TY - JOUR
T1 - β-crystallin mRNAs
T2 - Differential distribution in the developing chicken lens
AU - Ostrer, Harry
AU - Beebe, David C.
AU - Piatigorsky, Joram
PY - 1981/9
Y1 - 1981/9
N2 - The synthesis of the β-crystallin polypeptides has been studied in different regions of the embryonic chicken lens. Seven β-crystallin polypeptides ranging in molecular weight from approximately 19,000 (19K) to 35,000 (35K) daltons were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Each polypeptide was synthesized in a rabbit reticulocyte cell-free system supplemented with RNA from the embryonic lens fiber cells suggesting that each is encoded by a separate mRNA. Analysis of the cell-free translation products of the RNAs from 6-, 15-, and 19-day-old embryonic chicken lens fibers demonstrated that all seven polypeptides are translated at each of the stages and that the proportion of β-crystallin mRNAs increases as the chicken embryo matures. Fingerprints of methionine-containing tryptic peptides indicated that the three predominant β-crystallin polypeptides synthesized in the reticulocyte lysate (20K, 26K, and 35K) have related but distinct primary structures. Surprisingly, both the 35K β-crystallin polypeptide and its mRNA were selectively absent from the cells in the central region of the epithelium. Synthesis of this polypeptide from extracted RNAs was detected in the elongating cells of the equatorial region of the epithelium and from the fiber cells. In contrast to the 35K polypeptide, the six lower-molecular-weight β-crystallin polypeptides were synthesized in a reticulocyte lysate directed by RNAs extracted from all three regions of the lens. These data indicate that lens cell elongation and fiber cell differentiation in the embryonic chicken are accompanied by the appearance of the mRNA for the 35K polypeptide.
AB - The synthesis of the β-crystallin polypeptides has been studied in different regions of the embryonic chicken lens. Seven β-crystallin polypeptides ranging in molecular weight from approximately 19,000 (19K) to 35,000 (35K) daltons were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Each polypeptide was synthesized in a rabbit reticulocyte cell-free system supplemented with RNA from the embryonic lens fiber cells suggesting that each is encoded by a separate mRNA. Analysis of the cell-free translation products of the RNAs from 6-, 15-, and 19-day-old embryonic chicken lens fibers demonstrated that all seven polypeptides are translated at each of the stages and that the proportion of β-crystallin mRNAs increases as the chicken embryo matures. Fingerprints of methionine-containing tryptic peptides indicated that the three predominant β-crystallin polypeptides synthesized in the reticulocyte lysate (20K, 26K, and 35K) have related but distinct primary structures. Surprisingly, both the 35K β-crystallin polypeptide and its mRNA were selectively absent from the cells in the central region of the epithelium. Synthesis of this polypeptide from extracted RNAs was detected in the elongating cells of the equatorial region of the epithelium and from the fiber cells. In contrast to the 35K polypeptide, the six lower-molecular-weight β-crystallin polypeptides were synthesized in a reticulocyte lysate directed by RNAs extracted from all three regions of the lens. These data indicate that lens cell elongation and fiber cell differentiation in the embryonic chicken are accompanied by the appearance of the mRNA for the 35K polypeptide.
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U2 - 10.1016/0012-1606(81)90198-6
DO - 10.1016/0012-1606(81)90198-6
M3 - Article
C2 - 6169569
AN - SCOPUS:0019818161
SN - 0012-1606
VL - 86
SP - 403
EP - 408
JO - Developmental Biology
JF - Developmental Biology
IS - 2
ER -