Starch gel electrophoresis of the multiple haemoglobins of small and large larval Chironomus--a developmental haemoglobin sequence in an invertebrate.

Two interrelated aspects of haemoglobin differentiation in vertebrates are tissue specificity (muscle haemoglobin and blood haemoglobin) and time specificity (embryonic, larval or foetal haemoglobin, and adult haemoglobin). Tissue specificity of haemoglobin and of other respiratory proteins has been found in invertebrates and has been shown to be the result of differences in gene activity (Man well, 1963 a, 1964; Man well & Baker, 1966), as accounts for the time and tissue specificity of vertebrate haemoglobins (Ingram, 1963; Manwell, 19636) and of vertebrate lactate dehydrogenases (Markert, 1963; Blanco, Zinkham & Kupscyk, 1964). Besides being the first report of a haemoglobin time-sequence during the development of any invertebrate, the following data on the insect Chironomus plumosus L. are important in view of the use of larval chironomids in studies on changes in chromosomal morphology ('puffing') in relation to gene action and to the control of formation and transport of specific proteins (Beerman, 1952; Clever, 1964a, b; Laufer & Nakase, 1965).