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  1. Article ; Online: Effects of molting on the expression of ecdysteroid responsive genes in the crustacean molting gland (Y-organ).

    Benrabaa, Samiha A M / Chang, Sharon A / Chang, Ernest S / Mykles, Donald L

    General and comparative endocrinology

    2024  , Page(s) 114548

    Abstract: Ecdysteroid molting hormones coordinate arthropod growth and development. Binding of 20-hydroxyecdysone (20E) to ecdysteroid receptor EcR/RXR activates a cascade of nuclear receptor transcription factors that mediate tissue responses to hormone. Insect ... ...

    Abstract Ecdysteroid molting hormones coordinate arthropod growth and development. Binding of 20-hydroxyecdysone (20E) to ecdysteroid receptor EcR/RXR activates a cascade of nuclear receptor transcription factors that mediate tissue responses to hormone. Insect ecdysteroid responsive and Forkhead box class O (FOXO) transcription factor gene sequences were used to extract orthologs from blackback land crab (Gecarcinus lateralis) Y-organ (YO) transcriptome: Gl-Ecdysone Receptor (EcR), Gl-Broad Complex (Br-C), Gl-E74, Gl-Hormone Receptor 3 (HR3), Gl-Hormone Receptor 4 (HR4), Gl-FOXO, and Gl-Fushi tarazu factor-1 (Ftz-f1). Quantitative polymerase chain reaction quantified mRNA levels in tissues from intermolt animals and in YO of animals induced to molt by multiple limb autotomy (MLA) or eyestalk ablation (ESA). Gl-EcR, Gl-Retinoid X Receptor (RXR), Gl-Br-C, Gl-HR3, Gl-HR4, Gl-E74, Gl-E75, Gl-Ftz-f1, and Gl-FOXO were expressed in all 10 tissues, with Gl-Br-C, Gl-E74, Gl-E75, and Gl-HR4 mRNA levels in the YO lower than those in most of the other tissues. In MLA animals, molting had no effect on Gl-Br-C, Gl-E74, and Gl-Ftz-f1 mRNA levels and little effect on Gl-EcR, Gl-E75, and Gl-HR4 mRNA levels. Gl-HR3 and Gl-FOXO mRNA levels were increased during premolt stages, while Gl-RXR mRNA level was highest during intermolt and premolt stages and lowest at postmolt stage. In ESA animals, YO mRNA levels were not correlated with hemolymph ecdysteroid titers. ESA had no effect on Gl-EcR, Gl-E74, Gl-HR3, Gl-HR4, Gl-Ftz-f1, and Gl-FOXO mRNA levels, while Gl-RXR, Gl-Br-C, and Gl-E75 mRNA levels were decreased at 3 days post-ESA. These data suggest that transcriptional up-regulation of Gl-FOXO and Gl-HR3 contributes to increased YO ecdysteroidogenesis during premolt. By contrast, transcriptional regulation of ecdysteroid responsive genes and ecdysteroidogenesis were uncoupled in the YO of ESA animals.
    Language English
    Publishing date 2024-05-16
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1851-x
    ISSN 1095-6840 ; 0016-6480
    ISSN (online) 1095-6840
    ISSN 0016-6480
    DOI 10.1016/j.ygcen.2024.114548
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: The role of ecdysteroid in the regulation of ovarian growth and oocyte maturation in Rhodnius prolixus, a vector of Chagas disease.

    Benrabaa, Samiha A M / Orchard, Ian / Lange, Angela B

    The Journal of experimental biology

    2022  Volume 225, Issue 21

    Abstract: Rhodnius prolixus is a blood-gorging insect that is medically important since it transmits Chagas disease via feces and urine that contain the parasite Trypanosoma cruzi. In adult females, ecdysteroid hormone (20-hydroxyecdysone, 20E) is involved in the ... ...

    Abstract Rhodnius prolixus is a blood-gorging insect that is medically important since it transmits Chagas disease via feces and urine that contain the parasite Trypanosoma cruzi. In adult females, ecdysteroid hormone (20-hydroxyecdysone, 20E) is involved in the growth of the ovary and development of eggs post-blood meal (PBM). Halloween genes are essential for ecdysteroid synthesis since they code for cytochrome P450 enzymes in the ecdysteroidogenic pathway. The ecdysone receptor (EcR/USP) binds 20E, resulting in activation of ecdysone-responsive genes. We have identified and characterized the Halloween genes, and the non-Halloween gene, neverland, in the R. prolixus ovary using transcriptomic data. We used BLAST to compare transcriptome sequences with other arthropod sequences to identify similar transcripts. Our results indicate that the Halloween genes, neverland and ecdysone receptor transcripts are present in the ovaries of R. prolixus. We have quantified, by qPCR, Halloween gene transcript expression in the ovary following a blood meal. Most of the Halloween genes are upregulated during the first 3 days PBM. Knockdown of EcR, USP and shade transcripts, using RNA interference, results in a significant reduction in the number of eggs produced and a severe reduction in egg laying and hatching rate. Furthermore, knockdown of the EcR or shade transcripts altered the expression of the chorion gene transcripts Rp30 and Rp45 at day 3 and 6 PBM. These results indicate that ecdysteroids play critical roles in reproduction of female R. prolixus.
    MeSH term(s) Animals ; Female ; Ecdysteroids/metabolism ; Rhodnius/genetics ; Ovary ; Chagas Disease/metabolism ; Oocytes/metabolism
    Chemical Substances Ecdysteroids
    Language English
    Publishing date 2022-11-11
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 218085-6
    ISSN 1477-9145 ; 0022-0949
    ISSN (online) 1477-9145
    ISSN 0022-0949
    DOI 10.1242/jeb.244830
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 2629: Show issues Location:
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  3. Article ; Online: Effects of molting on the expression of ecdysteroid biosynthesis genes in the Y-organ of the blackback land crab, Gecarcinus lateralis.

    Benrabaa, Samiha A M / Chang, Sharon A / Chang, Ernest S / Mykles, Donald L

    General and comparative endocrinology

    2023  Volume 340, Page(s) 114304

    Abstract: A pair of Y-organs (YOs) synthesize ecdysteroids that initiate and coordinate molting processes in decapod crustaceans. The YO converts cholesterol to secreted products through a biosynthetic pathway involving a Rieske oxygenase encoded by Neverland (Nvd) ...

    Abstract A pair of Y-organs (YOs) synthesize ecdysteroids that initiate and coordinate molting processes in decapod crustaceans. The YO converts cholesterol to secreted products through a biosynthetic pathway involving a Rieske oxygenase encoded by Neverland (Nvd) and cytochrome P450 monooxygenases encoded by Halloween genes Spook (Spo; Cyp307a1), Phantom (Phm; Cyp306a1), Disembodied (Dib; Cyp302a1), and Shadow (Sad; Cyp315a1). NAD kinase (NADK) and 5-aminolevulinic acid synthase (ALAS) support ecdysteroid synthesis in insects. A 20-hydroxylase, encoded by Shed in decapods and Shade in insects, converts ecdysone to the active hormone 20-hydroxyecdysone (20E). 20E is inactivated by cytochrome P450 26-hydroxylase (Cyp18a1). Contigs encoding these eight proteins were extracted from a Gecarcinus lateralis YO transcriptome and their expression was quantified by quantitative polymerase chain reaction. mRNA levels of Gl-Spo and Gl-Phm were four orders of magnitude higher in YO than those in nine other tissues, while mRNA levels of Gl-NADK and Gl-ALAS were similar in all ten tissues. In G. lateralis induced to molt by multiple leg autotomy, YO mRNA levels of Gl-Nvd, Gl-Spo, Gl-Phm, Gl-NADK, and Gl-ALAS were highest in intermolt and premolt stages and lower in postmolt. Gl-Dib mRNA level was not affected by molt stage. mRNA level of Gl-Sad, which converts 2-deoxyecdysone to ecdysone, was higher in mid- and late premolt stages, when YO ecdysteroidogenic capacity is greatest. Gl-Cyp18a1 mRNA level was highest in intermolt, decreased in premolt stages, and was lowest in postmolt. In animals induced to molt by eyestalk ablation, YO mRNA levels of all eight genes were not correlated with increased hemolymph 20E titers. These results suggest that YO ecdysteroidogenic genes are differentially regulated at transcriptional and translational levels.
    MeSH term(s) Animals ; Brachyura/genetics ; Brachyura/metabolism ; Signal Transduction/genetics ; Ecdysteroids/metabolism ; Molting/genetics ; Ecdysone ; RNA, Messenger/metabolism
    Chemical Substances Ecdysteroids ; Ecdysone (3604-87-3) ; RNA, Messenger
    Language English
    Publishing date 2023-04-29
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1851-x
    ISSN 1095-6840 ; 0016-6480
    ISSN (online) 1095-6840
    ISSN 0016-6480
    DOI 10.1016/j.ygcen.2023.114304
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

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    ab Jg. 2022: Lesesaal (EG)

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  4. Article ; Online: Effects of mating on female reproductive physiology in the insect model, Rhodnius prolixus, a vector of the causative parasite of Chagas disease.

    Leyria, Jimena / Guarneri, Alessandra A / Lorenzo, Marcelo G / Nouzova, Marcela / Noriega, Fernando G / Benrabaa, Samiha A M / Fernandez-Lima, Francisco / Valadares Tose, Lilian / Orchard, Ian / Lange, Angela B

    PLoS neglected tropical diseases

    2023  Volume 17, Issue 9, Page(s) e0011640

    Abstract: The blood-sucking hemipteran Rhodnius prolixus is one of the main vectors of Chagas disease, a neglected tropical disease that affects several million people worldwide. Consuming a blood meal and mating are events with a high epidemiological impact since ...

    Abstract The blood-sucking hemipteran Rhodnius prolixus is one of the main vectors of Chagas disease, a neglected tropical disease that affects several million people worldwide. Consuming a blood meal and mating are events with a high epidemiological impact since after each meal, mated females can lay fertile eggs that result in hundreds of offspring. Thus, a better knowledge of the control of R. prolixus reproductive capacity may provide targets for developing novel strategies to control vector populations, thereby reducing vector-host contacts and disease transmission. Here, we have used a combination of gene transcript expression analysis, biochemical assays, hormone measurements and studies of locomotory activity to investigate how mating influences egg development and egg laying rates in R. prolixus females. The results demonstrate that a blood meal increases egg production capacity and leads to earlier egg laying in mated females compared to virgins. Virgin females, however, have increased survival rate over mated females. Circulating juvenile hormone (JH) and ecdysteroid titers are increased in mated females, a process mainly driven through an upregulation of the transcripts for their biosynthetic enzymes in the corpus allatum and ovaries, respectively. Mated females display weaker locomotory activity compared to virgin females, mainly during the photophase. In essence, this study shows how reproductive output and behaviour are profoundly influenced by mating, highlighting molecular, biochemical, endocrine and behavioral features differentially expressed in mated and virgin R. prolixus females.
    MeSH term(s) Animals ; Female ; Humans ; Rhodnius/physiology ; Parasites ; Chagas Disease ; Reproduction ; Oviposition/physiology
    Language English
    Publishing date 2023-09-20
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2429704-5
    ISSN 1935-2735 ; 1935-2735
    ISSN (online) 1935-2735
    ISSN 1935-2735
    DOI 10.1371/journal.pntd.0011640
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Characterization of Shed genes encoding ecdysone 20-monooxygenase (CYP314A1) in the Y-organ of the blackback land crab, Gecarcinus lateralis.

    Swall, Madeleine E / Benrabaa, Samiha A M / Tran, Nhut M / Tran, Trong D / Ventura, Tomer / Mykles, Donald L

    General and comparative endocrinology

    2020  Volume 301, Page(s) 113658

    Abstract: Molting in decapod crustaceans is controlled by ecdysteroid hormones synthesized and secreted by the molting gland, or Y-organ (YO). Halloween genes encode cytochrome P450 enzymes in the ecdysteroid synthetic pathway. The current paradigm is that YOs ... ...

    Abstract Molting in decapod crustaceans is controlled by ecdysteroid hormones synthesized and secreted by the molting gland, or Y-organ (YO). Halloween genes encode cytochrome P450 enzymes in the ecdysteroid synthetic pathway. The current paradigm is that YOs secrete an inactive precursor (e.g., ecdysone or E), which is hydroxylated at the #20 carbon to form an active hormone (20-hydroxyecdysone or 20E) by a mitochonrial 20-monooxygenase (CYP314A1) in peripheral tissues. 20-Monooxygenase is encoded by Shed in decapods and Shade in insects. We used eastern spiny lobster Shed sequences to extract six orthologs in the G. lateralis YO transcriptome. Phylogenetic analysis of the deduced amino acid sequences from six decapod species organized the Sheds into seven classes (Sheds 1-7), resulting in the assignment of the G. lateralis Sheds to Gl-Shed1, 2, 4A, 4B, 5A, and 5B. The mRNA levels of the six Gl-Sheds in the YO of intermolt animals were comparable to those in nine other tissues that included hepatopancreas and muscle. qPCR was used to compare the effects of molt induction by multiple leg autotomy (MLA) and eyestalk ablation (ESA) on Gl-Shed mRNA levels in the YO. Molt stage had little effect on Gl-Shed1 and Gl-Shed5B expression in the YO of MLA animals. Gl-Shed5A was expressed at the highest mRNA levels in the YO and was significantly increased during early and mid premolt stages. By contrast, ESA ± SB431542 had no effect on Gl-Shed expression at 1, 3, 5, and 7 days post-ESA. SB431542, which inhibits Transforming Growth Factor-β/activin signaling and blocks YO commitment, decreased Gl-Shed2 and Gl-Shed4A mRNA levels at 14 days post-ESA. A targeted metabolomic analysis showed that YOs cultured in vitro secreted E and 20E to the medium. These data suggest that the YO expresses 20-monooygenases that can convert E to 20E, which may contribute to the increase in active hormone in the hemolymph during premolt.
    MeSH term(s) Animals ; Aryl Hydrocarbon Hydroxylases ; Brachyura/genetics ; Ecdysone ; Ecdysteroids ; Molting/genetics ; Phylogeny ; Steroid Hydroxylases
    Chemical Substances Ecdysteroids ; Ecdysone (3604-87-3) ; Steroid Hydroxylases (EC 1.14.-) ; Aryl Hydrocarbon Hydroxylases (EC 1.14.14.1) ; ecdysone 20-hydroxylase (EC 1.14.99.22)
    Language English
    Publishing date 2020-11-05
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 1851-x
    ISSN 1095-6840 ; 0016-6480
    ISSN (online) 1095-6840
    ISSN 0016-6480
    DOI 10.1016/j.ygcen.2020.113658
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 164: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
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  6. Article ; Online: Effects of temperature on survival, moulting, and expression of neuropeptide and mTOR signalling genes in juvenile Dungeness crab (

    Wittmann, Astrid C / Benrabaa, Samiha A M / López-Cerón, Diego Alejandro / Chang, Ernest S / Mykles, Donald L

    The Journal of experimental biology

    2018  Volume 221, Issue Pt 21

    Abstract: Mechanistic target of rapamymcin (mTOR) is a highly conserved protein kinase that controls cellular protein synthesis and energy homeostasis. We hypothesize that mTOR integrates intrinsic signals (moulting hormones) and extrinsic signals (thermal stress) ...

    Abstract Mechanistic target of rapamymcin (mTOR) is a highly conserved protein kinase that controls cellular protein synthesis and energy homeostasis. We hypothesize that mTOR integrates intrinsic signals (moulting hormones) and extrinsic signals (thermal stress) to regulate moulting and growth in decapod crustaceans. The effects of temperature on survival, moulting and mRNA levels of mTOR signalling genes (
    MeSH term(s) Animals ; Arthropod Proteins/genetics ; Arthropod Proteins/metabolism ; Brachyura/genetics ; Brachyura/physiology ; Cold Temperature ; Gene Expression Regulation/physiology ; Hot Temperature ; Longevity/physiology ; Molting/physiology ; Neuropeptides/genetics ; Neuropeptides/metabolism ; TOR Serine-Threonine Kinases/genetics ; TOR Serine-Threonine Kinases/metabolism
    Chemical Substances Arthropod Proteins ; Neuropeptides ; TOR Serine-Threonine Kinases (EC 2.7.1.1)
    Language English
    Publishing date 2018-11-05
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 218085-6
    ISSN 1477-9145 ; 0022-0949
    ISSN (online) 1477-9145
    ISSN 0022-0949
    DOI 10.1242/jeb.187492
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 2629: Show issues Location:
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    ab Jg. 2022: Lesesaal (EG)

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