-1b esterase in inbred rats.

A previously unrecognized esterase from the sera of the appropriate strains of the rat Rattus norvegicus was revealed by a discontinuous polyacrylamide gel electrophoretic technique. This esterase migrated in the albumin region, whereas a previously known major albumin esterase controlled by the Es-2 locus migrated in the postalbumin region when the method was used. The new albumin esterase component which separated from the Es-2 esterase was identified as the product of the Es-1b gene. The new albumin esterase was not detectable in the sera of sexually mature males of the appropriate genotype, because the activity level of this esterase was influenced by sex hormones, especially androgen.

Age Factors↗

PubMed1991

Multidimensional health locus of control in nurses.

The importance of health belief and, in particular, health locus of control, in mediating health behaviours and resultant health status is discussed. It is suggested that it is not enough to consider the health beliefs of patients in isolation; the beliefs of health professionals must also be investigated. Health beliefs, conceptualised in terms of multidimensional health locus of control (MHLC) were assessed in a group of nurses working in the North West Regional Health Authority. Measures of 'internal', 'powerful others' and 'chance' health locus of control beliefs were obtained and comparisons with UK norms made. Significant differences in the structure of health locus of control beliefs were found and it was suggested that these differences may have important consequences for both the teaching and practice of nursing.

Adult↗

PubMed1988

The promoter for a sporulation gene in the spoIVC locus of Bacillus subtilis and its use in studies of temporal and spatial control of gene expression.

We have identified the transcription start site and regulatory region governing the expression of a sporulation gene in the spoIVC locus of Bacillus subtilis. Efficient expression and developmental regulation of this gene was controlled from a promoter region that extended no more than 110 base pairs upstream and no more than 4 base pairs downstream from the start site of transcription, on which basis we infer that spoIVC is regulated at the level of transcription initiation. Using a transcriptional fusion of the spoIVC gene to the lacZ gene of Escherichia coli, we found that spoIVC expression was turned on at the third to fourth hour of sporulation (at about the developmental stage [IV] that its products are required in spore formation) and that this transcription was largely restricted to the mother cell chamber of the sporangium. Mutations in many different spo genes (causing blocks at stages 0 to V) were found to influence (negatively and positively) the level of spoIVC expression. Our results distinguish the mode of spoIVC regulation from that of previously studied sporulation genes and indicate that it is representative of a new regulon of mother cell-specific gene expression.

Bacillus subtilis↗

PubMed1990

The lcrE gene is part of an operon in the lcr region of Yersinia enterocolitica O:3.

The low-calcium response (lcr) region of the virulence plasmid of Yersinia pestis, Yersinia pseudotuberculosis, and Yersinia enterocolitica has been associated with calcium-dependent growth of bacteria. Mutations in the previously identified lcrE locus within the lcr region lack the repressor control of production of the lcr specific proteins, Yersinia outer membrane proteins (Yops) and V and W antigens. We sequenced a 3.3-kilobase-pair BamHI-ClaI fragment of the lcrE locus of pYVO3, the virulence plasmid of Y. enterocolitica O:3. The sequence of lcrE locus revealed six tightly packed open reading frames (ORFs), one of which was identified as the structural gene, lcrE, of the 32.9-kilodalton outer membrane protein LcrE (formerly known as Yop4b or YopN). Detection of large (greater than 2.3-kilobase-pair) transcripts strongly supports the conclusion that the lcrE gene and ORF1 to -5 function as an operon. Transcription of the lcrE-containing operon and the adjacent lcrB locus was found to be divergent, and the corresponding transcripts overlapped about 1,200 nucleotides. This extremely long overlap of the 5' ends of the transcripts produced from face-to-face promoters is a new finding; the longest overlap thus far found has been a few hundred nucleotides. Temperature was found to play the major role in regulation of transcription of the lcrE-containing operon of pYVO3, whereas Ca2+ concentration seemed to affect it only moderately.

Amino Acid Sequence↗

PubMed1985

A human acetylcholinesterase gene identified by homology to the Ace region of Drosophila.

The Ace locus of the Drosophila genome controls biosynthesis of the neurotransmitter-hydrolyzing enzyme acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7). We injected the mRNA species hybridizing with DNA fragments from this region into Xenopus oocytes, in which acetylcholinesterase mRNA is translated into active acetylcholinesterase. A 2.0-kilobase (kb) fragment of DNA from this region selectively hybridizes with Drosophila mRNA capable of inducing the biosynthesis of acetylcholinesterase in oocytes. This Drosophila DNA fragment cross-hybridized with human brain poly(A)+ RNA. We therefore used this DNA fragment as a probe for homologous sequence(s) in a human genomic DNA library and thus selected a 13.5-kb human DNA segment. DNA blot-hybridization revealed that a 2.6-kb fragment of this human DNA segment hybridizes with the Drosophila 2.0-kb DNA fragment. Both Drosophila and human fragments hybridized with a human brain mRNA species of about 7.0-kb that was barely detectable in the acetylcholinesterase-deficient HEp carcinoma. A fraction containing mRNA of similar size, extracted from human brain, induced acetylcholinesterase biosynthesis in oocytes. The human DNA fragment also was used in hybridization-selection experiments. In oocytes, hybrid-selected human brain mRNA induced acetylcholinesterase activity that was completely inhibited by 1,5-bis[4-allyldimethylammonium)phenyl]pentan-3-one dibromide but not by tetraisopropyl pyrophosphamide, a differential response to these inhibitors characteristic of "true" human brain acetylcholinesterase. These findings strongly suggest that both the Drosophila and the human DNA fragments are directly involved in controlling acetylcholinesterase biosynthesis.

Acetylcholinesterase↗

PubMed1973

Evidence for the linkage of the IGC H locus to a gene controlling the idiotypic specificity of anti-p-azophenylarsonate antibodies in strain A mice.

Anti-p-azophenylarsonate (anti-Ar) antibodies elicited in all strain A/J mice tested share one or more idiotypic specificities. These specificities are also found in the anti-Ar antibodies of mice of the closely related strain, AL/N, but not in those of BALB/c mice. Anti-Ar antibodies were elicited in congenic mice in which the IgC(H) locus of AL/N mice, which controls allotypic markers in the constant regions of heavy chains, had been introgressively backcrossed for nine generations onto a BALB/c background; the mice were then rendered homozygous for the AL/N allotypic determinant. On the average, these antibodies were quantitatively equivalent, with respect to content of the cross-reactive idiotype, to those of AL/N mice. This indicates that the gene controlling the idiotype is closely linked to the IgC(H) locus. Since idiotype must be a function of V region sequences, the results suggest close linkage of V(H) and C(H) genes. The cross-reactive idiotype was found in nearly all F(1) mice (C57/BL x A/J or BALB/c x A/J) tested.

Animals↗

PubMed1984

Genetics and expression of kappa-type light chains in Basilea rabbits.

In contrast to rabbits of b4, b5, b6, and b9 allotypes whose serum immunoglobulins (Igs) are predominantly composed of kappa-type light chains, rabbits of the mutant Basilea strain have serum Igs that are largely of lambda type. We prepared several antisera that recognized a minor K2 (bas) light chain that is produced by Basilea rabbits. With these antisera we identified the K2 (bas) isotype in the serum of the original b9/b9 male rabbit whose offspring displayed the Basilea mutant phenotype. It was present in one half of his nonmutant offspring which inherited b9 from him and another b allotype from their mothers. Breeding was conducted both in Basel and at the NIH to develop and maintain colonies of mutant Basilea strain rabbits. The data obtained during colony development confirm that the trait of expression of the bas allotype maps to the same genetic region (b locus) that is known to control the allelic b allotypes b4, b5, b6 and b9. Homozygotes or heterozygotes of b4, b5 or b6 allotype (bb/bb) were mated with homozygous bbas / bbas rabbits to produce F1s , and then F2s as well as progeny of backcrosses to both homozygous parental types (bb/bb and bbas / bbas ) were produced. The bas allotype segregates as an allele (or pseudoallele ) at the b locus although there was a deficiency in recovery of homozygous bas offspring in both the F2 and backcross matings to bbas / bbas parental type in the NIH colony. This selective deficiency may reflect a deleterious effect on survival of homozygous bas progeny.

Animals↗

PubMedDate not supplied

[Functional differentiation of thymocytes induced by macrophages: cellular, humoral and genetic aspects].

The cellular, humoral and genetical mechanisms of induction of T-effectors of the graft vs. host reaction (GHR) were studied in a double-cell culture of phagocytizing mononuclears with thymocytes. Experiments were carried out on mice of inbred and recombinant strains. The GHR intensity was estimated by the increase in the number of cells in the popliteal lymph node, regional with reference to the introduction of parental thymocytes into the F1 hybrid. For the induction of the GHR T-effectors from the immature population of thymocytes to be realized, a direct physical contact and identity by the H-2K locus of the major histocompatibility complex between the cooperating cells in culture are indispensable. An antiserum containing antibodies against the H-2K locus products prevents the induction. At the same time antibodies against antigens controlled by loci of I-region or the H-2D locus do not affect the accumulation of T-effectors. Contact interaction of phagocytizing mononuclears with thymocytes results in accumulation of a 65,000 D humoral factor in the culture medium. Incubation of the intact thymocytes with this factor ensures functional transformation of immature thymocytes to corresponding effector cells. For the humoral induction of T-effectors to be successfully realized, identity by the T-2K locus between the factor producents and intact thymocytes is indispensable, as well as in the conditions of direct intercellular interaction. It is suggested that H-2K specificity is incorporated into the factor structure.

Animals↗

PubMed1987

Mutagenicity studies of different polycyclic aromatic hydrocarbons: the significance of enzymatic factors and molecular structure.

Dependence of polycyclic aromatic hydrocarbon (PAH)-induced mutagenicity on the bay region of the molecule and on the activating cytochrome P-450 enzyme was studied. Eleven PAHs with and six without a bay region were activated by postmitochondrial supernatants from control and 3-methylcholanthrene (MC)-pretreated C57BL/6 mice and from control, MC- and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-pretreated DBA/2 mice and from control and MC-pretreated Sprague-Dawley and Lewis rats. S-9 fractions from MC- or TCDD-treated animals induced more mutagenicity with PAHs with a bay region compared with S-9 fractions from control animals or MC-treated D2 mice. Mutagenicities of PAHs without a bay region were largely independent of the source of activating enzyme. There were three exceptions, namely benzo[e]pyrene, phenanthrene and perylene (each possessing a bay region), which were not mutagenic. These studies support the notion that the Ah-locus-controlled induction of cytochrome P1-450 activating PAHs into reactive intermediates at the bay region of the hydrocarbon molecule is of prime importance in the mutagenicity of PAHs. Qualitative correspondence to carcinogenicity is also apparent.

Animals↗

PubMed1990

A physical map and analysis of the murine C kappa-RS region show the presence of a conserved element.

Lambda-producing B lymphocytes have frequently deleted one or, more often, both Ig kappa loci. This deletion is mediated by the rearrangement of an element which lies 3' of C kappa and which is called RS (recombining sequence) in the mouse and Kde (kappa-deleting element) in the human. The tight correlation between V lambda to J lambda rearrangements and an RS-mediated deletion may indicate that sequences in the C kappa-RS region are controlling the activation of the Ig lambda locus. We have linked the C kappa exon and the RS element by phage cloning and compared the C kappa-RS region to the previously cloned human C kappa-Kde region. The distance between C kappa and RS is 25 kb and is thus similar to the distance of 24 kb separating the human C kappa exon and Kde element. Both mouse and man carry a conserved sequence of 470 bp (Rx) which lies 9 kb 3' of the mouse C kappa and 12 kb 3' of the human C kappa exon. The conserved mouse Rx sequence contains part of the kappa 3' enhancer.

Animals↗

PubMed1976

Guinea pig histocompatibility antigens. III. Analysis of normal lymphocyte transfer (NLT) reactions among guinea pigs with serologically defined phenotypes (GPL-AB locus and I region).

The normal lymphocyte transfer (NLT) reaction occurring upon intradermal injection of lymphocytes into a normal recipient may be considered as a kind of mixed lymphocyte reaction in vivo. In previous experiments, we have defined serologically a number of guinea pig lymphocyte antigens, controlled either by a GPL-A locus (equivalent of H-2 D locus in mice) or by a so-called I region (equivalent to the I region in mice). The I region also appears to control a number of immune response genes in the guinea pig. Using guinea pig inbred strains (such as 2, 13, OM3, BE), guinea pig families homozygous for their GPL-A antigens and serologically characterized outbreds, it has been possible to show that antigens of the I region probably play a higher role in NLT reactions. No NLT reactions occur among outbred animals of a closed colony which have been bred to homozygozity for their GPL-A antigens and thereby probably possess haplotype homozygozity for their major histocompatibility complex. The NLT reaction among serologically characterized guinea pigs may become a convenient way to detect new specificities and recombinant progeny.

Animals↗

PubMed1986

Assignment of symbiotic developmental phenotypes to common and specific nodulation (nod) genetic loci of Rhizobium meliloti.

Rhizobium meliloti nodulation (nod) genes required for specific infection and nodulation of alfalfa have been cloned. Transposon Tn5 mutagenesis defined three nod regions spanning 16 kilobases of the pSym megaplasmid. Genetic and cytological studies of 62 nodulation-defective mutants allowed the assignment of symbiotic developmental phenotypes to common and specific nod loci. Root hair curling was determined by both common (region I) and specific (region III) nod transcription units; locus IIIb (nodH gene) positively controlled curling on the homologous host alfalfa, whereas loci IIIa (nodFE) and IIIb (nodH) negatively controlled curling on heterologous hosts. Region I (nodABC) was required for bacterial penetration and infection thread initiation in shepherd's crooks, and the nodFE transcription unit controlled infection thread development within the alfalfa root hair. In contrast, induction of nodule organogenesis, which can be triggered from a distance, seemed to be controlled by common nodABC genes and not to require specific nod genes nodFE and nodH. Region II affected the efficiency of hair curling and infection thread formation.

Cloning, Molecular↗

PubMed1987

MAT alpha 1 protein, a yeast transcription activator, binds synergistically with a second protein to a set of cell-type-specific genes.

We show by electrophoresis mobility shift and by DNAase I footprinting assays that the alpha 1 product of the yeast alpha mating-type locus binds to homologous sequences within the control regions of the three known alpha-specific genes. Binding requires both alpha 1 and a second yeast protein(s) (called PRTF) that is present in all three cell types (a, alpha, and a/alpha); neither protein binds alone. Binding and competition experiments using synthetic oligonucleotides indicate that PRTF binds to only part of the homology found at alpha-specific genes and imply that alpha 1 binds to the remainder. Our results suggest that alpha 1 renders gene expression alpha-specific by creating a binding site for PRTF. Similar experiments lead to the idea that PRTF also plays a role in transcription of a-specific genes. Perhaps a-specificity is achieved through the occlusion of the PRTF binding site by alpha 2, the negative regulator encoded by the alpha mating-type locus.

Base Sequence↗