Semen evaluation in human and animal reproduction relies on sperm motility and morphology; however, these often fail to predict fertility. The domestic boar (Sus scrofa) serves as a biomedical model for male reproduction due to similarities in sperm size, capacitation dynamics, and acrosomal structure to humans in comparison to traditional rodent models. This study evaluated sperm capacitation biomarkers, particularly zinc signatures, to predict cleavage success after in vitro fertilization (IVF). Semen from 20 boars (3 replicates each) was analyzed at 0, 1 and 4 h post-in vitro capacitation (IVC) using image-based flow cytometry to assess 4 zinc signatures, plasma membrane integrity, and acrosomal remodeling. Capacitation kinetics were quantified between timepoints. Motility was measured by computer-assisted semen analysis, and IVF cleavage percentages were determined. Zinc signature 1 at 4 h post-IVC negatively correlated with cleavage percentage (r = -0.366), indicating higher noncapacitated sperm proportions reduce fertilization potential. The delta of zinc signature 3 from 1 to 0 h also negatively correlated (r = -0.441), suggesting excessively rapid capacitation impairs fertilization. Models combining capacitation biomarkers, motility, kinetics, and morphology parameters had higher predictive power (R2 = 0.469) than motility models alone. Zinc signatures may serve as mechanistic fertility biomarkers in a translational boar model applicable to animal breeding and human-assisted reproduction.
Exposure to low temperature prior to insemination increases the likelihood of polyspermy in Lytechinus variegatus eggs. Electrophysiological recordings reveal that cold shock partially disrupts the egg's action potential, producing a subthreshold depolarization during the fertilization response. This attenuated shift in membrane potential appears insufficient to activate the fast block to polyspermy, allowing entry of multiple sperm. These findings identify a temperature-sensitive vulnerability in the electrical barrier to polyspermy in sea urchin eggs.
Sponges (phylum Porifera) are an early-branching lineage of Metazoa. The long independent evolution of sponges makes them an essential group for comparative studies of the emergence and early evolution of various aspects of metazoan biology, including asexual reproduction. This review provides a current critical overview of the modes of asexual reproduction in sponges with an emphasis on the morphogeneses accompanying it. Asexual reproduction occurs in all poriferan clades and has three modes: fragmentation, budding, and gemmulation. Fragmentation seems to be a universal, but unspecialized and passive form of asexual reproduction; it relies on the pronounced regeneration capabilities of sponges. Budding and gemmulation are processes that are triggered by endogenous factors and are an integral part of the life cycle in many species. Budding seems to occur in all poriferan classes but differs in its mechanisms between classes: buds in Demospongiae are formed through mesenchymal morphogeneses, while in Homoscleromorpha and Calcarea-through epithelial ones. In contrast to other modes of asexual reproduction, gemmulation is restricted to freshwater demosponges and a few brackish-water marine demosponges. Gemmules represent compact groups of dormant cells, thesocytes, coated by a thick protective coat; in favorable conditions, these cells give rise to a new individual. Gemmulation represents not only a reproduction mechanism but also a mechanism for enduring adverse environmental conditions becoming a very important alternative reproduction strategy for sponges living in discontinuous-fragmented and/or unstable environments.
In vitro oocyte maturation and embryo culture are critical for preserving and expanding genetic lines, and are necessary to produce genetically engineered pigs for biomedical and agricultural purposes. However, suboptimal in vitro conditions compromise oocyte and embryo viability. Recent improvements to in vitro maturation medium, including the addition of FGF2, LIF, and IGF1 (FLI), have increased the number of oocytes that reached the metaphase II stage, doubled the number of oocytes that reached the blastocyst stage, and quadrupled the number of piglets born after embryo transfer. Despite these benefits, the underlying cellular mechanisms remain not fully understood. Given the essential role of cumulus cells (CCs) in oocyte maturation, we investigated how FLI affects CCs gene expression. Cumulus-oocyte complexes were matured for 24 h in control or FLI media, and CCs from oocytes that reached the blastocyst stage underwent RNA sequencing. FLI altered 1257 transcripts (423 upregulated, 834 downregulated; adj-p < 0.05), with enrichment of junctional communication genes and downregulation of extracellular matrix organization. Immunofluorescence confirmed increased TJP1, TJP2, and GJA4 in FLI-treated complexes. Additionally, cortical granule localization suggested enhanced cytoplasmic maturation with FLI supplementation. These findings indicate that FLI promotes CC communication and supports improved oocyte competence in porcine in vitro maturation.
7,12-Dimethylbenz(a)anthracene (DMBA) is a polycyclic aromatic hydrocarbon formed by the combustion of organic substances and has ovotoxic and carcinogenic effects on ovarian follicular development in rodents. The Hippo signaling pathway contributes to the understanding of various molecular mechanisms, including cell proliferation, differentiation, apoptosis, organ size regulation, and tumorigenesis, as an evolutionarily conserved pathway. In this study, we hypothesized that the Hippo signaling pathway may play a role in the mechanism of DMBA-induced ovotoxicity. We aimed to identify Hippo signaling pathway proteins in DMBA-treated ovaries via immunohistochemistry and quantitative real-time PCR (qRT-PCR). Twenty-eight-day-old 18 BalbC female mice were used and divided into three groups. The control group received no treatment, the vehicle group was injected daily with sesame oil, and the DMBA group was injected intraperitoneally with 1 mg/kg/day DMBA (dissolved in sesame oil) for 14 consecutive days. The sections were subjected to periodic acid-Schiff (PAS) staining to demonstrate the morphological differences between the DMBA and control groups of mouse ovaries. Anti-Mullerian hormone (AMH) serum levels were analyzed via ELISA, and follicles were counted to evaluate the follicle reserve. Immunohistochemistry was performed to determine the localization of the Hippo signaling pathway proteins MST1/2, LATS1/2, YAP1, and TEAD4 and to assess oxidative stress with a nitrotyrosine (NTY) antibody. The mRNA levels of Hippo signaling components were detected via qRT-PCR. The Hippo signaling pathway may play a role in the mechanisms underlying the rapid depletion of follicles through increased oxidative stress, an increased number of atretic follicles, and a decreased number of corpus luteum in DMBA-induced ovotoxicity. We demonstrated that in the DMBA-induced ovotoxicity model, the Hippo signaling pathway is inactivated by YAP/TAZ translocation to the nucleus, and the increase in YAP1 and TEAD4 expression is at the translational level. This study provides the first evidence of the relationship between ovotoxicity and the Hippo signaling pathway in DMBA-induced ovotoxicity in mice. Therefore, our findings suggest that the Hippo pathway could be pharmacologically targeted to regulate DMBA-induced ovotoxicity.
