scholarly journals Actin gene expression in developing sea urchin embryos.

1981 ◽  
Vol 1 (8) ◽  
pp. 711-720 ◽  
Author(s):  
W R Crain ◽  
D S Durica ◽  
K Van Doren
Keyword(s):  
Early Development ◽  
Sea Urchin ◽  
Messenger Rna ◽  
Developmental Stages ◽  
In Vitro Translation ◽  
Time Interval ◽  
Similar Time ◽  
Ribonucleic Acids ◽  
Size Classes

We show that the synthesis of actin is regulated developmentally during early sea urchin embryogenesis and that the level of synthesis of this protein parallels the steady-state amounts of the actin messenger ribonucleic acids (RNA). An in vitro translation and RNA blotting analysis of embryo RNA from several stages of early development indicated that during the first 8 h after fertilization there was a low and relatively constant level of actin messenger RNA in the embryo. Between 8 and 13 h of development, the amount of actin messenger RNA began to increase both in the cytoplasm and on polysomes, and by 18 h the amounts of actin message per embryo had risen between approximately 10- and 25-fold in the cytoplasm and between 15- and 40-fold on polysomes. Two size classes of actin messenger RNA (2.2 and 1.8 kilobases) were identified in unfertilized eggs and in all of the developmental stages examined. The amount of each actin message class increased over a similar time interval during early development. However, the amounts of these size classes in the cytoplasm relative to each other shifted between the earliest stages examined (2 to 5 h) and the hatching blastula stage (18 h), with the ratio of the 1.8-kilobase actin messenger RNA to the 2.2-kilobase actin messenger RNA increasing almost threefold during this period.

Actin gene expression in developing sea urchin embryos

1981 ◽  
Vol 1 (8) ◽  
pp. 711-720
Author(s):  
W R Crain ◽  
D S Durica ◽  
K Van Doren
Keyword(s):  
Early Development ◽  
Sea Urchin ◽  
Messenger Rna ◽  
Developmental Stages ◽  
In Vitro Translation ◽  
Time Interval ◽  
Similar Time ◽  
Ribonucleic Acids ◽  
Size Classes

We show that the synthesis of actin is regulated developmentally during early sea urchin embryogenesis and that the level of synthesis of this protein parallels the steady-state amounts of the actin messenger ribonucleic acids (RNA). An in vitro translation and RNA blotting analysis of embryo RNA from several stages of early development indicated that during the first 8 h after fertilization there was a low and relatively constant level of actin messenger RNA in the embryo. Between 8 and 13 h of development, the amount of actin messenger RNA began to increase both in the cytoplasm and on polysomes, and by 18 h the amounts of actin message per embryo had risen between approximately 10- and 25-fold in the cytoplasm and between 15- and 40-fold on polysomes. Two size classes of actin messenger RNA (2.2 and 1.8 kilobases) were identified in unfertilized eggs and in all of the developmental stages examined. The amount of each actin message class increased over a similar time interval during early development. However, the amounts of these size classes in the cytoplasm relative to each other shifted between the earliest stages examined (2 to 5 h) and the hatching blastula stage (18 h), with the ratio of the 1.8-kilobase actin messenger RNA to the 2.2-kilobase actin messenger RNA increasing almost threefold during this period.

Protein translation during early cell divisions of sea urchin embryos regulated at the level of polypeptide chain elongation and highly sensitive to natural polyamines

Zygote ◽  
2001 ◽  
Vol 9 (3) ◽  
pp. 229-236 ◽  
Author(s):  
Annabelle Monnier ◽  
Julia Morales ◽  
Patrick Cormier ◽  
Sandrine Boulben ◽  
Robert Bellé ◽  
...  
Keyword(s):  
Early Development ◽  
Sea Urchin ◽  
Protein Translation ◽  
Early Embryo ◽  
Chain Elongation ◽  
Time Interval ◽  
Short Time Interval ◽  
Cell Divisions ◽  
Highly Sensitive

Protein synthesis was analysed following fertilisation in sea urchin. Fluctuations in the accumulation of neo-synthesised proteins were observed during the first cell cycles. Accurate translation analyses were performed from lysates prepared from early embryos. The lysates readily translated endogenous pre-initiated mRNAs allowing the determination of elongation rates in the absence of re-initiation in vitro. The translation capacity of embryo lysates increased 18-fold from 0 to 90 min after fertilisation, reflecting the increase in the amount of pre-initiated mRNAs during early development. Kinetics analysis at a short time interval during the course of early development (240 min) showed an overall increase in the elongation rate (> 10-fold) which is regulated by pauses in synchrony with the cell divisions. Elongation activity in the lysates was highly sensitive to the natural polyamines, spermine (ID50 = 0.2 mM) and spermidine (ID50 = 1.8 mM), indicating high potential regulation by the intracellular level of polyamines in embryos. The regulation in the elongation changes associated with the early embryo cell divisions is discussed in the light of the physiological fluctuations in polyamine concentrations.

scholarly journals In vitro translation of avian vitellogenin messenger RNA.

1977 ◽  
Vol 252 (22) ◽  
pp. 8320-8327 ◽  
Author(s):  
J.I. Gordon ◽  
R.G. Deeley ◽  
A.T. Burns ◽  
B.M. Paterson ◽  
J.L. Christmann ◽  
...  
Keyword(s):  
Messenger Rna ◽  
In Vitro Translation

scholarly journals Comparison of messenger RNA pools in active and dormant Artemia franciscana embryos: evidence for translational control

1992 ◽  
Vol 164 (1) ◽  
pp. 103-116 ◽  
Author(s):  
G. E. Hofmann ◽  
S. C. Hand
Keyword(s):  
Protein Synthesis ◽  
Translational Control ◽  
Messenger Rna ◽  
Artemia Franciscana ◽  
In Vitro Translation ◽  
Translation Techniques ◽  
Polysome Profile ◽  
Anaerobic Dormancy ◽  
Qualitative Changes

In response to environmental anoxia, embryos of the brine shrimp Artemia franciscana enter a dormant state during which energy metabolism and development are arrested. The intracellular acidification that correlates with this transition into anaerobic dormancy has been linked to the inhibition of protein synthesis in quiescent embryos. In this study, we have addressed the level of control at which a mechanism mediated by intracellular pH might operate to arrest protein synthesis. Two independent lines of evidence suggest that there is an element of translational control when protein synthesis is arrested in dormant embryos. First, as determined by in vitro translation techniques, there were no significant quantitative differences in mRNA pools in dormant as compared to actively developing embryos. In addition, fluorography of the translation products showed that there are no large qualitative changes in mRNA species when embryos become dormant. These data suggest that there was no net degradation of mRNA pools in dormant embryos and that protein synthesis may therefore be controlled more strongly at translation than at transcription. Second, polysome profile studies showed that dormant embryos possess reduced levels of polysomes relative to those found in cells or active embryos. The disaggregation of polysomes is an indication that the initiation step in protein synthesis is disrupted and is further evidence that the mechanism involved in protein synthesis arrest in dormant Artemia involves translational control.

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