scholarly journals CRISP1 as a novel CatSper regulator that modulates sperm motility and orientation during fertilization

2015 ◽  
Vol 210 (7) ◽  
pp. 1213-1224 ◽  
Author(s):  
Juan I. Ernesto ◽  
Mariana Weigel Muñoz ◽  
María A. Battistone ◽  
Gustavo Vasen ◽  
Pablo Martínez-López ◽  
...  
Keyword(s):  
Sperm Motility ◽  
Critical Role ◽  
Cumulus Cells ◽  
Fine Tuning ◽  
Patch Clamping ◽  
Successful Completion ◽  
Tuning Mechanism ◽  
Mammalian Fertilization ◽  
Ca2 Channels

Ca2+-dependent mechanisms are critical for successful completion of fertilization. Here, we demonstrate that CRISP1, a sperm protein involved in mammalian fertilization, is also present in the female gamete and capable of modulating key sperm Ca2+ channels. Specifically, we show that CRISP1 is expressed by the cumulus cells that surround the egg and that fertilization of cumulus–oocyte complexes from CRISP1 knockout females is impaired because of a failure of sperm to penetrate the cumulus. We provide evidence that CRISP1 stimulates sperm orientation by modulating sperm hyperactivation, a vigorous motility required for penetration of the egg vestments. Moreover, patch clamping of sperm revealed that CRISP1 has the ability to regulate CatSper, the principal sperm Ca2+ channel involved in hyperactivation and essential for fertility. Given the critical role of Ca2+ for sperm motility, we propose a novel CRISP1-mediated fine-tuning mechanism to regulate sperm hyperactivation and orientation for successful penetration of the cumulus during fertilization.

scholarly journals PACAP-mediated sperm–cumulus cell interaction promotes fertilization

Reproduction ◽  
2011 ◽  
Vol 141 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Ichiro Tanii ◽  
Tadashi Aradate ◽  
Kouhei Matsuda ◽  
Akira Komiya ◽  
Hideki Fuse
Keyword(s):  
Sperm Motility ◽  
Acrosome Reaction ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Cell Interaction ◽  
Fertilization Rate ◽  
Type I ◽  
Dependent Manner ◽  
Sperm Penetration

The developing acrosome in spermatids contains pituitary adenylate cyclase-activating polypeptide (PACAP). However, the role of the acrosomal PACAP remains unclear because it has not been detected in mature spermatids and sperm. We reinvestigated whether the sperm acrosome contains PACAP. An antiserum produced against PACAP reacted to the anterior acrosome in epididymal sperm fixed under mild conditions, suggesting that PACAP acts on oocytes and/or cumulus cells at the site of fertilization. Immunolabeling and RT-PCR demonstrated the presence of PACAP type I receptor, a PACAP-specific receptor, in postovulatory cumulus cells. To investigate the role of PACAP in fertilization, we pretreated cumulus–oocyte complexes with the polypeptide. At a low concentration of sperm, the fertilization rate was significantly enhanced by PACAP in a dose-dependent manner. Sperm penetration through the oocyte investment, cumulus layer, and zona pellucida was also enhanced by PACAP. The enhancement was probably due to an enhancement in sperm motility and the zona-induced acrosome reaction, which were stimulated by a cumulus cell-releasing factor. Indeed, PACAP treatment increased the secretion of progesterone from the cumulus–oocyte complexes. These results strongly suggest that in response to PACAP, cumulus cells release a soluble factor that probably stimulates sperm motility and the acrosome reaction, thereby promoting fertilization.

scholarly journals Dual roles for the Drosophila PI 4-kinase Four wheel drive in localizing Rab11 during cytokinesis

2009 ◽  
Vol 187 (6) ◽  
pp. 847-858 ◽  
Author(s):  
Gordon Polevoy ◽  
Ho-Chun Wei ◽  
Raymond Wong ◽  
Zsofia Szentpetery ◽  
Yeun Ju Kim ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Critical Role ◽  
Successful Completion ◽  
Dual Roles ◽  
Recycling Endosome ◽  
Golgi Membranes ◽  
Wheel Drive ◽  
Dividing Cells ◽  
Four Wheel Drive

Successful completion of cytokinesis relies on addition of new membrane, and requires the recycling endosome regulator Rab11, which localizes to the midzone. Despite the critical role of Rab11 in this process, little is known about the formation and composition of Rab11-containing organelles. Here, we identify the phosphatidylinositol (PI) 4-kinase III β Four wheel drive (Fwd) as a key regulator of Rab11 during cytokinesis in Drosophila melanogaster spermatocytes. We show Fwd is required for synthesis of PI 4-phosphate (PI4P) on Golgi membranes and for formation of PI4P-containing secretory organelles that localize to the midzone. Fwd binds and colocalizes with Rab11 on Golgi membranes, and is required for localization of Rab11 in dividing cells. A kinase-dead version of Fwd also binds Rab11 and partially restores cytokinesis to fwd mutant flies. Moreover, activated Rab11 partially suppresses loss of fwd. Our data suggest Fwd plays catalytic and noncatalytic roles in regulating Rab11 during cytokinesis.

Functional analysis of the SUMOylation pathway in Drosophila

2008 ◽  
Vol 36 (5) ◽  
pp. 868-873 ◽  
Author(s):  
Ana Talamillo ◽  
Jonatan Sánchez ◽  
Rosa Barrio
Keyword(s):  
Functional Analysis ◽  
Fine Tuning ◽  
Model Systems ◽  
Post Translational Modification ◽  
Reversible Process ◽  
Cellular Processes ◽  
Tuning Mechanism ◽  
Sumo Conjugation

SUMOylation, a reversible process used as a ‘fine-tuning’ mechanism to regulate the role of multiple proteins, is conserved throughout evolution. This post-translational modification affects several cellular processes by the modulation of subcellular localization, activity or stability of a variety of substrates. A growing number of proteins have been identified as targets for SUMOylation, although, for many of them, the role of SUMO conjugation on their function is unknown. The use of model systems might facilitate the study of SUMOylation implications in vivo. In the present paper, we have compiled what is known about SUMOylation in Drosophila melanogaster, where the use of genetics provides new insights on SUMOylation's biological roles.

AMPK mediates regulation of voltage-gated calcium channels by leptin in isolated neurons from arcuate nucleus

2020 ◽  
Vol 319 (6) ◽  
pp. E1112-E1120
Author(s):  
K. Bermeo ◽  
H. Castro ◽  
I. Arenas ◽  
D. E. Garcia
Keyword(s):  
Energy Balance ◽  
Calcium Current ◽  
Arcuate Nucleus ◽  
Critical Role ◽  
Fine Tuning ◽  
Isolated Neurons ◽  
Voltage Gated ◽  
Voltage Gated Calcium Channels ◽  
General Energy

Our results readily support the hypothesis that AMPK is responsible for the maintenance of the calcium current and mediates the fine-tuning modulation of the leptin response. The novelty of these results strengthens the critical role of AMPK in the general energy balance and homeostasis.

176 REGULATORY ROLE OF miR-20a DURING BOVINE OOCYTE MATURATION

2017 ◽  
Vol 29 (1) ◽  
pp. 196 ◽  
Author(s):  
E. Andreas ◽  
D. Salilew-Wondim ◽  
F. Rings ◽  
E. Held ◽  
M. Hoelker ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Expression Analysis ◽  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Fine Tuning ◽  
Bovine Oocyte ◽  
Total Rna ◽  
Progesterone Synthesis ◽  
Spent Media

The role of microRNA in oocyte maturation is mostly associated with optimal turnover of the accumulated maternal transcripts during their growth to allow maturation. MiR-20a is a member of the miR-17–92 cluster, which has been found to be differentially expressed in bovine granulosa cells derived from preovulatory dominant and subordinate follicles. Our recent study showed that miR-20a is involved in the regulation of granulosa cell proliferation, differentiation, and progesterone synthesis by targeting PTEN and BMPR2 genes. Here, we aimed to investigate the role of miR-20a in the bovine oocyte maturation processes. For this, cumulus-oocyte complexes (COC) were aspirated from small antral follicles (2–8 mm in diameter) and cultured in groups of 50 in 400 µL of maturation media (TCM-199 media supplemented with 12% oestrus cow serum and 10 µg/ml Follitropin®) at 39°C in a humidified atmosphere with 5% (vol/vol) CO2 in the air for 22 h. The cumulus cells and oocytes before (germinal vesicle) and after maturation (metaphase II) were mechanically separated in 0.1% hyaluronidase (in TCM-199 media). To study whether the presence of cumulus cells or oocyte has an impact on the miR-20a expression, we cultured oocytectomized cumulus cells and oocytes with and without their companion cells. Moreover, COC were co-cultured with miR-20a mimic, inhibitor, or corresponding controls to investigate the role of this miRNA in oocyte maturation. The total RNA from cumulus cells and oocytes was extracted using miRNeasy® mini kit (Qiagen GmbH, Hilden, Germany). Total RNA from respective samples was reverse transcribed for mRNA and microRNA expression analysis. Quantitative expression analysis was performed using StepOnePlus™ System (Applied Biosystems, Foster City, CA, USA) and subsequent data were analysed using a comparative cycle threshold method. The progesterone released in the spent media was measured using progesterone enzyme-linked immunosorbent assay kit (ENZO Life Sciences GmbH, Loerrach, Germany). Here, we found that miR-20a expression in cumulus cells increased (P < 0.05) during oocyte maturation. Conversely, miR-20a expression in metaphase II stage oocytes was significantly lower (P < 0.001) compared with the germinal vesicle stage. The absence of oocyte cytoplasm resulted in reduced miR-20a expression in cumulus cells. On the other hand, the absent of cumulus cells increased miR-20a expression in oocytes. The miR-20a expression revealed that the microRNA transduction is restricted in the cumulus cells. The overexpression of miR-20a increased oocyte maturation rate (P < 0.05) by 4.8% (as determined by extrusion of the polar body) and the expression of oocyte maturation-related genes (INHBA, MAPK1, PTGS2, PTX3, and EGFR). The progesterone released in spent media of COC co-cultured with miR-20a mimic and inhibitor showed increasing (P = 0.0936) and decreasing (P = 0.0993) trends, respectively. In this study, we also found that miR-20a modulation altered the expression of PTEN and BMPR2 in cumulus cells. In conclusion, the modulation of miR-20a expression in cumulus cells regulates the oocyte maturation and partially involved in the progesterone synthesis by fine-tuning the expression of PTEN and BMPR2 genes.

Role of vision throughout the flight initiation sequence of the Colorado potato beetle

2005 ◽  
Vol 137 (4) ◽  
pp. 420-427
Author(s):  
Gilles Boiteau
Keyword(s):  
Colorado Potato Beetle ◽  
Leptinotarsa Decemlineata ◽  
Critical Role ◽  
Successful Completion ◽  
Flight Chamber ◽  
Potato Beetle ◽  
Key Factor ◽  
Initiation Sequence ◽  
Flight Initiation

AbstractThe role of vision in the flight initiation sequence of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), was assessed by comparing the behavioral sequences and frequencies of takeoffs of untethered and tethered beetles with and without vision. Results showed that vision plays a critical role in the successful completion of the launch and the maintenance of lift for the adult Colorado potato beetle. The sequence was interrupted immediately before or during the lifting of the mesothoracic legs or before the launch for most blind beetles. Liftoffs of untethered beetles over a 1-h period in a flight chamber were reduced significantly, by 77%, in blind beetles compared with normal beetles. In addition, the preponderance of upward (dispersal) flights following successful liftoffs of normal beetles was replaced by a preponderance of downward (short) flights for blind beetles. Blind beetles that did not have to launch themselves because they were tethered initiated flight as frequently as tethered normal Colorado potato beetles. The duration and repeatability of flights initiated by tethered blind Colorado potato beetles were also similar to those of flights initiated by tethered normal Colorado potato beetles in a stationary environment. Together, the results of the tests with untethered and tethered beetles indicate that vision is a key factor during flight launching and for flight continuation.

scholarly journals SH2-B Is Required for Both Male and Female Reproduction

2002 ◽  
Vol 22 (9) ◽  
pp. 3066-3077 ◽  
Author(s):  
Satoshi Ohtsuka ◽  
Satoshi Takaki ◽  
Masanori Iseki ◽  
Kanta Miyoshi ◽  
Naomi Nakagata ◽  
...  
Keyword(s):  
Growth Factors ◽  
Follicle Stimulating Hormone ◽  
Critical Role ◽  
Cumulus Cells ◽  
Female Reproduction ◽  
Targeted Disruption ◽  
Male And Female ◽  
Factor I ◽  
Igf I

ABSTRACT Many growth factors and hormones modulate the reproductive status in mammals. Among these, insulin and insulin-like growth factor I (IGF-I) regulate the development of gonadal tissues. SH2-B has been shown to interact with insulin and IGF-I receptors, although the role of SH2-B in these signals has not been clarified. To investigate the role of SH2-B, we generated mice with a targeted disruption of the SH2-B gene. Both male and female SH2-B−/− mice showed slight retardation in growth and impaired fertility. Female knockout mice possess small, anovulatory ovaries with reduced numbers of follicles and male SH2-B−/− mice have small testes with a reduced number of sperm. SH2-B−/− cumulus cells do not respond to either follicle-stimulating hormone or IGF-I. These data suggest that SH2-B plays a critical role in the IGF-I-mediated reproductive pathway in mice.

scholarly journals Brucella abortus and Pregnancy in Mice: Impact of Chronic Infection on Fertility and the Role of Regulatory T Cells in Tissue Colonization

2020 ◽  
Vol 88 (10) ◽  
Author(s):  
Shakirat A. Adetunji ◽  
Denise L. Faustman ◽  
L. Garry Adams ◽  
Daniel G. Garcia-Gonzalez ◽  
Martha E. Hensel ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Brucella Abortus ◽  
Chronic Infection ◽  
Bacterial Infections ◽  
Bacterial Pathogens ◽  
Critical Role ◽  
Fine Tuning ◽  
Content Type

ABSTRACT Stealthy intracellular bacterial pathogens are known to establish persistent and sometimes lifelong infections. Some of these pathogens also have a tropism for the reproductive system, thereby increasing the risk of reproductive disease and infertility. To date, the pathogenic mechanism involved remains poorly understood. Here, we demonstrate that Brucella abortus, a notorious reproductive pathogen, has the ability to infect the nonpregnant uterus, sustain infection, and induce inflammatory changes during both acute and chronic stages of infection. In addition, we demonstrated that chronically infected mice had a significantly reduced number of pregnancies compared to naive controls. To investigate the immunologic mechanism responsible for uterine tropism, we explored the role of regulatory T cells (Tregs) in the pathogenesis of Brucella abortus infection. We show that highly suppressive CD4+FOXP3+TNFR2+ Tregs contribute to the persistence of Brucella abortus infection and that inactivation of Tregs with tumor necrosis factor receptor II (TNFR2) antagonistic antibody protected mice by significantly reducing bacterial burden both systemically and within reproductive tissues. These findings support a critical role of Tregs in the pathogenesis of persistence induced by intracellular bacterial pathogens, including B. abortus. Results from this study indicate that adverse reproductive outcomes can occur as sequelae of chronic infection in nonpregnant animals and that fine-tuning Treg activity may provide novel immunotherapeutic and prevention strategies against intracellular bacterial infections such as brucellosis.

scholarly journals A critical role of solute carrier 22a14 in sperm motility and male fertility in mice

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Shin-ya Maruyama ◽  
Momoe Ito ◽  
Yuusuke Ikami ◽  
Yu Okitsu ◽  
Chizuru Ito ◽  
...  
Keyword(s):  
Sperm Motility ◽  
Male Fertility ◽  
Critical Role ◽  
Solute Carrier

Relationship between DNA fragmentation and nuclear status of in vitro-matured porcine oocytes: role of cumulus cells

2004 ◽  
Vol 16 (8) ◽  
pp. 773 ◽  
Author(s):  
Pimprapar Wongsrikeao ◽  
Takeshige Otoi ◽  
Masako Murakami ◽  
Ni Wayan Kurniani Karja ◽  
Agung Budiyanto ◽  
...  
Keyword(s):  
Dna Fragmentation ◽  
Critical Role ◽  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Fresh Medium ◽  
Tunel Method ◽  
Maturation Rate ◽  
Total Proportion

The present study was conducted to investigate the effects of the attachment of cumulus cells to oocytes and coculture with cumulus cells during maturation culture on the nuclear status and DNA fragmentation of porcine denuded oocytes (DOs). In the first experiment, cumulus cells were removed from cumulus–oocyte complexes (COCs) at 0, 8, 16, 24 or 32 h after the onset of maturation culture and the DOs were then cultured in their original droplets until 42 h of culture was reached. In the second experiment, all COCs were denuded before the onset of culture and the DOs were cocultured with their removed cumulus cells. The DOs were transferred into fresh medium at 0, 8, 16, 24 or 32 h after the onset of coculture with cumulus cells and then cultured until 42 h of culture was reached. After culture, DNA fragmentation and the nuclear status of oocytes were examined using the terminal deoxyribonucleotidyl transferase-mediated dUTP–digoxigenin nick end-labelling (TUNEL) method. When the DOs were returned to the same droplets after removal of the cumulus cells, the removal of the cumulus cells after 16 h of culture significantly decreased the proportion of oocytes remaining at the germinal vesicle (GV) stage. However, coculture treatment of DOs in the presence of their removed cumulus cells had no significant effects on the GV breakdown (GVBD) of oocytes. There were no significant differences in the proportion maturing to MII oocytes among the groups following removal of cumulus cells after the onset of maturation culture; however, DOs cocultured with cumulus cells until the end of maturation culture exhibited an increased maturation rate compared with DOs cocultured for 8 and 16 h. The total proportion of TUNEL-positive oocytes of oocytes remaining at the GV stage was higher than that of oocytes reaching other stages, irrespective of the removal of cumulus cells and coculture treatments. However, coculture for more than 16 h decreased the total proportion of TUNEL-positive oocytes. Our results indicate that the attachment of cumulus cells to oocytes may have a critical role for oocytes undergoing GVBD and that coculture with cumulus cells promotes the ability of oocytes to complete maturation. Moreover, coculture with cumulus cells may assist the oocyte to avoid undergoing DNA fragmentation.

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