Haemoglobin Synthesis by Fetal Erythroid Cells in an Adult Environment

Bunch, C; Wood, W. G.; Weatherall, D. J.; Robinson, Jeffrey S.; Corp, M.J.

doi:10.1111/j.1365-2141.1981.tb07234.x

Cited by 18 publications

(3 citation statements)

References 11 publications

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“…For example, studies of erythroid differentiation in the sheep indicate that the early fe tal HSC are committed to giving rise to fetal erythrocytes, which express iJ(2Y2 hemoglobin, whereas more mature HSC are committed to generating erythrocytes of the adult phenotype (iJ(2f32 hemoglobin) (10)(11)(12)(13). More recently, similar reconstitution studies showed that HSC in adult bone marrow fail to regenerate murine CD5+ B cells which were newly identified by multiparameter FACS analyses (14).…”

Section: Definition Of a Developmental Lineagementioning

confidence: 94%

Origin of Murine B Cell Lineages

Kantor¹,

Herzenberg²

1993

Annu. Rev. Immunol.

544

378

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Until recently, the hematopoietic stem cells (HSC) that appear early in ontogeny were thought to constitute a homogeneous, self-replenishing population whose developmental potential remains constant throughout the life of the animal. Studies reviewed here, however, demonstrated clear differences in the developmental potential of fetal and adult progenitor populations (including FACS-sorted HSC). These studies, which chart the ability of various progenitor sources to reconstitute functionally distinct B cell populations, define three B cell lineages: B-1a cells (CD5 B cells), derived from progenitors that are present in fetal omentum and fetal liver but are largely absent from adult bone marrow; B-1b cells ("sister" population), derived from progenitors that are present in fetal omentum, fetal liver, and also in adult bone marrow; and conventional B cells, whose progenitors are missing from fetal omentum but are found in fetal liver and adult bone marrow. B-1a and B-1b cells share many properties, including self-replenishment and feedback regulation of development. These B cell studies, in conjunction with evidence for a similar developmental switch for T cells and erythrocytes, suggest that evolution has created a "layered" immune system in which successive progenitors (HSC) reach predominance during development and give rise to differentiated cells (B, T, etc) responsible for progressively more complex immune functions.

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Section: Definition Of a Developmental Lineagementioning

confidence: 94%

Origin of Murine B Cell Lineages

Kantor¹,

Herzenberg²

1993

Annu. Rev. Immunol.

544

378

View full text Add to dashboard Cite

show abstract

“…It is not controlled by the site of erythropoiesis (Wood & Weatherall, 1973) nor is it affected by severe endocrine perturbations (Wood et al, 1978). Direct approaches to the problem have included the transplantation of foetal haemopoietic cells to irradiated adult animals in an attempt to distinguish between autonomous programming of the cells and extracellular inducers (Zanjani et al, 1979;Bunch et al, 1981). After transplantation foetal cells switch to adult haemoglobin production but the time at which they do so appears to depend on their gestational age, suggesting that their pattern of haemoglobin production may be largely determined by a developmental clock intrinsic to the haemopoietic cells but perhaps capable of modulation by extracellular influences (Wood & Bunch, 1983).…”

Section: Nondeletionforms Ofd/3 Thalassaemia and Hpfhmentioning

confidence: 99%

Developmental genetics of the human haemoglobins

Wood¹,

Weatherall²

1983

Biochemical Journal

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“…It was reported that in lambs carrying the PA gene a small proportion of PC (~1 5 % of total p) appears transiently after birth and persists for several months (10). Many attempts have been made to influence the time of onset of the switch from fetal (7) to adult (P) Hb but these have been largely unsuccessful (8,9,11,12). Once commenced, the rate of the switching process has been shown to be able to be modulated.…”

mentioning

confidence: 99%

Effect of Hormone-Induced Premature Parturition on Hemoglobin Switching in Sheep

et al. 1988

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ABSTRACT. This study examines the effect of premature delivery on the switch from fetal (a2 72) to adult (a2 @2) Hb, in lambs in which premature parturition was induced by the intrafetal infusion of ACTH or corticotropin releasing hormone. Of 10 chronically cannulated ovine fetuses given ACTH at the rate of 79 ng/min for a 15 min period every 2 h starting at days 125 (n = 9) or 126 (n = 1) of gestation, three died in utero at days 131, 131, and 130, respectively. The remaining seven were born alive at 133 2 1.6 days. Five control fetuses, treated with vehicle (0.9% NaCl, wtlvol) only were delivered at 149 f 2.7 days of gestation, which is not significantly different from the duration of pregnancy in other chronically cannulated lambs in this flock. Hb switching, as measured by the globin synthesis ratio, @/a, was complete at term in the control lambs. The @/a globin synthesis ratio of the prematurely delivered lambs was not accelerated by birth, and was similar to that of control fetuses of the same gestational age still in utero. The four lambs surviving premature birth more than 70 days did not complete the switch to normal adult Hb until after 220 days postconception. (Pediatr Res 24: 688-692, 1988) Hb disappears from neonatal blood (9). It was reported that in lambs carrying the PA gene a small proportion of PC (~1 5 % of total p) appears transiently after birth and persists for several months (10). Many attempts have been made to influence the time of onset of the switch from fetal (7) to adult (P) Hb but these have been largely unsuccessful (8,9,11,12). Once commenced, the rate of the switching process has been shown to be able to be modulated. Hypophysectomy or bilateral adrenalectomy of the chronically cannulated fetus causes the completion of the switch to be delayed considerably (8, 9). In the adrenalectomized fetus replacement of cortisol in gradually increasing amounts returned the rate of adult Hb synthesis to normal (9).An increase in fetal cortisol production precedes and indeed induces parturition at normal term in sheep (13). Premature parturition can be induced by the treatment of immature ovine fetuses with cortisol, ACTH, or CRF some 3 wk or more before normal term (14, 15). These fetuses show accelerated lung maturation. The purpose of this study was to investigate the effect of premature activation of the fetal adrenal on Hb switching in the ovine fetus. The hypothesis was that premature parturition, induced by the fetal infusion of ACTH or CRF, would accelerate the completion of the switch from fetal to adult Hb. Abbreviations MATERIALS AND METHODS CRH, corticotrophin-releasing hormoneA total of 54 blood samples (1 ml) from 20 fetuses chronically cannulated as described previously (16, 17) was used to establish a, p, and 7 globin synthesis in normal intact animals from 103 days of gestation until term. Then 39 samples were collected For most of gestation sheep fetal red blood cells contain a fetal from birth until 30 days postpartum, and three samples from Hb, with two a and two 7 globi...

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Haemoglobin Synthesis by Fetal Erythroid Cells in an Adult Environment

Cited by 18 publications

References 11 publications

Origin of Murine B Cell Lineages

Origin of Murine B Cell Lineages

Developmental genetics of the human haemoglobins

Effect of Hormone-Induced Premature Parturition on Hemoglobin Switching in Sheep

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