Semen promotes oocyte development in elucidating ovarian development dynamics in live-bearing fish.

In some vertebrates and invertebrates, semen release factors affecting female physiology and behavior. Here, we report that semen delivered to females is potentially beneficial for promoting oocyte development in a viviparous teleost, . 88% of mated ovaries develop normally and give birth to larval fish, whereas 61% of non-mated ovaries are arrested in the previtellogenic stage.

Comparative transcriptome analysis reveals growth and molecular pathway of body color regulation in turbot (Scophthalmus maximus) exposed to different light spectrum.

Fish body color changes play vital roles in adapting to ecological light environment and influencing market value. However, the initial mechanisms governing the changes remain unknown. Here, we scrutinized the impact of light spectrum on turbot (Scophthalmus maximus) body coloration, exposing them to red, blue, and full light spectra from embryo to 90 days post hatch.

Developmental regulation of the male urogenital papilla in the male marine teleost black rockfish, Sebastes schlegelii (Hilgendorf, 1880)†.

The male external genitalia of the black rockfish (Sebastes schlegelii Hilgendorf, 1880) is a fleshy protrusion known as the urogenital papilla (UGP), which functions to deliver sperm into the female reproductive tract for internal fertilization. It is not known which genes regulate the development of the UGP. The aim of this study was to identify key genes that regulate the development of the UGP in black rockfish and to determine the distribution of androgen receptor gene (ar) in the UGP.

Effect of ovarian fluid on sperm performance in teleost with internal and external fertilization strategies.

Ovarian fluid is essential for successful fertilization by maintaining the viability, motility, and velocity of sperm. The organic compounds and inorganic ions in ovarian fluid significantly influence spermatozoa's motility, velocity, and longevity. However, the effect of ovarian fluid on sperm performance is limited in teleost fish.

Acute low-dose phosphate disrupts glycerophospholipid metabolism and induces stress in juvenile turbot (Scophthalmus maximus).

Phosphate, as the main nutrient factor of lake eutrophication brought by pollutants discharged from agriculture and industry, is always considered to be a low-toxicity substance to aquatic animals. But the toxicity mechanism is unclear, and published information is limited. In this study, a 96 h acute stress experiment was conducted on juvenile turbot (Scophthalmus maximus) with 0, 10, and 60 mg/L phosphate solutions.

Morphology of the urogenital papilla of the male marine teleost Black Rockfish, Sebastes schlegelii (Hilgendorf, 1880), and its role in internal fertilization.

There are few detailed descriptions of the morphology of the male external genitalia, the urogenital papilla (UGP), of the Black Rockfish (Sebastes schlegelii Hilgendorf, 1880). The purpose of this study was to evaluate this organ histologically and to determine the time of development of the UGP in Black Rockfish. Twelve adult males, three adult females and around 500 juveniles were used in the experiment.

Rxrs and their partner receptor genes inducing masculinization plausibly mediated by endocrine disruption in Paralichthys olivaceus.

Retinoid X receptors (RXRs) can form homo- or heterodimers with orphan receptors involved in multiple intertwined signaling pathways. However, there is limited study on the formation of sex phenotypes and the regulation of steroidogenesis by RXRs in fish. Here, in Paralichthys olivaceus, we first indicated that PPARγ::RXRα was predictably a transcription factor for steroidogenesis genes, and Foxl2 and Dmrt1 were also transcription factors for rxrs and their partner receptor genes.

Characterization of vasa and dnd homologs in summer flounder, Paralichthys dentatus: Expression analysis and colocalization of PGCs during embryogenesis.

Specification of primordial germ cells (PGCs) is particularly important for germline formation. Many maternal-effect genes such as vasa, dnd, and nanos have been identified. However, the research on distribution patterns of PGCs in marine fish is limited.

Successful Spermatogonial Stem Cells Transplantation within Pleuronectiformes: First Breakthrough at inter-family Level in Marine Fish.

As a promising biotechnology, fish germ cell transplantation shows potentials in conservation germplasm resource, propagation of elite species, and generation of transgenic individuals. In this study, we successfully transplanted the Japanese flounder (), summer flounder (), and turbot () spermatogonia into triploid Japanese flounder larvae, and achieved high transplantation efficiency of 100%, 75-95% and 33-50% by fluorescence tracking and molecular analysis, respectively. Eventually, donor-derived spermatozoa produced offspring by artificial insemination.

Sexually dimorphic expression and regulatory sequence of dnali1 in the olive flounder Paralichthys olivaceus.

Dynein axonemal light intermediate chain 1 (dnali1) is an important part of axonemal dyneins and plays an important role in the growth and development of animals. However, there is little information about dnali1 in fish. Herein, we cloned dnali1 gene from the genome of olive flounder (Paralichthys olivaceus), a commercially important maricultured fish in China, Japan, and Korea, and analyzed its expression patterns in different gender fish.

Germline Specific Expression of a Homologue Gene in the Viviparous Fish Black Rockfish () and Functional Analysis of the 3 Untranslated Region.

Germ cells play a key role in gonad development. As precursors, primordial germ cells (PGCs) are particularly important for germline formation. However, the origination and migration patterns of PGCs are poorly studied in marine fish, especially for viviparous economic species.

Analyses of mRNA-seq and miRNA-seq of the brain reveal the sex differences of gene expression and regulation before and during gonadal differentiation in 17β-estradiol or 17α-methyltestosterone-induced olive flounder (Paralichthys olivaceus).

Olive flounder (Paralichthys olivaceus) is a commercially important flatfish species cultured in East Asia. Female flounders generally grow more rapidly than males, therefore control of the sex ratio seems to be a proposed way to increase production. However, the sex determination gene and sex determination mechanism have yet been elucidated.

Visualization of Turbot (Scophthalmus maximus) Primordial Germ Cells in vivo Using Fluorescent Protein Mediated by the 3' Untranslated Region of nanos3 or vasa Gene.

Primordial germ cells (PGCs) as the precursors of germ cells are responsible for transmitting genetic information to the next generation. Visualization of teleost PGCs in vivo is essential to research the origination and development of germ cells and facilitate further manipulation on PGCs isolation, cryopreservation, and surrogate breeding. In this study, artificially synthesized mRNAs constructed by fusing fluorescent protein coding region to the 3' untranslated region (3'UTR) of nanos3 or vasa (mCherry-Smnanos3 3'UTR or mCherry-Smvasa 3'UTR mRNA) were injected into turbot (Scophthalmus maximus) fertilized eggs for tracing PGCs.

Effects of different light spectra on embryo development and the performance of newly hatched turbot (Scophthalmus maximus) larvae.

Light is a key environmental factor that synchronizes various life stages from embryo development to sexual maturation in fish. For turbot, light spectra have the most influence at the larval and juvenile stages. In the current study, differences in the development of embryos and the performance of newly hatched turbot larvae exposed to five different spectra: full spectrum (LDF), blue (LDB, peak at 450 nm), green (LDG, peak at 533 nm), orange (LDO, peak at 595 nm) and red (LDR, peak at 629 nm), were examined.

High temperature increases the gsdf expression in masculinization of genetically female Japanese flounder (Paralichthys olivaceus).

In teleosts, sex is plastic and is influenced by environmental factors. Elevated temperatures have masculinizing effects on the phenotypic sex of certain sensitive species. In this study, we reared genetic XX Japanese flounder at a high temperature (27.

Transcriptome Dynamics During Turbot Spermatogenesis Predicting the Potential Key Genes Regulating Male Germ Cell Proliferation and Maturation.

Spermatogenesis is a dynamic developmental process in which spermatogonial stem cells proliferate, differentiate and mature into functional spermatozoa. These processes require an accurate gene regulation network. Here, we investigated the dynamic changes that occur during spermatogenesis through a combination of histological and transcriptome analyses of different developmental stages of the testis.

Comparative performance of growth, vertebral structure and muscle composition in diploid and triploid Paralichthys olivaceus.

Growth, skeletal structure and muscle composition of cold-shock-induced triploid olive flounder Paralichthys olivaceus were investigated. The average values of total length and total weight of triploids were higher than those of diploids from 5 to 11 months posthatch (mph). The growth difference disappeared after 11 mph.

Spermatogonial stem cells differentiation and testicular lobules formation in a seasonal breeding teleost: The evidence from the heat-induced masculinization of genetically female Japanese flounder (Paralichthys olivaceus).

Germ cells undergo a series of cellular changes including differentiation, mitosis, meiosis and maturation, and eventually develop into a large number of functional gametes. The available data regarding teleost gametogenesis in seasonal batch spawners is limited. In this study, we investigated spermatogenesis with special attention on spermatogonia differentiation using heat-induced masculine juveniles of genetically female Japanese flounder.

Identification of type A spermatogonia in turbot (Scophthalmus maximus) using a new cell-surface marker of Lymphocyte antigen 75 (ly75/CD205).

Turbot (Schophthalmus maximus) is one of the most important economic marine flatfish species. However, due to rapid development of the industry, genetic resource recession has brought down the efficiency of aquaculture. Therefore, conservation of the genetic resource is increasingly demanded.

Germ Cell Migration, Proliferation and Differentiation during Gonadal Morphogenesis in All-Female Japanese Flounder (Paralichthys Olivaceus).

In this study, all genetic female (XX) broods of Japanese flounder were produced artificially by mating the females with sex-reversed males. The proliferation and migration of primordial germ cells (PGCs), formation of ovary and oogenesis were described in detail. After hatching, around 20 individual PGCs migrated from the lateral to the dorsal of trunk region.

Insight into the heat resistance of fish via blood: Effects of heat stress on metabolism, oxidative stress and antioxidant response of olive flounder Paralichthys olivaceus and turbot Scophthalmus maximus.

High temperature has direct confinement on fish survival and growth, especially under the background of global warming. Selection of fish line with heat resistance is an important means to address this problem. In the present study, we analyzed the difference in heat resistance between families of olive flounder Paralichthys olivaceus and turbot Scophthalmus maximus, two flatfish species occupying slightly different thermal niches.

The dnd RNA Identifies Germ Cell Origin and Migration in Olive Flounder (Paralichthys olivaceus).

The present study obtained a germ cell-specific marker dead end (dnd) in olive flounder (Paralichthys olivaceus) named Podnd. The tissue-specific expressions of Podnd transcripts were present in testis and ovary but were not detectable in other somatic tissues detected. SISH showed that Podnd expressed only in germ cells at different developmental stages but not in surrounding somatic cells.