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Yongxu Cheng - One of the best experts on this subject based on the ideXlab platform.
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Comparative transcriptome reveals the potential modulation mechanisms of estradiol affecting Ovarian Development of female Portunus trituberculatus.
PloS one, 2019Co-Authors: Meimei Liu, Jie Pan, Zhiguo Dong, Yongxu Cheng, Jie GongAbstract:Estradiol is an important sex steroid hormone that is involved in the regulation of crustacean Ovarian Development. However, the molecular regulatory mechanisms of estradiol on Ovarian Development are largely unknown. This study performed transcriptome sequencing of ovary, hepatopancreas, brain ganglion, eyestalk, and mandibular organ of crabs after estradiol treatment (0.1μg g-1 crab weight). A total of 23, 806 genes were annotated, and 316, 1300, 669, 142, 383 genes were expressed differently in ovary, hepatopancreas, brain ganglion, eyestalk, and mandibular organ respectively. Differentially expressed gene enrichment analysis revealed several crucial pathways including protein digestion and absorption, pancreatic secretion, insect hormone biosynthesis, drug metabolism-cytochrome P450 and signal transduction pathway. Through this study, some key genes in correlation with the Ovarian Development and nutrition metabolism were significantly affected by estradiol, such as vitelline membrane outer layer 1-like protein, heat shock protein 70, Wnt5, JHE-like carboxylesterase 1, cytochrome P302a1, crustacean hyperglycemic hormone, neuropeptide F2, trypsin, carboxypeptidase B, pancreatic triacylglycerol lipase-like, and lipid storage droplet protein. Moreover, RT-qPCR validation demonstrated that expression of transcripts related to Ovarian Development (vitelline membrane outer layer 1-like protein and cytochrome P302a1) and nutrition metabolism (trypsin, glucose dehydrogenase and lipid storage droplet protein) were significantly affected by estradiol treatment. This study not only has identified relevant genes and several pathways that are involved in estradiol regulation on Ovarian Development of P. trituberculatus, but also provided new insight into the understanding of the molecular function mechanisms of estradiol in crustacean.
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immunolocalization and changes of 17beta estradiol during Ovarian Development of chinese mitten crab eriocheir sinensis
Cell and Tissue Research, 2018Co-Authors: Jie Pan, Meimei Liu, Ting Chen, Yongxu ChengAbstract:17beta-estradiol (E2) is important for crustacean Ovarian Development. This study aims to investigate the distribution and change pattern of E2 in the ovary, hepatopancreas, thoracic ganglion and brain ganglion as well as Vg-mRNA expression level during Ovarian Development of Chinese mitten crab Eriocheir sinensis. Results showed that strongly positive signals of E2 were mainly distributed in follicle cells of ovaries for all Developmental stages as well as oocyte cytoplasm of stages III to V ovaries. In hepatopancreas, the E2-positive signal was mainly detected in the cytoplasm and nucleus of fibrillar cells and the nucleus of resorptive cells, while the maximum fluorescence intensity was observed in stage III hepatopancreas. On the contrary, the E2 immunoreactivities in nervous tissues were relatively stable during Ovarian Development. Moreover, the changing pattern of E2 concentration was similar within hemolymph, ovary and hepatopancreas during the Ovarian Development. From stages I to III, the E2 content in three tissues increased significantly, then decreased gradually until stage V. As for the Vg-mRNA expression level in hepatopancreas and ovaries, an increasing trend was found in ovaries but no significant difference was detected during the period of Ovarian stages III to V. Hepatopancreatic Vg-mRNA expression level increased significantly during stages I to IV and dramatically decreased at stage V. In conclusion, our study suggests that ovary, hepatopancreas, hemolymph and nervous tissues are the target organs of E2 in E. sinensis and E2 concentrations in different tissues are closely related to vitellogenesis in ovary and hepatopancreas during Ovarian Development.
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Immunorecognition and distribution of progestin receptor in the swimming crab Portunus trituberculatus during Ovarian Development
Journal of Fisheries of China, 2013Co-Authors: Hao Chen, Zhi-jun Liu, Yongxu ChengAbstract:Progesterone is one of very important sex steroid hormones,which plays an important role during the Ovarian Development of crustaceans.In vertebrate,progesterone regulates the reproduction generally via progestin receptor(PR).Previous studies have shown PR is present in the ovary,hepatopancreas and nervous tissues for some crustacean species.The swimming crab,Portunus trituberculatus,is a commercially important fisheries resource and mariculture species in East Asian countries.The better understanding of reproductive mechanism would potentially benefit artificial propagation as well as fisheries management of P.trituberculatus.The present study was conducted to immunorecognize and immunolocalize PR in the ovary,hepatopancreas,mandibular organ,Y-organ,optic ganglia and thoracic ganglion mass of female P.trituberculatus via Western-blotting and immunohistochemistry.Then,the change and distribution of PR was also investigated in these tissues during the Ovarian Development of female P.trituberculatus.The results showed that PR with an apparent molecular weight of 100 ku was identified in the optic ganglia of female P.trituberculatus.By means of immunohistochemistry,PR was detected in the ovary,hepatopancreas,mandibular organ,optic ganglia and thoracic ganglion mass.During the Ovarian Development of female P.trituberculatus,the follicule cells were stained with strongly positive PR at each Ovarian stage.As for the germinal cells,the strongly positive PR only exsited in the cytoplasm from the early ovary Developmental stages,including stagesⅠ,Ⅱ and Ⅲ,while the strongly positive PR was stained in the nucleus of germinal cells during the stage Ⅲ to stage Ⅴ.For the female hepatopancreas,PR was mainly localized in the cytoplasm and nucleus of the fibrillar cell at all Ovarian Developmental stages,and PR was also present in the nucleus of stage Ⅲ resorptive cell.On the contrary,no positive PR-like substance was found in the other types of hepatopancreas cells,such as blister-like cell and embryonic cell during the Ovarian Development of female P.trituberculatus.As for the endocrine organ,PR was only localized in the cellular cytoplasm of the stage Ⅳ mandibular organ while positive PR-like substance was not found in the gland cell of Y-organ.Moreover,PR-like substance was also detected in the nervous tissues of female P.trituberculatus.As for the optic ganglia,PR was mainly localized in nerve cells from stage Ⅲ to stage Ⅴ.In addition,PR was also localized in the thoracic ganglion mass.Nerve cell and nerve medulla were stained positively with PR-anti-body from the Ovarian stage Ⅰ to stage Ⅴ.In conclusion,these results suggest that progesterone not only can regulate the vitellogenesis and Ovarian Development directly via interacting with PR in ovary and hepatopancreas,but also may indirectly modulate Ovarian Development through the synthesis and secretion of other endocrine hormones.
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The Second Ovarian Development of Swimming Crab, Portunus trituberculatus
Zoological Research, 2007Co-Authors: Gui-gui Yao, Yongxu Cheng, Xiaozhen Yang, Chunlin WangAbstract:During March to May of 2005, mature female swimming crabs were held in captive conditions and fed with fresh clam, Sinonovacula constricta . The spawned crabs were sampled and dissected to investigate the changes to the gonadosomatic index (GSI), hepatosomatic index (HSI), external features of ovary, Ovarian histology and its stages during the second Ovarian Development of Portunus trituberculatus. The results demonstrated that: (1) the process of the second Ovarian Development could be divided into four stages: stage I ovary was ribbonlike and milk white or buff, the main cells in the ovary were endogenous vitellogenic oocytes (EN) and previtellogenic oocytes (PR); stage II ovary was buff and orange, the main cells were exogenous vitellogenic oocytes(EX); stage III ovary was deep orange, the main cell types were ex and nearly-mature oocytes (NO); stage IV ovary was ripe, the main cell type was mature oocytes(MO); (2) During the period, the GSI increased significantly, while the HSI did not show a significant difference. A positive correlation could be found between GSI and Ovarian Development, days after spawning, however there was no significant correlation between GSI and HSI.
Peter Koopman - One of the best experts on this subject based on the ideXlab platform.
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nr5a1 suppression during the murine fetal period optimizes Ovarian Development by fine tuning notch signaling
Journal of Cell Science, 2019Co-Authors: Risa Nomura, Kenichi Kashimada, Masatoshi Takagi, Hitomi Suzuki, Liang Zhao, Atsumi Tsujihosokawa, Hideo Yagita, Yoshiakira Kanai, Josephine Bowles, Peter KoopmanAbstract:The nuclear receptor NR5A1 is equally expressed and required for Development of the gonadal primordia of both sexes, but, after sex determination, it is upregulated in XY testes and downregulated in XX ovaries. We have recently demonstrated, in mice, that this downregulation is mediated by forkhead box L2 (FOXL2) and hypothesized that adequate suppression of Nr5a1 is essential for normal Ovarian Development. Further, analysis of human patients with disorders/differences of sex Development suggests that overexpression of NR5A1 can result in XX (ovo)testicular Development. Here, we tested the role of Nr5a1 by overexpression in fetal gonads using a Wt1-BAC (bacterial artificial chromosome) transgene system. Enforced Nr5a1 expression compromised Ovarian Development in 46,XX mice, resulting in late-onset infertility, but did not induce (ovo)testis differentiation. The phenotype was similar to that of XX mice lacking Notch signaling. The expression level of Notch2 was significantly reduced in Nr5a1 transgenic mice, and the Ovarian phenotype was almost completely rescued by in utero treatment with a NOTCH2 agonist. We conclude that suppression of Nr5a1 during the fetal period optimizes Ovarian Development by fine-tuning Notch signaling.
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foxl2 transcriptionally represses sf1 expression by antagonizing wt1 during Ovarian Development in mice
The FASEB Journal, 2014Co-Authors: Kei Takasawa, Kenichi Kashimada, Emanuele Pelosi, David Schlessinger, Masatoshi Takagi, Tomohiro Morio, Hiroshi Asahara, Shuki Mizutani, Peter KoopmanAbstract:Steroidogenic factor 1 (SF1; Ad4BP/NR5A1) plays key roles in gonadal Development. Initially, the Sf1 gene is expressed in mouse fetal gonads of both sexes, but later is up-regulated in testes and down-regulated in ovaries. While Sf1 expression is activated and maintained by Wilms tumor 1 (WT1) and LIM homeobox 9 (LHX9), the mechanism of sex-specific regulation remains unclear. We hypothesized that Sf1 is repressed by the transcription factor Forkhead box L2 (FOXL2) during Ovarian Development. In an in vitro system (TM3 cells), up-regulation of Sf1 by the WT1 splice variant WT1-KTS was antagonized by FOXL2, as determined by quantitative RT-PCR. Using reporter assays, we localized the Sf1 proximal promoter region involved in this antagonism to a 674-bp interval. A conserved FOXL2 binding site was identified in this interval by in vitro chromatin immunoprecipitation. Introducing mutations into this site abolished negative regulation by FOXL2 in reporter assays. Finally, in Foxl2-null mice, Sf1 expression was increased 2-fold relative to wild-type XX fetal gonads. Our results support the hypothesis that FOXL2 negatively regulates Sf1 expression by antagonizing WT1-KTS during early Ovarian Development in mice.—Takasawa, K., Kashimada, K., Pelosi, E., Takagi, M., Morio, T., Asahara, H., Schlessinger, D., Mizutani, S., Koopman, P. FOXL2 transcriptionally represses Sf1 expression by antagonizing WT1 during Ovarian Development in mice.
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foxl2 and bmp2 act cooperatively to regulate follistatin gene expression during Ovarian Development
Endocrinology, 2011Co-Authors: Kenichi Kashimada, Emanuele Pelosi, Huijun Chen, David Schlessinger, Dagmar Wilhelm, Peter KoopmanAbstract:Follistatin is a secreted glycoprotein required for female sex determination and early Ovarian Development, but the precise mechanisms regulating follistatin (Fst) gene expression are not known. Here, we investigate the roles of bone morphogenetic protein 2 (BMP2) and forkhead-domain transcription factor L2 (FOXL2) in the regulation of Fst expression in the developing mouse ovary. Bmp2 and Fst showed similar temporal profiles of mRNA expression, whereas FOXL2 protein and Fst mRNA were coexpressed in the same Ovarian cells. In a cell culture model, both FOXL2 and BMP2 up-regulated Fst expression. In ex vivo mouse fetal gonad culture, exogenous BMP2 increased Fst expression, but this effect was counteracted by the BMP antagonist Noggin. Moreover, in Foxl2-null mice, Fst expression was reduced throughout fetal Ovarian Development, and Bmp2 expression was also reduced. Our data support a model in which FOXL2 and BMP2 cooperate to ensure correct expression of Fst in the developing ovary. Further, Wnt4-knockout mice showed reduced expression of Fst limited to early Ovarian Development, suggesting a role for WNT4 in the initiation, but not the maintenance, of Fst expression.
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Charting the course of Ovarian Development in vertebrates
The International journal of developmental biology, 2002Co-Authors: Kelly A. Loffler, Peter KoopmanAbstract:The decision of the embryonic gonad to differentiate as either a testis or an ovary is a critical step in vertebrate Development. The molecular basis of this decision has been the focus of much study, particularly over the past decade. Here we contrast the knowledge of early gonadal Development and the switch to testis differentiation with the lack of molecular understanding of Ovarian Development at early stages. We review current knowledge regarding mechanisms of Ovarian morphogenesis and propose a model for the hierarchical control of Development of the fetal ovary, incorporating the few genes already known to be important and several signals or factors that are hypothesised to exist in the early ovary.
Jie Gong - One of the best experts on this subject based on the ideXlab platform.
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Comparative transcriptome reveals the potential modulation mechanisms of estradiol affecting Ovarian Development of female Portunus trituberculatus.
PloS one, 2019Co-Authors: Meimei Liu, Jie Pan, Zhiguo Dong, Yongxu Cheng, Jie GongAbstract:Estradiol is an important sex steroid hormone that is involved in the regulation of crustacean Ovarian Development. However, the molecular regulatory mechanisms of estradiol on Ovarian Development are largely unknown. This study performed transcriptome sequencing of ovary, hepatopancreas, brain ganglion, eyestalk, and mandibular organ of crabs after estradiol treatment (0.1μg g-1 crab weight). A total of 23, 806 genes were annotated, and 316, 1300, 669, 142, 383 genes were expressed differently in ovary, hepatopancreas, brain ganglion, eyestalk, and mandibular organ respectively. Differentially expressed gene enrichment analysis revealed several crucial pathways including protein digestion and absorption, pancreatic secretion, insect hormone biosynthesis, drug metabolism-cytochrome P450 and signal transduction pathway. Through this study, some key genes in correlation with the Ovarian Development and nutrition metabolism were significantly affected by estradiol, such as vitelline membrane outer layer 1-like protein, heat shock protein 70, Wnt5, JHE-like carboxylesterase 1, cytochrome P302a1, crustacean hyperglycemic hormone, neuropeptide F2, trypsin, carboxypeptidase B, pancreatic triacylglycerol lipase-like, and lipid storage droplet protein. Moreover, RT-qPCR validation demonstrated that expression of transcripts related to Ovarian Development (vitelline membrane outer layer 1-like protein and cytochrome P302a1) and nutrition metabolism (trypsin, glucose dehydrogenase and lipid storage droplet protein) were significantly affected by estradiol treatment. This study not only has identified relevant genes and several pathways that are involved in estradiol regulation on Ovarian Development of P. trituberculatus, but also provided new insight into the understanding of the molecular function mechanisms of estradiol in crustacean.
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ecdysone receptor in the mud crab scylla paramamosain a possible role in promoting Ovarian Development
Journal of Endocrinology, 2015Co-Authors: Jie Gong, Yinjie Xie, Yanan Yang, Huiyang Huang, Chaoshu ZengAbstract:In arthropods, it is known that ecdysteroids regulate molting, limb regeneration, and reproduction through activation of the ecdysone receptor (EcR). However, the ecdysteroid signaling pathway for promotion of Ovarian Development in crustaceans is still unclear. In this study, three cDNA isoforms of EcR were cloned from the mud crab Scylla paramamosain. qRT-PCR revealed that the SpEcR mRNA was abundant in the eyestalk, ovary and epidermis. During Ovarian Development, the SpEcR transcripts increased from stage I (undeveloped stage) and reached a peak at stage IV (late vitellogenic stage) before dropping to a lower level at stage V (mature stage). Meanwhile, levels of 20-hydroxyecdysone (20E) in the hemolymph, detected by HPLC-MS, displayed a similar pattern of increase with Ovarian Development. Results from in situ hybridization indicated that SpEcR mRNA was present in the follicular cells during vitellogenesis. Results from in vivo experiments revealed that 20E at 0.2 μg/g body weight significantly stimulated the expression of SpEcR and vitellogenin (SpVg) in female crabs during the early vitellogenic stage but not during the previtellogenic stage. This was confirmed by results from in vitro experiments which indicated that SpEcR and SpVg expression levels were significantly upregulated in early vitellogenic Ovarian explants incubated with 5.0 μM 20E at 3 and 6 h but not in previtellogenic Ovarian explants. Finally, results from in vitro gene silencing experiments indicated that the expression of SpEcR and SpVg in the ovary was significantly inhibited by SpEcR dsRNA. All these results together indicated that in S. paramamosain, 20E, and SpEcR, located in the follicular cells, play important roles in the promotion of Ovarian Development via regulating the expression of SpVg.
Meimei Liu - One of the best experts on this subject based on the ideXlab platform.
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Comparative transcriptome reveals the potential modulation mechanisms of estradiol affecting Ovarian Development of female Portunus trituberculatus.
PloS one, 2019Co-Authors: Meimei Liu, Jie Pan, Zhiguo Dong, Yongxu Cheng, Jie GongAbstract:Estradiol is an important sex steroid hormone that is involved in the regulation of crustacean Ovarian Development. However, the molecular regulatory mechanisms of estradiol on Ovarian Development are largely unknown. This study performed transcriptome sequencing of ovary, hepatopancreas, brain ganglion, eyestalk, and mandibular organ of crabs after estradiol treatment (0.1μg g-1 crab weight). A total of 23, 806 genes were annotated, and 316, 1300, 669, 142, 383 genes were expressed differently in ovary, hepatopancreas, brain ganglion, eyestalk, and mandibular organ respectively. Differentially expressed gene enrichment analysis revealed several crucial pathways including protein digestion and absorption, pancreatic secretion, insect hormone biosynthesis, drug metabolism-cytochrome P450 and signal transduction pathway. Through this study, some key genes in correlation with the Ovarian Development and nutrition metabolism were significantly affected by estradiol, such as vitelline membrane outer layer 1-like protein, heat shock protein 70, Wnt5, JHE-like carboxylesterase 1, cytochrome P302a1, crustacean hyperglycemic hormone, neuropeptide F2, trypsin, carboxypeptidase B, pancreatic triacylglycerol lipase-like, and lipid storage droplet protein. Moreover, RT-qPCR validation demonstrated that expression of transcripts related to Ovarian Development (vitelline membrane outer layer 1-like protein and cytochrome P302a1) and nutrition metabolism (trypsin, glucose dehydrogenase and lipid storage droplet protein) were significantly affected by estradiol treatment. This study not only has identified relevant genes and several pathways that are involved in estradiol regulation on Ovarian Development of P. trituberculatus, but also provided new insight into the understanding of the molecular function mechanisms of estradiol in crustacean.
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immunolocalization and changes of 17beta estradiol during Ovarian Development of chinese mitten crab eriocheir sinensis
Cell and Tissue Research, 2018Co-Authors: Jie Pan, Meimei Liu, Ting Chen, Yongxu ChengAbstract:17beta-estradiol (E2) is important for crustacean Ovarian Development. This study aims to investigate the distribution and change pattern of E2 in the ovary, hepatopancreas, thoracic ganglion and brain ganglion as well as Vg-mRNA expression level during Ovarian Development of Chinese mitten crab Eriocheir sinensis. Results showed that strongly positive signals of E2 were mainly distributed in follicle cells of ovaries for all Developmental stages as well as oocyte cytoplasm of stages III to V ovaries. In hepatopancreas, the E2-positive signal was mainly detected in the cytoplasm and nucleus of fibrillar cells and the nucleus of resorptive cells, while the maximum fluorescence intensity was observed in stage III hepatopancreas. On the contrary, the E2 immunoreactivities in nervous tissues were relatively stable during Ovarian Development. Moreover, the changing pattern of E2 concentration was similar within hemolymph, ovary and hepatopancreas during the Ovarian Development. From stages I to III, the E2 content in three tissues increased significantly, then decreased gradually until stage V. As for the Vg-mRNA expression level in hepatopancreas and ovaries, an increasing trend was found in ovaries but no significant difference was detected during the period of Ovarian stages III to V. Hepatopancreatic Vg-mRNA expression level increased significantly during stages I to IV and dramatically decreased at stage V. In conclusion, our study suggests that ovary, hepatopancreas, hemolymph and nervous tissues are the target organs of E2 in E. sinensis and E2 concentrations in different tissues are closely related to vitellogenesis in ovary and hepatopancreas during Ovarian Development.
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The Growth and Ovarian Development Pattern of Pond-Reared Swimming Crab Portunus trituberculatus
Journal of Shellfish Research, 2018Co-Authors: Jie Che, Meimei Liu, Zhiguo Dong, Wenjie Hou, Guiping PanAbstract:The most common method for farming swimming crab Portunus trituberculatus in China is pond culture; however, their growth performance and Ovarian Development under these conditions are unclear. This study was conducted to investigate growth parameters, gonadosomatic index (GSI), hepatosomatic index, and monthly variation in the Ovarian Development of pond-reared female P. trituberculatus. The results showed (1) a significant increase in body weight (BW) and carapace width (CW) of female P. trituberculatus mainly during June to October, and the highest growth rate and specific growth rate of BW and CW were found during June to July. In addition, a significantly positive correlation was also found between BW and CW for pond-cultured P. trituberculatus females; (2) GSI increased significantly during Ovarian Development of pond-reared female P. trituberculatus and the mean GSI of Ovarian stage I was 0.32%, whereas the mean GSI of Ovarian stage V reached 7.92%; (3) Female P. trituberculatus started their pubertal molt at the end of July and the peak pubertal molt occurred from mid-August to early September; females nearly completed their pubertal molt in mid-October. Before pubertal molt, Ovarian Development of pond-reared P. trituberculatus was mainly at Ovarian stage I during July to August; after the pubertal molt, females developed their ovaries quickly, with more than 80% at Ovarian stage III inOctober. A second period of rapid Ovarian Development occurred at the end of January to the end of February, with a mean GSI reaching 5.25% at the end of February. From February to the end of March, no significant GSI changes were observed in female P. trituberculatus, indicating that the Ovarian status of pond-reared female P. trituberculatus matured by the end of February.
Mark L. Winston - One of the best experts on this subject based on the ideXlab platform.
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INFLUENCE OF AGE AND POPULATION SIZE ON Ovarian Development, AND OF TROPHALLAXIS ON Ovarian Development AND VITELLOGENIN TITRES OF QUEENLESS WORKER HONEY BEE (HYMENOPTERA: APIDAE)
The Canadian Entomologist, 1999Co-Authors: Huarong Lin, Mark L. Winston, Norbert H. Haunerland, Keith N. SlessorAbstract:We examined the factors that might influence ovary Development in worker honey bees, Apis mellifera L. Queenless workers at different ages (≤ 12 h, and 4, 8, and 21 d) were tested in cages for Ovarian Development. Newly emerged, 4- and 8-d-old, and 21-d-old workers had medium-, large-, and small-sized ovaries, respectively, suggesting that of the worker ages tested only 4- and 8-d-old workers are likely to become egg layers in a queenless colony. Also, we compared Ovarian Development of newly emerged workers that were caged for 14 d and allowed to consume either pollen or royal jelly to that of another group of workers similarly caged but screened so that they could only obtain food via trophallaxis from young bees. Ovaries of newly emerged workers that received food from young bees were as well developed as those of newly emerged workers allowed to take pollen or royal jelly directly. Screened workers also had lower but still elevated vitellogenin levels compared with bees having direct access to food. These results indicate that nurse-age bees functioning as pollen-digesting units affect the Ovarian Development of other workers and to a lesser extent vitellogenesis via food exchange. We compared the influence of group sizes of 25, 125, and 600 bees per cage on Ovarian Development for 14 d. The two groups of 25 and 125 bees had similar mean ovary scores, and higher scores than a group of 600 bees. Our findings suggest that nurse-age bees could play an important role in mediating worker fertility via trophallaxis, possibly by differentiating worker dominance status, and generally only young workers become fertile when a queen is lost in a colony. Vitellogenin is a more sensitive parameter to measure bee fertility, and might be a useful tool to further explore ovary Development and egg laying in worker social insects. We recommend measuring haemolymph vitellogenin titres and (or) oocyte length of workers in a group of 25 bees per cage, supplied with 50% royal jelly in honey as a standard method to assess honey bee worker fertility in future experiments.
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THE ROLE OF NUTRITION AND TEMPERATURE IN THE Ovarian Development OF THE WORKER HONEY BEE ( APIS MELLIFERA )
The Canadian Entomologist, 1998Co-Authors: Huarong Lin, Mark L. WinstonAbstract:Queenless, caged, newly emerged worker bees (Apis mellifera L.) were fed honey, 22 and 40% pollen in honey, and 22 and 40% royal jelly in honey for 14 days. Workers fed royal jelly, pollen, and honey had large, medium, and small ovaries, respectively. Royal jelly had higher nutritive value for workers’ Ovarian Development than did pollen, possibly because royal jelly is predigested by nurse bees and easily used by adult and larval bees. These results suggest that nurse bees could mediate workers’ Ovarian Development in colonies via trophallactic exchange of royal jelly. Six levels of royal jelly in honey, 0, 20, 40, 60, 80, and 100% (royal jelly without honey), were tested for their effects on workers’ Ovarian Development and mortality for 10 days. High levels of royal jelly increased Ovarian Development, but also increased worker mortality. All caged bees treated with 100% royal jelly died within 3 days. When workers were incubated at 20, 27, and 34 °C for 10 days, only bees at 34 °C developed ovaries. These findings suggest that nurse bees functioning as units which digest pollen and produce royal jelly may feed some potentially egg-laying workers in a brood chamber with royal jelly when a queen is lost in a colony. Feeding workers a diet of 50% royal jelly in honey and incubating at 34 °C for 10 days is recommended for tests of Ovarian Development.
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Mandibular gland components and Ovarian Development as measures of caste differentiation in the honey bee (Apis mellifera L.)
Journal of Insect Physiology, 1993Co-Authors: Erika Plettner, Gene E Robinson, Keith N. Slessor, Mark L. Winston, Robert E. PageAbstract:Abstract Changes in mandibular gland pheromone production and Ovarian Development were investigated in queenless North American honey bees (Apis mellifera L.). An intercaste, false queens, laying workers, queenless foragers and queenright workers were analyzed for the amounts of five mandibular gland pheromone components and for Ovarian Development. Pheromone composition was not related to Ovarian Development, in contrast to some previous studies with the African race, Apis mellifera capensis. These results suggest that queen/worker caste differentiation may be more strongly fixed during Development in some honey bee races than in others.