[Expression of myelin basic protein gene in the developing human brain].
The expression of myelin basic protein (MBP) gene in the developing human brain was studied by using Northern dot blot and in situ hybridization with 32P- and biotin-labeled rat MBP cDNA and Diglabeled human MBP cRNA probes so as to explore the relation of temporal and spatial expression of human MBP gene to myelinogenesis and myelination. The results of dot blot analysis showed that the expression of MBP mRNA was near 2.0 A590/microgram of RNA in the fetal brain at 16 weeks of conceptional age, and it increased progressively with development to have 9-fold increment (18 A590/microgram of RNA) in the adult brain. The insitu hybridization was performed with the sections of fetal spinal cord and medulla oblongata at 8-25 weeks of conceptional age, and of pons, midbrain, thalamus, cerebellum and cerebrum at 20, 22 and 25 weeks. The results indicated that the expression of MBP mRNA was found as early as 8-9 weeks and localized within the perinuclear cytoplasm of the scattered cells in the ventral horn of spinal cord and near the basis of the fourth ventricle of medulla oblongata. Whether the above-mentioned labeled cells are neurons or precursors of glial cell remains to be identified because they are larger in size and have more abundant cytoplasm than oligodendrocytes. The labeling of MBP mRNA abruptly increased and spread with the processes of oligodendrocytes to form a network in spinal cord and medulla at 20 weeks; meanwhile, labeling was obvious in pons and scattering in the other brain regions examined.
Chen
J
J
Recombinant DNA Laboratory, School of Basic Medical Sciences, Chengdu.
Zhao
J
J
Xiong
C
C
Lin
J
J
Wang
R
R
Li
C
C
Ou
K
K
Ma
Y
Y
Zeng
B
B
Zeng
M
M
D000328:Adult; D001921:Brain / Q000196:embryology / Q000254:growth & development*; D005314:Embryonic and Fetal Development; D015870:Gene Expression; D006801:Humans; D007231:Infant, Newborn; D008526:Medulla Oblongata / Q000378:metabolism; D004676:Myelin Basic Protein / Q000096:biosynthesis / Q000235:genetics*; D009186:Myelin Sheath / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis*; D013116:Spinal Cord / Q000378:metabolism
D004676:Myelin Basic Protein; D012333:RNA, Messenger