67 results about "Sex reversal" patented technology

The invention belongs to the aquaculture technology field, in particular relating to an artificial control method for the improvement of female finless eel parent fecundity. The finless eel has special physiological phenomena and sex reversal characteristics with small size, large egg granules and low fecundity. Thus the scale finless eel propagation is subject to the restrictions of the female finless eel parent self-conditions. In the invention, through the artificial simulation of female finless eel culture and development environment, the rational selection of parental finless eels, the reasonable stocking density arrangement, the appropriate feeding and management methods, the pre-oviposition period intensive culture and the artificial control measures, the female finless eel fecundity in natural state can be enhanced to the fecundity up to 450 to 1300 grains each and the 680 grains average level from 170 to 650 grains each and the average 260 grains. Therefore, the average fecundity of finless eel is improved by 161%.

The invention discloses a method for establishing a full-female pelteobagrus fulvidraco breeding population, which comprises the following steps of: 1) manually hastening parturition and manually inseminating; 2) reversing sex; 3) identifying inheritance sex of the sex reversal pelteobagrus fulvidraco; 4) expanding the population; and 5) establishing the full-female pelteobagrus fulvidraco breeding population, so as to finally establish the full-female pelteobagrus fulvidraco breeding population. According to the invention, an integrating technology of hormone sex reversal combined with pelteobagrus fulvidraco chromosome peculiar molecular markers is adopted, so that XX physiological milter can be confirmed without adopting a test mating method and the breeding time is shortened; compared with the test mating method, one generation can be shortened; the gynogenesis step is omitted, so that the damage to the germ cell genetic material caused by manual induction gynogenesis is reduced; the yield of the XX raun is increased; and the economic and social benefits are obvious.

A method for inducing the sex reversal of half-smooth tongue-sole including temp inducing and hormone inducing is disclosed. Said temp inducing method features that the fry is cultured at 28-32 deg.C for 50-60 days. Said hormone inducing method is characterized by that the fry is immersed in the aqueous solution of methyl testosterone for 50-60 days.

The invention discloses a PCR primer pair used for identifying the genetic sex of Pseudobagrus ussuriensis, and a rapid identification method thereof. The identification method comprises the steps of examined individual tissue drawing, genome DNA extraction, sex specific DNA fragment PCR amplification, agarose gel electrophoresis, ultraviolet light detection shooting and examined individual genetic sex determination. High-quality genome DNA is extracted through an optimized process, a sex specific DNA fragment is amplified, and the existence or not and the existence characteristic of the sex specific fragment are detected under ultraviolet lights, so the genetic constitution of Pseudobagrus ussuriensis is identified, and the genetic sex is discriminated in 1-2d. The PCR primer pair and the rapid identification method provide a rapid identification method for identifying sex reversal fish and super-male fish, provide technical support for breeding all-male fish, and have the advantages of breeding time shortening, great increase of the output, breeding cost reduction, and profound economic and social values.

Method for producing YY super-male and XY physiological female common carps, with which YY-chromosome super-male common carp can be cultivated and androgenetic YY super-male common carp is produced, where microsatellite markers are used for paternity testing and test crossing confirmation. The YY common carp is crossed with normal female common carp to produce the progenies of only male common carp, and without sex identification, the juvenile male common carp with known sex are subjected to artificial sex reversal to produce XY physiological female common carp.

The invention discloses a method for quickly establishing cross-bred XY holandric pelteobagrus fulvidraco. The method is characterized in that based on mating offspring of pelteobagrus fulvidraco YY physiological female fish and pelteobagrus vachelli XY male fish, cross-bred YY super-male fish is obtained by cultivation through a genetic method so as to mate with common pelteobagrus fulvidraco female fish to produce the XY holandric pelteobagrus fulvidraco. According to the method disclosed by the invention, the breeding period can be obviously shortened; compared with technologies such as Varadaraj and the like, two generations can be shortened; and compared with a method of continuously producing the holandric pelteobagrus fulvidraco by using sex reversal and gynogenesis, one generation can be shortened. Besides, the cross-bred holandric pelteobagrus fulvidraco obtained by the method disclosed by the invention is stable in genetic character, high in growth speed, large, and strong in adaptive capacity to the environment, has cross-breeding advantages and inherits advantages of the holandric fish, so that better breeding and economic benefits can be obtained.

The invention relates to a sex development regulation and control technology for the male Chinese mitten crab, in particular to a sex reversal siRNA of the Chinese mitten crab and application of the siRNA. A nucleotide sequence of a positive-sense strand of the sex reversal siRNA of the male Chinese mitten crab is shown in SEQ ID NO.1, and a nucleotide sequence of an antisense strand is shown in SEQ ID NO.2. according to the sex reversal siRNA, an IAG gene segment of the Chinese mitten crab is screened from an androgenic gland transcriptome of the Chinese mitten crab, the total-length cDNA sequence of the segment is cloned, according to an IAG gene sequence of the Chinese mitten crab, the siRNA is designed, synthesized and guided into a body of the Chinese mitten crab in the sex differentiation period, expression of an IAG gene in an androgenic gland cell is disturbed, and sex reversal of the male crab is achieved. Compared with androgenic gland removal through surgery, a micro-injection method is adopted and has the advantages that the trauma to the body of the Chinese mitten crab is small, and the situation is avoided that due to wound infection after surgery, the Chinese mittencrab dies; the injection dose is extremely low, the immunological stress reaction of a tested animal is not easily triggered, and accordingly the success rate of sex reversal is increased.

The invention provides a sustained release medicine for artificially inducing sex reversal of grouper and its preparation method, wherein the medicine comprises aromatase inhibitor 1.5-15%, synthetic rubber base material for medical purpose 75-90%, hardening agent 8.5-10%, the process for preparing the medicament comprises mixing homogeneously, dry forming, and refrigerated preservation.

The invention discloses a method for producing gynoecial loaches. The method comprises the following steps: (1) artificial propagation and artificial insemination; (2) sex reversal: reversing most XX male fishes in fries into XX physiological male fishes by taking artemia larvae soaked into a male hormone solution as a bait, remaining XY male fishes unchanged, and removing XX female fishes till male fishes and female fishes can be distinguished; (3) test mating: feeding the XX physiological male fishes and the XY male fishes to a sexually mature state, mating with the XX female fishes respectively, and remaining a parent of which all offspring are XX female fishes, namely, the XX physiological male fishes; (4) reproduction: mating the XX physiological male fishes and the XY male fishes to produce 100 percent XX female fries, and carrying out sex-reversing on a part of the female fries into XX physiological male fishes according to the step (2); (5) establishment of a population: mating the XX female fishes and the XX physiological male fishes to produce 100 percent XX female fishes, and repeating the steps (4) and (5) to continuously produce gynoecial loaches on a large scale.

The invention discloses an efficient induction method and a microsatellite molecular marker identification method of Nile tilapia pseudo-female fishes. Different doses of estrogen diethylstilbestrol (DES) are used for sex reversal processing of different groups of Nile tilapia fishes to establish the efficient induction method of the Nile tilapia pseudo-female fishes; and a newly-developed microsatellite molecular marker tlp-23-sd and a primer thereof are further used for identification of the Nile tilapia pseudo-female fishes to establish the microsatellite molecular marker rapid identification method of the pseudo-female fishes, wherein the microsatellite molecular marker tlp-23-sd is closely linked with the sex. The efficient induction method is high in pseudo-female fish induction efficiency, and the microsatellite molecular marker rapid identification method is rapid, accurate and reliable in identification, and can be used for the production and identification of the Nile tilapia pseudo-female fishes.

The invention belongs to the technical field of fish breeding, and discloses a breeding method of all-male hybrid snakehead. The method includes the following steps of bred channa maculata sex reversal, identification of pseudo-female fishes, reproduction of the pseudo-female fishes, identification of super-male fishes and expanding propagation of the super-male fishes. By using the method, the all-male hybrid snakehead can be bred, and the male rate is 93% or above; after being bred for 7 months, the all-male varieties are increased by 8% or above in yield compared with normal varieties, andthe all-male varieties with the height of 2 jin or more are increased by 15%; the coefficient of a novel fish feed in the current year of breeding is reduced by 0.1; after being bred for 7 months, theall-male varieties are increased by 26.6% in yield compared with normal varieties, and the feed coefficient is reduced by 0.175-0.21. The new varieties 'hybrid snakehead' obtained through hybridization have the advantages of being high in growth speed and strong in low temperature resistance, can replace snakehead breeding in the north area and become national breeding varieties.

The invention discloses an artificially induced gynogenesis method for Pseudobagrus ussuriensis, comprising the steps of heredity inactivation of sperms, cold shock treatment of germ cells, and hatching; the best time for inactivating the sperms of the Pseudobagrus ussuriensis is found out by regulating the irradiation distance and the irradiation time of ultraviolet; the cold shocks with different time spans are carried out at different time starts after fertilization, the treatment time for a highest survival rate is determined to be the proper time span of the cold shock, and thus the optimal condition suitable for artificially induced gynogenesis of the Pseudobagrus ussuriensis is screened out. According to the technical route of milter sex reversal-artificial gynogenesis-super-milter cultivating-complete milter cultivating, the invention provides a technological base for cultivating the super-milter of the Pseudobagrus ussuriensis and cultivating the monotropic complete milter, so that the cultivation scale is exoanded and the yield is greatly increased, so that the income of farmers is greatly increased, and therefore, the method has a broad industrialized cultivation prospect.

The invention relates to an ecology regulation and control method for delaying the sex reversal time of eels. The ecology regulation and control method for delaying the sex reversal time of the eels is characterized in that under an ecology imitation condition, young eels with the same specification are massively produced, and moreover, with the adoption of a pond net cage breeding method, the young eels obtained in the same year are bred and overwinter to grow into 30-40g 1-full-age eels; and after the overwintering, the 30-40g 1-full-age eels are fed for one year with high protein nutrients at a high density in a pond net cage, wherein the feeding density is 50-80 eels per square meter and the feed protein content is 40% to 42%. Through the method, 2-winter-age female eel parents with great brood amount and an individual specification of more than 100g can be produced; the colony reproductive capacity of the female eel parents can be improved by 200% to 300%; the quantity of the produced young eels is correspondingly improved by 200% to 300%; and therefore, the demand on the large-scale breeding of the young eels can be met.

The invention relates to a directional breeding method of female parents of finless eel and belongs to the technical field of fishery science application. The directional breeding method of female parents of finless eel is characterized by comprising the steps of obtaining one-full-age eels growing consistently and having the individual specification of 30-40g by virtue of breeding in pond net cages under imitated ecological conditions, after overwintering, feeding the one-full-age eels of 30-40g in the pond net cages by high density and with high-protein nutrition for a year, namely the feeding density of 50-80 eels per square meter and the feed protein content of 40%-42%, and postponing the sex reversal of the parents of the eels by more than 12 months, thereby obtaining two winter-age female eel parents having large brood amount and the individual specification of more than 100g; the population fertility of the female eel parents can be improved by 200%-300% and the number of the bred eel seedlings is also improved by 200%-300% correspondingly; as a result, the population fertility of the female eel parents is effectively improved and the requirements of large-scale eel breeding on the seedlings can be met.

The invention provides a production method of sex-reversed male loach. The method comprises the first step of conducting incubation; the second step of conducting temperature regulatory reversion, wherein after loach fry is hatched and out of membrane, and before genital ridge of the loach fry is formed, the water temperature is gradually raised to 27-32 DEG C to cultivate the loach fry to juvenile loach; the third step of conducting male hormone regulatory reversion, wherein after the loach fry is hatched and out of membrane, artemia larva and pellet feed which are treated by a male hormone solution are mixed and continuously thrown through a gradual-transition mode; the fourth step of conducting normal feeding, wherein the water temperature is adjusted to a normal water temperature, then the pellet feed which is not treated by the male hormone solution is thrown, and then XX male loach is removed when the loach is fed to the state that the male loach and the female loach can be distinguished; the fifth step of conducting test cross, wherein XX physiological male loach and XY male loach are fed to be sexually mature, then the XX physiological male loach and XY male loach are mated with XX male loach separately, and then male parent of which the filial generation is 100%XX male loach is screened out, namely, XX sex-reversed male loach. Through a joint effect of the temperature and male hormone, regulatory reversion is conducted, so that the survival rate and the sex reversal rate of the loach fry can reach an optimal state simultaneously, and further the production method of the sex-reversed male loach can be used for conducting scale production of full-female loach.

The invention discloses an anti-mullerian hormone AMH gene for epinephelus lanceolatus. A nucleotide sequence of the anti-mullerian hormone AMH gene is shown as SEQ ID NO:1. The invention also discloses protein encoded by the gene, a preparation method for producing anti-mullerian hormone AMH recombinant protein by adopting the anti-mullerian hormone AMH gene as a target gene, and a polyclonal antibody prepared by adopting the anti-mullerian hormone AMH recombinant protein obtained by the method as antigen to immunize animals. The invention further discloses application of anti-mullerian hormone AMH recombinant plasmid to preparation of an inducer in a sex-reversal process of the epinephelus lanceolatus and application of the polyclonal antibody to preparation of detecting agents for different developmental periods of the epinephelus lanceolatus.

The invention discloses a method for cultivating pure aristichthys nobilis red.var groups. The method comprises activating roe of aristichthys nobilis red.var with diploid sperms of allotetraploid crucian carps, performing cold shock treatment after activation, and controlling the temperature through flowing water to obtain gynogenesis aristichthys nobilis red.var; feeding feeds containing male hormone after incubation for several days to obtain sex reversal male gynogenesis aristichthys nobilis red.var; and performing selfing with gynogenesis aristichthys nobilis red.var serving as the female parent and with male gynogenesis gynogenesis aristichthys nobilis red.var serving as the male parent to obtain gynogenesis pure aristichthys nobilis red.var groups. Further, the gynogenesis aristichthys nobilis red.var can serve as the female parent, a common male aristichthys nobilis red.var serves as the male parent, and the female parent and the male parent are hybridized to obtain gynogenesis pure aristichthys nobilis red.var groups. According to the method, the roe hatchability and the survival rate can be improved greatly, and the pure aristichthys nobilis red.var groups stable in body color and excellent in performance can be cultivated.

The present invention relates the function of Dickkopf 3 (Dkk3 ) in testis using shRNA mediated knock down model. Specifically, the present invention provides knock down model comprising reduction in Dkk3 activity. The knock down model of Dkk3 consisting of non human vertebrates which have, incorporated in their genome, shRNA construct targeting mammalian Dkk3 gene exhibits low testis weight, low sperm count and has low litter size. The knock down model displays disrupted seminiferous tubules and are subfertile. The present invention model has a role in sex determination as its interruption leads to sex reversal of XY gonads, converting males to females. Sex reversal role of Dkk3 knock down model can find its utility in agricultural applications. The present invention describes Dkk3 as a dual function protein which is associated with sex determination as well as is essential for the process of spermatogenesis. Such testicular functional studies are useful as a model for various disease states of infertility or subfertility and for identifying a potential treatment to overcome idiopathic infertility.