A developmental biological study of aldolase gene expression in Xenopus laevis.
We cloned cDNAs for Xenopus aldolases A, B and C. These three aldolase genes are localized on different chromosomes as a single copy gene. In the adult, the aldolase A gene is expressed extensively in muscle tissues, whereas the aldolase B gene is expressed strongly in kidney, liver, stomach and intestine, while the aldolase C gene is expressed in brain, heart and ovary. In oocytes aldolase A and C mRNAs, but not aldolase B mRNA, are extensively transcribed. Thus, aldolase A and C mRNAs, but not B mRNA, occur abundantly in eggs as maternal mRNAs, and strong expression of aldolase B mRNA is seen only after the late neurula stage. We conclude that aldolase A and C mRNAs are major aldolase mRNAs in early stages of Xenopus embryogenesis which proceeds utilizing yolk as the only energy source. aldolase B mRNA, on the other hand, is expressed only later in development in tissues which are required for dietary fructose metabolism. We also isolated the Xenopus aldolase C genomic gene (ca. 12 kb) and found that its promoter (ca. 2 kb) contains regions necessary for tissue-specific expression and also a GC rich region which is essential for basal transcriptional activity.
Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Japan. xlshioka@io.ocn.ne.jp
Koichiro
K
Shiokawa
Eri
E
Kajita
Hiroshi
H
Hara
Hitomi
H
Yatsuki
Katsuji
K
Hori
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D005634:Fructose-Bisphosphate Aldolase / Q000096:biosynthesis* / Q000235:genetics*; D008953:Models, Anatomic; D008957:Models, Genetic; D008958:Models, Molecular; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014018:Tissue Distribution; D014982:Xenopus laevis / Q000196:embryology* / Q000378:metabolism*
D018076:DNA, Complementary; D012333:RNA, Messenger; D005634:Fructose-Bisphosphate Aldolase