A 28-fold increase in secretory protein synthesis is associated with DNA puff activity in the salivary gland of Bradysia hygida (Diptera, Sciaridae)

Abstract

A 28-fold increase in secretory protein synthesis is associated with DNA puff activity in the salivary gland of Bradysia hygida (Diptera, Sciaridae) AbstractWhen the first group of DNA puffs is active in the salivary gland regions S1 and S3 of Bradysia hygida larvae, there is a large increase in the production and secretion of new salivary proteins demonstrable by [ 3 H]-Leu incorporation. The present study shows that protein separation by SDS-PAGE and detection by fluorography demonstrated that these polypeptides range in molecular mass from about 23 to 100 kDa. Furthermore, these proteins were synthesized mainly in the S1 and S3 salivary gland regions where the DNA puffs C7, C5, C4 and B10 are conspicuous, while in the S2 region protein synthesis was very low. Others have shown that the extent of amplification for DNA sequences that code for mRNA in the DNA puffs C4 and B10 was about 22 and 10 times, respectively. The present data for this group of DNA puffs are consistent with the proposition that gene amplification is necessary to provide some cells with additional gene copies for the production of massive amounts of proteins within a short period of time (Spradling AC and Mahowald AP (1980) Proceedings of the National Academy of Sciences, USA, 77: 1096-1100).

Functional and bioinformatics analyses reveal conservation of cis‐regulatory elements between sciaridae and drosophilidae

“…The biological purpose of gene amplification in Sciaridae appears to be the production of large quantities of the proteins that are employed to build the cocoon in which the larvae pupate (de-Almeida, 1997;Fontes et al, 1999;Monesi et al, 2004;Winter et al, 1977a,b). The BhC4-1 protein is expressed at the time DNA puff C4 is formed and is found both in secretory granules, in the salivary gland, and in fibrous structures present in the saliva of fourth instar larvae (Monesi et al, 2004), a subcellular localization consistent with the proposed role for DNA puff proteins.…”

Bradysia hygida (Diptera, Sciaridae) presents two eukaryotic Elongation Factor 1A gene homologues: partial characterization of the eukaryotic Elongation Factor 1A-F1 gene

“…The end of the fourth larval instar of B. hygida has been previously characterized as a developmental time during which dynamic and abundant protein synthesis occurs in the salivary glands (6,7). After an initial period of nine days during which a characteristic set of polypeptides are synthesized, the salivary glands carry out two successive programs of specialized protein synthesis that last about 12 h each.…”

“…These studies led to the suggestion that the biological role of gene amplification is to provide large amounts of salivary gland proteins that are employed in the construction of the cocoon in which the larvae pupate (5)(6)(7)(8). This suggestion was confirmed by the demonstration that polyclonal antibodies raised against either the product of DNA puff B10…”

“…The expansion and regression of specific DNA puffs can be related to the developmentally regulated synthesis of groups of salivary gland polypeptides (5)(6)(7)(8). These studies led to the suggestion that the biological role of gene amplification is to provide large amounts of salivary gland proteins that are employed in the construction of the cocoon in which the larvae pupate (5)(6)(7)(8).…”

Feulgen Stain in Heterogeneous Egg Samples from Non-Synchronized Bradysia hygida (Diptera: Sciaridae) Laboratory Culture.

“…Bradysia hygida Sauaia et Alves (1968) is maintained in two laboratories in Brazil (Laboratory of Cellular Biology of FMRP-USP, Ribeirao Preto, SP, and Laboratory of Functional Organization of the Nucleus DBC-UEM, Maringa, PR) and it has been extensively used as a model system to study developmentally regulated gene transcription and amplification (Laicine et al 1984, Fontes et al 1992, Coelho et al 1993, Monesi et al 1995, De Almeida 1997. However, the utilization of the embryo as a biological material is very difficult since a detailed description of B. hygida embryogenesis has not been reported yet, and its approximated duration used to be estimated by the daily observation of the eggs.…”