Genetic Analysis On Dorsal Fin Of Goldfish

Goldfish(Carassius auratus) is one of the Chinese traditional ornamental fish. As artificial domesticated varieties rich in morphological features, goldfish is an excellent material for the study of the shape of genetics. But at present the molecular genetics of external characters of goldfish is still very scarce.So through this study, we carried out the following research on goldfish dorsal traits。1. Analysis on dorsal fin of goldfishIn this chapter, though the hybridization tests of different strains of Egg-goldfish and Wen-goldfish, we found the dorsal fin was characteristic of a special trait with maternal inheritance and individual difference phenomenon. It further supporting the hypothesis, which means the disappearance of goldfish dorsal fin is likely to occur before double tail trait. In addition, through the X-ray scanning analysis of 3 different strains goldfish, the results showed that characteristics of egg-goldfish dorsal fin traits is same to the saddleback syndrome. The egg-goldfish should be the first symptoms in the saddle syndrome of fish. Combined with the saddle syndrome research in other fish, the phenomenon of goldfish lack of dorsal fin should have a close relationship with environmental factors.In addition, the result of morphological observation also show that Tiger head goldfish and Ranchu goldfish has different forms of internal bone changes with similarly in the absence of dorsal fin in the meantime.So, the mechanism still need to be further studied.2.Traits analysis of Ranchu goldfish and Tiger-head goldfishThis chapter focuses on 28 different characters of Ranchu goldfish and fish of tiger head goldfish external morphological measurement. From the result, we get an cyclic system composed by 11 morphological parameters after the R cluster and regression equation analysis. So this chapter put forward a new hypothesis: under the influence of different environment, the effect of dorsal fin trait differences to other traits of the fish body is indeed exist. And, because the environment has many aspects to the fish body influence, so we can conclude that the fish fin shape mutation is a new factor in the process of evolution for the goldfish, a new phenomenon in biological systems but also the goldfish in the evolutionary process is influenced by many factors is shown.3. Goldfish Ammecr1 gene DNA methylation analysisBased on the previous studies, the change of goldfish dorsal fin traits and environmental factors are inseparable, so this chapter to epigenetic as the starting angle.The Ammecr1 has important effect on the dorsal fin development of zebra fish, which has the characteristic of maternal inheritance. So we take the goldfish as the experimental material, and get the full length c DNA sequence(1194bp) with RACE technology. The coding region sequence was 960 bp. According this data, we used the chromosome walking technology to obtain the sequence of the upstream 5 flanking regulatory region, 1556 bp. Compared with other fish sequences, the similarity was up to 80%, which means the gene was highly conserved. Combined with the previous assumption, by detecting the methylation level of the first exon and promoter region, which has very important effect on the gene expression, we received a total of 113 Cp G island. The results show that the changes are mainly concentrated in the coding region of. The results show that, there are gene imprinting phenomenon of goldfish Ammecr1 gene mutation, but because of the low quantity, its mechanism of action, still need to be further studied.