| Observe the early embryonic development of Amphilophus Citrinellus, to describes the morphological characteristics and speed development in embryonic development stage. Its development process is divided into: Fertilization,One cell stage,Multi-cell stage,blastula, Neurula stage,Crystal stage, Otocyst stage, Heart-beat stage,blood-circulation stage,hatching stage. When water temperature is between 27 and 29 ℃, Fertilized eggs took 51 h to take off the membrane hatched. the egg yolk and oil, It is energy source for Fish in early embryonic development.Amphilophus Citrinellus’ Fertilized eggs only have yolk sac, have no oil, but it took 51 h to hatch, It is hatch time still faster than the fish has oil ball eggs. It shows that the oil does not affect how eggs embryonic development. This experiment observed the melanin cell development early. melanocytes have begun to development in the embryonic period of blood circulation.The environmental impact on body color changes of fish. By discussing the illumination, the density of feed, environmental factors on the Amphilophus Citrinellus, They influence on fade of body color. To know the external factor to effect on body color change Amphilophus Citrinellus. Lighting effect on deposition rate of the pigment, affect the amount of deposit in the pigment in the skin and muscle, affect the change of the fish body color.This experiment under the condition of feed engouh food, 5 months of darkness team without all faded phenomenon, lighting group’ fading rate was obviously higher than dark group, the all faded rate is 20 times the dark group, half faded rate was 24 times; In the case of hunger, fade rate was 0% in dark group, the light group is 6 times for it. At the same time,it shows the feed is the Essential nutrients to growth and maintain normal life activities of fish,feed nutrition effect on body color of fish. This experiment under the condition of feed engough and feed hungry, density of high(4 z/L) group’s all faded rate and half rate than higher density of low(2 z/L) group. It showed that appropriate The density of livestock affects on the fish body color changes. Amphilophus Citrinellus ’fading rate under normal circumstances(light and feed)higher than under abnormal conditions(dark and satiety) of Amphilophus Citrinellus ’fading rate.Tyrosinase(TYR) gene is the one of the most important rate-limiting enzymes in animals within the signal path of melanin synthesis, which plays a crucial role in the formation of melanin. So the expression and activity level decides the speed and type of melanin. This study was conducted to reveal the relationship between genes related to pigment and body color. We obtained tyrosinase(TYR) gene sequence of Amphilophus citrinellus by RACE technique and also investigated the expression of TYR gene in different developmental stages and tissues using qRT-PCR. The total length of TYR gene was 2 683 bp which contained 246 bp 5’-UTR, 817 bp 3’-UTR, and 1 620 bp open reading frame(ORF) encoding 540 amino acids in Amphilophus citrinellus. Sequence analysis of amino acids and phylogenetic tree analysis indicated that conservation of TYR gene was higher in fish than that in other vertebrates. qRTPCR analysis revealed that TYR gene expressed in embryonic periods was lower in the conception and began to sharply rise in the circu Lation of the blood period. In the process of body color changes(black to gray to bright yellow), the expression of the TYR gene in black period of all tissues was significantly higher than that in grey and bright yellow period(P<0.05). TYR gene expression of tail fin and scale was gradually reduced in gray to bright yellow period, while there is no significant difference between these two periods(P>0.05). However, expression of TYR gene in skin significantly decreased during the body color developmental stages(P<0.05). In the bright yellow period, TYR gene expressed in all kinds of tissues(heart, kidney, brain, maw, gonad, tail fin and eye), which expressed the highest amount in eyes, intermediate in swim bladder and tail fin and the lowest in skin and glands. Also, TYR gene expression gradually decreased among three periods of body color development. It may be related to the gradual increase of red and yellow pigment cells, as well as the changes of the number and distribution proportion of melanocytes. At the same time, The study found that Transetta(DE3) induced the quantity of protein expression is the most in IPTG 1.0 mmol/L,It shows that it will effect the TYR protein expression by adjusting the IPTG and inducing strain. As the effects to influence of the outside source purpose gene to many.so it is need to further optimize the TYR prokaryotic expression, to obtain high purity of the protein.This paper accumulated data for body color genetic and modified research of the body color in fish by revealing the molecular basis of body color variations. |
PDF Full Text Request