Effects Of Oceanic Acidification On The Sexual Differentiation Of Oryzias Melastigma

After the industrial revolution,from the burning of fossil fuels and the impact of human activities,the atmospheric CO₂ concentration continues to increase.The 24% to 35% of the CO₂ released into the atmosphere is absorbed by the oceans,resulting in increased acidity of the seawater and the main reason for the change of the carbonate balance system.The current surface seawater pH has been reduced by 0.1 units compared to the industrial revolution period.2100 atmospheric CO₂ concentration increased to 800 1000?L / L??tam?.Scientists have realized that changes in the chemical environment of seawater caused by excessive CO₂ emissions are changing the chemical environment in which marine organisms depend,and as the CO₂ increases in the ocean changes in the chemical environment of seawater are Boundless marine creatures are also deeply affected,is likely to have an impact on the growth and development of marine organisms,and even affect the breeding of offspring fish.Therefore,it is very important to study the effect of CO₂ in seawater on fish.Medaka?Oryzias melastigma?belongs to the Chordat a vertebrate vertebrate of the vertebrate subfamily?Oryzias?.The research on the anatomical and physiological aspects of the Japanese medaka fish has been improved and the system has been developed,which facilitates the corresponding study of the fish in the sea.So that the marine medaka fish to become marine ecology toxicology research model of biological.Median fish is small and has strong tolerance to the environment.It is easy to carry out large-scale feeding under laboratory conditions.It adapts to temperature range and has a wide salinity range.It can construct sensitive mutations that are sensitive to temperature and salinity Species.And can make full use of the same species for comparative biology research.Gender difference can be quickly identified by the different shape of the caudal fin;and the female fecundity is large,the generation cycle is short;the male andfemale secondary sexual characteristics are obvious,the larger the volume of the eggs,the color is transparent and not easy to break,the development stage changes obviously,Easy to carry out a variety of laboratory observation and operation;eggs and juveniles on the living environment of various types of pollutants in the intervention sensitive to the rapid determination of pollutants on specific genes or other changes in the molecule.In this paper,the effects of ocean acidification on gonadal development and sex differentiation of.The effects of acidification on the expression rate of c-fos protein in the brain of adult medaka fish were observed by immunohistochemistry and WB method.The effects of acidification on embryonic development and gonadal development of fertilized eggs were studied.Finally,we observed the developmental stage of the fish gland with the H.E.slice.C-fos found in the living environment of adult medaka fish,and found that c-fos could be detected in most of the brain regions of the marine medaka fish,especially the terminal brain,the top cover and the extension brain.The results of CO₂ treatment and control group can conclude that CO₂ has a certain effect on the expression of c-fos in the brain of medaka fish,and the expression level of c-fos is up-regulated and stored in different brain regions Differences,due to the end of the brain to receive the function of olfactory stimulation,access to CO₂ in the water after the chemical balance changes,immune images and WB experiments found that access to CO₂ will cause the terminal area of the protein changes,that is,after the introduction of CO₂ The smell of the medaka fish can feel the seawater acid-base balance has changed,so that in the terminal area of c-fos protein expression.View the leaves in the back of the brain,is the visual center of the fish,and integrated parts of the high-level center,with the maintenance of fish balance,coordination and control of muscle tension and other effects,affecting fish swimming speed.After CO₂ was introduced,the formation site of c-fos protein in the roof was observed.It was found that the content of c-fos protein in the edge of the top of the cap was higher than that in the control group,which was consistent with the study of the phototaxis of juvenile eggs after the study of excessive dissolved CO₂ in the ocean.Yan brain is located in the brain at the end of the rear covered with choroid plexus,the bottom of the fourth ventricle,ventricle and spinal cord in the same tube.Immediate on both sides of the extension of the ear-shaped protrusion,listening to the side of the box and the feeling of the center.Delayed brain is a variety of physiologicalfunctions and the center of feeling and breathing,or the role of the role of pigment cells to adjust the center.The expression of c-fos protein was observed in the central part of the brain after CO₂ exposure,which was significantly different from that in the control group.There are more c-fos proteins in the brain,that is,a variety of physiological functions,sensory or respiratory center of the medaka fish are affected by CO₂.In this experiment,the effects of CO₂ on the sea water medaka.In this study,fertilized egg fertilization rate was lower than that of control.It is speculated that CO₂ may affect the mackerel fish spawning and fertilization activities,resulting in fertilization rate changes.The results showed that the outcry rate,hatching time and sex ratio of mackerel fish were affected by CO₂,and the results were as follows: We can get CO₂ concentration of 1000 ppm,by the living environment of the impact of CO₂ concentration,but there is no linear trend,while the fertilization rate at 1000 ppm than the current concentration of CO₂ in the air fertilization rate is lower,but than the CO₂ The concentration of 2000 ppm is also low.At the same time,when the CO₂ concentration was 1000 ppm,the film yield was much higher than that of the control group.When the concentration of CO₂ was increased,the film rate decreased.It is speculated that low concentration of CO₂ is likely to be an external stimulus,causing the juvenile hatchery to respond to this stimulus;stress response promotes the increase in the rate of hatching of the larvae and the shortening of hatching time.However,when the ambient CO₂ concentration is too high,the larvae in the hatch will be a hazard signal,resulting in juvenile self-protection to avoid the danger of the outside world to extend the incubation time.But when the juvenile fish in the fish eggs within a long time without film,often in the egg yolk in the consumption of nutrients is still not after the film,resulting in the incubation time is too long and the emergence of dead eggs.The sex ratio of these young larvae treated with different concentrations of CO₂ was compared with the untreated control group.Through the morphological and molecular level observation of its second sexual characteristics and gene sex,found:1)Under the stereomicroscope,the male caudal fin is larger than the female caudal fin and the dorsal fin is also male relative to the female.Female broods of the anal nipples to be significantly greater than the male,and male and female sphincter wrapped around a layer of fat layer.2)37% of the contaminated fish were found to be reversible when the CO₂ concentration was1000 ppm.When the CO₂ concentration continued to increase to 2000 ppm,approximately 47% of the individuals were genetically reversed and genotype For the male of XX,but did not find the genotype XY female.It is speculated that the acidification caused by CO₂ may be a major factor in the reversal of the growth and development of medaka fish,and the reversal rate will increase with the increase of CO₂ concentration.3)Observation of the HE staining of the medaka fish on the gonads found that the gonadal development of the sea water medaka fish than the freshwater medaka fish gonadal development earlier,in the film 2 days after the gonadal tissue can be significantly observed in the fresh water The gonadal tissue was observed 5 days after hatching.And sexual maturity than freshwater medaka fish development earlier,a month of medaka fish body has mature sperm cells.While freshwater medaka fish has no mature germ cells in one month.We have explored the growth and development of sea water medaka in the environment of ocean acidification after CO₂,suggesting that CO₂ can be used as an important factor in the development of fish gland during the sea.