RESUMEN
This study aimed to evaluate the effect of vitamin E on the reproductive responses and the expression of reproductive genes in butter catfish (Ompok bimaculatus). Diets with different levels of vitamin E supplementation (0, 100, and 150 mg/kg) were provided to groups of fish for 60 days. After rearing for 60 days fish were induced with synthetic hormone, that is, Ovatide to study the breeding performance. Ovatide was administrated intramuscularly at the rate of 0.5 and 0.25 mL/kg of body weight for females and males, respectively, in all the treatments. Breeding performance result shows that supplements of vitamin E positively influenced the GSI%, fertilization rate, fecundity, and hatching rate. To understand the relationship between vitamin E and the breeding performance of the fish at the molecular level, a gene expression study was conducted. This study employed real-time PCR for the selected genes critical for reproductive function. In the brain, testis, and ovary dietary vitamin E supplementation of 100 mg/kg significantly enhanced the mRNA transcription of FSHR, Brdt, ESR1, 17beta2, and LHR. Hence, it can be said that 100 mg/kg of vitamin E supplementation in the diet during the reproductive period of O. bimaculatus could improve breeding performance and the mRNA expression of reproductive hormone receptor genes in both males and females of O. bimaculatus.
RESUMEN
Fish pigmentation study can reveal understandings in dermatological research based on functional genomics. Cultured ornamental fish becomes dull coloured and antityrosinase activity through sesame seed may enhance skin colour, which has not been studied. Botia dario is an indigenous fish, having ornamental and aesthetic value and can be studied as a model for fish pigmentation genetics. In this study, fish specimens were fed with 15% marigold petal meal along with 5, 10 and 15% w/w sesame seed in diet. Pigmentation genes, that is, tyr, tyrp1a, asip1, gnaq, kitlga, mc1r, mitf, pax7a, rab38, slc7a11, sox9a, sox10, csf1r, bcdo2 and gsta2 in skin and immunogens, that is, il20, nramp, tlr9 and trail in kidney were studied. Gene expression in tissues revealed enhanced pigmentation and immunity as well as the role of tyr, tyrp1a and asip1 in pigmentation. Immunogenes and blood parameters confirmed the best pigmentation diet. Colorimetric analysis also showed the enhancement of pigmentation. Insights from sesame seed and marigold-induced antityrosinase effects will be applied in aquaculture to develop natural, dietary formulations that will enhance pigmentation in ornamental fish, leading to improved skin colour and market value.
RESUMEN
The genetic basis and expression patterns of key genes are important aspects of study to understand the colouration. This trait differs between wild and domesticated fish which is a matter of research. Botia dario is an indigenous fish, having ornamental and aesthetic value, which shows faded appearance in terms of colour in domesticated condition than wild. In the present study the carotenoid-fed B. dario were examined through incorporation of marigold petal meal in the diets at the rate of 5, 10 and 15% w/w along with wild fish. The carotenoid content of tissues that is skin, muscle and intestine along with intensity of colouration increased in a dose dependant manner of carotenoid in the diet. Important carotenoid-based colouration genes that is csf1r, BCDO2, SR-B1, MLN64, STAR5, GSTA2 and PLIN2 were characterized in the fish, to find out their role in fish pigmentation. The significant difference (p < 0.05) in the expression of these genes in different tissues, when compared among carotenoid-fed domesticated and wild fish, revealed the mechanism responsible for faded colouration and also revealed the means to enhance colour in the fish.