Hæmoglobins of Fœtal C57BL/6 Mice

Abstract

THE existence and nature of differences within species between adult and fœtal hæmoglobins have attracted much attention^1,7, but until very recently a distinct fœtal hæmoglobin type had not been demonstrated in the mouse. Filter paper^8,9, starch block¹⁰ and starch-gel electrophoresis of hæmoglobins of adult mice from different inbred strains and inter-strain crosses have shown inherited strain specificity for either of two general types of electrophoretic pattern, ‘diffuse’ (two or more components) or ‘single’ (discrete single band). Tests of haemoglobin of newborn mice from several different inbred strains have given electrophoretic patterns indistinguishable from those of adults of the same strain^11,12. However, starch-gel electrophoresis of adult and fœtal hæmoglobins in the CBA strain of mouse has shown the presence in early fœtal samples of a slowly moving component which disappears after 15 days gestation¹¹. The CBA adult mouse has ‘diffuse’ hæmoglobin (three bands on starch-gel)¹¹, which renders interpretation of variations in the pattern rather difficult. The concept of a change in hæmoglobin type in mid-fœtal life rather than at birth is sufficiently novel to warrant repetition of the experiment with more favourable genetic material. Starch-gel electrophoresis of hæmoglobin of adult C57BL/6 mice reveals the presence of only one component, which provides a simple background against which to analyse variations in pattern. The present communication is a comparison of the starch-gel electrophoretic pattern of hæmoglobin from early and late fœtal and adult C57BL/6 mice.