TY - JOUR
T1 - Isolation and partial characterization of a gene from trachea of Manduca sexta that requires and is negatively regulated by ecdysteroids
AU - Mészáros, Melinda
AU - Morton, David B.
PY - 1994/4
Y1 - 1994/4
N2 - The molting cycle in insects is regulated by the fluctuating levels of ecdysteroids. Twenty-four hours prior to the pupal molt in Manduca sexta steroid titers are relatively high and they fall to very low levels at 4 hr before the molt. Several physiological events accompanying molts have been shown to require the rise and then the subsequent decline of ecdysteroid levels. These events also require the expression of a new set of genes. We used subtractive hybridization to isolate genes that are expressed 4 hr, but not 24 hr, prior to the pupal molt in the nervous system of Manduca. These genes are expected to play a role either in ecdysis behavior or in the development of pupal/adult structures. The first such gene we have identified, esr20 (EcdySteroid Regulated) encodes a 20-kDa protein. The deduced amino acid sequence of the protein shows similarity to acidic domains in three unrelated proteins, chick nucleolin, rat heavy-molecular-weight neurofilament, and the Drosophila steroid orphan receptor, knirps-related. The similarity among the four proteins appears to be in regions implicated in protein-protein interactions. The accumulation of esr20 mRNA starts 16 hr prior to the pupal molt and abruptly stops at ecdysis. Expression of esr20 was localized to tracheal epithelial cells within all tissue types, and the transcript was present prior to the larval, pupal, and adult molts only after the molting peak of ecdysteroids had declined. Its expression was inhibited in the presence of ecdysteroids in vitro and required protein synthesis.
AB - The molting cycle in insects is regulated by the fluctuating levels of ecdysteroids. Twenty-four hours prior to the pupal molt in Manduca sexta steroid titers are relatively high and they fall to very low levels at 4 hr before the molt. Several physiological events accompanying molts have been shown to require the rise and then the subsequent decline of ecdysteroid levels. These events also require the expression of a new set of genes. We used subtractive hybridization to isolate genes that are expressed 4 hr, but not 24 hr, prior to the pupal molt in the nervous system of Manduca. These genes are expected to play a role either in ecdysis behavior or in the development of pupal/adult structures. The first such gene we have identified, esr20 (EcdySteroid Regulated) encodes a 20-kDa protein. The deduced amino acid sequence of the protein shows similarity to acidic domains in three unrelated proteins, chick nucleolin, rat heavy-molecular-weight neurofilament, and the Drosophila steroid orphan receptor, knirps-related. The similarity among the four proteins appears to be in regions implicated in protein-protein interactions. The accumulation of esr20 mRNA starts 16 hr prior to the pupal molt and abruptly stops at ecdysis. Expression of esr20 was localized to tracheal epithelial cells within all tissue types, and the transcript was present prior to the larval, pupal, and adult molts only after the molting peak of ecdysteroids had declined. Its expression was inhibited in the presence of ecdysteroids in vitro and required protein synthesis.
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U2 - 10.1006/dbio.1994.1115
DO - 10.1006/dbio.1994.1115
M3 - Article
C2 - 8150220
AN - SCOPUS:0028296893
SN - 0012-1606
VL - 162
SP - 618
EP - 630
JO - Developmental Biology
JF - Developmental Biology
IS - 2
ER -