The Control of Hemoglobin Phenotype in Calves and Sheep*

Gabuzda, Thomas G.; Schuman, Marc A.; Silver, Ruth; Lewis, Hugh B.

doi:10.1111/j.1749-6632.1969.tb27804.x

Cited by 5 publications

(5 citation statements)

References 5 publications

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“…Firstly by determining the sequence of changes which take place in the blood after an episode of severe blood loss Ebaugh, '956, '957). (Moore et al 1966;Tucker, 1966;Kitchen, Eaton & Taylor, 1968); secondly by following the changes in the circulating blood, and also in the bone marrow by studies of haemoglobin synthesis in oitro, after transfusion of plasma from anaemic sheep or of extracts of erythropoietin into non-anaemic recipients (Boyer et al 1968a;Gabuzda et al 1968Gabuzda et al , 1969Thurmon et al 1970). During the early phases following blood loss or plasma infusion, after an initial latent period of I to 2 days, two types of cell appear in the circulation, large cells, presumably reticulocytes which are resistant to acid elution and relatively few in number, and also red cells of small size, not identifiable as reticulocytes.…”

Section: (6) Frequencies In Diyerent Breedsmentioning

confidence: 99%

Genetic Variation in the Sheep Red Blood Cell

Tucker¹

1971

Biological Reviews

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Summary 1. There are 7 well‐established red‐cell antigen (blood group) loci. The R‐O system has 3 phenotypes, R, O and i, identified by the ‘naturally occurring’ antibodies, anti‐R and anti‐O. The R and O substances are also present in soluble form in some body secretions. The expression of R and O is controlled by a dominant gene I, epistatic in effect, at an independent locus from that of R. The systems, A, C, M‐L, B, D and X‐2 are identified by means of ‘immune‐type’ antibodies, and several of the loci have multiple alleles. An isoenzymic form of serum alkaline phosphatase is associated with the R‐O system. The frequency for the genes at the various loci has been determined in a limited number of breeds. 2. Some sheep red cells have high K+ and low Na+ concentrations (HK type, or Key), others have low K+ and high Na+ concentrations (LK type or Kea). Two other rare forms exist; Key type which is HK but with lower than normal K+ values, and Kep type which has approximately equal Na+ and K+ concentrations. The red cells of foetuses and newborn lambs have high K+ levels irrespective of their potassium genotype. HK cells have 3–4 times greater (Na+‐K+)‐activated ATPase activity, a 3–4 times increased rate of active K+ transport and a larger number of ouabain‐binding sites than LK cells. Antigen M is present on homozygous HK and heterozygous LK red cells, and antigen L is present on homozygous and heterozygous LK red cells. Sensitization of LK cells with anti‐L stimulates active K+ transport and ATPase activity and exposes a larger number of ouabain‐binding sites in these cells. Anti‐M has no effect. The red cells of newborn lambs only show weak L and M antigen activity. It is postulated that L antigen inhibits cation transport in LK cells by masking the pump sites on the membrane. Immature red cells in LK‐type sheep have a high rate of active K+ transport and yet have L antigen present. No satisfactory explanation for this has yet been advanced. There is no conclusive evidence that the potassium types have any significance from the point of view of adaptation or sheep breeding. The potassium‐gene frequencies are known for a large number of breeds. 3. Two allelic genes, Hb4 and HbB control 3 haemoglobin phenotypes, A, AB, and B. Foetal haemoglobin (HbF) is present in foetuses and newborn lambs. Sheep with HbA also synthesize small amounts of another haemoglobin (HbC) and under conditions of severe anaemia, synthesis of HbC takes over from that of HbA. No change in HbB is observed in anaemia. A rare haemoglobin (HbD) has been found in 3 Yugoslavian sheep. Hbs A, B, C and F differ in their physicochemical properties; they share the same alpha chains but their non‐alpha chains differ in a number of amino acids. HbD differs from HbA in one amino acid in the alpha chain. Certain genetic aspects are discussed. There is some evidence that sheep with HbA are less fertile than those with HbB. The gene frequencies for Hb are known for a large number of breeds. 4. Two isoenzymic forms of carbonic anhydrase are found in red‐cel...

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Section: (6) Frequencies In Diyerent Breedsmentioning

confidence: 99%

Genetic Variation in the Sheep Red Blood Cell

Tucker¹

1971

Biological Reviews

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“…The ratio Gy: Ay is high in newborns and declines during subsequent development (13). Indirect evidence consistent with a close linkage of mutually exclusive genes for the non-a chains also exists in sheep (and, similarly, in 29, 327 (1964)] polypeptides differ by seven amino acid replacements (14). Heterozygous sheep contain Hb A and Hb B intermixed within single erythrocytes (15).…”

Section: Clustering Of Mutually Exclusive Hemoglobin Genes In Man Andmentioning

confidence: 99%

“…Heterozygous sheep contain Hb A and Hb B intermixed within single erythrocytes (15). Furthermore, when adult sheep with the A allele are made anemic, they synthesize a different non-a chain, /3c, and cease producing any /A chains (5, [14][15][16]. An electrophoretic analysis of these sheep hemoglobins is shown in Fig.…”

Section: Clustering Of Mutually Exclusive Hemoglobin Genes In Man Andmentioning

confidence: 99%

“…The replacement of /3A chains by /c chains is stoichiometric in anemic animals. The ,30 polypeptide chain differs from /8A at 17 positions and from /3B at 21 positions (14). The /c chain is normally present briefly during neonatal life (as synthesis of y chain declines) and it is later replaced with /A synthesis when the animal is approximately 80 days of age (5, 16).…”

Section: Clustering Of Mutually Exclusive Hemoglobin Genes In Man Andmentioning

confidence: 99%

“…The 8c0 polypeptide is normally present in early neonatal life and is replaced with lA chains in adult animals (5, 15,16). This activation of the /c "silent gene" can be induced by erythropoietin injections into nonanemic adult sheep (5, [14][15][16]. Similar changes in hemoglobins of anemic animals occur in goats (5, 16) and to a lesser extent in mice and in ducks (28).…”

Section: Globin Synthesis Changes Accompanying Anemiamentioning

confidence: 99%

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Gene Selection in Hemoglobin and in Antibody-Synthesizing Cells

Kabat

1972

Science

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Close linkage of mutually exclusive genes occurs in the non-alpha chain hemoglobin genes and in the immunoglobulin genes of man and other mammals. The expression of one gene in the cluster precludes the expression of any other linked gene. A simple, testable theory of gene selection called "looping-out excision"which was designed only to explain this mutual exclusivity in the hemoglobin system is described. The theory is closely concordant with a wide range of previously unexplained findings concerning hematopoiesis- including the developmental changes of hemoglobins, the increases in immature or fetal forms of hemoglobin that accompany anemia, and with the distribution of adult and fetal hemoglobins among erythrocytes during normal embryogenesis and in various pathological conditions. One corollary of this theory is that erythroid tissue in the normal adult bone marrow is constantly recapitulating the developmental stages of its embryogenesis. Another corollary is that the selection from among the linked globin genes occurs independently on the two chromosomes of the diploid organism. Both of these corollaries are supported by the available data. The same theory of gene selection is also remarkably consistent with known data for immunoglobulin synthesis; it could explain not only the mutually exclusive activation of linked variable genes but also the splicing which occurs between genetically linked variable and constant region genes for the immunoglobulin polypeptide chains. The agreement between these two different tissues is considered to be strong evidence that the proposed mechanism is correct at least in broad outline. Evidence from the genetics of maize and of drosophila also supports this theory of somatic tissue variegation. On the basis of these comparisons, I suggest that looping-out excision probably occurs also in other tissues and may be one means of gene selection and activation in differentiating cells.

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Studies of Transfer Ribonucleic Acids and of Hemoglobin Synthesis in Sheep Reticulocytes

Litt

Kabat

1972

Journal of Biological Chemistry

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The Control of Hemoglobin Phenotype in Calves and Sheep*

Cited by 5 publications

References 5 publications

Genetic Variation in the Sheep Red Blood Cell

Genetic Variation in the Sheep Red Blood Cell

Gene Selection in Hemoglobin and in Antibody-Synthesizing Cells

Studies of Transfer Ribonucleic Acids and of Hemoglobin Synthesis in Sheep Reticulocytes

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