Development & reproduction最新文献

Germline cells are specified early in embryogenesis and are encapsulated by somatic cells to form the gonads (testis or ovary). This development requires genes with expression restricted to germline cells, such as the DEAD-box RNA helicase Vasa, an evolutionarily conserved protein exclusively expressed in the germline of the testis. However, the mechanisms underlying germline-specific expression remain poorly understood. To identify microRNAs that function in the somatic cells of the testis, we employed the binary Gal4/UAS expression system, which enables the expression of UAS-microRNA sponges in somatic cells driven by somatic Gal4 drivers. The screening identified the miR-932 sponge as a regulator. Testes with hub-specific Gal4 driven expression of the UAS-miR-932 sponge exhibit ectopic Vasa expression in the hub cells. Thus, our findings suggest that miR-932 in the somatic hub cells prevents Vasa expression in these cells.

Previously, we developed a short-term incubation method of rat adrenal and demonstrated that nonylphenol (NP) exposure could induce changes in secretions of adrenal hormones. In the present study, the effects of NP on changes in hormonal secretion from hypothalamus were investigated. The catecholamine levels were measured using high-performance liquid chromatography with electrochemical detection (HPLC-ECD) and the levels of gonadotropin-releasing hormone (GnRH) and kisspeptin were measured using enzyme-linked immunosorbent assay (ELISA). The norepinephrine (NE) levels from NP-treated male and female hypothalamus were not significantly changed across the entire treatment concentration (from 1 nM to 1 μM), except male 10 nM-treated group which were significantly lower than control (p<0.05). The epinephrine (E) levels from NP-treated female hypothalamus were significantly increased in 100 pM- and 1 nM-trated group (p<0.05). However, the E levels from NP-treated male hypothalamus were significantly decreased in 100 pM- and 10 nM-treated group (p<0.05). The GnRH levels from NP-treated hypothalamus showed an increasing trend, especially significant in male 10 nM- and 100 nM-treated groups (p<0.001) and female 1 nM-, 100 nM- and 1 μM-trated groups (p<0.05, p<0.01 and p<0.05, respectively). Also, the kisspeptin levels in incubated media of both sexes showed a strong increasing trend, especially significant in male 1 nM- and 10 nM-treated groups (p<0.05) and all of female groups except 10 nM-treated. In conclusion, our incubation method could be quite suitable for rapidly and effectively measuring endocrine disrupting chemicals (EDC) activity in hypothalamus. NP treatment shown stimulatory effects on both GnRH and kisspeptin secretions from hypothalamus of both sexes, suggesting possible relationship between NP exposure and reproductive phenomena and related disorders.

Gonadotropins, such as follicle-stimulating hormone (FSH) and human chorionic gonadotropin (hCG), are widely used to induce ovarian hyperovulation during in vitro fertilization and embryo transfer (IVF-ET) for the treatment of infertility. However, the effects of repeated administration of these gonadotropins on immune function, particularly on T cell development in the thymus, remain poorly understood. This study investigated the effects of repeated administration of pregnant mare serum gonadotropin (PMSG) and hCG on thymic T cell development in mice. Histological analysis revealed structural changes in the thymus, including a blurred boundary between the medulla and cortex and reduced vascularization after repeated administration of PMSG and hCG. Quantitative real-time PCR showed increased expression of adipogenesis-related genes [phosphoenolpyruvate carboxykinase (PEPCK), adipocyte fatty acid-binding protein 2 (aP2), peroxisome proliferator-activated receptor gamma (PPARγ)] but no significant changes in thymic epithelial cell-related genes [autoimmune regulator (AIRE), epithelial V-like antigen (EVA), interleukin 7 (IL-7)]. Flow cytometry revealed a decrease in CD4⁺CD8⁺ T cells and an increase in CD4-CD8-T cells with altered CD25/CD44 subsets. In addition, CD4⁺ and CD8⁺ T cells in the spleen were significantly reduced. These findings suggest that repeated gonadotropin exposure may disrupt thymic T cell development and peripheral T cell populations, potentially impairing immune function. Further research is needed to elucidate the underlying mechanisms and broader immunologic consequences of gonadotropin use in infertility treatment.

The egg quality is a representative limiting factor in developing culture techniques for certain fish species. It is a known predictor of subsequent larval viability, quality, and stress resistance related to aquaculture productivity. Here we tracked egg quality in a second generation of broodstock small yellow croacker, Larimichthys polyactis. Cultured second generation broodstock (3 years old, 600 fishes) was reared in indoor tank (30 tons). We induced natural spawning with increasing water temperature (11.5°C22.0°C) and regulation of photoperiod (9L:15D). We used spawning events from spawning period and monitored basic morphometrics such as: egg viability, egg diameter (ED), oil droplet diameter (OD) and oil droplet volume. Natural spawning of the broodstock was maintained for 23 days. EDs and OD for L. polyactis decreased as the spawning season progressed and water temperature increased. We showed that smaller eggs lead to higher quality with viability, and that using eggs later in the spawning season would lead to better production. In addition, the volume of oil droplet was the strongest factors for prediction of egg viability for cultured second generation of small yellow croaker.

While Pacific oysters are important commercial aquaculture species worldwide, the effect of hormonal regulation and environmental conditions on growth and taste profile have not been fully known. Insulin-like growth factor (IGF) systems are known to play a major role in regulating neuroendocrine functions across various physiological processes and are particularly involved in growth. IGFs expression also is directly related to the nutritional status of vertebrates, however, full mechanism has not been clearly identified in bivalves. In this study, differences in growth, IGFs expression, and taste according to cultivation site of Pacific oysters were investigated. Oysters were collected in three different spawning sites located on the south coast of Korea in July 2022 and hardened until June 2023. Then, the oysters were cultured in two different growing sites (Tongyeong site, TS; Geoje site, GS) for six months. The total weight of oysters, along with their condition index and tissue weight rate, was significantly higher in TS. Additionally, IGF expression was higher in TS during most of the sampled months. However, oysters from the GS scored higher in taste evaluations. The IGFs system in oysters shows a similar trend to previous studies, with higher levels in faster-growing individuals, suggesting oysters in TS were more adequately nourished by the surrounding environment in this research. However, in taste evaluation, oysters from the GS showed better results than those from the TS. Despite these results, determining whether one site is superior in certain aspects is still not fully possible, which warrants further investigations.

We previously reported that metformin, a widely prescribed antidiabetic drug, induces the accumulation of triglyceride (TG) together with the apoptotic death of H4IIE via AMP-activated protein kinase (AMPK) in hepatocellular carcinoma (HCC) cells. However, the effect of cytoplasmic fat accumulation on the growth of HCCs remains controversial. Herein, we investigated the effect of fatty acid synthase (FASN) inhibitors on the basal- or metformin-induced changes including the content of cytoplasmic TG and the viability of HCC cells. Cerulenin and C75, inhibitors of FASN, did not significantly affect the basal TG content but dose-dependently suppressed the metformin-induced increase in the cytoplasmic TG content. Metformin-induced apoptosis of H4IIE cells was also significantly reduced by cerulenin and C75. Metformin enhanced the generation of reactive oxygen species which was suppressed by adding cerulenin or T75. Cerulenin also stimulated cell migration, which was suppressed by metformin. However, the degree of suppressive effect of metformin on TG synthesis, apoptosis, and cell migration was much more prominent by the inhibition of AMPK by compound C than cerulenin. In conclusion, our study found that excess fat accumulation is responsible for the apoptosis of H4IIE HCC cells and is informative for designing anti-tumor reagents, especially in HCC.

Lutropin/choriogonadotropin receptor (LH/CGR) is a member of the G protein-coupled receptor superfamily. LH/CGRs in fish and mammalian species have been reported to contain naturally occurring, constitutively activating, and inactivating mutations in highly conserved regions. The present study was designed to determine the functional aspect of eel LH/CGR signal transduction. Biochemical analysis was performed using cells transfected with wild-type eel LH/CG (eel LH/CGR-wt) or with activating (designated eel LH/CGR-M410T, L469R, and D590Y) and inactivating (eel LH/CGR-D 417N and Y558F) mutants. We also generated a mutant (eel LH/CGR-t651) in which the C-terminal cytoplasmic tail was truncated at residue 651. Activating mutant cells expressing eel LH/CGR-M410T, L469R, and D590Y exhibited 1.4-, 8.7-, and 4.0-fold increases in the basal cAMP response, respectively, without recombinant equine chorionic gonadotropin (rec-eCG) agonist treatment. In inactivating mutants (eel LH/CGR-D417N and Y558F), the cyclic adenosine monophosphate (cAMP) response did not result in completely impaired signal transduction. However, the eel LH/CGR-t651 mutant did not exhibit any cAMP signaling following high-agonist treatment. Rmax values did not increase with further rec-eCG agonist stimulation. Our results suggest that constitutively activating and inactivating eel LH/CGR mutants with highly conserved amino acids exhibit a significant signal transduction pathway for glycoprotein hormone receptors. Eel LH/CGRs in activating and inactivating mutants are usually processed by receptor-mediated signaling following rec-eCG agonist stimulation.

Maintenance of neural progenitors requires Notch signaling in vertebrate development. Previous study has shown that Jagged2-mediated Notch signaling maintains proliferating neural progenitors in the ventral spinal cord. However, components for Jagged-mediated signaling remain poorly defined during late neurogenesis. Here we performed yeast-two hybrid screening by using the intracellular domain (ICD) of zebrafish Jagged2, and investigated a possible role of PEX1 as a component of Notch signaling for the cell-fate decision and the differentiation of neural precursors in p3 domain. Western blotting showed that zebrafish PEX1 might interacts with the ICD of zebrafish Jagged2 physically. PEX1 morpholino-injected embryos showed the increased number of GABAergic KA" neurons as well as the ectopic expression of secondary motor neurons in the p3 domain. The increased number of KA" neurons was also observed in the zebrafish embryos with PEX1 mutation induced by CRISPR/Cas9. These phenotypes resemble with that of Jagged2 morphant. Our observations imply that a critical role of PEX1 in the cell-fate decision of proliferating neural precursors in the p3 domain during the continuing growth and development of the vertebrate nervous system.

The epididymal fat is required for the maintenance of normal spermatogenesis, and the lipectomy of epididymal fat at different postnatal age results in disrupted expression patterns of several testicular steroidogenic enzymes. The current research examined the effect of epididymal fat lipectomy at different postnatal ages on expression of cytochrome 5α-reductase I, cytochrome P450 aromatase, androgen receptor (AR), and estrogen receptors (ER) α and β in the mouse testis after 2 weeks of the lipectomy. The lipectomy of epididymal fat at 2 months of postnatal age resulted in significant increases of expression levels of cytochrome 5α-reductase I, cytochrome P450 aromatase, AR, and ER α and β. However, expressions of these genes in the testis were significantly decreased by the lipectomy of epididymal fat at 5 months of postnatal age. The lipectomy of epididymal fat at 8 months and 12 months of postnatal ages did not influence expression levels of cytochrome 5α-reductase I, cytochrome P450 aromatase, AR, and ER β. However, a significant decrease of ER α was detected with the lipectomy of epididymal fat at 12 months of postnatal age. These observations suggest that expression of these genes in the testis by the influence of the epididymal fat is more susceptible at the earlier postnatal development than at the later postnatal period.

The ascidian larvae, which display a chordate ground body plan, are left-right asymmetric in several structures, including the brain vesicle. In ascidian larvae, the ocellus and otolith pigment cells, which are thought to detect light and gravity respectively, are located on the right side of the brain vesicle, while the coronet cells, which are presumed to be dopaminergic, are located on the left side. To study how left-right asymmetry of the brain vesicle in the ascidian Halocynthia roretzi larva is determined, I attempted to isolate a gene that is expressed in the brain vesicle. As a result, an ascidian Parkin co-regulated gene (PACRG) orthologue was cloned. Expression of PACRG begins weakly in the head region of the late tailbud embryos, and it thereafter is observed on the left side of the brain vesicle of the larvae just before hatching. The location of PACRG expression is estimated to overlap with the area stained by the coronet cell-specific antibody. Thus, it is suggested that PACRG might be involved in the formation of the left-side structures of the brain vesicle, including coronet cells, during ascidian embryogenesis.