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Current Biology : CB Jun 2023Mechanosensory feedback of the internal reproductive state drives decisions about when and where to reproduce. For instance, stretch in the Drosophila reproductive tract...
Mechanosensory feedback of the internal reproductive state drives decisions about when and where to reproduce. For instance, stretch in the Drosophila reproductive tract produced by artificial distention or from accumulated eggs regulates the attraction to acetic acid to ensure optimal oviposition. How such mechanosensory feedback modulates neural circuits to coordinate reproductive behaviors is incompletely understood. We previously identified a stretch-dependent homeostat that regulates egg laying in Caenorhabditis elegans. Sterilized animals lacking eggs show reduced Ca transient activity in the presynaptic HSN command motoneurons that drive egg-laying behavior, while animals forced to accumulate extra eggs show dramatically increased circuit activity that restores egg laying. Interestingly, genetic ablation or electrical silencing of the HSNs delays, but does not abolish, the onset of egg laying, with animals recovering vulval muscle Ca transient activity upon egg accumulation. Using an acute gonad microinjection technique to mimic changes in pressure and stretch resulting from germline activity and egg accumulation, we find that injection rapidly stimulates Ca activity in both neurons and muscles of the egg-laying circuit. Injection-induced vulval muscle Ca activity requires L-type Ca channels but is independent of presynaptic input. Conversely, injection-induced neural activity is disrupted in mutants lacking the vulval muscles, suggesting "bottom-up" feedback from muscles to neurons. Direct mechanical prodding activates the vulval muscles, suggesting that they are the proximal targets of the stretch-dependent stimulus. Our results show that egg-laying behavior in C. elegans is regulated by a stretch-dependent homeostat that scales postsynaptic muscle responses with egg accumulation in the uterus.
Topics: Caenorhabditis elegans; Ovum; Animals; Muscle, Skeletal; Feedback; Motor Neurons
PubMed: 37236183
DOI: 10.1016/j.cub.2023.05.008 -
Journal of Assisted Reproduction and... Jul 2019
Topics: Cell Lineage; Cumulus Cells; Female; Fertilization in Vitro; Humans; Male; Oocytes; Semen; Sperm Injections, Intracytoplasmic; Sperm-Ovum Interactions
PubMed: 31297655
DOI: 10.1007/s10815-019-01518-6 -
Biology of Reproduction Oct 2021In many non-mammalian organisms, a population of germ-line stem cells supports continuing production of gametes during post-natal life, and germ-line stem cells are also... (Review)
Review
In many non-mammalian organisms, a population of germ-line stem cells supports continuing production of gametes during post-natal life, and germ-line stem cells are also present and functional in male mammals. Traditionally, however, they have been thought not to exist in female mammals, who instead generate all their germ cells during fetal life. Over the last several years, this dogma has been challenged by several reports, while being supported by others. We describe and compare these conflicting studies with the aim of understanding how they came to opposing conclusions. We first consider studies that, by examining marker-gene expression, the fate of genetically marked cells, and consequences of depleting the oocyte population, addressed whether ovaries of post-natal females contain oogonial stem cells that give rise to new oocytes. We next discuss whether ovaries contain cells that, even if inactive under physiological conditions, nonetheless possess oogonial stem cell properties that can be revealed through cell culture. We then examine studies of whether cells harvested after long-term culture of cells obtained from ovaries can, following transplantation into ovaries of recipient females, give rise to oocytes and offspring. Finally, we note studies where somatic cells have been re-programmed to acquire a female germ-cell fate. We conclude that the weight of evidence strongly supports the traditional interpretation that germ-line stem cells do not exist post-natally in female mammals. However, the ability to generate germ cells from somatic cells in vitro establishes a method to generate new gametes from cells of post-natal mammalian females.
Topics: Animals; Female; Germ Cells; Mammals; Ovum
PubMed: 34114006
DOI: 10.1093/biolre/ioab115 -
International Journal of Molecular... Jan 2021The number of sources of anthropogenic magnetic and electromagnetic fields generated by various underwater facilities, industrial equipment, and transferring devices in... (Review)
Review
The number of sources of anthropogenic magnetic and electromagnetic fields generated by various underwater facilities, industrial equipment, and transferring devices in aquatic environment is increasing. These have an effect on an array of fish life processes, but especially the early developmental stages. The magnitude of these effects depends on field strength and time of exposure and is species-specific. We review studies on the effect of magnetic fields on the course of embryogenesis, with special reference to survival, the size of the embryos, embryonic motor function, changes in pigment cells, respiration hatching, and directional reactions. We also describe the effect of magnetic fields on sperm motility and egg activation. Magnetic fields can exert positive effects, as in the case of the considerable extension of sperm capability of activation, or have a negative influence in the form of a disturbance in heart rate or developmental instability in inner ear organs.
Topics: Animals; Cell Membrane Permeability; Embryo, Nonmammalian; Embryonic Development; Fishes; Larva; Magnetic Fields; Ovum
PubMed: 33530555
DOI: 10.3390/ijms22031210 -
Journal of Insect Science (Online) Mar 2023Stink bugs, including Halyomorpha halys (Stål) and Nezara viridula (L.), are agricultural pests that feed on fruit in a variety of crops. Monitoring predation and...
Predation and parasitism of naturally occurring and sentinel stink bug egg masses of Halyomorpha halys (Stål) and Nezara viridula (L.) (Hemiptera: Pentatomidae) in various southeastern habitats.
Stink bugs, including Halyomorpha halys (Stål) and Nezara viridula (L.), are agricultural pests that feed on fruit in a variety of crops. Monitoring predation and parasitism of stink bug egg masses furthers our understanding of potential biological control tactics. However, best practices for laboratory and field assessments of parasitism and predation of egg masses require further attention. We carried out a series of laboratory and field experiments to test whether parasitism and predation for three types of sentinel H. halys egg masses, fresh, frozen, and refrigerated, varied in agricultural commodities. In addition, we asked if predation and parasitism differed between sentinel and naturally occurring H. halys and N. viridula egg masses in soybean. In the laboratory, more H. halys eggs were parasitized by Trissolcus euschisti (Ashmead) (Hymenoptera: Scelionidae) if they were frozen or refrigerated compared to fresh eggs. Similarly, in the field, parasitism was higher for frozen egg masses than fresh. In 2018 and 2019, H. halys natural egg masses had higher parasitism and lower predation compared to sentinel egg masses in soybean. In a paired field test during 2020 and 2021, there was no difference in parasitism between H. halys natural and sentinel eggs, but much higher incidence of parasitism was detected in natural N. viridula egg masses than sentinel eggs. Collecting natural egg masses is the best methodology for field assessment of parasitism of stink bug egg masses; however, if natural egg masses are not easily available, deploying refrigerated sentinel egg masses is a good alternative.
Topics: Animals; Predatory Behavior; Ovum; Heteroptera; Ecosystem; Hymenoptera; Glycine max
PubMed: 37004146
DOI: 10.1093/jisesa/iead012 -
Poultry Science Mar 2023Pickled eggs enjoy a long processing history with unique flavor and rich nutrition but suffer from long pickling cycle due to the limitations of traditional processing... (Review)
Review
Pickled eggs enjoy a long processing history with unique flavor and rich nutrition but suffer from long pickling cycle due to the limitations of traditional processing methods. In terms of quality, salted egg whites have the disadvantage of high sodium content, and salted egg yolks have problems such as hard core and black circle around outer layer. Likewise, the quality of preserved eggs is challenged by the black spots (dots) on the eggshells and the high content of heavy metals in the egg contents. The sustainable development of traditional pickled eggs are hindered by these defects and extensive research has been carried out in recent years. Based on the elaboration of the quality formation mechanism of salted eggs and preserved eggs, this paper reviewed the processing principles and applications of rapid pickling technologies like ultrasonic technology, magnetoelectric-assisted technology, water cycle technology, vacuum decompression technology, and pulsed pressure technology, as well as the quality optimization methods such as controlling the sodium content of the salted egg whites, improving the quality of salted egg yolks, promoting the quality of lead-free preserved eggs, and developing heavy metal-free preserved eggs. In the end, the future development trend of traditional pickled eggs was summarized and prospected in order to provide theoretical guidance for the actual production.
Topics: Animals; Chickens; Ovum; Egg Yolk; Egg White; Sodium; Eggs
PubMed: 36682130
DOI: 10.1016/j.psj.2022.102468 -
Poultry Science Apr 2023For laying hens, the immediate aftermath and healing period of a keel fracture (KF) is characterized by reduced ability to perform species-specific behavior, access...
For laying hens, the immediate aftermath and healing period of a keel fracture (KF) is characterized by reduced ability to perform species-specific behavior, access resources, and pain. However, the longer-term impacts, once the fracture is completely healed, are less clear. As well as acute pain and behavioral changes, a negative experience can shape future responses to putatively threatening stimuli, raising future fear, and anxiety levels during husbandry-related events. We aimed to determine whether hens that had previously sustained keel bone fractures, but were now outside of the peak age range for new fractures, showed higher fear and anxiety levels compared to intact hens. We also determined if healed keel bone fractures were associated with reduced production, changes in behavior and resource use. One hundred and fifty hens with a palpation score of 1 ( "KF") and 150 hens with a palpation score of 0 (keel fracture free, "KFF") were selected from a commercial farm at 63 wk of age and housed in 6 groups (3 × KF and 3 × KFF). We compared production (hen weight and feed consumption, egg quantity, quality and weight, floor eggs, shell thickness, and weight) and home pen behavior (behaviors and transitional movements) in both groups. Finally, we measured the responses of KF (n = 75) and KFF (n = 75) during tonic immobility, novel arena, and novel object tests. KF and KFF hens did not differ in their responses to the tonic immobility, novel arena, and novel object tests, nor were there differences between the 2 groups in home pen behavior and transitional movements. KFF birds were lighter and laid eggs with less eggshell membrane compared KF birds, but no differences were found between KF and KFF in any other production measures. We found no evidence that healed KFs were associated with detrimental welfare effects in laying hens, but further work is required to determine the mechanisms and implications of the lower body weight and egg shell membrane.
Topics: Animals; Female; Chickens; Ovum; Fractures, Bone; Anxiety; Fear; Housing, Animal
PubMed: 36805403
DOI: 10.1016/j.psj.2023.102514 -
Upsala Journal of Medical Sciences May 2020
Topics: Age Factors; Female; Humans; Infertility, Female; Meta-Analysis as Topic; Ovum; Randomized Controlled Trials as Topic; Reproductive Techniques, Assisted; Treatment Outcome
PubMed: 32423270
DOI: 10.1080/03009734.2020.1755398 -
Cells May 2022After its discovery in 1825 by the physiologist J.E. Purkinje, the human germinal vesicle (GV) attracted the interest of scientists. Discarded after laparotomy or... (Review)
Review
After its discovery in 1825 by the physiologist J.E. Purkinje, the human germinal vesicle (GV) attracted the interest of scientists. Discarded after laparotomy or laparoscopic ovum pick up from the pool of retrieved mature oocytes, the leftover GV was mainly used for research purposes. After the discovery of Assisted Reproductive Technologies (ARTs) such as maturation (IVM), fertilization and embryo transfer (IVF-ET) and intracytoplasmic sperm injection (ICSI), its developing potential was explored, and recognized as an important source of germ cells, especially in the case of scarce availability of mature oocytes for pathological/clinical conditions or in the case of previous recurrent implantation failure. We here review the ultrastructural data available on GV-stage human oocytes and their application to ARTs.
Topics: Cell Nucleus; Fertilization in Vitro; Humans; Oocytes; Sperm Injections, Intracytoplasmic
PubMed: 35626673
DOI: 10.3390/cells11101636 -
International Journal of Molecular... Apr 2021Based on the abundance of scientific publications, the polymodal sensor TRPV1 is known as one of the most studied proteins within the TRP channel family. This receptor... (Review)
Review
Based on the abundance of scientific publications, the polymodal sensor TRPV1 is known as one of the most studied proteins within the TRP channel family. This receptor has been found in numerous cell types from different species as well as in spermatozoa. The present review is focused on analyzing the role played by this important channel in the post-ejaculatory life of spermatozoa, where it has been described to be involved in events such as capacitation, acrosome reaction, calcium trafficking, sperm migration, and fertilization. By performing an exhaustive bibliographic search, this review gathers, for the first time, all the modulators of the TRPV1 function that, to our knowledge, were described to date in different species and cell types. Moreover, all those modulators with a relationship with the reproductive process, either found in the female tract, seminal plasma, or spermatozoa, are presented here. Since the sperm migration through the female reproductive tract is one of the most intriguing and less understood events of the fertilization process, in the present work, chemotaxis, thermotaxis, and rheotaxis guiding mechanisms and their relationship with TRPV1 receptor are deeply analyzed, hypothesizing its (in)direct participation during the sperm migration. Last, TRPV1 is presented as a pharmacological target, with a special focus on humans and some pathologies in mammals strictly related to the male reproductive system.
Topics: Animals; Female; Humans; Male; Ovum; Sperm Motility; Spermatozoa; TRPV Cation Channels
PubMed: 33919147
DOI: 10.3390/ijms22094306