Early Stages Of Ovarian Development Research Articles

Effects of flowing water stimulation on hormone regulation during the maturation process of Conger myriaster ovaries.

Conger eel (Conger myriaster) is an economically important species in China. Due to the complex life history of the conger eel, achieving artificial reproduction has remained elusive. This study aimed to explore the effect of water stimulation on hormonal regulation during the artificial reproduction of conger eel. The experiment was divided into four groups: A1 (no hormone injection, still water), A2 (no hormone injection, flowing water), B1 (hormone injection, still water), and B2 (hormone injection, flowing water). The flowing water group maintained a flow velocity of 0.4 ± 0.05m/s for 12h daily throughout the 60-day period. Steroid hormone levels in the serum and ovaries of conger eels were analyzed using UPLC-MS/MS and ELISA on the 30th and 60th days of the experiment. The relative expression levels of follicle-stimulating hormone (FSHβ) and luteinizing hormone (LHβ) in the pituitary were determined by quantitative PCR. The results showed a significantly lower gonadosomatic index (GSI) in B2 compared to B1 (p < 0.05) on the 30th day. FSH was found to act only in the early stages of ovarian development, with water stimulation significantly enhancing FSH synthesis (p < 0.05), while FSHβ gene was not expressed after hormone injection. Conversely, LH was highly expressed in late ovarian development, with flowing water stimulation significantly promoting LH synthesis (p < 0.05). Serum cortisol (COR) levels were significantly higher in the flowing water group than in the still water group (p < 0.05). Furthermore, estradiol (E2) content of B2 was significantly lower than that of B1 on the 30th and 60th day. Overall, flowing water stimulation enhanced the synthesis of FSH in early ovarian development and LH in late ovarian development, while reducing E2 accumulation in the ovaries. In this study, the effect of flowing water stimulation on hormone regulation during the artificial reproduction of conger eel was initially investigated to provide a theoretical basis for optimizing artificial reproduction techniques.

Comparative transcriptomic analysis of the different developmental stages of ovary in the cuttlefish Sepia pharaonis

The cuttlefish, Sepia pharaonis, is characterized by rapid growth and strong disease resistance, making it an important commercially farmed cephalopod species in the southeastern coastal regions of China. However, in the reproductive process of S. pharaonis, there are challenges such as a low output of eggs, poor quality, and low survival rates of newly hatched juveniles. Therefore, there is an urgent need to study the molecular mechanisms underlying ovarian development in this species. In this study, we conducted the first transcriptomic analysis of the ovary at four developmental stages: the undeveloped stage, developing stage, nearly-ripe stage, and ripe stage, and compared the transcriptomics among these four stages using Illumina sequencing technology. The total numbers of clean reads of the four stages ranged from 40,890,772 to 52,055,714 reads. A total of 136,829 DEGs were obtained, GC base ratios of raw data were between 38.44 and 44.59%, and the number of uniquely mapped reads spanned from 88.08 to 95.90%. The Pearson correlation coefficient demonstrated a strong correlation among different samples within the same group, PCA and Anosim analysis also revealed that the grouping of these four stages was feasible, and each stage could be distinguished from the others. GO enrichment analysis demonstrated that ovarian follicle growth, sex differentiation, and transforming growth factor beta receptor, played a foreshadowing role at the early ovarian development stage, and the terms of small molecule metabolic process, peptide metabolic process, and catalytic activity were prominent at the mature stage. Meanwhile, KEGG analysis showed that the early ovarian development of S. pharaonis was mainly associated with the cell cycle, DNA replication, and carbon metabolism, while the mid-late ovarian development was involved with the signal transduction, endocrine system, and reproduction pathway. RT-qPCR further confirmed the consistent expression patterns of genes such as 17β-HSD, GH, VGS, NFR, and NYR in the ovaries of S. pharaonis, exhibiting elevated levels of expression during the maturation stage. Conversely, ER and OM exhibited high expression levels during the early stages of ovarian development. These transcriptomic data provide insights into the molecular mechanisms of S. pharaonis ovarian development. The findings of this study will contribute to improving the reproduction and development of cuttlefish and enriching the bioinformatics knowledge of cephalopods.

Posthatch developmental changes in the ovary with emphasis on follicular development and atresia in the native chicken (Uttara fowl) of Uttarakhand, India.

This experiment was designed to investigate the postnatal development of the ovary in the Uttara fowl chicken and was conducted on 54 apparently healthy female birds divided into different age groups, namely Day 1 and Weeks 1, 4, 8, 12, 16, 20, 24, 28 with six birds each. During postnatal development, the left ovary gradually increased in size and complexity. The segmentation of the ovary started by 4 weeks, follicular eruption by 8 weeks, small liquor follicles (1-5 mm) appeared by 16 weeks, pre-hierarchical follicles by 20 weeks and hierarchical follicles by 24 weeks of age. The cortex was distinctly differentiated from the medulla in the early stage of ovarian development. However, the division between cortex and medulla was gradually obscured with age (transitional stage) and distinction was completely lost in the mature ovary. The different stages of follicular development in the chicken ovary were classified as primordial, primary, growing at Stage I, II and III stromal follicles besides pre-hierarchical and hierarchical surface follicles. The primordial and primary follicles showed cytoplasmic sudanophilic substances, especially in the Balbiani's yolk body, indicating the presence of lipids (Sudan Black B) with no activity for neutral polysaccharides (periodic acid Schiff method). It was observed that apoptotic changes may affect any stage of developing follicle resulting in arrested growth and atrophy. An early form of follicular atresia was the fate of the growth-arrested primordial and primary follicles, whereas the glandular form of atresia was commonly observed in growing follicles arrested at Stages I and II. The scanning electron micrographs unveiled the follicles as hollow oval structures with a follicular lumen lined by the perivitelline membrane (glycoprotein membrane) having lacunae giving a honeycomb-like appearance.

Molecular Characterization Related to Ovary Early Development Mechanisms after Eyestalk Ablation in Exopalaemon carinicauda.

Eyestalk ablation is an effective method to promote ovarian development in crustaceans. Herein, we performed transcriptome sequencing of ovary and hepatopancreas tissues after eyestalk ablation in Exopalaemon carinicauda to identify genes related to ovarian development. Our analyses led to the identification of 97,383 unigenes and 190,757 transcripts, with an average N50 length of 1757 bp. In the ovary, four pathways related to oogenesis and three related to oocyte rapid growth were enriched. In the hepatopancreas, two vitellogenesis-associated transcripts were identified. Furthermore, short time-series expression miner (STEM) and gene ontology (GO) enrichment analyses revealed five terms related to gamete generation. In addition, two-color fluorescent in situ hybridization results suggested that dmrt1 might play a vital role in oogenesis during the early stage of ovarian development. Overall, our insights should support future studies focusing on investigating oogenesis and ovarian development in E. carinicauda.

Sex steroids and steroidogenesis-related genes in the sea cucumber, Holothuria scabra and their potential role in gonad maturation

The sea cucumber Holothuria scabra is an economically valuable marine species which is distributed throughout the Asia–Pacific region. With the natural population declining due to over fishing, aquaculture of this species is deemed necessary. Hence, it is essential to understand the mechanisms regulating the reproduction in order to increase their populations. Sex steroids, including estrogens, androgens and progestogens, play an important role in reproduction in most vertebrates and several invertebrates. It has been proposed that sea cucumbers have the same sex steroids as vertebrates but the steroidogenic pathway in the sea cucumbers is still unclear. In this study, we demonstrated by using liquid chromatography-tandem mass spectrometry (LC–MS/MS) that sex steroids (estradiol, progesterone, and testosterone) were present in H. scabra neural and gonadal tissues. In silico searches of available sea cucumber transcriptome data identified 26 steroidogenesis-related genes. Comparative analysis of encoded proteins for the steroidogenic acute regulatory protein (HscStAR), CYP P450 10, 17 and 3A (HscCYP10, HscCYP17, HscCYP3A) and hydroxysteroid dehydrogenases (Hsc3β-HSD, Hsc17β-HSD) with other species was performed to confirm their evolutionary conservation. Gene expression analyses revealed widespread tissue expression. Real-time PCR analysis revealed that HscStAR, HscCYP10, Hsc3β-HSD, and Hsc17β-HSD gene expressions were similar to those in ovaries and testes, which increased during the gonad maturation. HscCYP17 mRNA was increased during ovarian development and its expression declined at late stages in females but continued high level in males. The expression of the HscCYP3A was high at the early stages of ovarian development, but not at other later stages in ovaries, however it remained low in testes. Moreover, a role for steroids in reproduction was confirmed following the effect of sex steroids on vitellogenin (Vtg) expression in ovary explant culture, showing upregulation of Vtg level. Collectively, this study has confirmed the existence of steroids in an echinoderm, as well as characterizing key genes associated with the steroidogenic pathway. We propose that sex steroids might also be associated with the reproduction of H. scabra, and the identification of biosynthetic genes enables future functional studies to be performed.

Identification and functional analysis of the doublesex gene in the redclaw crayfish, Cherax quadricarinatus

DM-domain (Zn-finger motif domain) genes play an important role in the sex determination and differentiation among animal kingdom. In the present study, the gene of Doublesex (Cqdsx) was identified and characterized for the first time in the redclaw crayfish, Cherax quadricarinatus. The full-length cDNA was 1271 bp, comprising a 155 bp 5′-untranslated region (5′-UTR), an 885 bp predicted open reading frame (ORF) encoding 294 amino acid polypeptides, and a 231 bp 3′-UTR. The deduced amino acid sequence of Cqdsx was predicted to contain a highly conserved DM domain and shared nearly 50% identity to DM-peptides from other species. The results of quantitative Real-time PCR in various tissues revealed that Cqdsx was strongly expressed in gonads, while was almost undetectable in gill, heart, hepatopancreas, muscle and intestine. Comparing expression level in different embryonic stages found that Cqdsx was gradually increased with the development of the embryos. In situ hybridization to gonad sections showed that intensive hybridization signals were mainly observed in oocytes and ovarian lamellae and weak signals were detected in spermatocyte. Additionally, Cqdsx gene exhibited higher transcript levels in the early stage of ovarian development. Furthermore, RNAi-targeting Cqdsx silencing induced a decrease of Cq-IAG trascripts, which regulate the male sexual differentiation in crustaceans. Taken together, these findings strongly suggest an essential role for Cqdsx in the female ovarian development/differentiation of the redclaw crayfish.

TGF-β1 sustains germ cell cyst reservoir via restraining follicle formation in the chicken.

The transforming growth factor β (TGF-β) superfamily members are important molecules that regulate many ovarian functions under normal physiological and pathological conditions. TGF-β1 and its receptors are highly expressed in the ovarian cells of many species. However, the effect of TGF-β1 on the capacity of the avian germ cell reservoir remains unknown. In this study, 5-day-old chicks were injected with TGF-β1 (2.5, 12.5, and 62.5 μg/kg body weight) for 3 days to assess the effect of TGF-β1 on early follicle development. Morphological analysis showed that treatment with TGF-β1 (12.5 μg/kg) increased the number of germ cell cysts and reduced the number of primordial and growing follicles. The diameter and area of oocytes and follicles were decreased after TGF-β1 treatment. Immunohistochemical staining of the proliferating cell nuclear antigen revealed that the ratios of the positive somatic and granulosa cells were decreased by 16.2% and 2.48%, respectively. Furthermore, more apoptotic cells were observed in the TGF-β1 group than thoseof the control by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. In addition, we cultured the 5d chicken ovaries for 3 days in vitro and found that treatment with TGF-β1 (10 ng/mL) manifested similar results as the in vivo experiment. However, the negative effect of TGF-β1 on early ovary development was rescued by treatment with a TGF-βR1 inhibitor SD208, resulting in increased expression of steroidogenic enzymes and cell cycle-regulating proteins. In conclusion, TGF-β1 could maintain the germ cell reservoir by restraining follicle activation involving reduced cell proliferation and steroidogenic enzymes gene expression at the early stage of ovarian development.

In vitro study of a putative role of gonad-inhibiting hormone in oocyte growth stimulation inPenaeus monodon

Ovarian development in crustacean is controlled by several factors, among which a neuropeptide gonad-inhibiting hormone (GIH) is known to inhibit vitellogenin (Vg) synthesis in the ovary. It has been postulated that GIH may control Vg synthesis by inhibiting the release of gonad-stimulating factor (GSF) from brain and thoracic ganglia. To prove this hypothesis, this study was primarily aimed to investigate the influence of GIH on the release of GSF from thoracic ganglia of Penaeus monodon. Our result showed that GIH did not suppress the release of putative GSF from thoracic ganglia by calcium ionophore A23187 as the induction of oocyte growth in the ovary explants that were cocultured with thoracic ganglia in the presence of A23187 was not affected by the addition of recombinant GIH protein. In addition and interestingly, when the ovary explants were incubated with the recombinant GIH alone, the oocyte growth was increased at the rate comparable to that induced by A23187 in the presence of thoracic ganglia. Hence, our in vitro study demonstrated that the stimulation of GSF released from thoracic ganglia is independent of GIH, and that the GIH has a dual function in oocyte growth stimulation and inhibition of Vg synthesis in the early stage of ovarian development. This expands our knowledge on the regulation of ovarian development in shrimp by GIH. Further in vivo studies in this novel aspect of GIH function will be useful for the improvement of shrimp ovarian maturation in the future.

Effect of estrogen on chick primordial follicle development and activation.

Steroid hormones and their receptors play pivotal roles in avian reproduction and development. 17β-estradiol (E2 ) is an essential mediator in ovarian development. In this study, Day 3 (D3) chicks were injected with E2 (0.025, 0.25 or 2.5 mg/kg body weight) for 4 days to assess the effects of estrogen on avian follicle development. Morphological analysis showed that treatment of E2 at 2.5 mg/kg increased the number of growing follicles by 28. 5% and activated follicles by 8.9%, compared with the group. Treatment of E2 also led to increased diameter and area of three kinds of follicles and oocytes, respectively. However, this stimulating effect of E2 was inhibited by combined treatment of the estrogen receptor antagonist tamoxifen, resulting in decreased number of the growing follicles by 14.3% and the activated follicles by 5.8%, respectively. Immunohistochemical staining of the proliferating cell nuclear antigen (PCNA) revealed that the ratios of the PCNA-positive granulosa and interstitial cells were increased by 14.0% and 21.5%, respectively. Western blot analysis of PCNA confirmed this stimulating effect of E2 . Expression of ERα mRNAs was elevated by administration of E2 in vivo and in vitro. Furthermore, E- and N-cadherin displayed increased expression after E2 treatment in vivo and in vitro. In conclusion, E2 can promote chicken primordial follicle development and activation involving its increased receptor and cadherin production at the early stage of ovarian development.

Immunolocalization and changes in 17β-estradiol in Portunus trituberculatus during ovarian development

PDF HTML阅读 XML下载 导出引用 引用提醒 三疣梭子蟹卵巢发育过程中雌二醇的免疫定位和变化 DOI: 作者: 作者单位: 1. 上海海洋大学 省部共建水产种质资源发掘与利用教育部重点实验室, 上海 201306;2. 上海海洋大学 上海市水产动物遗传育种协同创新中心, 上海 201306 作者简介: 柳梅梅(1990),女,硕士研究生,主要从事甲壳动物繁殖生物学的研究.E-mail:15105517287@163.com 通讯作者: 中图分类号: S96 基金项目: 国家自然科学基金项目（41276158）；上海市自然科学基金项目（12ZR1413000）；上海市科技兴农重点攻关项目[（沪农科攻字（2013）第6-3号）]；上海市科技兴农推广项目[沪农科攻字（2016）第1-1-8号]；上海市高峰学科建设项目（2012-62-0908）；浙江省东海海水养殖产业升级协同创新中心项目. Immunolocalization and changes in 17β-estradiol in Portunus trituberculatus during ovarian development Author: Affiliation: 1. Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education;Shanghai Ocean University, Shanghai 201306, China;2. Collaborative Innovation Center of Aquatic Animal Breeding Center Certified by the Shanghai Municipal Education Commission;Shanghai Ocean University, Shanghai 201306, China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:雌二醇（estradiol，E2）是甲壳动物体内重要的性类固醇激素，对其卵巢发育和卵黄发生起着十分重要的调控作用。本实验采用免疫组织化学方法系统研究了三疣梭子蟹（在卵巢、肝胰腺、胸神经节、脑神经节和大颚器中的分布及变化。结果表明：（1）蟹卵巢中E2的免疫阳性主要分布于滤泡细胞和卵巢发育中后期的卵母细胞细胞质（II-V期），卵巢发育过程中卵母细胞细胞质和细胞核中的E2免疫阳性均为先上升后下降的趋势，最大免疫阳性分别出现在IV期和II-III期，滤泡细胞中始终存在较强的E2免疫阳性；（2）肝胰腺中的E2免疫阳性主要分布于F细胞及R细胞细胞核中，R细胞细胞核中的E2免疫阳性从III期开始显著下降，F细胞中始终存在较强的E2免疫阳性；（3）卵巢发育（I-V期）的神经组织，E2主要分布于胸神经团的神经细胞和神经髓质以及脑神经节神经细胞细胞核内，其中脑神经节神经细胞细胞核中始终保持着强免疫阳性，卵巢发育早期（I-II期）胸神经团中的神经髓质中为E2中等免疫阳性，神经细胞中一直为弱免疫阳性；（4）就大颚器而言，E2强免疫阳性始终存在于大颚器腺细胞的核仁以及细胞核周围的细胞质内。以上结果表明，E2在三疣梭子蟹卵巢、肝胰腺、神经组织和大颚器中广泛分布，且免疫阳性与卵巢发育具有一定的相关性，E2可能通过作用于多个靶器官来调控三疣梭子蟹的卵巢发育。 Abstract:17β-Estradiol (E2) is among the most important sex steroid hormones during ovarian development and vitellogenesis in crustaceans. In this study, an immunofluorescence assay was used to identify the immunopositive distribution and variations in E2 in the ovary, hepatopancreas, thoracic ganglia, brain ganglion, and the mandibular organ during ovarian development in the swimming crab, was mainly distributed in the follicular cells and the cytoplasm of late-stage oocytes (II-V). Follicular cells stained strongly positive for E2 at all ovarian stages; the immunoreactivities of E2 in the oocyte cytoplasm and nucleus trended as "low-high-low", and maximum positive staining appeared during ovarian stage IV and stages II-III, respectively. In the hepatopancreas, E2-positive staining was mainly distributed in F cells and R nuclei, and E2 immunoreactivity in the R nucleus tended to decrease from stages III to IV. However, strong positive E2 immunoreactivity was always detected in F cells at all ovarian stages. E2 was mainly distributed in neurons, the nerve medulla of thoracic ganglia, and cell nuclei of cerebral ganglion nerve cells during the early stages of ovarian development (I-II). E2 immunore activity in the nerve medulla of the thoracic ganglion was moderately positive, where as neurons were always weakly positive. Strong positive E2 staining was always distributed in the nuclei of mandibular gland cells and the cytoplasm around mandibular gland cellnuclei. These results suggest that E2 is widely distributed in the ovary, hepatopancreas, thoracic ganglion, cerebral ganglion, and mandibular gland of immunoreactivity and ovarian developmental stage. E2 may act through multiple target organs to regulate ovarian development in 参考文献 相似文献 引证文献

Molecular characterization and developmental expression of Ras-related nuclear protein in the oriental river prawn Macrobrachium nipponense and the effects of RNA interference on ovarian maturation

PDF HTML阅读 XML下载 导出引用 引用提醒 青虾Ran基因的克隆、表达及其在卵巢发育中的功能 DOI: 作者: 作者单位: 1. 南京农业大学 无锡渔业学院, 江苏 无锡 214081;2. 中国水产科学研究院 淡水渔业研究中心, 农业部淡水渔业和种质资源利用重点实验室, 江苏 无锡 214081 作者简介: 卜宗元(1991-),男,硕士研究生,研究方向为水产动物遗传育种.E-mail:375334258@qq.com 通讯作者: 中图分类号: S917 基金项目: 江苏省重点研发计划（现代农业）重点项目（BE2016308）；中国水产科学研究院基本科研业务费专项项目（2016HY-ZD0402）；国家自然科学基金面上项目（31572617）；江苏省农业科技自主创新基金项目[CX（15）10124]；江苏省水产三新工程（D2015-16）；无锡科学科技发展基金项目（CLE02N1514） Molecular characterization and developmental expression of Ras-related nuclear protein in the oriental river prawn Macrobrachium nipponense and the effects of RNA interference on ovarian maturation Author: Affiliation: 1. Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China;2. Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture; Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:本研究应用RACE技术克隆了青虾（（Ras related nuclear protein，Ras 相关核蛋白）基因全长cDNA序列，该基因cDNA全长1191 bp，包括218 bp的5'UTR，648 bp的开放阅读框（ORF），405 bp的3'UTR，编码215个氨基酸。青虾基因属于P-loop-NTPase超级家族，拥有PTZ00132跨结构域，多肽分子量约为24.57 kDa，理论等电点7.13。系统进化树分析表明，在动物界进化中非常保守的青虾Ran多肽与罗氏沼虾（基因在成体青虾不同组织和卵巢不同发育期的表达差异，结果显示，基因的表达水平呈现上升趋势，在卵巢消退期又恢复到较低水平。RNA干扰后，实验组（vitellogenin）在卵巢中的表达量也显著低于对照组（基因的表达起到调控作用。 Abstract:Ras-related nuclear protein (Ran) is a small GTPase with many functions, such as hydrolysis of GTP, control of cell development, replication of DNA, and RNA transcription. In this study, the cDNA-encoding ) was cloned using expressed sequence tag (EST) analysis and a rapid amplification of cDNA ends (RACE) approach. The full-length cDNA of was 1191 bp, comprising a 5' untranslated region of 218 bp, a 3' untranslated region of 405 bp, and an open reading frame of 648 bp. The deduced protein had 215 amino acid residues with a molecular mass of 24.6 kD, and 7.13 point of theoretical isoelectric. Ran belongs to the P-loop NTPase super family. Ran has a PTZ00132 model that crosses multiple domains. The members of P-loop NTPase super family have extremely conservative nucleotide sequences. Phylogenetic analyses indicate evolution of Ran proteins within the animal kingdom is very conservative, with that of . Quantitative real-time RT-PCR analysis revealed the gene was expressed in testis, ovary, brain, muscle, eyestalk, abdominal nerve, heart and gill tissues. The ovary has the highest level of expression and the eyestalk has the lowest level of expression ( gene expression of ovary is seven-eight times higher than that of testis, and the expression level of gene increased with the development of ovary. After ovulation in ovarian regression period, the expression level of gene was at a low level. After RNA interference (RNAi), expression of gene in an experimental group of adult females was significantly lower than in the control group (<0.05). After RNA interference (RNAi) in the mature female prawns, the expression of gene in experimental group (injected dsRNA solution into the shrimp's pericardial cavity) was significantly lower than in the control group (injected equal amount of DEPC water into the pranw's pericardial cavity) ( gene changes with the development of ovary. The expression of gene increased from the early stage of ovarian development to the mature stage and decreased rapidly after ovulation in the ovary. Expression of in ovarian tissues in the experimental group was also significantly lower than that of control group (<0.05), indicating RNA interference was effective. Expression of vitellogenin was significantly affected by RNA interference, with expression in the experimental group significantly lower than in the control group ( gene plays a regulatory role in expression of the gene is involved in female ovary development. 参考文献 相似文献 引证文献

Stimulation of ovarian development in white shrimp, Fenneropenaeus merguiensis De Man, with a recombinant ribosomal protein L10a

Abstract Ribosomal protein L10a (RpL10a) is encoded by an essential gene related to the early stages of ovarian development. A recombinant RpL10a protein was produced and evaluated to determine its ability to stimulate ovarian development in the white shrimp Fenneropenaeus merguiensis De Man. The transportation of injected recombinant RpL10a to the ovary was monitored using FITC-conjugated rRpL10a in an in vivo assay. FITC-rRpL10a was imported into the ovarian tissue within 24 h after injection, observed with a fluorescence microscope. The signal was not detected in muscle tissue; thus, muscle was not a target tissue. A dose of 180 μg of rRpL10a/shrimp was effective for inducing the ovaries to reach stages I and II of vitellogenesis within 7 days after the first injection. Observations of the ovarian natural autofluorescence in tissue sections were performed to determine the stage of vitellogenesis in F. merguiensis and were shown to provide the same results as were obtained using sections stained according to the standard hematoxylin and eosin staining procedure, which spent more time. Methyl farnesoate (MF) levels were examined via a HPLC technique in different stages of ovarian development following RpL10a injection, and the observed MF levels indicated that the concentration of MF in the hemolymph increased in stage II of vitellogenesis.

The expression of FOXL2 in pancreatic, hepatobiliary, and renal tumors with ovarian-type stroma.

FOXL2, a gene encoding a member of the fork-head-winged-helix family of transcription factors, is one of the earliest expressed genes during female gonadal development. It is expressed in normal ovarian stroma and ovarian neoplasms with granulosa cell lineage. Nonovarian tumors such as pancreatic mucinous cystic neoplasms (PMCs), hepatobiliary cystadenomas (HBCs), and mixed epithelial and stromal tumor of the kidney (MEST) have ovarian-type stroma. Immunohistochemical staining with FOXL2, estrogen receptor, and progesterone receptor was performed on 21 PMCs, 13 HBCs, and 10 MESTs and assessed for nuclear immunohistochemical positivity in the tumor stroma. All cases of PMC and HBC demonstrated nuclear reactivity for FOXL2 in the subepithelial stromal cells. Ninety percent of MEST demonstrated nuclear FOXL2 positivity. Estrogen receptor nuclear positivity was demonstrated in 57% of PMC, 77% of HBC, and 80% of MEST. Progesterone receptor nuclear positivity was present in 67% of PMC, 100% of HBC, and 90% of MEST. Clinical information was available for 37 patients. Seventy-eight percent of the patients had a history of obesity, heavy alcohol use, or hormone-related therapy. The 2 male patients had histories significant for morbid obesity and chronic alcoholism. FOXL2 is expressed from the early stages of ovarian development and has been shown to be mandatory for normal ovarian function. We have shown that it is also expressed in the aberrant ovarian-type stroma characteristic of PMC, HBC, and MEST. Most of such patients, including the rare male patients, have risk factors for hormonal abnormalities such as obesity and hormonal replacement therapy.

Expression profile of ribosomal protein L10a throughout gonadal development in rainbow trout (Oncorhynchus mykiss)

Ribosomal protein L10a (RpL10A) has been previously established as a stimulator during the early stages of ovarian development in both the banana prawn and the fruit fly. In order to develop a greater understanding of the role of this protein in vertebrates, the present study aimed to characterize the expression profile of rpl10a during gonadal development in fish. It was determined that the expression of rpl10a within genital ridges increased during embryonic development. Although rpl10a expression was observed in both gonadal somatic cells and primordial germ cells, higher levels of both transcript and protein expression were detected in somatic cells. rpl10a transcripts were observed in all of the adult tissues examined. Cellular level expression of rpl10a was subsequently characterized across various maturational stages using in situ hybridization and immunohistochemistry of both testes and ovaries. Analysis of tissue derived from the testis showed high levels of rpl10a expression within spermatogonia and the Sertoli cells attached to them. In ovarian tissue, rpl10a was strongly expressed in chromatin-nucleolus-stage and peri-nucleolus-stage oocytes. The relationship between rpl10a expression and regulation of gonadal development was confirmed using real-time PCR, which was performed in order to analyze rpl10a expression in testicular and ovarian tissues subsequent to incubation with salmon pituitary extract and various sex steroids for 24h. Among them, 11-ketotestosterone at 100ng/mL effectively up-regulated expression of rpl10a in testicular tissues, while 17β-estradiol down-regulated rpl10a expression in ovarian tissues. These results suggested that rpl10a played a role in the regulation of gonadal development in fish.

The roles of ribosomal protein S3a in ovarian development of Fenneropenaeus merguiensis (De Man)

Shrimp ovarian development is a pivotal step for aquaculture in order to maintain broodstocks. The molecular processes in the ovaries of Fenneropenaeus merguiensis De Man during vitellogenesis were investigated. A quantitative real time PCR (Q-PCR) assay showed a high expression of ribosomal protein S3a (RPS3a) in the early stage of ovarian development and a decline in the later stages. Serotonin (5-HT) increased the expression of RPS3a significantly at 4h after incubating with the ovarian explants. A full-length RPS3a was amplified by the RACE technique and expressed in Escherichia coli BL21 (DE3). Western blot analysis showed that the molecular weight of the recombinant histidine (His)-RPS3a was approximately 33kDa. Its function was tested by incubating undeveloped ovarian explants with His-RPS3a. In vitro assays indicated that the His-RPS3a stimulated the expression of shrimp ovarian peritrophin (SOP) and translational controlled tumor protein (TCTP) genes significantly when compared to the untreated ovarian explants. In addition, the SOP and TCTP genes had been previously reported to be highly expressed during the early stages of ovarian development. In addition, FITC-RPS3a was shown to be imported into the ovarian cells. Therefore, RPS3a may act as a stimulator for the development of shrimp ovaries.

Effects of polychaete extracts on reproductive performance of kuruma shrimp, Marsupenaeus japonicus Bate. – Part II. Ovarian maturation and tissue lipid compositions

A 32-day feeding trial was conducted to examine effects of marine polychaete extracts on ovarian maturation and tissue lipid compositions of Marsupenaeus japonicus. Three fractions extracted from polychaetes such as trichloroacetic-soluble (TSF), neutral lipids (NLF) and polar lipids (PLF) fractions at 0.5% (dry matter basis) were supplemented to a basal diet (BD). Frozen polychaetes (FPC) and BD were used as positive and negative controls, respectively. Each treatment with triplicate groups of ten unilaterally eyestalk-ablated wild caught females at early stages of ovarian development were fed test diets above once a day at 5:00pm with excess of pellet diets and 10% of biomass with FPC. The ovarian development was tracked every 4 days. The maximum ovary shadow ratios (OSR=ovary width×100/body width) were not significantly different among treatments. Ovarian maturation time (OMT), defined as the time elapsed for ovaries to develop from initial to maximum OSR, of NLF and FPC groups were significantly shorter than those of other groups. Maturation response (MR=proportion (%) of females achieving ovarian maturity within each treatment) had some distinctive trends during the course of the trial. The study also indicated that NLF was the most effective on M. japonicus ovarian maturation and followed by TSF. Phospholipids were dominant in the ovarian lipid compositions while contents of neutral lipids were relatively high in hepatopancreas in all diet groups. Hepatopancreatic and ovarian fatty acid profiles showed significant differences in proportions of some important fatty acids. Furthermore, this study demonstrated that formulated feed being fed solely was able to promote the ovarian maturation in kuruma shrimp broodstock.

Expression of 3β-HSD1 and P450 Aromatase enzymes during mouse gonad differentiation

In sheep embryos, steroidogenic activity has been reported as taking place during the period of sexual differentiation. In the case of mouse embryos, the sporadic detection or absence of steroidogenic enzymes suggests that the ovary is inactive. The purpose of this work was to establish if mouse undifferentiated gonads express steroidogenic enzymes in a similar way as in sheep embryos. To know this, we analyzed the mRNA expression pattern of 3β-Hsd1 and P450arom as well as protein expression pattern of 3β-HSD1 and Testosterone in normal undifferentiated and differentiated gonads from both male and female mice embryo. Our data indicate that there is expression of 3β-Hsd1 in XX gonads during gonad differentiation period. Nevertheless the Testosterone which would indicate steroidogenic activity is not produced. Besides, the absence of P450arom indicates that the production of Estradiol as observed in the ovaries of sheep does not occur. The detection of 3β-Hsd1 in the early stages of ovarian development, as well as the absence of Testosterone suggests that XX gonads are not steroidogenic and that 3β-Hsd1 enzyme may play a different role than in the steroidogenesis process.

Effect of temperature decrease on oocyte development, sex steroids, and gonadotropin β-subunit mRNA expression levels in female Japanese eel Anguilla japonica

To improve understanding of the mechanism of early ovarian development in eels, the effects of water temperature decrease on oocyte development, plasma levels of sex steroids [estradiol 17β (E2), testosterone (T), 11-ketotestosterone (11-KT)], and gonadotropin β-subunit [follicle-stimulating hormone (FSHβ), luteinizing hormone (LHβ)] messenger RNA (mRNA) expression levels were investigated. A total of 27 female Japanese eels Anguilla japonica were divided into initial, control, and test (water temperature decrease) groups. Starting on 22 September 2009, eels in the test group were reared in a tank with gradual temperature decrease from 25°C to 15°C over 39 days, while the control group was maintained at 25°C. The test group accumulated more oil droplets in their oocytes than did the other groups. Levels of sex steroids, especially 11-KT, were higher in the test group. In contrast, FSHβ and LHβ mRNA expression levels were lower in the test group. These results suggest that water temperature decrease only induced an early stage of ovarian development that was partly affected by an 11-KT increase. For further maturation, other environmental factors related to induction of gonadotropin increase appear to be needed.

Development of the ovary and ontongeny of mRNA and protein for P450 aromatase (arom) and estrogen receptors (ER) α and β during early fetal life in cattle

Estradiol-17β is the predominant steroid produced during early stages of ovarian development in ruminants and steroid hormones have been hypothesized to regulate ovigerous cord formation, germ cell meiosis and ovarian vascular development. Therefore, the objective was to determine the presence and localization of mRNA and protein encoding cytochrome P450 aromatase (P450arom), and estrogen receptors α (ERα) and β (ERβ) during ovarian development in fetuses of cattle on days 35, 45, 60, 75, 90 and 105 after breeding ( n = 4/age) using in situ hybridization and immunohistochemistry. No ovarian tissue was found in the day 35 fetuses, but was found in all later ages studied. There appeared to be little organization of specific structures in ovaries on days 45 and 60, although germ cells could be identified. Evidence of the beginning of ovigerous cord formation was found on day 60. By day 75 of gestation, the ovigerous cords were more extensive and mesonephric-derived cell streams were detectable. By day 90 (and still present at day 105), both ovigerous cords and cell streams/rete tubules were definitive structures of the developing ovaries. Ovaries appeared to develop in “lobular” segments around the periphery of the ovary. Some lobes appeared to be at slightly different developmental stages, as assessed by the extent or definition of ovigerous cord formation. The localization of mRNAs for P450arom, ERα and ERβ were closely associated with protein content. At days 45 and 60, mRNA and protein of P450arom and ERβ were located throughout ovaries with signal in medulla being denser than in the cortex. P450arom mRNA or protein was punctate, but not evident in germ cells. From day 75, P450arom was increasingly becoming localized to cell streams or clusters of cells (rete tubules) in the medulla, and by days 90 and 105 of gestation, was more definitively localized to cell streams and/or rete tubules. Similar to P450arom, ERβ mRNA and protein were observed in cells in the medulla, and also in germ cells, pre-granulosa cells and some surface epithelial cells. ERα mRNA and protein were predominately in the surface epithelium in ovaries of all ages with fainter signal for ERα protein also being observed in pre-granulosa and stromal cells including the cell streams/rete tubules. ERα protein was also detected in a few germ cells at days 90 and 105 of gestation. Thus, in cattle, estradiol-17β has the potential to regulate, in an autocrine/paracrine manner, a number of different cell types during ovarian development.

MRNA expression of GnRH variants and receptors in the brain, pituitary and ovaries of pejerrey (Odontesthes bonariensis) in relation to the reproductive status

The present study examined the differential mRNA expression levels of three forms of GnRH (sGnRH, pjGnRH and cGnRH-II) and two forms of GnRH receptor (pjGnRH-R I and pjGnRH-R II) in the brain, pituitary, and ovaries of pejerrey in relation to the reproductive status. The analysis revealed the presence of significant amounts of mRNA of the three GnRH forms while the ovaries showed only two (sGnRH and pjGnRH). The GnRH receptor II was found ubiquitously in the brain, pituitary, and ovaries while the form I was detected only in the brain. The levels of pjGnRH mRNA in the brain and pjGnRH-R II in the pituitary gland varied in correlation with the ovarian condition. However, brain sGnRH and pjGnRH-R I mRNA levels reached a maximum during early stages of ovarian development. In contrast, the brain levels of cGnRH-II mRNA showed no variation. The present study also shows a good correlation of ovarian sGnRH and pjGnRH-R II mRNA levels with the reproductive condition, suggesting that these molecules are may be involved in the regulation of pejerrey ovarian function.