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Trends in Plant Science Mar 2024Plant reproduction is a complex, highly-coordinated process in which a single, male germ cell grows through the maternal reproductive tissues to reach and fertilise the... (Review)
Review
Plant reproduction is a complex, highly-coordinated process in which a single, male germ cell grows through the maternal reproductive tissues to reach and fertilise the egg cell. Focussing on Arabidopsis thaliana, we review signalling between male and female partners which is important throughout the pollen tube journey, especially during pollen tube reception at the ovule. Numerous receptor kinases and their coreceptors are implicated in signal perception in both the pollen tube and synergid cells at the ovule entrance, and several specific peptide and carbohydrate ligands for these receptors have recently been identified. Clarifying the interplay between these signals and the downstream responses they instigate presents a challenge for future research and may help to illuminate broader principles of plant cell-cell communication.
Topics: Pollen Tube; Signal Transduction; Arabidopsis; Arabidopsis Proteins; Fertilization
PubMed: 37640641
DOI: 10.1016/j.tplants.2023.07.011 -
The Plant Cell Dec 2023Temperature is a major factor that regulates plant growth and phenotypic diversity. To ensure reproductive success at a range of temperatures, plants must maintain...
Temperature is a major factor that regulates plant growth and phenotypic diversity. To ensure reproductive success at a range of temperatures, plants must maintain developmental stability of their sexual organs when exposed to temperature fluctuations. However, the mechanisms integrating plant floral organ development and temperature responses are largely unknown. Here, we generated barley and rice loss-of-function mutants in the SEPALLATA-like MADS-box gene MADS8. The mutants in both species form multiple carpels that lack ovules at high ambient temperatures. Tissue-specific markers revealed that HvMADS8 is required to maintain floral meristem determinacy and ovule initiation at high temperatures, and transcriptome analyses confirmed that temperature-dependent differentially expressed genes in Hvmads8 mutants predominantly associate with floral organ and meristem regulation. HvMADS8 temperature-responsive activity relies on increased binding to promoters of downstream targets, as revealed by a cleavage under targets and tagmentation (CUT&Tag) analysis. We also demonstrate that HvMADS8 directly binds to 2 orthologs of D-class floral homeotic genes to activate their expression. Overall, our findings revealed a new, conserved role for MADS8 in maintaining pistil number and ovule initiation in cereal crops, extending the known function of plant MADS-box proteins in floral organ regulation.
Topics: Edible Grain; Temperature; Genes, Homeobox; Plant Proteins; Flowers; MADS Domain Proteins; Gene Expression Regulation, Plant; Meristem
PubMed: 37738656
DOI: 10.1093/plcell/koad246 -
Plants (Basel, Switzerland) Dec 2023The phenomenon of heterochrony, or shifts in the relative timing of ontogenetic events, is important for understanding many aspects of plant evolution, including applied... (Review)
Review
The phenomenon of heterochrony, or shifts in the relative timing of ontogenetic events, is important for understanding many aspects of plant evolution, including applied issues such as crop yield. In this paper, we review heterochronic shifts in the evolution of an important floral organ, the carpel. The carpels, being ovule-bearing organs, facilitate fertilisation, seed, and fruit formation. It is the carpel that provides the key character of flowering plants, angiospermy. In many angiosperms, a carpel has two zones: proximal ascidiate and distal plicate. When carpels are free (apocarpous gynoecium), the plicate zone has a ventral slit where carpel margins meet and fuse during ontogeny; the ascidiate zone is sac-like from inception and has no ventral slit. When carpels are united in a syncarpous gynoecium, a synascidiate zone has as many locules as carpels, whereas a symplicate zone is unilocular, at least early in ontogeny. In ontogeny, either the (syn)ascidiate or (sym)plicate zone is first to initiate. The two developmental patterns are called early and late peltation, respectively. In extreme cases, either the (sym)plicate or (syn)ascidiate zone is completely lacking. Here, we discuss the diversity of carpel structure and development in a well-defined clade of angiosperms, the monocotyledons. We conclude that the common ancestor of monocots had carpels with both zones and late peltation. This result was found irrespective of the use of the plastid or nuclear phylogeny. Early peltation generally correlates with ovules belonging to the (syn)ascidiate zone, whereas late peltation is found mostly in monocots with a fertile (sym)plicate zone.
PubMed: 38140465
DOI: 10.3390/plants12244138 -
Frontiers in Neural Circuits 2024Sexual behavior is crucial for reproduction in many animals. In many vertebrates, females exhibit sexual behavior only during a brief period surrounding ovulation. Over... (Review)
Review
Sexual behavior is crucial for reproduction in many animals. In many vertebrates, females exhibit sexual behavior only during a brief period surrounding ovulation. Over the decades, studies have identified the roles of ovarian sex hormones, which peak in levels around the time of ovulation, and the critical brain regions involved in the regulation of female sexual behavior. Modern technical innovations have enabled a deeper understanding of the neural circuit mechanisms controlling this behavior. In this review, I summarize our current knowledge and discuss the neural circuit mechanisms by which female sexual behavior occurs in association with the ovulatory phase of their cycle.
Topics: Animals; Female; Sexual Behavior, Animal; Humans; Brain; Gonadal Steroid Hormones; Ovulation; Neural Pathways
PubMed: 38752168
DOI: 10.3389/fncir.2024.1409349 -
Expert Reviews in Molecular Medicine Dec 2023In vitro fertilization (IVF) and embryo transfer and intracytoplasmic sperm injection (ICSI) have allowed millions of infertile couples to achieve pregnancy. As an... (Meta-Analysis)
Meta-Analysis Review
Live birth rate of gonadotropin-releasing hormone antagonist versus luteal phase gonadotropin-releasing hormone agonist protocol in IVF/ICSI: a systematic review and meta-analysis.
In vitro fertilization (IVF) and embryo transfer and intracytoplasmic sperm injection (ICSI) have allowed millions of infertile couples to achieve pregnancy. As an essential part of IVF/ICSI enabling the retrieval of a high number of oocytes in one cycle, controlled ovarian stimulation (COS) treatment mainly composes of the standard long gonadotrophin-releasing hormone agonist (GnRH-a) protocol and the gonadotrophin-releasing hormone antagonist (GnRH-ant) protocol. However, the effectiveness of GnRH-ant protocol is still debated because of inconsistent conclusions and insufficient subgroup analyses. This systematic review and meta-analysis included a total of 52 studies, encompassing 5193 participants in the GnRH-ant group and 4757 in the GnRH-a group. The findings of this study revealed that the GnRH-ant protocol is comparable with the long GnRH-a protocol when considering live birth as the primary outcome, and it is a favourable protocol with evidence reducing the incidence of ovarian hyperstimulation syndrome in women undergoing IVF/ICSI, especially in women with polycystic ovary syndrome. Further research is needed to compare the subsequent cumulative live birth rate between the two protocols among the general and poor ovarian response patients since those patients have a lower clinical pregnancy rate, fewer oocytes retrieved or fewer high-grade embryos in the GnRH-ant protocol.
Topics: Female; Humans; Male; Pregnancy; Birth Rate; Fertilization in Vitro; Gonadotropin-Releasing Hormone; Hormone Antagonists; Luteal Phase; Meta-Analysis as Topic; Ovulation Induction; Semen; Sperm Injections, Intracytoplasmic; Systematic Reviews as Topic
PubMed: 38095077
DOI: 10.1017/erm.2023.25 -
European Journal of Obstetrics,... Oct 2023To conduct a systematic review andmeta-analysis of all randomized controlled trials (RCTs) that investigated whether dual triggering [a combination of... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To conduct a systematic review andmeta-analysis of all randomized controlled trials (RCTs) that investigated whether dual triggering [a combination of gonadotropin-releasing hormone (GnRH) agonist and human chorionic gonadotropin (hCG)] of final oocyte maturation can improve the number of oocytes retrieved and clinical pregnancy rate in low or normal responders undergoing in-vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles using a GnRH-antagonist protocol.
STUDY DESIGN
Studies up to October 2022 were identified from PubMed, Scopus, Cochrane Library and Web of Science. The risk of bias of included studies was assessed. Dichotomous outcomes were reported as relative risks (RR), and continuous outcomes were reported as weighted mean differences (WMD) with 95% confidence intervals (CI). The primary outcomes were number of oocytes retrieved, number of mature [metaphase II (MII)] oocytes, clinical pregnancy rate and ongoing pregnancy rate; other IVF outcomes were considered as secondary outcomes.
RESULTS
Seven studies were identified, and 898 patients were eligible for inclusion in this meta-analysis. The results showed that the number of oocytes retrieved [WMD = 1.38 (95% CI 0.47-2.28), I = 66%, p = 0.003, low evidence], number of MII oocytes [WMD = 0.7 (95% CI 0.35-1.05), I = 42%, p < 0.0001, moderate evidence], number of embryos [WMD = 0.68 (95% CI 0.07-1.3), I = 67%, p = 0.03, low evidence] and number of good-quality embryos [WMD = 1.14 (95% CI 0.35-1.93), I = 0%, p = 0.005, moderate evidence] in the dual trigger group were significantly higher than in the hCG trigger group. The results of the ovarian response subgroup analysis showed significant differences in all of these outcomes in normal responders, and no differences in any of the outcomes in low responders, except for the number of MII oocytes. In low responders, clinical pregnancy rates may be improved in the dual trigger group [RR = 2.2 (95% CI 1.05-4.61), I = 28%, p = 0.04, low evidence].
CONCLUSION
Dual triggering by GnRH agonist and hCG improved oocyte maturity and embryo grading for normal responders in GnRH-antagonist cycles. Dual triggering for final oocyte maturation may improve clinical pregnancy rates in low responders.
Topics: Female; Pregnancy; Humans; Sperm Injections, Intracytoplasmic; Randomized Controlled Trials as Topic; Ovulation; Fertilization in Vitro; Chorionic Gonadotropin; Hormone Antagonists; Gonadotropin-Releasing Hormone
PubMed: 37639817
DOI: 10.1016/j.ejogrb.2023.08.014 -
Sensors (Basel, Switzerland) Dec 2023(1) Background: Hormonal fluctuations across the menstrual cycle lead to multiple changes in physiological parameters such as body temperature, cardiovascular function,... (Observational Study)
Observational Study
(1) Background: Hormonal fluctuations across the menstrual cycle lead to multiple changes in physiological parameters such as body temperature, cardiovascular function, respiratory rate and perfusion. Electronic wearables analyzing those parameters might present a convenient alternative to urinary ovulation tests for predicting the fertile window. (2) Methods: We conducted a prospective observational study including women aged 18-45 years without current hormonal therapy who used a wrist-worn medical device and urinary ovulation tests for a minimum of three cycles. We analyzed the accuracy of both the retrospective and prospective algorithms using a generalized linear mixed-effects model. The findings were compared to real-world data from bracelet users who also reported urinary ovulation tests. (3) Results: A total of 61 study participants contributing 205 cycles and 6081 real-life cycles from 3268 bracelet users were included in the analysis. The mean error in identifying ovulation with the wrist-worn medical device retrospective algorithm in the clinical study was 0.31 days (95% CI -0.13 to 0.75). The retrospective algorithm identified 75.4% of fertile days, and the prospective algorithm identified 73.8% of fertile days correctly within the pre-specified equivalence limits (±2 days). The quality of the retrospective algorithm in the clinical study could be confirmed by real-world data. (4) Conclusion: Our data indicate that wearable sensors may be used to accurately detect the periovulatory period.
Topics: Female; Humans; Wrist; Retrospective Studies; Prospective Studies; Ovulation; Menstrual Cycle
PubMed: 38139575
DOI: 10.3390/s23249730 -
Open Veterinary Journal Dec 2023It is documented that the reproductive performance of postpartum dairy cows is influenced by both internal and external factors. One of the most important reproductive... (Review)
Review
It is documented that the reproductive performance of postpartum dairy cows is influenced by both internal and external factors. One of the most important reproductive performance indices is the first ovulation postpartum. This review aimed to describe factors affecting first ovulation postpartum in dairy cows, particularly those raised under tropical climates. Negative energy balance and its consequences; metabolic disorders; uterine pathology; udder health; lameness; and heat stress are discussed for their potential effects on the first ovulation postpartum. Understanding the underlying mechanisms of those affecting factors would assist in justifying the treatment and prevention plans in order to optimize the reproductive performance of postpartum dairy cows.
Topics: Female; Cattle; Animals; Lactation; Ovulation; Postpartum Period; Reproduction; Energy Metabolism
PubMed: 38292713
DOI: 10.5455/OVJ.2023.v13.i12.3 -
Veterinary Sciences Oct 2023The purpose of the present research was to define ovarian follicular dynamics and plasma endocrine profiles in response to a single PGF injection, administered...
Ovarian Dynamics and Changes in Estradiol-17β and Progesterone Relationship with Standing Estrus, Preovulatory Follicles, and Ovulation Using Single Prostaglandin F2α Injection in Barbari Goats.
The purpose of the present research was to define ovarian follicular dynamics and plasma endocrine profiles in response to a single PGF injection, administered indiscriminately during the breeding season of Barbari goats. Ovarian dynamics were observed at every 12 h interval by using B mode ultrasonography, blood samples for hormonal analysis such as estradiol 17β and progesterone were collected at every 12 h interval, and bucks with aprons were used to identify standing estrus at every 6 h interval. Relative to PGF, the start of standing estrus and ovulation differ ( < 0.05) between early- (n = 7), intermediate- (n = 6), and late-responding (n = 6) goats. The highest plasma level of estradiol 17β was detected 12 h prior to ovulation. The average diameter of the ovulatory follicle and length of standing estrus were comparable ( > 0.05) between the goats. The corpus luteum degenerated more quickly ( < 0.05) in early- than intermediate- and late-responding goats. Dominant follicle diameter and estradiol 17β concentration also differ ( < 0.05) among groups. Although the plasma level of progesterone did not vary ( = 0.065), the variation in progesterone concentration with time differed ( < 0.05) amongst the goats. As a result, this research indirectly reveals that the beginning of standing estrus, end of estrus, and ovulation after PGF might fluctuate in Barbari goats because of follicular and hormonal dynamics during the luteal phase.
PubMed: 37888576
DOI: 10.3390/vetsci10100624 -
The Journal of Maternal-fetal &... Dec 2023There is ongoing interest in glucocorticoid treatment during oocyte stimulation to treat infertility in women who have undergone Assisted Reproductive Technology (ART). (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
There is ongoing interest in glucocorticoid treatment during oocyte stimulation to treat infertility in women who have undergone Assisted Reproductive Technology (ART).
OBJECTIVE
This meta-analysis was performed to evaluate the efficiency and safety of adjuvant glucocorticoid therapy on pregnancy outcomes in infertile women undergoing ART cycles.
STUDY DESIGN
A literature search was performed in PubMed, EMBASE, Web of Science, and the Cochrane Library up to December 2022. To assess the efficacy and safety of additional glucocorticoid treatment during ovulation induction in women who underwent IVF or ICSI treatment, only randomized controlled trials were included.
RESULTS
Overall, glucocorticoid therapy during ovulation showed a nonsignificant effect of prednisolone improving the live birth rate (OR = 1.03, 95% CI [.75, 1.43], I = .0%, = .84), abortion rate (OR = 1.14, 95% CI [.62, 2.08], I = 31%, = .68), and implantation rate (OR = 1.1, 95% CI [.82, 1.5], I = 8%, = .52) of infertile women compared to the control group. The present meta-analysis revealed that the clinical pregnancy rate per cycle tended to increase after glucocorticoid treatment (OR = 1.29, 95% CI [1.02, 1.63], I = 8%, = .52).
CONCLUSIONS
The present meta-analysis suggested that ovarian stimulation prednisolone therapy does not significantly improve clinical outcomes in women undergoing IVF/ICSI. Although the results indicated that adjuvant glucocorticoid therapy during ovarian stimulation may increase the clinical pregnancy rate, subgroup analysis showed that it was affected by infertility factors, dose schedules, and length of treatment. Therefore, these results should be interpreted with caution.
Topics: Female; Pregnancy; Humans; Glucocorticoids; Infertility, Female; Ovulation Induction; Prednisolone; Adjuvants, Pharmaceutic; Dietary Supplements
PubMed: 37385781
DOI: 10.1080/14767058.2023.2227310