Mole Rat Hemoglobin: Primary Structure and Evolutionary Aspects in a Second Karyotypeof Spalax ehrenbergi,Rodentia, (2n = 52)

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Abstract
The Hb of the 4 karyotypes of S. ehrenbergi (2n = 52, 54, 58, 60) did not show any differences in their electrophoretic pattern and in high performance liquid chromatography. The complete amino-acid sequence of mole rat Hb (S. ehrenbergi), chromosome species 2n = 52, is presented. It was elucidated by automatic Edman degradation of the chains, the tryptic peptides and the C-terminal peptide obtained by acid hydrolysis of the Asp.sbd.Pro bond in .beta.-chains. The .alpha.- and .beta.-chains are identical with those of the chromosome species 2n = 60. A comparison of the Hb of mole rat, mouse and other rodents shows homology but no indication of adaptation to subterranean life. In all probability .alpha.1 1(A9)Arg and .alpha.1 20(H3)Gly, unique in mole rat among all mammalian Hb, are not involved in high O affinity. The construction of a phylogenetic tree by the maximum parsimony method, based on Hb sequences, made it possible to show that Rodentia originated as a monophyletic clade and to find the phylogenetic relationship of Spalacidae to other Rodentia (Mus, rattus, Ondatra, Mesocricetus, Citellus and Cavia). Among all rodents the slowest rate of nucleotide replacements occurred in the lineage to Spalax (20%) and the fastest in the lineage to Cavia (59%).