The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Angela B. Lange - One of the best experts on this subject based on the ideXlab platform.
-
myoinhibitors controlling Oviduct contraction within the female blood gorging insect rhodnius prolixus
General and Comparative Endocrinology, 2015Co-Authors: Laura Sedra, Amir Haddad, Angela B. LangeAbstract:Abstract Muscle activity can be regulated by stimulatory and inhibitory neuropeptides allowing for contraction and relaxation. There are various families of neuropeptides that can be classified as inhibitors of insect muscle contraction. This study focuses on Rhodnius prolixus and three neuropeptide families that have been shown to be myoinhibitors in insects: A-type allatostatins, myoinhibiting peptides (B-type allatostatins) and myosuppressins. FGLa/AST-like immunoreactive axons and blebs were found on the anterior of the dorsal vessel and on the abdominal nerves. FGLa/AST-like immunoreactive axons were also seen in the trunk nerves and on the bursa. The effects of RhoprAST-2 (FGLa/AST or A-type allatostatins) and RhoprMIP-4 (MIP/AST or B-type allatostatins) were similar, producing dose-dependent inhibition of R. prolixus spontaneous Oviduct contractions with a maximum of 70% inhibition and an EC 50 at approximately 10 −8 M. The myosuppressin of R. prolixus (RhoprMS) has an unusual FMRFamide C -terminal motif (pQDIDHVFMRFa) as compared to myosuppressins from other insects. Quantitative PCR results show that the RhoprMS receptor transcript is present in adult female Oviducts; however, RhoprMS does not have an inhibitory effect on R. prolixus Oviduct contractions, but does have a dose-dependent inhibitory effect on the spontaneous contraction of Locusta migratoria Oviducts. SchistoFLRFamide, the myosuppressin of Schistocerca gregaria and L. migratoria , also does not inhibit R. prolixus Oviduct contractions. This implies that FGLa/ASTs and MIP/ASTs may play a role in regulating egg movement within the Oviducts, and that the myosuppressin although myoinhibitory on other muscles in R. prolixus , does not inhibit the contractions of R. prolixus Oviducts and may play another role in the reproductive system.
-
octopamine modulates a central pattern generator associated with egg laying in the locust locusta migratoria
Journal of Insect Physiology, 2014Co-Authors: Raymond Wong, Angela B. LangeAbstract:Egg-laying in Locusta migratoria involves the control of a variety of complex behavioural patterns including those that regulate digging of the oviposition hole and retention of eggs during digging. These two behavioural patterns are under the control of central pattern generators (CPGs). The digging and egg-retention CPGs are coordinated and integrated with overlapping locations of neural substrate within the VIIth and VIIIth abdominal ganglia of the central nervous system (CNS). In fact, the egg-retention CPG of the VIIth abdominal ganglion is involved in both egg-retention and protraction of the abdomen during digging. The biogenic amine, octopamine, has peripheral effects on Oviduct muscle, relaxing basal tension of the lateral and upper common Oviduct and enabling egg passage. Here we show that octopamine also modulates the pattern of the egg-retention CPG by altering the motor pattern that controls the external ventral protractor of the VIIth abdominal segment. There is no change in the motor pattern that goes to the Oviducts. Octopamine decreased the frequency of the largest amplitude action potential and decreased burst duration while leading to an increase in cycle duration and interburst interval. The effects of octopamine were greatly reduced in the presence of the α-adrenergic blocker, phentolamine, indicating that the action of octopamine was via a receptor. Thus, octopamine orchestrates events that can lead to oviposition, centrally inhibiting the digging behavior and peripherally relaxing the lateral and common Oviducts to enable egg-laying.
-
the female reproductive system of the kissing bug rhodnius prolixus arrangements of muscles distribution and myoactivity of two endogenous fmrfamide like peptides
Peptides, 2014Co-Authors: Laura Sedra, Angela B. LangeAbstract:Phalloidin staining F-actin was used to image muscle fiber arrangements present in the reproductive system of the adult female Rhodnius prolixus. A mesh of muscle fibers encircles the ovaries whereas a criss-cross pattern of finer muscle fibers covers each ovariole. Two layers of muscle fibers (arranged longitudinally and circularly) form the lateral Oviducts. The circular layer of muscle fibers extends throughout the common Oviduct and spermathecae. A chevron pattern of thicker muscle fibers makes up the bursa. All of these structures show spontaneous contractions that are stimulated in a dose-dependent manner by the endogenous peptides, GNDNFMRFamide and AKDNFIRFamide which belong to the family of the FMRFamide-like peptides (FLP). Immunohistochemistry shows that these peptides could be supplied via nerves to the Oviducts, spermathecae and bursa. Although no FMRF-like immunoreactivity was observed on the ovarioles/ovary they still exhibited a stimulatory response to the peptides indicating that they may be under the influence of FLPs as neurohormones. This work implicates FLPs in the control of ovulation, egg movement and oviposition in this insect.
-
the female reproductive system and control of oviposition in locusta migratoria migratorioides
Canadian Journal of Zoology, 2009Co-Authors: Angela B. LangeAbstract:The spermatheca acts as a repository for sperm deposited by the male and, in the African migratory locust (Locusta migratoria migratorioides (Fairmaire and Reiche, 1849)), is situated dorsal to the lateral and common Oviducts. In the locust, eggs mature in the ovaries and are ovulated into the lateral Oviducts where they are held until a suitable oviposition site is found. At that time, a hole is dug in the soil by the locust and, aided by muscular contractions of the upper lateral Oviducts, the eggs are propelled through the common Oviduct and genital chamber and deposited in a pod in the soil. Contractions of the spermathecal sac lead to sperm release, resulting in fertilization of eggs in the genital chamber. Coordination of digging and of the Oviducts and spermatheca is clearly critical to the production of viable eggs. The muscles responsible for digging and both reproductive structures are under central neuronal control, incorporating neurons that express an array of neuropeptide and amine phenotype...
-
crustacean cardioactive peptide is a modulator of Oviduct contractions in locusta migratoria
Journal of Insect Physiology, 2001Co-Authors: Andrew Donini, Hansjurgen Agricola, Angela B. LangeAbstract:Crustacean cardioactive peptide (CCAP) stimulates the contractions of locust Oviducts. CCAP increased the basal tonus and increased the frequency and amplitude of phasic contractions, as well as the amplitude of neurally-evoked Oviduct contractions in a dose-dependent manner. Oviducts from Vth instar larvae and adult locusts aged 10 days or less, were more sensitive to CCAP than Oviducts from adult locusts aged 12 days or more. This may be indicative of a differential expression of number or subtypes of CCAP receptors on the Oviducts at different ages, and may be related to reproductive functions or to functions of CCAP on the Oviducts during ecdysis. The Oviducts appear more sensitive to CCAP when compared with previously published reports of CCAP actions on the hindgut. CCAP actions on the amplitude of neurally-evoked contractions of the Oviducts are similar to those of proctolin, however, the Oviducts are more sensitive to CCAP. No CCAP-like immunoreactive structures were discovered in the nerves innervating the Oviducts, or on the Oviducts themselves, confirming the previously published suggestion (Dircksen et al., 1991) that CCAP acts as a neurohormone at the Oviducts. Cells showing CCAP-like immunoreactivity were discovered in the fat body associated with the Oviducts and represent a potential source of CCAP, along with CCAP released from the transverse nerve and perivisceral organs.
Sabine Kölle - One of the best experts on this subject based on the ideXlab platform.
-
bovine sperm Oviduct interactions are characterized by specific sperm behaviour ultrastructure and tubal reactions which are impacted by sex sorting
Scientific Reports, 2020Co-Authors: Miguel Camara Pirez, Sven Reese, Heather Steele, Sabine KölleAbstract:To date sperm-Oviduct interactions have largely been investigated under in vitro conditions. Therefore we set out to characterize the behaviour of bovine spermatozoa within the sperm reservoir under near in vivo conditions and in real-time using a novel live cell imaging technology and a newly established fluorescent sperm binding assay. Sperm structure and tubal reactions after sperm binding were analysed using scanning and transmission electron microscopy and histochemistry. As a model to specify the impact of stress on sperm-Oviduct interactions, frozen-thawed conventional and sex-sorted spermatozoa from the same bulls (n = 7) were co-incubated with Oviducts obtained from cows immediately after slaughter. Our studies revealed that within the Oviductal sperm reservoir agile (bound at a tangential angle of about 30°, actively beating undulating tail), lagging (bound at a lower angle, reduced tail movement), immotile (absence of tail movement) and hyperactivated (whip-like movement of tail) spermatozoa occur, the prevalence of which changes in a time-dependent pattern. After formation of the sperm reservoir, tubal ciliary beat frequency is significantly increased (p = 0.022) and the epithelial cells show increased activity of endoplasmic reticula. After sex sorting, spermatozoa occasionally display abnormal movement patterns characterized by a 360° rotating head and tail. Sperm binding in the Oviduct is significantly reduced (p = 0.008) following sexing. Sex-sorted spermatozoa reveal deformations in the head, sharp bends in the tail and a significantly increased prevalence of damaged mitochondria (p < 0.001). Our results imply that the Oviductal cells specifically react to the binding of spermatozoa, maintaining sperm survival within the tubal reservoir. The sex-sorting process, which is associated with mechanical, chemical and time stress, impacts sperm binding to the Oviduct and mitochondrial integrity affecting sperm motility and function.
-
5 transport and cholinergic innervation in the bovine Oviduct are dysregulated in cystic ovary disease
Reproduction Fertility and Development, 2020Co-Authors: Deidre Scully, D. P. Campion, Fiona Mccartney, Sven Reese, Sabine KölleAbstract:Cystic ovary disease (COD) is one of the most common causes of bovine infertility and affects 7-14% of cows in European herds. The morphological and molecular causes of this disease are largely unknown. Because the Oviduct is pivotal to gamete transport, fertilization, and early embryonic development, the aim of this study was to analyse the effects of COD on the function of the Oviduct. Oviducts were excised from cows affected by COD (n = 29) as well as from healthy cows in mid diestrus (n = 20) immediately after slaughter. A unique digital live cell imaging system established in our laboratory was used to capture real-time videos of ciliary beat and tubal fluid flow under near in vivo conditions. For ciliary beat frequency, the differences in grayscale of beating cilia were transformed into frequencies using ImageJ (National Institutes for Health) and AutoSignal (SyStat Software Inc.). For particle transport speed (PTS), polystyrene beads were added to the buffer media and were automatically tracked using ImagePro (Media Cybernetics). Additionally, smooth muscle contraction and epithelial ion transport were investigated using organ baths and Ussing chambers. Our results showed that PTS was significantly decreased in Oviducts from cows affected by COD as compared with controls (P = 0.01, unpaired t-test). Further, in healthy control cows, PTS was consistently increased in the Oviduct ipsilateral to ovulation as compared with the contralateral Oviduct (P = 0.03, paired t-test). This was not the case in cows affected by COD (P = 0.47, paired t-test). Reduced PTS in Oviducts from cows with COD was not due to changes in ciliary beat frequency. Although smooth muscle contraction was similar in Oviducts from healthy and COD cows, the contractile response (mN) to the cholinomimetic drug carbachol (10−7-10−4 M) was significantly reduced in COD as compared with the controls (P < 0.0001, nonlinear regression best fit analysis). Active epithelial ion transport, as measured by the change in short circuit current (μA cm−2), was stimulated by carbachol. Carbachol-induced active ion transport in the oviducal epithelium of COD cows was significantly decreased as compared with controls (P = 0.03, unpaired t-test of area under the curve). These results suggest, for the first time, that the transport of the gametes and the early embryo might be impaired in COD. Further, inadequate or insufficient cholinergic innervation may result in dysregulated fluid flow, which might be associated with alterations in oviducal metabolism and gamete or embryo nutrition. This knowledge is pivotal to establish novel therapeutic concepts for successful treatment of infertility in individuals affected by COD.
Wei Yan - One of the best experts on this subject based on the ideXlab platform.
-
Oviductal motile cilia are essential for oocyte pickup but dispensable for sperm and embryo transport
Proceedings of the National Academy of Sciences of the United States of America, 2021Co-Authors: Shuiqiao Yuan, Grant W. Hennig, Sean M. Ward, Zhuqing Wang, Hongying Peng, Huili Zheng, Wei YanAbstract:Mammalian Oviducts play an essential role in female fertility by picking up ovulated oocytes and transporting and nurturing gametes (sperm/oocytes) and early embryos. However, the relative contributions to these functions from various cell types within the Oviduct remain controversial. The Oviduct in mice deficient in two microRNA (miRNA) clusters (miR-34b/c and miR-449) lacks cilia, thus allowing us to define the physiological role of Oviductal motile cilia. Here, we report that the infundibulum without functional motile cilia failed to pick up the ovulated oocytes. In the absence of functional motile cilia, sperm could still reach the ampulla region, and early embryos managed to migrate to the uterus, but the efficiency was reduced. Further transcriptomic analyses revealed that the five messenger ribonucleic acids (mRNAs) encoded by miR-34b/c and miR-449 function to stabilize a large number of mRNAs involved in cilium organization and assembly and that Tubb4b was one of their target genes. Our data demonstrate that motile cilia in the infundibulum are essential for oocyte pickup and thus, female fertility, whereas motile cilia in other parts of the Oviduct facilitate gamete and embryo transport but are not absolutely required for female fertility.
Sean M. Ward - One of the best experts on this subject based on the ideXlab platform.
-
Oviductal motile cilia are essential for oocyte pickup but dispensable for sperm and embryo transport
Proceedings of the National Academy of Sciences of the United States of America, 2021Co-Authors: Shuiqiao Yuan, Grant W. Hennig, Sean M. Ward, Zhuqing Wang, Hongying Peng, Huili Zheng, Wei YanAbstract:Mammalian Oviducts play an essential role in female fertility by picking up ovulated oocytes and transporting and nurturing gametes (sperm/oocytes) and early embryos. However, the relative contributions to these functions from various cell types within the Oviduct remain controversial. The Oviduct in mice deficient in two microRNA (miRNA) clusters (miR-34b/c and miR-449) lacks cilia, thus allowing us to define the physiological role of Oviductal motile cilia. Here, we report that the infundibulum without functional motile cilia failed to pick up the ovulated oocytes. In the absence of functional motile cilia, sperm could still reach the ampulla region, and early embryos managed to migrate to the uterus, but the efficiency was reduced. Further transcriptomic analyses revealed that the five messenger ribonucleic acids (mRNAs) encoded by miR-34b/c and miR-449 function to stabilize a large number of mRNAs involved in cilium organization and assembly and that Tubb4b was one of their target genes. Our data demonstrate that motile cilia in the infundibulum are essential for oocyte pickup and thus, female fertility, whereas motile cilia in other parts of the Oviduct facilitate gamete and embryo transport but are not absolutely required for female fertility.
-
electrical slow waves in the mouse Oviduct are dependent upon a calcium activated chloride conductance encoded by tmem16a
Biology of Reproduction, 2012Co-Authors: Rose E. Dixon, Grant W. Hennig, Kenton M. Sanders, Salah A Baker, Fiona C Britton, Brian D Harfe, Jason R Rock, Sean M. WardAbstract:Myosalpinx contractions are critical for oocyte transport along the Oviduct. A specialized population of pacemaker cells—Oviduct interstitial cells of Cajal—generate slow waves, the electrical events underlying myosalpinx contractions. The ionic basis of Oviduct pacemaker activity is unknown. We examined the role of a new class of Ca2+-activated Cl− channels (CaCCs)—anoctamin 1, encoded by Tmem16a—in Oviduct slow wave generation. RT-PCR revealed the transcriptional expression of Tmem16a-encoded CaCCs in the myosalpinx. Intracellular microelectrode recordings were performed in the presence of two pharmacologically distinct Cl− channel antagonists, anthracene-9-carboxylic acid and niflumic acid. Both of these inhibitors caused membrane hyperpolarization, reduced the duration of slow waves, and ultimately inhibited pacemaker activity. Niflumic acid also inhibited propagating calcium waves within the myosalpinx. Slow waves were present at birth in wild-type and heterozygous Oviducts but failed to develop by birth in mice homozygous for a null allele of Tmem16a (Tmem16atm1Bdh/tm1Bdh). These data suggest that Tmem16a-encoded CaCCs contribute to membrane potential and are responsible for the upstroke and plateau phases of Oviduct slow waves.
-
Chlamydia Infection Causes Loss of Pacemaker Cells and Inhibits Oocyte Transport in the Mouse Oviduct
Biology of reproduction, 2008Co-Authors: Rose E. Dixon, Sung Jin Hwang, Grant W. Hennig, Kyle H. Ramsey, Justin H. Schripsema, Kenton M. Sanders, Sean M. WardAbstract:Chlamydia trachomatis is a common sexually transmitted bacterial infection that results in health care costs in the United States that exceed $2 billion per year. Chlamydia infections cause damage to the Oviducts, resulting in ectopic pregnancy and tubal factor infertility, but the reasons for defective Oviduct function are poorly understood. We have investigated the role of Oviduct contractions in egg transport and found that underlying electrical pacemaker activity is responsible for Oviduct motility and egg transport. Specialized pacemaker cells, referred to as Oviduct interstitial cells of Cajal (ICC-OVI), are responsible for pacemaker activity. The ICC-OVI, labeled with antibodies to KIT protein, form a dense network associated with the smooth muscle cells along the entire length of the Oviduct. Selective removal of ICC-OVI with KIT-neutralizing antibody resulted in loss of electrical rhythmicity and loss of propulsive contractions of the Oviduct. We tested whether infection might adversely affect the ICC-OVI. Mice infected with Chlamydia muridarum displayed dilation of Oviducts, pyosalpinx, and loss of spontaneous contractile activity. Morphological inspection showed disruption of ICC-OVI networks, and electrophysiological recordings showed loss of intrinsic pacemaker activity without change in basal smooth muscle membrane potential. Chlamydia infection also was associated with upregulation of NOS2 (iNOS) and PTGS2 (COX II) in leukocytes. Loss of ICC-OVI and pacemaker activity causes Oviduct pseudo-obstruction and loss of propulsive contractions for oocytes. This, accompanied by retention of Oviduct secretions, may contribute to the development of tubal factor infertility.
Kenneth W Beagley - One of the best experts on this subject based on the ideXlab platform.
-
The Duration of Chlamydia muridarum Genital Tract Infection and Associated Chronic Pathological Changes Are Reduced in IL-17 Knockout Mice but Protection Is Not Increased Further by Immunization
2016Co-Authors: Dean W. Andrew, Kyle H. Ramsey, Justin H. Schripsema, Melanie Cochrane, Peter Timms, Samantha J. D, Connor P. O’meara, Kenneth W BeagleyAbstract:IL-17 is believed to be important for protection against extracellular pathogens, where clearance is dependent on neutrophil recruitment and local activation of epithelial cell defences. However, the role of IL-17 in protection against intracellular pathogens such as Chlamydia is less clear. We have compared (i) the course of natural genital tract C. muridarum infection, (ii) the development of Oviduct pathology and (iii) the development of vaccine-induced immunity against infection in wild type (WT) BALB/c and IL-17 knockout mice (IL-17-/-) to determine if IL-17-mediated immunity is implicated in the development of infection-induced pathology and/or protection. Both the magnitude and duration of genital infection was significantly reduced in IL-17-/- mice compared to BALB/c. Similarly, hydrosalpinx was also greatly reduced in IL-17-/- mice and this correlated with reduced neutrophil and macrophage infiltration of Oviduct tissues. Matrix metalloproteinase (MMP) 9 and MMP2 were increased in WT Oviducts compared to IL-17-/- animals at day 7 post-infection. In contrast, Oviducts from IL-17-/- mice contained higher MMP9 and MMP2 at day 21. Infection also elicited higher levels of Chlamydia-neutralizing antibody in serum of IL-17-/- mice than WT mice. Following intranasal immunization with C. muridarum Major Outer Membrane Protein (MOMP) and cholera toxin plus CpG adjuvants, significantly higher levels of chlamydial MOMP-specific IgG and IgA were found in serum and vaginal washes of IL-17-/- mice. T cell proliferation and IFNγ production by splenocytes was greater in WT animals followin
-
the duration of chlamydia muridarum genital tract infection and associated chronic pathological changes are reduced in il 17 knockout mice but protection is not increased further by immunization
PLOS ONE, 2013Co-Authors: Dean Andrew, Kyle H. Ramsey, Justin H. Schripsema, Melanie Cochrane, Samantha J Dando, Connor P Omeara, Peter Timms, Kenneth W BeagleyAbstract:IL-17 is believed to be important for protection against extracellular pathogens, where clearance is dependent on neutrophil recruitment and local activation of epithelial cell defences. However, the role of IL-17 in protection against intracellular pathogens such as Chlamydia is less clear. We have compared (i) the course of natural genital tract C. muridarum infection, (ii) the development of Oviduct pathology and (iii) the development of vaccine-induced immunity against infection in wild type (WT) BALB/c and IL-17 knockout mice (IL-17-/-) to determine if IL-17-mediated immunity is implicated in the development of infection-induced pathology and/or protection. Both the magnitude and duration of genital infection was significantly reduced in IL-17-/- mice compared to BALB/c. Similarly, hydrosalpinx was also greatly reduced in IL-17-/- mice and this correlated with reduced neutrophil and macrophage infiltration of Oviduct tissues. Matrix metalloproteinase (MMP) 9 and MMP2 were increased in WT Oviducts compared to IL-17-/- animals at day 7 post-infection. In contrast, Oviducts from IL-17-/- mice contained higher MMP9 and MMP2 at day 21. Infection also elicited higher levels of Chlamydia-neutralizing antibody in serum of IL-17-/- mice than WT mice. Following intranasal immunization with C. muridarum Major Outer Membrane Protein (MOMP) and cholera toxin plus CpG adjuvants, significantly higher levels of chlamydial MOMP-specific IgG and IgA were found in serum and vaginal washes of IL-17-/- mice. T cell proliferation and IFNγ production by splenocytes was greater in WT animals following in vitro re-stimulation, however vaccination was only effective at reducing infection in WT, not IL-17-/- mice. Intranasal or transcutaneous immunization protected WT but not IL-17-/- mice against hydrosalpinx development. Our data show that in the absence of IL-17, the severity of C. muridarum genital infection and associated Oviduct pathology are significantly attenuated, however neither infection or pathology can be reduced further by vaccination protocols that effectively protect WT mice.
