A Fetal Hemoglobin with Abnormal γ-Polypeptide Chains: Hemoglobin Warren

Abstract The discovery of a variant of fetal hemoglobin in the cord blood of a Negro newborn is reported. The abnormal hemoglobin, designated as Hb-Warren, was studied by different analytic procedures, such as starch gel electrophoresis, anion exchange chromatography, ultraviolet spectral absorption, immunologic reactivity with various antisera, hybridization with canine hemoglobin and the determination of the total amino acid composition. It was concluded that Hb-Warren was composed of normal α-polypeptide chains and abnormal γ-polypeptide chains.

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Re-evaluation of the presence of multiple haemoglobins during the ontogenesis of the chicken

Development ◽

10.1242/dev.28.3.681 ◽

1972 ◽

Vol 28 (3) ◽

pp. 681-713

Author(s):

M. Schalekamp ◽

D. Van Goor ◽

R. Slingerland

Keyword(s):

Developmental Stages ◽

Polypeptide Chain ◽

Age Groups ◽

Exchange Chromatography ◽

Starch Gel Electrophoresis ◽

Starch Gel ◽

Total Haemoglobin ◽

Haemoglobin A2 ◽

Polypeptide Chains ◽

Haemoglobin Synthesis

Haemolysates of red blood cells from embryos of several developmental stages ranging from 2 to 21 incubation days and from post-hatching chickens of various age groups were analysed by ion-exchange chromatography, agar- and starch-gel electrophoresis, immuno-electrophoresis with specific antisera and polypeptide chain electrophoresis. With these methods two adult (A1 and A2) and six embryonic (E1–E6) haemoglobin types were identified. Antisera specific for the major adult haemoglobins (A1 and A2) as well as antisera specific for the major embryonic haemoglobins (E3, E4) could be prepared. Throughout embryogenesis the haemoglobin types contribute in varying amounts to the total haemoglobin pattern. Three periods of haemoglobin synthesis could be recognized, the transition between these periods occurred at the 6th and 12th incubation day. The first period is characterized by the presence of two major embryonic haemoglobins (E3 and E4) and two minor embryonic haemoglobins (E2 and E5). During the second period E3 and E4 are largely replaced by a major adult haemoglobin (A2) and a new embryonic haemoglobin (E1). The third period is characterized by the appearance of a second adult haemoglobin (A1) and a new minor embryonic haemoglobin (E6) with a concomitant decrease of E2 and E5. At the time of hatching two embryonic haemoglobins (E1 and E6) are still present. Besides A1 and A2, several minor haemoglobin fractions were inconsistently found in adult chickens. Evidence has been obtained that these additional fractions are reflecting a so called minor heterogeneity or separation artifacts. The haemoglobins A1, A2 and E1–E6 show different polypeptide chain compositions. Three embryo-specific chains could be demonstrated (β E2E5, γ E4 and δ E3). The production of the polypeptide chains appears to be correlated with the aforementioned periods of haemoglobin synthesis. The genetic and morphological implications of the findings are discussed.

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