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Plants (Basel, Switzerland) Jun 2024(Laxm.) is a leguminous plant with significant ecological benefits, but its embryonic development mechanism remains unclear. We investigated the flower bud...
(Laxm.) is a leguminous plant with significant ecological benefits, but its embryonic development mechanism remains unclear. We investigated the flower bud differentiation, megaspore and microspore formation, gametophyte development, and embryo and endosperm development in . Our aim was to elucidate the relationship between the external morphology and internal development processes of male and female floral organs during growth, as well as the reproductive factors influencing fruiting. The results indicated that although the pistil develops later than the stamen during flower bud differentiation, both organs mature synchronously before flowering. pollen exhibits three germination grooves, a reticulate outer wall, and papillary structures on the anther surface. In vivo pollination experiments revealed abnormal spiral growth of pollen tubes within the style and the occurrence of callus plugs, which may reduce the seed setting rate. The anther wall development follows the dicotyledonous type, with tetrads formed through microspore meiosis exhibiting both left-right symmetry and tetrahedral arrangements. has a single ovule, and the embryo sac develops in the monosporic polygonum type. After dormancy, the zygote undergoes multiple divisions, progressing through spherical, heart-shaped, and torpedo-shaped embryo stages, culminating in a mature embryo. A mature seed comprises cotyledons, hypocotyl, embryo, radicle, and seed coat. Phylogenetic tree analysis reveals a close genetic relationship between and other leguminous plants from the genera and . This study provides valuable insights into the regulation of flowering and hybrid breeding in leguminous plants and offers a new perspective on the development of floral organs and seed setting rates.
PubMed: 38931095
DOI: 10.3390/plants13121661 -
International Journal of Molecular... Jun 2024The physiology of reproduction has been of interest to researchers for centuries. The purpose of this work is to review the development of our knowledge on the... (Review)
Review
The physiology of reproduction has been of interest to researchers for centuries. The purpose of this work is to review the development of our knowledge on the neuroendocrine background of the regulation of ovulation. We first describe the development of the pituitary gland, the structure of the median eminence (ME), the connection between the hypothalamus and the pituitary gland, the ovarian and pituitary hormones involved in ovulation, and the pituitary cell composition. We recall the pioneer physiological and morphological investigations that drove development forward. The description of the supraoptic-paraventricular magnocellular and tuberoinfundibular parvocellular systems and recognizing the role of the hypophysiotropic area were major milestones in understanding the anatomical and physiological basis of reproduction. The discovery of releasing and inhibiting hormones, the significance of pulse and surge generators, the pulsatile secretion of the gonadotropin-releasing hormone (GnRH), and the subsequent pulsatility of luteinizing (LH) and follicle-stimulating hormones (FSH) in the human reproductive physiology were truly transformative. The roles of three critical neuropeptides, kisspeptin (KP), neurokinin B (NKB), and dynorphin (Dy), were also identified. This review also touches on the endocrine background of human infertility and assisted fertilization.
Topics: Humans; Ovulation; Female; Neurosecretory Systems; Animals; Pituitary Gland; Kisspeptins; Neurokinin B; Luteinizing Hormone; Gonadotropin-Releasing Hormone; Dynorphins; Hypothalamus
PubMed: 38928237
DOI: 10.3390/ijms25126531 -
Biology Jun 2024Pollinators are needed for the reproduction of , and only sphingid moths have mouthparts long enough to reach the nectar at the bottom of the species' long, twisted...
Pollinators are needed for the reproduction of , and only sphingid moths have mouthparts long enough to reach the nectar at the bottom of the species' long, twisted floral tube. Though plants produce many flowers over a period of several months, one observes very few fruits in nature. We asked: (1) Are plants self-compatible, or do they need pollen from another individual to set fruit and seed? (2) Are cross-pollinations between unrelated individuals more successful than crosses with relatives? (3) How does the relatedness of pollen and ovule parent plants affect fruit set, seed number, and seed quality? We investigated the breeding system of by collecting fruits from seven sites, growing plants and performing hand pollinations over a period of several years, collecting and measuring fruits and counting seeds. is self-incompatible, though some individuals produce fruit by self-pollination. Cross-pollinations between unrelated individuals set the most fruit (59%), and those that were self-pollinated set the least (9%). Fruit set from cross-pollinations between related individuals was intermediate (32%). Although the number of seeds per fruit did not differ significantly among pollination treatments, fruits from self-pollinations had substantially fewer viable seeds than outcrossed fruits, with fruits from sibling crosses being intermediate. There were higher levels of self-compatibility in the fragment populations compared with plants from intact habitats. Self-incompatibility may explain why fruit set is low in this plant species; future investigation into the breakdown of self-incompatibility in smaller populations is warranted.
PubMed: 38927303
DOI: 10.3390/biology13060423 -
Biomolecules May 2024Potato is the most important non-cereal crop worldwide, and, yet, genetic gains in potato have been traditionally delayed by the crop's biology, mostly the genetic... (Review)
Review
Potato is the most important non-cereal crop worldwide, and, yet, genetic gains in potato have been traditionally delayed by the crop's biology, mostly the genetic heterozygosity of autotetraploid cultivars and the intricacies of the reproductive system. Novel site-directed genetic modification techniques provide opportunities for designing climate-smart cultivars, but they also pose new possibilities (and challenges) for breeding potato. As potato species show a remarkable reproductive diversity, and their ovules have a propensity to develop apomixis-like phenotypes, tinkering with reproductive genes in potato is opening new frontiers in potato breeding. Developing diploid varieties instead of tetraploid ones has been proposed as an alternative way to fill the gap in genetic gain, that is being achieved by using gene-edited self-compatible genotypes and inbred lines to exploit hybrid seed technology. In a similar way, modulating the formation of unreduced gametes and synthesizing apomixis in diploid or tetraploid potatoes may help to reinforce the transition to a diploid hybrid crop or enhance introgression schemes and fix highly heterozygous genotypes in tetraploid varieties. In any case, the induction of apomixis-like phenotypes will shorten the time and costs of developing new varieties by allowing the multi-generational propagation through true seeds. In this review, we summarize the current knowledge on potato reproductive phenotypes and underlying genes, discuss the advantages and disadvantages of using potato's natural variability to modulate reproductive steps during seed formation, and consider strategies to synthesize apomixis. However, before we can fully modulate the reproductive phenotypes, we need to understand the genetic basis of such diversity. Finally, we visualize an active, central role for genebanks in this endeavor by phenotyping properly genotyped genebank accessions and new introductions to provide scientists and breeders with reliable data and resources for developing innovations to exploit market opportunities.
Topics: Solanum tuberosum; Plant Breeding; Apomixis; Reproduction; Genes, Plant; Phenotype; Tetraploidy; Genotype
PubMed: 38927018
DOI: 10.3390/biom14060614 -
BMC Veterinary Research Jun 2024The present study was performed to characterize and compare the perfusion of vaginal and uterine arteries after challenging the reproductive tract of dairy cows via...
AIM
The present study was performed to characterize and compare the perfusion of vaginal and uterine arteries after challenging the reproductive tract of dairy cows via natural mating, artificial insemination (AI), or intravaginal deposition (vaginal fundus) of different biological fluids or a placebo.
MATERIALS AND METHODS
In a double-blind study, six German Holstein cows were administered PGF during dioestrus and 48 h later treated with GnRH. Intravaginal or intrauterine treatments were carried out 12 h after GnRH was administered. Animals served as their controls, using a cross-over design with an interval of 14 days between experiments. The experimental animals were allocated to receive the following treatments: natural mating (N), intrauterine artificial insemination (A), intravaginal deposition (vaginal fundus) of 6 mL raw semen (R) or 6 mL seminal plasma (S), and compared to their controls [control 1: 6 mL placebo (P: physiological saline); control 2: no treatment (C)). Corresponding time intervals were chosen for the untreated control oestrus. Blood flow volume (BFV) in the uterine (u) and vaginal (v) arteries ipsilateral to the ovary bearing the preovulatory follicle was determined using transrectal Doppler sonography.
RESULTS
All animals exhibited oestrus and ovulated between 30 and 36 h after GnRH. Transient increases (P < 0.05) in vaginal blood flow occurred between 3 and 12 h following mating as well as 3 to 9 h after deposition of raw semen and seminal plasma, respectively. The most distinct increases (199%) in vBFV occurred 6 h after mating compared to values immediately before mating (= time 0 h). Neither AI nor deposition of a placebo into the vagina affected vBFV (P > 0.05). Only mating and deposition of either raw semen, seminal plasma or AI increased uBFV (P < 0.003). The greatest rise in uBFV occurred after natural mating. Maximum uBFV values were detected 9 h after mating when values were 79% greater (P < 0.05) than at 0 h.
CONCLUSIONS
The natural mating, deposition of raw semen or seminal plasma and conventional AI affect vaginal and/or uterine blood flow to different degrees. The factors responsible for these alterations in blood flow and their effects on fertility remain to be clarified in future studies.
Topics: Animals; Insemination, Artificial; Female; Semen; Cattle; Vagina; Uterus; Male; Administration, Intravaginal; Double-Blind Method; Gonadotropin-Releasing Hormone; Cross-Over Studies; Regional Blood Flow
PubMed: 38926710
DOI: 10.1186/s12917-024-03919-x -
Journal of Assisted Reproduction and... Jun 2024Techniques of medically assisted reproduction interact with the embryo at crucial developmental stages, yet their impact on the fetus and subsequent child's health...
PURPOSE
Techniques of medically assisted reproduction interact with the embryo at crucial developmental stages, yet their impact on the fetus and subsequent child's health remains unclear. Given rising infertility rates and more frequent use of fertility treatments, we aimed to investigate if these methods heighten the risk of autism spectrum disorder (ASD) in children.
METHODS
A population-based cohort study was conducted at Soroka University Medical Center, a tertiary referral hospital, encompassing singleton births. The incidence of ASD in offspring, incorporating either hospital or community-based diagnoses, was compared in relation to the conception method. To examine the cumulative incidence of ASD, a Kaplan-Meier survival curve was utilized. Cox proportional hazards model was employed to adjust for confounders.
RESULTS
Among 115,081 pregnancies, 0.5% involved ovulation induction (OI) and 1.7% in vitro fertilization (IVF), with the rest conceived naturally. Fertility treatments were more common in older patients and linked to more diabetes, hypertensive disorders, preterm, and cesarean deliveries. Out of 767 ASD diagnoses, offspring from OI and IVF had higher initial ASD rates (2.1% and 1.3%) than natural conceptions (0.6%). In a Cox model accounting for maternal age, ethnicity, and gender, neither OI nor IVF was significantly associated with ASD. The adjusted hazard ratios were 0.83 (95% CI 0.48-1.43) for OI and 1.34 (95% CI 0.91-1.99) for IVF. When considering fertility treatments combined, the association with ASD remained non-significant (aHR 1.11, 95% CI 0.80-1.54, p = 0.52).
CONCLUSION
Fertility treatments, including OI and IVF, do not exhibit a significant association with heightened ASD risk in offspring.
PubMed: 38926295
DOI: 10.1007/s10815-024-03180-z -
Theriogenology Jun 2024Although anti-Müllerian hormone (AMH) is involved in the regulation of granulosa cell function in female animals, its role in tissues other than ovarian follicles...
Although anti-Müllerian hormone (AMH) is involved in the regulation of granulosa cell function in female animals, its role in tissues other than ovarian follicles remains poorly understood. It has also been suggested that cows with high circulating AMH concentrations have increased fertility; however, the mechanism has not been elucidated. This study was conducted to identify the presence of the AMH-signaling system and its target cells in the bovine corpus luteum formed from an ovulated follicle. Immunoblotting revealed that the proteolytically cleaved C-terminal region in AMH (AMH), a biologically active peptide, was present in trace amounts in the early corpus luteum and significantly increased during the mid to regressed stages. AMH and cleaved N-terminal region (AMH) in AMH generate a noncovalent isoform that improves the activity of AMH signaling. An immunohistochemical analysis revealed that AMH, AMH, and type II AMH receptor (AMHR2) were localized to luteal cells during the entire estrous cycle. AMH in the corpus luteum seemed to be newly synthesized since AMH expression was detected. These findings suggest that AMH signaling is involved in the regulation of luteal cell function through an autocrine and post-translational processing mechanism. The level of AMHR2 and mRNA expression of AMHR2 and type I AMH receptors (activin-like kinase 2, 3, and 6) were highest in the mid stage. Thus, AMH signaling in the corpus luteum may also be regulated by changes in the receptor levels. Since the transforming growth factor-beta superfamily, to which AMH belongs, is a multifunctional polypeptide growth factor, further studies are needed to evaluate whether AMH signaling has a role in facilitating or inhibiting luteal cell functions.
PubMed: 38924892
DOI: 10.1016/j.theriogenology.2024.06.017 -
Journal of Applied Genetics Jun 2024Expression of the telomerase reverse-transcriptase (TERT) gene and activity of telomerase have been reported in the somatic tissues and gonads in fish irrespective of...
Expression of the telomerase reverse-transcriptase (TERT) gene and activity of telomerase have been reported in the somatic tissues and gonads in fish irrespective of their age and size. Nevertheless, little is known about TERT expression in the fish eggs. In the current study, the presence of the TERT transcripts was confirmed in the rainbow trout ovulated eggs before and after activation with nonirradiated and UV-irradiated (gynogenesis) sperm. Eggs originating from eight females had high and comparable quality expressed by similar hatching rates. However, survival of the gynogenetic larvae that hatched from eggs activated with UV-irradiated sperm and further exposed to the high hydrostatic pressure (HHP) shock for duplication of the maternal chromosomes varied between females from 2.1 ± 0.4 to 40.5 ± 2.2%. Increased level of TERT transcripts was observed in eggs originating from two females, and gametes from only one of them showed improved competence for gynogenesis (27.3 ± 1.9%). In turn, eggs from the female that exhibited the highest survival after gynogenetic activation were characterized by the lowest expression of the TERT gene. Telomerase in rainbow trout eggs may compensate erosion of the telomeres during early embryonic development; however, its upregulation does not assure better development after gynogenetic activation.
PubMed: 38922511
DOI: 10.1007/s13353-024-00887-8 -
Veterinary Sciences Jun 2024The allogeneic follicular fosterage (AFF) technique transfers cumulus-oocyte complexes (COCs) from pubertal female animals to the dominant follicles of adult female... (Review)
Review
The allogeneic follicular fosterage (AFF) technique transfers cumulus-oocyte complexes (COCs) from pubertal female animals to the dominant follicles of adult female animals for further development, allowing the COCs to further develop in a completely in vivo environment. This article reviews the history of AFF and JIVET and their effects on oocyte and embryo development as well as freezing resistance. Improving the efficiency and reproducibility of AFF technology is crucial to its clinical application. This article discusses factors that affect the success rate of AFF, including differences in specific technical procedures and differences between pubertal and adult follicles. Designing standardized procedures and details to improve the synchronization of donor COCs and recipient follicle maturity and reducing the damage to COCs caused by follicular aspiration may be the direction for improving the success rate of AFF in the future.
PubMed: 38922023
DOI: 10.3390/vetsci11060276 -
Annals of the Academy of Medicine,... Jan 2024Female fecundity decreases significantly after the age of 32, and rapidly so after age 37. There is no treatment to prevent this decline. Furthermore, globally, women... (Review)
Review
INTRODUCTION
Female fecundity decreases significantly after the age of 32, and rapidly so after age 37. There is no treatment to prevent this decline. Furthermore, globally, women are getting married later and the age at which they have their first child is increasing. As of July 2023, elective egg freezing (EEF) or oocyte cryopreservation (OC) for age-related fertility decline, commenced in Singapore. With medical advancements in OC, EEF is no longer considered experimental. The aim of this review is to examine the existing literature around EEF with regard to reproductive outcomes and its safety, to better guide clinicians in counselling young single women.
METHOD
Published studies were examined to increase understanding on optimal age for EEF, ideal number of oocytes for a live birth, recommended OC protocols, cryopreservation techniques affecting thaw survival or fertilisation, oocyte storage and pregnancy risks.
RESULTS
Models predict that EEF should be performed at age <37 years and to achieve a 70% chance of live birth, women would need 14, 15 and 26 mature oocytes at ages 30-34, 35-37 and >38 years, respec-tively. An antagonist stimulation protocol with an agonist trigger would minimise ovarian hyper-stimulation syndrome and duration of stimulation without affecting outcomes. Oocyte vitrification in comparison to slow freezing increases thaw survival, fertilisation and clinical pregnancy rates. No increased risks exist for the woman, future pregnancy or child when compared with conventional IVF.
CONCLUSION
EEF is a viable option for single women desiring fertility preservation. Financial costs are significant, but returns are worthwhile if oocytes are utilised.
Topics: Humans; Cryopreservation; Female; Oocytes; Pregnancy; Fertility Preservation; Adult; Pregnancy Rate; Singapore; Vitrification; Live Birth; Ovulation Induction; Age Factors
PubMed: 38920213
DOI: 10.47102/annals-acadmedsg.2023226