TY - JOUR
T1 - Hormonal control of vitellogenesis in the gypsy moth, Lymantria dispar (L.)
T2 - Suppression of haemolymph vitellogenin by the juvenile hormone analogue, methoprene
AU - Davis, Robin E.
AU - Kelly, Thomas J.
AU - Masler, Edward P.
AU - Fescemyer, Howard W.
AU - Thyagaraja, Belgaum S.
AU - Borkovec, Alexej B.
N1 - Funding Information:
Acknowledgements-We would like to thank LaVern R. Whisenton and Richard B. Imberski for helpful comments on manuscript preparation and Robert A. Bell (I.R.L.. U.S.D.A., Beltsville) for providing the gypsy moth larvae used in this study. R.E.D. was supported by an ARS Postdoctoral Fellowship to T.J.K., H.W.F. by USDA Competitive Grant No. 86-CRCR-1-21 I1 to E.P.M. and T.J.K., and B.S.T. in part by Ministry of Home Affairs, Government of India, Postdoctoral Research Assistantship No. BC-11015/5/84.
PY - 1990
Y1 - 1990
N2 - In most insects, female-specific egg-protein precursors (vitellogenins) are synthesized during pupal or adult stages in response to 20-hydroxyecdysone and/or juvenile hormone. In the gypsy moth, two female-specific haemolymph polypeptides (apo-vitellogenins) having electrophoretic and immunologic identity with Lymantria dispar egg-vitellin apo-proteins begin to accumulate in the haemolymph after day 3 of the fifth larval instar. Head ligation, starvation or treatment with doses of a juvenile hormone analogue, methoprene, >10 μg prior to day 3 block the accumulation of apo-vitellogenin in the haemolymph. Unlike head-ligated or starved larvae which do not gain weight and do no accumulate normal levels of non-vitellogenin haemolymph proteins following treatment, methoprene-treated larvae grow normally and accumulate non-vitellogenin haemolymph proteins. 20-Hydroxyecdysone (2.5 μg) has no effect on the haemolymph accumulation of apo-vitellogenins in normal larvae, and does not restore haemolymph apo-vitellogenins in methoprene-treated, head-ligated or starved larvae. The above results suggest that a low (or declining) juvenile hormone titre during a critical stage early in the last larval instar (prior to day 3) is necessary for the accumulation of vitellogenin in the haemolymph to proceed normally in the gypsy moth. Other factors such as nutrient intake may also be involved. This role of juvenile hormone as an inhibitor of vitellogenin accumulation/synthesis is a novel one for insect species.
AB - In most insects, female-specific egg-protein precursors (vitellogenins) are synthesized during pupal or adult stages in response to 20-hydroxyecdysone and/or juvenile hormone. In the gypsy moth, two female-specific haemolymph polypeptides (apo-vitellogenins) having electrophoretic and immunologic identity with Lymantria dispar egg-vitellin apo-proteins begin to accumulate in the haemolymph after day 3 of the fifth larval instar. Head ligation, starvation or treatment with doses of a juvenile hormone analogue, methoprene, >10 μg prior to day 3 block the accumulation of apo-vitellogenin in the haemolymph. Unlike head-ligated or starved larvae which do not gain weight and do no accumulate normal levels of non-vitellogenin haemolymph proteins following treatment, methoprene-treated larvae grow normally and accumulate non-vitellogenin haemolymph proteins. 20-Hydroxyecdysone (2.5 μg) has no effect on the haemolymph accumulation of apo-vitellogenins in normal larvae, and does not restore haemolymph apo-vitellogenins in methoprene-treated, head-ligated or starved larvae. The above results suggest that a low (or declining) juvenile hormone titre during a critical stage early in the last larval instar (prior to day 3) is necessary for the accumulation of vitellogenin in the haemolymph to proceed normally in the gypsy moth. Other factors such as nutrient intake may also be involved. This role of juvenile hormone as an inhibitor of vitellogenin accumulation/synthesis is a novel one for insect species.
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U2 - 10.1016/0022-1910(90)90107-Q
DO - 10.1016/0022-1910(90)90107-Q
M3 - Article
AN - SCOPUS:0000559031
VL - 36
SP - 231
EP - 238
JO - Journal of Insect Physiology
JF - Journal of Insect Physiology
SN - 0022-1910
IS - 4
ER -