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The current research work provided insights into the expression patterns of key genes in the BPG axis of Mugil cephalus females, highlighting differences between wild and captive environments during the spawning season. The investigated genes include Kiss2, Gpr54, Gnrh1, and Drd2 in the brain and ovary, as well as Lhβ, Fshβ, and Slα in the pituitary and ovary. The finding indicated that the relative expression of all examined genes is elevated in mature females compared to immature ones across all examined tissues (brain, pituitary, and ovary). The observation that the expressions of the examined genes in wild females of M. cephalus are highly correlated, either directly or inversely, with their counterparts in captive females, indicated a connection between gene expression patterns and the different environments (wild vs. captive). The results between wild and captive females were in significant values (P≤ 0.05). Overall, the observed correlations and significant differences in gene expression proposed potential impacts of captivity on the reproductive physiology of these fish. [ABSTRACT FROM AUTHOR]

El-Manzala Wetland is known to be of the most significant sources of inexpensive different fish species for human consumption in Egypt. The Lake receives pollution from various sources; domestic wastewater, industrial wastewater, and agricultural drainage directly without any treatments, which leads to many environmental disorders. The following research was conducted for lake water quality evaluation and how it impacts the expression of the aromatase (CYP19a&b) genes in Oreochromis niloticus tissues at different locations of El-Manzala Lake. Sampling was done during the summer of 2018 when water and fish samples were collected from five different locations of El-Manzala Lake. It was found that the studied locations recorded hazardous concentrations of polyaromatic hydrocarbons (PAHs) that may cause significant defects to aquatic organisms except in the reference location and affect the expression of CYP19a&b genes. The relative gene expressions of CYP19a in the ovary and the testis were measured and recorded in positive ranges, but revealed the controversial expression pattern of CYP19b gene in the brain tissues. Our results revealed that PAHs discharges at El-Manzala Lake are correlated with the gene expression of CYP19 genes. The current findings suggested a correlation between biomarkers response and wastewater exposure as stressors. Besides, the assessed multiple general health indicators give prospective insights for Nile tilapia adaptive pattern and monitoring of pollution of freshwater ecosystems. [ABSTRACT FROM AUTHOR]

The cytochrome P450 superfamily (cyp) is a unique, diverse group of enzymes that catalyze the oxidation of organic pollutants such as polycyclic hydrocarbons (PAHs). Both levels of cyp1a expression in Oreochromis aureus organs and the accumulation of PAHs in water were determined in five different locations of Lake Manzala; namely, El-Inaniya, El-Serw, El- Temsah, El-Gamil, and El-Bashtir during December 2011. The area of Al- Qanater was included as a reference site from the River Nile. The cyp1a gene was highly expressed in the liver of all fish populations followed by gill, testis, ovary and muscle. The liver and gonads of the fish population in the El-Gamil location exhibited the greatest cyp1a gene expression, while the gills and muscles in the El-Serw fish population were the highest in the expression pattern among Lake Manzala regions. A higher accumulation profile of PAHs in water was found in the El-Gamil location followed by El-Serw, El-Bashtir, El-Inaniya and El-Temsah. The correlation between PAHs and cyp1a expression of fish organs showed a significant positive correlation. The highest positive correlation was observed between the gill and liver based on the expression of cyp1a. The obtained cDNA of the cyp1a gene from O. aureus was 569 base pairs, and it exhibited 86.8% of the identity with cyp1a of O. niloticus. The phylogenetic tree of cyp1 family genes showed a closer relationship between cyp1a and cyp1d subfamily compared to cyp1b or cyp1c subfamily members. The results showed the sensitivity of cyp1a expression in fish as a biomarker for PAHs concentrations in the regions of Lake Manzala. [ABSTRACT FROM AUTHOR]

The CYP1 family, one of the gene families of the CYP superfamily, has four subfamilies deposited in the GenBank/EMBL so far; CYP1A, CYP1B, CYP1C, and the newly identified CYP1D. The metabolic activation and elimination of polyaromatic hydrocarbons, polychlorinated biphenyls, and aryl amines from fish body is largely mediated by the CYP enzymes. A new cDNA of the CYP1B subfamily encoding CYP1B1 was isolated from Japanese eel liver after a single intraperitoneal injection of β-naphthoflavone (BNF). The full-length cDNA obtained was 2985 bp and contained a 5' noncoding region of 294 bp, an open reading frame of 1626 bp coding for 541 amino acids and a stop codon and a 3' noncoding region of 1065 bp. The predicted molecular weight of the protein was approximately 61.27 kDa. The deduced amino acid sequence of Japanese eel CYP1B1 showed 62% similarity to three-spined stickleback CYP1B1 and zebrafish CYP1B1. It exhibited similarities of 66% with that of killifish, Indian medaka and our previously reported carp CYP1B1 and -1B2 while the higher similarities (67 and 69%) of the deduced amino acids was observed with that of Nile tilapia CYP1B1 and rainbow trout respectively. The percent identities of Japanese eel CYP1B1 cDNA showed similarities with those of the reported CYP1Bs of mammals of 57, 57, and 56% for human, rat, and mouse CYP1B1, respectively. Japanese eel CYP1B1 was aligned with the CYP1 sequences and has been deposited in the GenBank/EMBL data bank with the accession number AY518340. The phylogenetic tree constructed using the previously reported CYP1B sequences of mammals and fish suggested the closer relationship of the newly identified Japanese eel CYP1B1 to rainbow trout CYP1B1. QRT-PCR analysis of liver, kidney, gills and intestine revealed a distinct induced expression in liver, kidney and gills (71.93, 3.87 and 539.56 respectively) while the constitutive expression (0.062) was observed in intestine. [ABSTRACT FROM AUTHOR]

Cytochrome P450 (CYP) enzymes constitute a multigene family of many endogenous and xenobiotic substances. The CYP1 family is of particular interest in environmental toxicology because its members are dominant in the metabolism of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and aryl amines. A new cDNA of the CYP1C subfamily encoding CYP1C1 was isolated from Japanese eel (Anguilla japonica) liver after intraperitoneal injection with β- naphthoflavone (BNF). The full-length cDNA obtained (3508 bp) contained a 5' noncoding region of 355 bp, an open reading frame of 1581 bp coding for 526 amino acids, a stop codon, and a 3' noncoding region of 1572 bp. The predicted molecular weight of the protein was approximately 59.33 kDa. The deduced amino acid sequence of Japanese eel CYP1C1 had the lower similarity of 70% with that of killifish CYP1C1 while the higher similarity (79 and 81%) was observed with that of rainbow trout CYP1C2 and -1C1 sequences respectively. It exhibited similarities of 71% with that of Indian medaka CYP1C1 and zebrafish CYP1C2. Also the similarity of 74% was registered with the sequence of three-spined stickleback fish CYP1C1, - 1C2 and carp CYP1C2. It showed similarity of 77% with that of Nile tilapia CYP1C1, scup CYP1C1 and scup CYP1C2. The phylogenetic tree showed the newly identified Japanese eel CYP1C1 sequence to be clustered with rainbow trout CYP1C1 and -1C2. Japanese eel CYP1C1 was aligned with the CYP1 sequences and has been deposited in the Gen Bank / EMBL data bank with the accession number AY444748. Quantitative real-time polymerase chain reaction (QRT-PCR) analysis of liver, kidney, intestine and gills revealed a distinct induced expression in all organs studied (283.33, 579.35, 20.96 and 3642.32 respectively). [ABSTRACT FROM AUTHOR]

The thin-lipped grey mullet, Liza ramada, a commercially significant fish in Egypt, was studied for its expression patterns along the brain-pituitarygonad axis in female L. ramada during the spawning season of 2022 in both captive and wild habitats. The inspected genes included Kiss2, Gpr54, Gnrh1, and Drd2 genes in the brain and ovary, as well as Lhβ, Fshβ, and Slα genes in the pituitary and ovary. Relative expressions of all studied genes either in the brain, or pituitary, and ovary were higher in ripe females than in immature ones. Captive females had higher Drd2 gene expressions; nevertheless, mature wild females had higher expression values for the other investigated genes that were measured in the brain, or pituitary and ovary. The study found correlations between gene expression patterns in wild and captive females (P< 0.05), suggesting that confinement may affect reproductive physiology. The findings suggest focusing on hormones for artificial fertilization therapies in confined females. [ABSTRACT FROM AUTHOR]