IDENTIFICATION OF A LOCUS ON MOUSE CHROMOSOME-17 ASSOCIATED WITH HIGH-AFFINITY CHOLINE UPTAKE USING BXD RECOMBINANT INBRED MICE AND QUANTITATIVE TRAIT LOCI ANALYSIS
GENOMICS
Authors: TARRICONE, BJ; HWANG, WG; HINGTGEN, JN; MITCHELL, SR; BELKNAP, JK; NURNBERGER, JI
Abstract
Using the quantitative trait loci (QTL) approach, preliminary identification has been made of a region on mouse chromosome 17 that influences high-affinity choline uptake (HACU) in the mouse brain, The rate of HACU was measured in synaptosomes prepared from the frontal cortex, hippocampus, and striatum of C57BL/6J (B6), DBA/2J (D2), and 25 BXD recombinant inbred (RI) strains of mice, using a final concentration of 0.5 mu M [H-3]choline, The strain means of HACU in each area were then correlated with the strain distribution pattern of each of 1300 known genetic markers using a point biserial correlation and 0 (B6 allele) and 1 (D2 allele), Correlations of P < 0.00001 were found between striatal HACU and chromosome 17 markers D17Tu50 and Tcp1. Correlations of P < 0.0001 were found between striatal HACU and chromosome 17 markers D17Leh66e, D17Leh119, D17Rp17e, Plg, D17Leh66d, Ckb-rs2, and Trp53-ps, QTL analyses of HACU in the frontal cortex and hippocampus also revealed correlations with these markers at the level of P < 0.05 and P < 0.01. These data suggest that at least one locus located on mouse chromosome 17 near or between 6 and 13 cM from the centromere influences HACU in the striatum and possibly the frontal cortex and hippocampus of the mouse. (C) 1995 Academic Press, Inc.
Expression of creatine kinase isoenzyme genes during postnatal development of rat brain cerebellum: evidence for transcriptional regulation
BIOCHEMICAL JOURNAL
Authors: Shen, W; Willis, D; Zhang, YP; Schlattner, U; Wallimann, T; Molloy, GR
Abstract
Transcription and accumulation of brain-type creatine kinase mRNA and its protein was examined during postnatal development of rat brain cerebellum, the brain region containing highest CKB mRNA in the adult. CKB protein was extremely low at day 1, increased about 10-fold until week 4 and remained constant until week 10. This time course was paralleled by cerebellar CKB mRNA, which was also extremely low at day 1 and increased 5-fold during the first 3 weeks and then remained constant. High levels of CKB protein were also detected in cultured primary cerebellar granular neurons. Nuclear run-on assays directly showed that CKB mRNA accumulation during postnatal cerebellar development was due to increased transcription. When compared with cerebrum and whole brain, cerebellar CKB mRNA accumulation during postnatal development was temporally delayed. Analysis of myocyte enhancer factor (MEF)-2 and Sp1, factors known to initiate or sustain CKB transcription in tissues other than brain, revealed that MEF-2 in cerebellum was low at week 1 but increased 3.5-fold by week 7, while Sp1 remained unchanged. The increase in CKB protein during cerebellar postnatal development was coincident with that of the ubiquitous mitochondrial CK protein and mRNA, indicating that a functional phosphocreatine energy shuttle probably exists for efficient ATP regeneration in the cerebellum. This should be beneficial for the many energy-demanding requirements during cerebellar development, as indicated by the observed temporal co-expression of CKB with myelin basic protein, which is involved in axon myelination by oligodendrocytes.