A STUDY OF LIPID COMPONENTS IN BRAIN OF JIMPY MOUSE A MUTANT WITH MYELIN DEFICIENCY

(1) Brain composition and developmental changes were investigated in a mutant (‘Jimpy’) mouse characterized by a severe myelin deficiency. (2) Significantly lower cholesterol, phospholipid and galactolipid values were observed, and the accumulation of these lipids during the myelination period was markedly reduced or absent. (3) The most remarkable feature of ‘Jimpy’ brain was a very small galactolipid content. In 29‐day‐old mutants the concentration of galactolipids was 0‐18 μ moles/g wet wt., representing a 46‐fold decrease when compared to values determined in normal mice. (4) There was no such striking change in the distribution of different phospholipids. However, lowered relative amounts of some phospholipids, e.g. ethanolamine plasmalogen, sphingomyelin and phosphatidylserine, were observed in ‘Jimpy’ brain. (5) Protein content was also lower in mutant brains and showed an absolute decrease after 23 days of life. (6) These data support the statement that the process of myelination is disturbed at an early stage, resulting in a deficiency of mature myelin sheaths and leading probably to the breakdown of primitive myelin structures. Copyright © 1969, Wiley Blackwell. All rights reserved