Search Results (530)

Background: Lappula patula (L. patula) is a plant with known medicinal properties, and its extracts have shown promise as potential anti-cancer agents. This study aimed to evaluate the nematocidal effects of L. patula extracts and investigate their impact on germline development, DNA damage responses, and apoptosis in Caenorhabditis elegans (C. elegans), a model organism for studying these processes. Methods: C. elegans was exposed to L. patula extracts to assess survival, development, and incidence of male phenotype. Germline abnormalities were examined using microscopy at different developmental stages. The DNA damage response was evaluated through the expression of the atm-1, atl-1 and pCHK-1. Apoptosis was quantified by monitoring cell death during the pachytene stage. LC-MS was used to identify bioactive compounds within the extracts. Results: Exposure to L. patula extracts resulted in a dose-dependent reduction in worm survival and larval developmental progress, with no significant impact on the male incidence. Germline defects were observed, including increased nuclear spacing at premeiotic and pachytene stages, altered number of bivalents during diakinesis. These defects correlated with a significant decrease in brood size. Also, L. patula extracts activated the DNA damage response pathway, marked by increased expression of atm-1 and atl-1. Moreover, the extracts induced apoptosis in the germline in a pCHK-1-independent manner. LC-MS analysis revealed 31 potential anti-tumor compounds, supporting the extract’s cytotoxic properties. Conclusions: Lappula patula extracts exhibit potent nematocidal and cytotoxic properties, suggesting their potential for cancer therapy. The observed DNA damage and apoptosis in C. elegans emphasize the extract’s promising role in anti-cancer drug development. Further studies are needed to explore the therapeutic potential of these compounds in clinical settings. Full article

Aromatase inhibitor letrozole (LZ) and 17α-methyltestosterone (MT) are commonly used for sex control breeding to induce female-to-male sex reversal in aquaculture. However, studies on the molecular regulatory mechanisms of LZ and MT are still limited. Here, a comparative transcriptome analysis was conducted on the hypothalamus, the gonad, and the liver of golden pompano (Trachinotus ovatus) after 30 days of LZ and MT treatment, which demonstrated significant sexual size dimorphism. Following LZ treatment, the transcriptome data identified 156, 890, and 1286 different expression genes (DEGs) in the hypothalamus, the liver, and the gonad, respectively. After MT treatment, the transcriptome data identified 114, 876, and 950 DEGs in the hypothalamus, the liver, and the gonad, respectively. Functional enrichment analysis revealed that DEGs were involved in oocyte meiosis and steroid-hormone synthesis following LZ treatment. Similarly, the analysis indicated that DEGs were associated with cysteine and methionine metabolism and steroid-hormone synthesis after MT treatment. Further analysis showed that LZ treatment can promote the first meiotic division but inhibit the second meiotic division of the oocyte. MT treatment promotes polyamine synthesis to induce oocyte apoptosis, both of which affect the trajectory of ovarian differentiation in golden pompano. However, LZ and MT have converse effects in sex hormone synthesis. LZ inhibits estrogen metabolism but promotes cholesterol synthesis by regulating sqle, cyp3a40, ugt1a1, and ugt2a1, while MT promotes estrogen metabolism but inhibits the conversion of cholesterol to pregnenolone by regulating cyp19a1, cyp1a, and hsd17b7. This study reveals that both LZ and MT may inhibit the ovarian differentiation and induce masculinization through different regulatory mechanisms, which provides a fundamental insight into the sex control breeding in aquaculture. Full article

Retinoic acid (RA) plays a critical role in initiating meiosis in primordial germ cells (PGC), yet the specific mechanisms of its interaction with PGC remain unclear. In this study, we used an in vitro feeder-free culture system with chicken PGC as a model to explore the mechanisms by which RA induces the entry of PGC into meiosis. Results demonstrated that exogenous RA treatment altered the cell cycle distribution of PGC, significantly increasing the proportion of cells in the G1 phase and decreasing those in the G2 phase, suggesting that RA may promote the transition of PGC from proliferation to differentiation. Giemsa staining further revealed that chromosomes in a subset of RA-treated PGC exhibited meiotic characteristics. Through combined RNA-seq and ATAC-seq analyses, we identified that CYP26A1, a gene involved in RA degradation, was significantly upregulated in the RA-treated group, with enhanced accessibility in its chromatin regions. This finding suggests a robust mechanism for self-regulation of RA levels within PGC, indicating that CYP26A1 may play a pivotal role in the degradation of exogenous RA in chicken PGC. This study elucidated the effects of RA on chicken PGC and provided new insights into the role of RA in germ cell differentiation. Full article

In eukaryotes, mRNAs with long poly(A) tails are translationally active, but deadenylation and uridylation of these tails generally cause mRNA degradation. However, the fate of uridylated mRNAs that are not degraded quickly remains obscure. Here, using tail-seq and microinjection of the 3′ region of mRNA, we report that some mRNAs in starfish are re-polyadenylated to be translationally active after deadenylation and uridylation. In oocytes, uridylated maternal cyclin B mRNAs are stable without decay, and they are polyadenylated to be translated after hormonal stimulation to resume meiosis, whereas they are deadenylated and re-uridylated at the blastula stage, followed by decay. Similarly, deadenylated and uridylated maternal ribosomal protein mRNAs, Rps29 and Rpl27a, were stable and inactive after hormonal stimulation, but they had been polyadenylated and active before hormonal stimulation. At the morula stage, uridylated maternal ribosomal protein mRNAs were re-polyadenylated, rendering them translationally active. These results indicate that uridylated mRNAs in starfish exist in a poised state, allowing them to be recycled or decayed. Full article

Zea mays (maize) is both an agronomically important crop and a powerful genetic model system with an extensive molecular toolkit and genomic resources. With these tools, maize is an optimal system for cytogenetic study, particularly in the investigation of chromosome segregation. Here, we review the advances made in maize chromosome segregation, specifically in the regulation and dynamic assembly of the mitotic and meiotic spindle, the inheritance and mechanisms of the abnormal chromosome variant Ab10, the regulation of chromosome–spindle interactions via the spindle assembly checkpoint, and the function of kinetochore proteins that bridge chromosomes and spindles. In this review, we discuss these processes in a species-specific context including features that are both conserved and unique to Z. mays. Additionally, we highlight new protein structure prediction tools and make use of these tools to identify several novel kinetochore and spindle assembly checkpoint proteins in Z. mays. Full article

Alternative splicing of ddx4 (DEAD-box helicase 4), a key germline marker gene, has been reported to generate sex-specific transcripts in zebrafish gonads. The biological functions and regulatory mechanisms of the ddx4 ovary-specific transcript (ddx4-L) during oogenesis remain unclear. In this study, we found that ddx4-L mutants, in which ddx4-L was specifically deleted, had enlarged ovaries but laid fewer eggs, along with having a lower fertilization rate compared to WT controls. RNA-seq analysis was performed to detect the changes in gene expression between WT and ddx4-L mutant ovaries. A total of 524 upregulated and 610 downregulated DEGs were identified. GO and GSEA enrichment analyses showed that genes involved in fertilization and reproduction biological processes were significantly downregulated. More specifically, we observed a remarkable reduction in Sycp1, a core component of synaptonemal complex, in ddx4-L mutant ovaries at both the mRNA and protein levels. In addition, the expressions of transposon elements, as well as the events of alternative splicing, alternative polyadenylation, and RNA editing, were analyzed based on the RNA-seq data. We found that the deletion of ddx4-L resulted in derepression of DNA transposons in zebrafish ovaries, possibly causing genome instability. In conclusion, our work demonstrates that the ovary-specific ddx4 transcript plays important roles in oocyte meiosis and DNA transposon repression, which extends our understanding of the biological functions and regulatory mechanisms of sex-specific alternative splicing in zebrafish oogenesis and reproduction. Full article

Genetic anomalies in oocyte maturation present significant fertility and embryonic development challenges. This review explores the intricate mechanisms of nuclear and cytoplasmic maturation, emphasizing the genetic and molecular factors contributing to oocyte quality and competence. Chromosomal mutations, errors in segregation, genetic mutations in signaling pathways and meiosis-related genes, and epigenetic alterations are discussed as critical contributors to oocyte maturation defects. The role of mitochondrial defects, maternal mRNA dysregulation, and critical proteins such as NLRP14 and BMP6 are highlighted. Understanding these genetic factors is crucial for improving diagnostic approaches and therapeutic interventions in reproductive medicine, particularly for couples encountering recurrent in vitro fertilization failures. This review will explore how specific genetic mutations impact fertility treatments and reproductive success by examining the intricate oocyte maturation process. We will focus on genetic abnormalities that may disrupt the oocyte maturation pathway, discussing the underlying mechanisms involved and considering their potential clinical implications for enhancing fertility outcomes. Full article

The cell cycle, essential for growth, reproduction, and genetic stability, is regulated by a complex network of cyclins, Cyclin-Dependent Kinases (CDKs), phosphatases, and checkpoints that ensure accurate cell division. CDKs and phosphatases are crucial for controlling cell cycle progression, with CDKs promoting it and phosphatases counteracting their activity to maintain balance. The nucleolus, as a biomolecular condensate, plays a key regulatory role by serving as a hub for ribosome biogenesis and the sequestration and release of various cell cycle regulators. This phase separation characteristic of the nucleolus is vital for the specific and timely release of Cdc14, required for most essential functions of phosphatase in the cell cycle. While mitosis distributes chromosomes to daughter cells, meiosis is a specialized division process that produces gametes and introduces genetic diversity. Central to meiosis is meiotic recombination, which enhances genetic diversity by generating crossover and non-crossover products. This process begins with the introduction of double-strand breaks, which are then processed by numerous repair enzymes. Meiotic recombination and progression are regulated by proteins and feedback mechanisms. CDKs and polo-like kinase Cdc5 drive recombination through positive feedback, while phosphatases like Cdc14 are crucial for activating Yen1, a Holliday junction resolvase involved in repairing unresolved recombination intermediates in both mitosis and meiosis. Cdc14 is released from the nucleolus in a regulated manner, especially during the transition between meiosis I and II, where it helps inactivate CDK activity and promote proper chromosome segregation. This review integrates current knowledge, providing a synthesis of these interconnected processes and an overview of the mechanisms governing cell cycle regulation and meiotic recombination. Full article

Background: Balanced chromosomal translocations occur in approximately 0.16 to 0.20% of live births. While most carriers are phenotypically normal, they are at risk of generating unbalanced gametes during meiosis, leading to genetic anomalies such as aneuploidies, deletions, duplications, and gene disruptions. These anomalies can result in spontaneous abortions or congenital anomalies, including neurodevelopmental disorders. Complex chromosomal rearrangements (CCRs) involving more than two chromosomes are rare but further increase the probability of producing unbalanced gametes. Neurodevelopmental disorders such as Angelman syndrome (AS) and duplication 15q11q13 syndrome (Dup15q) are associated with such chromosomal abnormalities. Methods: This study describes a family with a de novo maternal balanced double translocation involving chromosomes 13, 19, and 15, resulting in two offspring with unbalanced chromosomal abnormalities. Cytogenetic evaluations were performed using GTG banding, fluorescence in situ hybridization (FISH), and low-pass whole-genome sequencing (LP-WGS). Methylation analysis was conducted using methylation-sensitive high-resolution melting (MS-HRM) to diagnose Angelman syndrome. Results: The cytogenetic and molecular analyses identified an 8.9 Mb duplication in 15q11.2q13.3 in one child, and an 8.9 Mb deletion in the same region in the second child. Both abnormalities affected critical neurodevelopmental genes, such as SNRPN. FISH and MS-HRM confirmed the chromosomal imbalances and the diagnosis of Angelman syndrome in the second child. The maternal balanced translocation was found to be cryptic, contributing to the complex inheritance pattern. Conclusion: This case highlights the importance of using multiple genetic platforms to uncover complex chromosomal rearrangements and their impact on neurodevelopmental disorders. The findings underscore the need for thorough genetic counseling, especially in families with such rare chromosomal alterations, to manage reproductive outcomes and neurodevelopmental risks. Full article

Barth syndrome (BTHS) is a rare, infantile-onset, X-linked mitochondriopathy exhibiting a variable presentation of failure to thrive, growth insufficiency, skeletal myopathy, neutropenia, and heart anomalies due to mitochondrial dysfunction secondary to inherited TAFAZZIN transacetylase mutations. Although not reported in BTHS patients, male infertility is observed in several Tafazzin (Taz) mouse alleles and in a Drosophila mutant. Herein, we examined the male infertility phenotype in a BTHS-patient-derived D75H point-mutant knockin mouse (Taz^PM) allele that expresses a mutant protein lacking transacetylase activity. Neonatal and adult Taz^PM testes were hypoplastic, and their epididymis lacked sperm. Histology and biomarker analysis revealed Taz^PM spermatogenesis is arrested prior to sexual maturation due to an inability to undergo meiosis and the generation of haploid spermatids. Moreover, Taz^PM testicular mitochondria were found to be structurally abnormal, and there was an elevation of p53-dependent apoptosis within Taz^PM seminiferous tubules. Immunoblot analysis revealed that Taz^PM gamete genome integrity was compromised, and both histone γ-H2Ax and Nucleoside diphosphate kinase-5 protein expression were absent in juvenile Taz^PM testes when compared to controls. We demonstrate that Taz-mediated transacetylase activity is required within mitochondria for normal spermatogenesis, and its absence results in meiotic arrest. We hypothesize that elevated Taz^PM spermatogonial apoptosis causes azoospermia and complete infertility. Full article

Gonadotropins and progestins are the primary regulators of follicle maturation and ovulation in fish, and they require complex communication among the oocyte and somatic cells of the follicle. The major progestin and the maturation-inducing hormone in salmonids is 17α,20β-dihdroxy-4-pregnen-3-one (17,20βP), and traditional nuclear receptors and membrane steroid receptors for the progestin have been identified within the follicle. Herein, RNA-seq was used to conduct a comprehensive survey of changes in gene expression throughout the intact follicle in response to in vitro treatment with these hormones to provide a foundation for understanding the coordination of their actions in regulating follicle maturation and preparation for ovulation. A total of 5292 differentially expressed genes were identified from our transcriptome sequencing datasets comparing four treatments: fresh tissue; untreated control; 17,20βP-treated; and salmon pituitary homogenate-treated follicles. Extensive overlap in affected genes suggests many gonadotropin actions leading to the acquisition of maturational and ovulatory competence are mediated in part by gonadotropin induction of 17,20βP synthesis. KEGG analysis identified signaling pathways, including MAPK, TGFβ, FoxO, and Wnt signaling pathways, among the most significantly enriched pathways altered by 17,20βP treatment, suggesting pervasive influences of 17,20βP on actions of other endocrine and paracrine factors in the follicle complex. Full article

Background/Objectives: We analyzed the relationship between synapsis, recombination, and transcription during the spermatogenesis of the grasshopper Eyprepocnemis plorans carrying B chromosomes (type B1). Methods: The progression of synapsis was interpreted according to the dynamics of the cohesin subunit SMC3 axes. DNA double-strand breaks were revealed by RAD51 immunolabeling, while transcriptional activity was determined by the presence of RNA polymerase II phosphorylated at serine 2 (pRNApol II) immunolabeling. The two repressive epigenetic modifications, histone H3 methylated at lysine 9 (H3K9me3) and histone H2AX phosphorylated at serine 139 (γ-H2AX), were employed to reveal transcriptional inactivity. Results: During prophase I, spermatocytes with one B1 chromosome showed overall transcription except in the regions occupied by both the X and the B1 chromosomes. This transcriptional inactivity was accompanied by the accumulation of repressive epigenetic modifications. When two B1 chromosomes were present, they could appear as a fully synapsed monochiasmatic bivalent, showing intense H3K9me3 labeling and absence of pRNApol II, while γ-H2AX labeling was similar to that shown by the autosomes. Conclusions: According to our results, B1 transcriptional inactivation was triggered in spermatogonia, long before the beginning of meiosis, and was accompanied by H3K9me3 heterochromatinization that was maintained throughout spermatogenesis. Moreover, when two B1 were present, the transcriptional inactivation did not preclude synapsis and recombination achievement by these chromosomes. Full article

(1) Background: Nucleosomes represent the essential structural units of chromatin and serve as key regulators of cell function and gene expression. Oocytes in the germinal vesicle (GV) stage will later undergo meiosis and become haploid cells ready for fertilization, while somatic cells undergo mitosis after DNA replication. (2) Purpose: To furnish theoretical insights and data that support the process of cell reprogramming after nuclear transplantation. (3) Methods: We compared the nucleosome occupancy, distribution, and transcription of genes between two types of cells: fully grown GV oocytes from big follicles (BF) and somatic cells (porcine embryonic fibroblast, PEF). (4) Results: The nucleosome occupancy in the promoter of BF was 4.85%, which was significantly higher than that of 3.3% in PEF (p < 0.05), and the nucleosome distribution showed a noticeable increase surrounding transcriptional start sites (TSSs) in BF. Next, we reanalyzed the currently published transcriptome of fully grown GV oocytes and PEF, and a total of 51 genes in BF and 80 genes in PEF were identified as being uniquely expressed. The nucleosome distribution around gene TSSs correlated with expression levels in somatic cells, yet the results in BF differed from those in PEF. (5) Conclusion: This study uncovers the dynamic nature and significance of nucleosome positioning and chromatin organization across various cell types, providing a basis for nuclear transplantation. Full article

In a study involving 385 Large White pigs, a genome-wide association study (GWAS) was conducted to investigate reproductive traits, specifically the number of healthy litters (NHs) and the number of weaned litters (NWs). Several SNP loci, including ALGA0098819, ALGA0037969, and H3GA0032302, were significantly associated with these traits. In the combined-parity analysis, candidate genes, such as BLVRA, STK17A, PSMA2, and C7orf25, were identified. GO and KEGG pathway enrichment analyses revealed that these genes are involved in key biological processes, including organic synthesis, the regulation of sperm activity, spermatogenesis, and meiosis. In the by-parity analysis, the PLCXD3 gene was significantly associated with the NW trait in the second and fourth parities, while RNASEH1, PYM1, and SEPTIN9 were linked to cell proliferation, DNA repair, and metabolism, suggesting their potential role in regulating reproductive traits. These findings provide new molecular markers for the genetic study of reproductive traits in Large White pigs. For the phenotypic prediction of NH and NW traits, several machine learning models (GBDT, RF, LightGBM, and Adaboost.R2), as well as traditional models (GBLUP, BRR, and BL), were evaluated using SNP data in varying proportions. After PCA processing, the GBDT model achieved the highest PCC for NH (0.141), while LightGBM reached the highest PCC for NW (0.146). The MAE, MSE, and RMSE results showed that the traditional models exhibited stable error rates, while the machine learning models performed comparatively better across the different SNP ratios. Overall, PCA processing provided some improvement in the predictive performance of all of the models, though the overall increase in accuracy was limited. Full article

The goat breeding industry on the Tibetan Plateau faces strong selection pressure to enhance fertility. Consequently, there is an urgent need to develop goat lines with higher fertility and adaptability. The ovary, as a key organ determining reproductive performance, is regulated by a complex transcriptional network involving numerous protein-coding and non-coding genes. However, the molecular mechanisms of the key mRNA–miRNA–lncRNA regulatory network in goat ovaries remain largely unknown. This study focused on the histology and differential mRNA/miRNA/lncRNA between Chuanzhong black goat (CBG, high productivity, multiple births) and Tibetan goat (TG, strong adaptability, single birth) ovaries. Histomorphological analysis showed that the medulla proportion in CBG ovaries was significantly reduced compared to TG. RNA-Seq and small RNA-Seq analysis identified 1218 differentially expressed (DE) mRNAs, 100 DE miRNAs, and 326 DE lncRNAs, which were mainly enriched in ovarian steroidogenesis, oocyte meiosis, biosynthesis of amino acids and protein digestion, and absorption signaling pathways. Additionally, five key mRNA–miRNA–lncRNA interaction networks regulating goat reproductive performance were identified, including TCL1B–novel68_mature–ENSCHIT00000010023, AKAP6–novel475_mature–ENSCHIT00000003176, GLI2–novel68_mature–XR_001919123.1, ITGB5–novel65_star–TCONS_00013850, and VWA2–novel71_mature–XR_001919911.1. Further analyses showed that these networks mainly affected ovarian function and reproductive performance by regulating biological processes such as germ cell development and oocyte development, which also affected the plateau adaptive capacity of the ovary by participating in the individual immune and metabolic capacities. In conclusion, we identified numerous mRNA–miRNA–lncRNA interaction networks involved in regulating ovarian function and reproductive performance in goats. This discovery offers new insights into the molecular breeding of Tibetan Plateau goats and provides a theoretical foundation for developing new goat lines with high reproductive capacity and strong adaptability to the plateau environment. Full article