Quantitative expression studies of aldolase A, B and C genes in developing embryos and adult tissues of Xenopus laevis

Abstract

We previously cloned cDNAs for all the members (A, B and C) of Xenopus aldolase gene family, and using in vitro transcribed RNAs as references, performed quantitative studies of the expression of three aldolase mRNAs in embryos and adult tissues. A Xenopus egg contains ca. 60 pg aldolase A mRNA and ca. 45 pg aldolase C mRNA, but contains only ca. 1.5 pg aldolase B mRNA. The percent composition of three aldolase mRNAs (A:B:C) changes from 56:1.5:42.5 (fertilized egg) to 54:10:36 (gastrula), to 71:14.5:14.5 (neurula) and to 73:20:7 (tadpole) during development. These results are compatible with the previous results of zymogram analysis that aldolases A and C are the major aldolases in early embryos, whose development proceeds depending on yolk as the only energy source. Aldolase B mRNA is expressed only late in development in tissues such as pronephros, liver rudiment and proctodeum which are necessary for the future dietary fructose metabolism, and the expression pattern is consistent to that in adult tissues. We also show that three aldolase genes are localized on different chromosomes as single copy genes.

Research Article Tissue distribution and early developmental expression patterns of aldolase A, B, and C in grass carp Ctenopharyngodon idellus.

“…Aldolase is an important enzyme in glycolysis; the three vertebrate homologs have been cloned in humans (Besmond et al, 1983), mice (Tsutsumi et al, 1983(Tsutsumi et al, , 1984, and Xenopus (Atsuchi et al, 1994;Hikasa et al, 1997;Kajita et al, 2001). In the present study, we isolated the aldolase A, B, and C genes in grass carp and characterized their expression.…”

“…Besides, upregulation of the aldolase A and C genes and downregulation of aldolase B gene have been observed in the hepatic tissue of liver cancer patients (Schapira et al, 1963). Aldolase A, B, and C genes have been isolated from amphibian species such as Xenopus laevis (Atsuchi et al, 1994;Hikasa et al, 1997;Kajita et al, 2001) and their spatial and temporal expression patterns have been characterized (Kajita et al, 2001). The aldolase B gene in fish has been cloned in bream (Llewellyn et al, 1995) and salmon (Llewellyn et al, 1998), while the aldolase C gene has been cloned in goldfish (Berardini et al, 1997); however, there have been no reports on the cloning of all three aldolase genes in a single fish species.…”

A developmental biological study of aldolase gene expression in Xenopus laevis

“…A Xenopus fertilized egg contained approximately 60 pg of aldolase A mRNA, 45 pg of aldolase C mRNA but only 1.5 pg or less aldolase B mRNA. Thus, aldolase A and C Fig 3. Expression of three aldolase mRNAs in developing embryos from Kijita et al [17]. Size of the circle is comparable among different stages.…”

“…We obtained a cell line from Xenopus adult kidney and Fluorescence in situ hybridization (FISH) studies showed that the three aldolase genes are located on different chromosomes [17].…”

“…It is worth pointing out that the kidney, which is mesodermal in origin, has an aldolase mRNA composition almost identical to that of the liver, which is Fig 2. aldolase mRNA expression in various adult organs {from Kajita et al [17]. Sizes of circles indicate the relative amount of aldolase mRNAs which is comparable among tissues.…”