TY - JOUR
T1 - Ovarian development and insulin-signaling pathways during reproductive differentiation in the queenless ponerine ant Diacamma sp.
AU - Okada, Yasukazu
AU - Miyazaki, Satoshi
AU - Miyakawa, Hitoshi
AU - Ishikawa, Asano
AU - Tsuji, Kazuki
AU - Miura, Toru
N1 - Funding Information:
We thank K. Hartfelder, C. Peeters, M. T. Kimura, and S. Higashi for providing valuable suggestions for improving the early version of this article. We are also grateful to T. Kikuchi, M. Suwabe, H. Onishi, and H. Shimoji for their assistance in our field sampling, and to S. Koshikawa, A. Hattori, and Y. Okumura for their support in laboratory experiments. This work was supported by Grants-in-Aid for Scientific Research (Nos. 18047002, 18370007, 20033002, 20370030, and 21677001) from the Ministry of Education, Culture, Sports, Science and Technology of Japan. YO, SM and AI were supported by the Japan Society for the Promotion of Science (JSPS) research fellowship for young scientists.
PY - 2010/3
Y1 - 2010/3
N2 - In many social hymenopteran species, workers possess functional ovaries that are physiologically inactive in the presence of queens. We investigated the ovarian regulatory mechanism of workers and reproductives in a queenless ponerine ant, Diacamma sp., using histological and molecular techniques. In this ant, clear reproductive differentiation occurs via a highly sophisticated dominance behavioral interaction called "gemmae mutilation". This clear and rapid bifurcation of reproductive physiology allows us to elucidate the detailed ovarian differentiation process. Histological characteristics of functional ovaries (fusomes and ring canals) were found in both workers and reproductives, suggesting that early oogenesis is not blocked in workers. Since insulin/insulin-like growth factor signaling (IIS) is known to control insect reproduction, orthologs of 2 positive IIS regulators, insulin receptor and serine-threonine kinase Akt (protein kinase B), were cloned in Diacamma (DiaInR, DiaAkt); their expression patterns during reproductive differentiation were examined by real-time quantitative polymerase chain reaction; DiaInR and DiaAkt were strongly expressed in the gasters of reproductives. Whole-mount in situ hybridization of ovaries indicated that DiaInR and DiaAkt were expressed in nurse cells, oocytes, and upper germarial regions of reproductives but not of workers. Our data suggest that the IIS pathway accounts for reproductive differentiation in late oogenesis.
AB - In many social hymenopteran species, workers possess functional ovaries that are physiologically inactive in the presence of queens. We investigated the ovarian regulatory mechanism of workers and reproductives in a queenless ponerine ant, Diacamma sp., using histological and molecular techniques. In this ant, clear reproductive differentiation occurs via a highly sophisticated dominance behavioral interaction called "gemmae mutilation". This clear and rapid bifurcation of reproductive physiology allows us to elucidate the detailed ovarian differentiation process. Histological characteristics of functional ovaries (fusomes and ring canals) were found in both workers and reproductives, suggesting that early oogenesis is not blocked in workers. Since insulin/insulin-like growth factor signaling (IIS) is known to control insect reproduction, orthologs of 2 positive IIS regulators, insulin receptor and serine-threonine kinase Akt (protein kinase B), were cloned in Diacamma (DiaInR, DiaAkt); their expression patterns during reproductive differentiation were examined by real-time quantitative polymerase chain reaction; DiaInR and DiaAkt were strongly expressed in the gasters of reproductives. Whole-mount in situ hybridization of ovaries indicated that DiaInR and DiaAkt were expressed in nurse cells, oocytes, and upper germarial regions of reproductives but not of workers. Our data suggest that the IIS pathway accounts for reproductive differentiation in late oogenesis.
KW - Insulin signaling
KW - Ovary
KW - Ponerine ant
KW - Reproductive division of labor
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U2 - 10.1016/j.jinsphys.2009.10.013
DO - 10.1016/j.jinsphys.2009.10.013
M3 - Article
C2 - 19896951
AN - SCOPUS:75749148305
VL - 56
SP - 288
EP - 295
JO - Journal of Insect Physiology
JF - Journal of Insect Physiology
SN - 0022-1910
IS - 3
ER -