TY - JOUR
T1 - Differential mRNA accumulation and translation during Spisula development
AU - Tansey, Terese R.
AU - Ruderman, Joan V.
N1 - Funding Information:
We thank B. Savakis for his advice during the construction of the cDNA library, and are grateful to D. Alexandraki and E. Rosenthal for many helpful suggestions throughout the course of this work. This work was supported by NSF Grant PCM 7923046 and NIH Research Career Development Award K04 HD00349 to J.V.R. T.R.T. was supported by a NIH predoctoral training grant.
PY - 1983/10
Y1 - 1983/10
N2 - The patterns of proteins synthesized in developing Spisula embryos and larvae were compared with in vitro translation products by one-dimensional gel electrophoresis. Major changes in the in vivo pattern occur at fertilization; these are regulated at the translational level (Rosenthal, Hunt, and Ruderman, 1980, Cell 20, 487-494). The pattern is further altered by midcleavage, and subsequent development is accompanied by frequent changes in the kinds of proteins made. By midcleavage many of the in vivo changes are paralleled by alterations in mRNA levels. Three cDNA clones containing developmentally regulated, nonmitochondrial sequences were isolated from a library constructed from veliger larval RNA. Clone 3v4 encodes α-tubulin. Clone 12v4 encodes a 35,000-D protein of unknown function. The protein product of clone 10v8 has not been identified. The concentration of α-tubulin RNA is relatively low through midcleavage, increases by the swimming gastrula stage, and is maintained at a moderately high level throughout larval development. 10v8 and 12v4 RNAs first appear in trochophore larvae; their concentrations peak 10-12 hr later, and then decline. The proportions of α-tubulin and 10v8 RNA that are translated vary with developmental stage. During early cleavage very little α-tubulin RNA is on polysomes; in swimming gastrulae 64% of this mRNA is polysomal. Seventy percent of 10v8 RNA is translated in the trochophore larva, while only ∼40% is polysomal in the 21-hr veliger. These results show that translational regulation may be superimposed on changes in cytoplasmic mRNA concentrations to determine the level of gene expression during embryogenesis.
AB - The patterns of proteins synthesized in developing Spisula embryos and larvae were compared with in vitro translation products by one-dimensional gel electrophoresis. Major changes in the in vivo pattern occur at fertilization; these are regulated at the translational level (Rosenthal, Hunt, and Ruderman, 1980, Cell 20, 487-494). The pattern is further altered by midcleavage, and subsequent development is accompanied by frequent changes in the kinds of proteins made. By midcleavage many of the in vivo changes are paralleled by alterations in mRNA levels. Three cDNA clones containing developmentally regulated, nonmitochondrial sequences were isolated from a library constructed from veliger larval RNA. Clone 3v4 encodes α-tubulin. Clone 12v4 encodes a 35,000-D protein of unknown function. The protein product of clone 10v8 has not been identified. The concentration of α-tubulin RNA is relatively low through midcleavage, increases by the swimming gastrula stage, and is maintained at a moderately high level throughout larval development. 10v8 and 12v4 RNAs first appear in trochophore larvae; their concentrations peak 10-12 hr later, and then decline. The proportions of α-tubulin and 10v8 RNA that are translated vary with developmental stage. During early cleavage very little α-tubulin RNA is on polysomes; in swimming gastrulae 64% of this mRNA is polysomal. Seventy percent of 10v8 RNA is translated in the trochophore larva, while only ∼40% is polysomal in the 21-hr veliger. These results show that translational regulation may be superimposed on changes in cytoplasmic mRNA concentrations to determine the level of gene expression during embryogenesis.
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U2 - 10.1016/0012-1606(83)90284-1
DO - 10.1016/0012-1606(83)90284-1
M3 - Article
C2 - 6194031
AN - SCOPUS:0020841940
SN - 0012-1606
VL - 99
SP - 338
EP - 351
JO - Developmental biology
JF - Developmental biology
IS - 2
ER -