Transcriptome-derived evidence reveals the regulatory network in the skeletal muscle of the fast-growth mstnb male tilapia.

Myostatin (Mstn) negatively regulates muscle growth and Mstn deficiency induced "double-skeletal muscle" development in vertebrates, including tilapias. In this study, we performed a transcriptomic analysis of skeletal muscle from both wild-type and mstnb males to investigate the molecular mechanisms underlying skeletal muscle hypertrophy in mstnb mutants. We identified 4697 differentially expressed genes (DEGs), 113 differentially expressed long non-coding RNAs (DE lncRNAs), 211 differentially expressed circular RNAs (DE circRNAs), and 98 differentially expressed microRNAs (DE miRNAs).

Investigating the molecular mechanisms of oocyte maturation and ovulation in Nile tilapia: A focus on the steroidogenic enzyme Cyp17a2.

Previous research has highlighted the significant role of progestins and glucocorticoids in fish oocyte maturation and ovulation. To clarify the molecular mechanisms underlying these processes, comprehensive investigations were conducted using a mutant Nile tilapia ( ) model. Analysis revealed pronounced Cyp17a2 expression in ovarian somatic cells of the tilapia.

Is Responsible for Androgen-Induced Masculinization in Nile Tilapia.

17α-Methyltestosterone (MT) is a widely used androgen for all-male fish production in aquaculture. However, the molecular mechanism underlying MT-induced masculinization remains unclear. In this study, we aim to identify the key gene responsible for MT-induced masculinization using the Nile tilapia () , , and mutants, which exhibit male-to-female sex reversal.

Steroid hormone-deprived sex reversal in cyp11a1 mutant XX tilapia experiences an ovary-like stage at molecular level.

Fish sex is largely influenced by steroid hormones, especially sex hormones. Here, we established a steroid hormone-free genetic model by mutation of cyp11a1 in Nile tilapia, which was confirmed by EIA assay. Gonadal phenotype and transcriptome analyses showed that the XX mutants displayed sex reversal from female to male but with defective spermatogenesis.

Sex chromosome turnover and biodiversity in fishes.

The impact of sex chromosomes and their turnover in speciation remains a subject of ongoing debate in the field of evolutionary biology. Fishes are the largest group of vertebrates, and they exhibit unparalleled sexual plasticity, as well as diverse sex-determining (SD) genes, sex chromosomes, and sex-determination mechanisms. This diversity is hypothesized to be associated with the frequent turnover of sex chromosomes in fishes.

Mutation of mpv17 results in loss of iridophores due to mitochondrial dysfunction in tilapia.

Mpv17 (mitochondrial inner membrane protein MPV17) deficiency causes severe mitochondrial DNA depletion syndrome in mammals and loss of pigmentation of iridophores and a significant decrease of melanophores in zebrafish. The reasons for this are still unclear. In this study, we established an mpv17 homozygous mutant line in Nile tilapia.

Hypogonadotropic hypogonadism in male tilapia lacking a functional rln3b gene.

Relaxin 3 is a neuropeptide that plays a crucial role in reproductive functions of mammals. Previous studies have confirmed that rln3a plays an important role in the male reproduction of tilapia. To further understand the significance of its paralogous gene rln3b in male fertility, we generated a homozygous mutant line of rln3b in Nile tilapia.

Star1 gene mutation reveals the essentiality of 11-ketotestosterone and glucocorticoids for male fertility in Nile Tilapia (Oreochromis niloticus).

Steroidogenic acute regulatory protein (Star) plays an essential role in the biosynthesis of corticosteroids and sex steroids by mediating the transport of cholesterol from the outer to the inner membrane of mitochondria. Two duplicated Star genes, namely star1 and star2, have been identified in non-mammalian vertebrates. To investigate the roles of star genes in fish steriodogenesis, we generated two mutation lines of star1 and star1/star2 in Nile tilapia (Oreochromis niloticus).

The cellular expression patterns of gdnfa and gdnfb in the gonads of Nile tilapia and their differential response to retinoic acid.

In mammals, glial cell derived neurotrophic factor (GDNF) plays a critical role in the self-renewal and maintenance of spermatogonial stem cells (SSCs) in testis and oogenesis in ovary, whilst retinoic acid (RA), the key factor of meiosis initiation, can downregulate its expression. Unlike mammals, two Gdnf replication genes are widely present in teleost fishes, however, our understanding of them is still poor. In the present study, two paralogous gdnf from Nile tilapia (Oreochromis niloticus), namely as Ongdnfa and Ongdnfb, were characterized, and then their cellular expression profiles in testis and ovary and responsiveness to RA treatment at the tissue and cellular levels were investigated.

Genome-wide analysis of two different regions of brain reveals the molecular changes of fertility related genes in rln3a mutants in male Nile tilapia (Oreochromis niloticus).

Relaxin3 (rln3) has been associated with various emotional and cognitive processes, including stress, anxiety, learning, memory, motivational behavior, and circadian rhythm. Notably, previous report revealed that Rln3a played an indispensable role in testicular development and male fertility in Nile tilapia (Oreochromis niloticus). However, the underlying molecular mechanisms remain largely unknown.

Nile Tilapia () Mutations Disrupt Cardiovascular Development and Vascular Integrity through Smoothened Signaling.

Hedgehog (Hh) signaling is crucial in cardiovascular development and maintenance. However, the biological role of Patched1 (Ptch1), an inhibitory receptor of the Hh signaling pathway, remains elusive. In this study, a Ptch1 ortholog was characterized in Nile tilapia (), and its function was investigated through CRISPR/Cas9 gene knockout.

Dmrt1 is the only male pathway gene tested indispensable for sex determination and functional testis development in tilapia.

Sex is determined by multiple factors derived from somatic and germ cells in vertebrates. We have identified amhy, dmrt1, gsdf as male and foxl2, foxl3, cyp19a1a as female sex determination pathway genes in Nile tilapia. However, the relationship among these genes is largely unclear.

Disruption of Zar1 leads to arrested oogenesis by regulating polyadenylation via Cpeb1 in tilapia (Oreochromis niloticus).

Oogenesis is a complex process regulated by precise coordination of multiple factors, including maternal genes. Zygote arrest 1 (zar1) has been identified as an ovary-specific maternal gene that is vital for oocyte-to-embryo transition and oogenesis in mouse and zebrafish. However, its function in other species remains to be elucidated.

Smoothened mediates medaka spermatogonia proliferation via Gli1-Rgcc-Cdk1 axis†.

The proliferation of spermatogonia directly affects spermatogenesis and male fertility, but its underlying molecular mechanisms are poorly understood. In this study, Smoothened (Smo), the central transducer of Hedgehog signaling pathway, was characterized in medaka (Oryzias latipes), and its role and underlying mechanisms in the proliferation of spermatogonia were investigated. Smo was highly expressed in spermatogonia.

Characterization of the male-specific region containing the candidate sex-determining gene in Amur catfish (Silurus asotus) using third-generation- and pool-sequencing data.

Amur catfish (Silurus asotus) is an ecologically and economically important fish species in Asia. Here, we assembled the female and male Amur catfish genomes, with genome sizes of 757.15 and 755.

Mutation Causes Progressive Microphthalmia and Blindness in Nile Tilapia.

The normal development of lens fiber cells plays a critical role in lens morphogenesis and maintaining transparency. Factors involved in the development of lens fiber cells are largely unknown in vertebrates. In this study, we reported that GATA2 is essential for lens morphogenesis in Nile tilapia ().

Establishment of an Integrated CRISPR/Cas9 Plasmid System for Simple and Efficient Genome Editing in Medaka In Vitro and In Vivo.

Although CRISPR/Cas9 has been used in gene manipulation of several fish species in vivo, its application in fish cultured cells is still challenged and limited. In this study, we established an integrated CRISPR/Cas9 plasmid system and evaluated its efficiency of gene knock-out or knock-in at a specific site in medaka (Oryzias latipes) in vitro and in vivo. By using the enhanced green fluorescent protein reporter plasmid pGNtsf1, we demonstrate that pCas9-U6sgRNA driven by endogenous U6 promoter (pCas9-mU6sgRNA) mediated very high gene editing efficiency in medaka cultured cells, but not by exogenous U6 promoters.

Cyp17a2 is involved in testicular development and fertility in male Nile tilapia, .

Background: Steroid hormones play an essential role in many reproductive processes of vertebrates. Previous studies revealed that teleost-specific Cyp17a2 (cytochrome P450 family 17 subfamily a 2) might be required for the production of cortisol in the head-kidney and 17α,20β-dihydroxy-4-pregnen-3-one (DHP) in ovary during oocyte maturation. However, the role of Cyp17a2 in male reproduction remains to be largely unknown.

Nile tilapia (Oreochromis niloticus) Nanog co-expression with Pou5f3, transcriptional regulation and biological activity in embyonic development and embryonic cells.

Mammalian Nanog is critical in pluripotency acquisition and maintenance. Nonetheless, a recent report from zebrafish (Danio rerio) suggests that Nanog is not required for embryonic cells which is not like the mammalian homologs, but is necessary for the proper formation of the extra-embryonic yolk syncytial layer (YSL). However, whether its biological function in other fishes is conservative remains to be investigated.

Transcription factor Sox3 is required for oogenesis in the teleost fish Nile tilapia.

Oogenesis is a complex developmental process responsible for the production of eggs from oogonia in fish and other animals. However, transcriptional regulation underlying oogenesis is not fully understood. In the present study, we demonstrated in the teleost fish Nile tilapia that the Sox transcription factor family member Sox3 was involved in regulating oocyte growth during oogenesis.

Genome-Wide Identification and Characterization of the BRD Family in Nile Tilapia ().

The bromodomain (BRD) proteins specifically recognize the N-acetyllysine motifs, which is a key event in the reading process of epigenetic marks. BRDs are evolutionarily highly conserved. Over recent years, BRDs attracted great interest because of their important roles in biological processes.