RNA metabolism during the sexual differentiation of rat hypothalamus.
Modifications in the basal molecular biology parameters (total concentrations of RNA, DNA, proteins, rRNA, tRNa, free and polysomal bound poly-A+ mRNA) have been determined daily in the growing hypothalamus of male and female rats from day 1 to day 8 after birth. Changes observed in the parameters studied in this work occurred mainly in the first 48 h after birth. In males tRNA and free mRNA (f-mRNA) contents decreased from day 1 to day 2 and then their concentrations remained more or less constant. Total mRNA significantly decreased from day 1 to day 3 and showed a further significant decrease from day 6 to day 8. Polysomal bound-mRNA (b-mRNA) decreased from day 1 to day 3, then increased to day 6, and finally decreased once more from day 6 to day 8. The b-mRNA/f-mRNA, mRNA/rRNA and mRNA/total RNA ratios showed a bimodal behavior with a first peak on day 2, and a second, smaller peak, on days 6-7. The changes observed in the females on the first 2-3 days of life were the inverse of those observed in the males, most of the parameters studied showed a sharp increase from day 1 to day 2 or to day 3 and then a drastic decrease. The only exception to this behavior was the b-mRNA/f-mRNA ratio which showed a small decrease from day 1 to day 2, followed by a continuous increase from day 2 to day 8. b-mRNA concentrations, after the sharp decrease from day 2 to day 3 of life, increased from day 3 to day 7.(ABSTRACT TRUNCATED AT 250 WORDS)
Ballesteros
L M
LM
Laboratorio de Bioquímica Molecular, Unidad de Investigación Biomédica, Centro Médico Nacional, Instituto Mexicano del Seguro Social, D.F.
Delgado
N M
NM
García
R
R
Hernández-Pérez
O
O
Rosado
A
A
D000818:Animals; D000831:Animals, Newborn; D005260:Female; D007031:Hypothalamus / Q000254:growth & development* / Q000378:metabolism; D008297:Male; D012313:RNA / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley / Q000254:growth & development; D012733:Sex Differentiation
D012313:RNA