| In this study,Amphiprion and Premnas from Pomacentridae fish as the object of the research to explore the development of embry and pigment mechanism.Using the second-generation transcriptome sequencing as an analytical method,this paper studied several aspects of fishes,which include embryonic development,the composed of pigment cells,the changes of pigment cells after photochromic and the differences of related pigment genes.The purpose of these analyses is to provide theoretical support for artificial breeding of ornamental fish and provide new materials for body color research.Moreover it provides important theoretical supplement for the existing body color formation mechanism.1、Studies on Comparative Embryology and Discussion of Evolutiology in Four Varieties of AmphiprionThe embryonic development of Amphiprion frenatus,A.ocellaris,the A.percula of artificial breeding,and the A.ocellaris of artificial breeding are observed and compared under captive condition.The results show that the four varieties of Amphiprion almost all spawn twice monthly.The difference of spawning time is smaller and the regularity of spawning interval is relatively strong of all Amphiprion in the same breeding environment.However,there is significant difference of embryonic development time,in which the longest one is A.percula of artificial breeding and shortest one is A.ocellaris of artificial breeding.The four varieties of Amphiprion have same embryonic development characteristic and incubation period.But the embryonic development duration is different,they are 244 h,240h,260 h,and 181 h,respectively.The developmental duration is difference between the cleavage stage and the neurula stage is less than 2h,the period from the turning phase to the hatching phase determines the embryonic development duration.This study indicates that the developmental duration of embryonic development in different Amphiprion may be related to the evolutionary distance.In addition,the temperature,photoperiod,quality and morphology of the eggs have a great influence on the embryonic development duration.In this study,the A.percula of artificial breeding(Picasso)is a purely artificial offspring which have a great difference with the wild.The embryonic developmental duration of the A.ocellaris of artificial breeding(Snowflake)is the shortest,which is significantly different from the wild A.ocellaris.2、Observation and statics on chromatophores in five strains of PomacentridaeIn this paper,observation on pigment cells of fins,skins and scals in Amphiprion frenatus,Amphiprion ocellar(common,mutant and wild),and Premnas.The scales are thin and transparent,thus,we can be directly observed under a microscope.The substratum of the scales with guanophores are close to the skin,and the superstratum of the scales are opposite.The posterior of the scale exposed and has pigment.The anterior of the scale is embedded in the dermis.Melanophores,xanthophores,erythrophores and iridophores are found in the scales and skins of fishes body.And there are abundant iridophores in scales.There are two types of chromatophores,melanophore and iridophore in the stripe of body of different clownfish.But there are different proportion.Comparison of three kinds of Amphiprion ocellar(common,mutant and wild),we can see that the wild contain less melanophores than common.Moreover,melanophores account for the highest proportion of mutant(Amphiprion ocellaris var).Interestingly,all kinds of fish have no iridophores in fins.3、Different light color has an effect on the body color of Amphoprion frenatusAmphoprion fernatus as the object of the research,white light was used as the control group,and red light blue light was used to observe the changes of body color of Amphoprion fernatus by different light colors.The mechanism of body color change of different light color Amphoprion fernatus was discussed by second generation transcriptome sequencing technology.The results showed that when the blue light was irradiated,the body color of the Amphoprion fernatus was obviously darker than that of the red and white light bodies,while the red color of the red light was deeper.In the case of white light,the color did not change significantly.8 significant differential genes were screened from the transcriptome sequencing results,namely aim1,dct,oca2,shady,slc24a5,tyr,tyrp1,mitf.Among the 8 genes except shady gene,the rest were related to melanin.Genes expression have a tendency to increase in blue light.Therefore,different light colors have the greatest influence on the expression of melanocyte-related genes,and weaker effects on other pigment cell-related genes.The migration and development of melanocytes affect the development of other types of pigment cells. |
