The Study About Genome Stability Of Mated Triploid Loach

In order to discuss the Chromosome Sets Stability of progeny of mated polyploid fishes, this study useloaches as object of study, follow the air dying method to make chromosome specimen, then systematic studythe Chromosome number, karyotype, banding patten and FISH, as follows:1. The chromosome sets stability of hybrid progeny in different ploidy loach(1) The development in early stages of triploid loach: the difference of average fertilization rate amongcontrol group(87.45%), original group(81.47%) and reciprocal group(80.68%) is not significantly(p>0.05); thedifference of average hatching rate of control group(81.35%) and original group(87.73%), originalgroup(87.73%) and reciprocal group(90.13%) is not significantly(p>0.05); the difference of average normalhatching rate between original group(96.44%) and reciprocal group(92.02%) is very significantly(p<0.01); thedifference of average survival rate among control group(83.55%), original group(91.93%) and reciprocalgroup(87.66%) is significantly(p<0.05); the difference of average survival rate between original group(91.93%)and reciprocal group(87.66%) is very significantly(p<0.01).(2) The percentage of chromosome number(3n=75) of early mixed embryo,6month old loaches,12monthold loaches by original crossed is22%,26%,28%, the percentage of chromosome number(3n=75) of earlymixed embryo,6month old loaches,12month old loaches by reciprocal crossed is20%,41%,54%, thepercentage of non integral triploid of early mixed embryo,6month old loaches,12month old loaches byoriginal crossed is80%,59%,46%, the percentage of non integral triploid of early mixed embryo,6month oldloaches,12month old loaches by reciprocal crossed is80%,59%,46%. Obviusly, the percentage ofchromosome number(3n=75) by original and reciprocal crossed are increased with the extension of culture.and the percentage of non integral triploid are decreased With the extension of culture.(3) Early single embryo of original and reciprocal mated triploid loach: the number of early embryochromosome between41-50by statistical data.the percentage of whole diploid embryo(2n=50) is50%, thepercentage of hypodiploid embryo(2n<50) is also50%; the embryo chromosome number of original matedbetween64-82, the percentage of whole triploid embryo(3n=75) of30embryos is45.8%. The percentage ofhypotriploid embryo(3n<75) of30embryos is26.9%, and the percentage of embryo(3n>75) of30embryos is26.9%; the embryo chromosome number of reciprocal mated between61-82, the percentage of whole triploidembryo(3n=75) of30embryos is42%. The percentage of hypotriploid embryo(3n<75) of30embryos is47.8%,and the percentage of embryo(3n>75) of30embryos is10.2%.(4) Analysis of chromosome karotypes in different development stages among mated triploid loach: thechromosome number of original mated loaches is3n=75, karyotype formula is15m+6sm+54t, and armnumber (NF) is96; chromosome number is3n=73, karyotype formula is15m+6sm+52t, and arm number (NF)is94, chromosome number is3n=76, karyotype formula is16m+6sm+54t, and arm number (NF) is98;chromosome number of original mated loaches developed to6month is3n=75,karyotype formula is15m+6sm+54t, and arm number (NF) is96;chromosome number is3n=72, karyotype formula is15m+6sm+51t, and arm number (NF) is93,chromosome number is3n=77, karyotype formula is16m+6sm+56t, and arm number (NF) is98; chromosome number of original mated loaches developed to12month is3n=75, karyotype formula is12m+8sm+55t,and arm number (NF) is95; chromosome number is3n=71,karyotype formula is16m+6sm+49t,and arm number (NF) is93, chromosome number is3n=76,karyotype formula is18m+8sm+50t, and arm number (NF) is102; the chromosome number ofreciprocal mated loaches is3n=75, karyotype formula is14m+9sm+52t, and arm number (NF) is98;chromosome number is3n=73, karyotype formula is13m+6sm+54t, and arm number (NF) is92,chromosome number is3n=77, karyotype formula is18m+7sm+52t, and arm number (NF) is102;chromosome number of original mated loaches developed to6month is3n=75, karyotype formula is 15m+5sm+55t, and arm number (NF) is95; chromosome number is3n=73, karyotype formula is13m+6sm+54t, and arm number (NF) is92, chromosome number is3n=76, karyotype formula is14m+6sm+56t, and arm number (NF) is96; chromosome number of original mated loaches developed to12month is3n=75, karyotype formula is16m+6sm+53t, and arm number (NF) is97; chromosome number is3n=72, karyotype formula is13m+6sm+53t, and arm number (NF) is91, chromosome number is3n=77,karyotype formula is13m+6sm+58t, and arm number (NF) is96.2. The Ag-NORs, CMA3/DA/DAPI, FISH of mated triploid loach(1) Ag-NORs: There are2Ag-NORs in interphase nucleus of control group mated progeny, theAg-NORs are located on the end region of No.1Central centromere chromosomes(M1), and there are3Ag-NORs in interphase nucleus of original and reciprocal mated triploid progeny, the Ag-NORs are located onthe end region of No.1Central centromere chromosomes(M1).(2) CMA3: There are2bright CMA3fluorescence band in control group(2n×2n), and in this study canfind3bright CMA3fluorescence band in original and reciproca group(2n×4n,4n×2n).(3) FISH: There are2fluorescence signals located at the end region of Central centromere chromosomesof control group(2n×2n), and there are3fluorescence signals located at the end region of Central centromerechromosomes in original and reciproca group(2n×4n,4n×2n), It same as Ag-NORs and CMA3, the matedprogeny can be considered as triploid.From the results above, the mated progeny of diploid and tetraploid can be concerned as the triploidcontain3sets genome, it is a effective way to breed polyploid by biological method.