Salivary Gland Secretion and Its Relation to Chromosomal Puffing in the Dipteran, Chironomus Thummi

Laufer, Hans; Nakase, Yasukiyo

doi:10.1073/pnas.53.3.511

Cited by 44 publications

(18 citation statements)

References 11 publications

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“…Although some synthetic activity takes place in quiescent larvae, accounting for at least part of the increase in fat body protein at this stage, transfer of protein from the haemolymph may also contribute. Uptake of plasma protein has been demonstrated in Lepidoptera (Loughton and West 1965;Locke and Collins 1968), and in Diptera (Laufer and Nakase 1965). In C. stygia, the observed drop in both the concentration and in the total amount of haemolymph protein at the end of larval life (Kinnear et al 1968) is consistent with the occurrence of such uptake.…”

Section: (I) Fat Bodysupporting

confidence: 68%

Developmental Changes in Tile Late Laitv a of Calliphora Stygia II. Protein Synthesis

Martín¹,

Kinnear²,

Thomson³

1969

Aust. Jnl. Of Bio. Sci.

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SummaryThe pattern of incorporation of [3H]leucine into proteins of fat body, plasma, body wall, and salivary gland has been studied in third-instar larvae of O. stygia. The rate of incorporation is higher in these tissues at day 5 of development than at days 7 and 11 (quiescent stage).The amount of acid-precipitable protein in the fat body increases little between days 5 and 7 in spite of the high synthetic rate early in the instar, whereas from day 7 to 11 there is almost a threefold increase. Simultaneously, the protein content of the plasma increases fourfold from day 5 to 7, and decreases by approximately one-third from day 7 to 11. The total protein of the body wall tissues remains constant from day 5 on, whilst that of the salivary gland cells shows a slow and steady increase during the instar.Changes in the relative specific activities of fat body and plasma proteins with age suggest two major alterations in the biosynthetic functions of fat body: (1) the cessation, between days 5 and 7, of the phase of intense protein synthesis associated with rising levels of plasma protein; (2) the initiation, at the quiescent stage, of a new phase of synthesis involving protein retention in the fat body. In addition, the reduced level of plasma protein between days 7 and 11 apparently reflects uptake by the fat body at this time. Protein synthesis in the tissues of the body wall decreases after day 5, and there is no evidence of any subsequent major change in protein biosynthesis in this tissue. Salivary gland cells appear to show a transition from rapid protein synthesis and quick release of protein at day 5, to slower synthesis with increased protein storage at the quiescent stage.

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Section: (I) Fat Bodysupporting

confidence: 68%

Developmental Changes in Tile Late Laitv a of Calliphora Stygia II. Protein Synthesis

Martín¹,

Kinnear²,

Thomson³

1969

Aust. Jnl. Of Bio. Sci.

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show abstract

“…It is concluded there¬ fore that the relationship between chromosomal puffing and the synthesis of the salivary gland secretion may be less direct than was originally assumed, and the puffing activity may in fact be concerned with the elaboration of macromolecules concerned with the uptake, transfer and secretion of proteins synthesized elsewhere than in the salivary glands (Laufer, 1965a;Laufer & Nakase, 1965a, 6). In C. thummi, the onset of metamorphosis is characterized by a marked accumulation of DNAase in the salivary glands, particularly during the time when the other enzymes investi¬ gated are decreasing in amount, and as the enzyme increases, the amount of DNA in the cells decreases (Laufer & Nakase, 19656;Laufer, 19656). Very shortly after pupation, the salivary glands are grossly disrupted (Laufer, 1965 a;Laufer & Gold¬ smith, 1965;Schin & Clever, 1965).…”

Section: A)mentioning

confidence: 98%

Insect Hormones

Highnam¹

1967

Journal of Endocrinology

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“…The silk proteins of Chironomus are present in its salivary secretion, and this secretion is formed by proteins sequestered from the hemolymph and by proteins synthesized in the salivary secretion (4,5,6) . Therefore, there is a possibility, as proposed above for R. americana, that the silk synthesis in this animal has a double origin as occurs with its salivary secretion .…”

Section: Discussionmentioning

confidence: 99%

“…Larvae of several Chironomus species produce a salivary secretion which, according to its properties (2), fits the silk definition given by Rudall and Kenchington (3) . Formation of Diptera salivary secretion has been investigated in some species of Chironomus (4,5,6) . The results obtained indicate that the proteins present in the salivary secretion are in part synthesized by the salivary gland and in part sequestered from the hemolymph .…”

Section: Introductionmentioning

confidence: 99%