[Zhu, Hua Ping; Lu, Mai Xin; Gao, Feng Ying; Huang, Zhang Han; Yang, Li Ping] Chinese Acad Fishery Sci, Pearl River Fisheries Res Inst, Guangzhou 510380, Guangdong, Peoples R China; [Gui, Jian Fang] Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Peoples R China
WOS标题词:
Science & Technology
; Life Sciences & Biomedicine
In this study, classical and molecular cytogenetic analyses were performed in tilapia fishes, Oreochromis mossambicus (XX/XY sex determination system), O urolepis hornorum (WZ/ZZ sex determination system) and their hybrid by crossing O mossambicus female x O. u hornorum male. An identical karyotype ((2n = 44, NF (total number of chromosomal arms) = 50) was obtained from three examined tilapia samples. Genomic organization analysis of 5S rDNA revealed two different types of 5S rDNA sequences, 5S type I and 5S type II. Moreover, fluorescence in situ hybridization (FISH) with 5S rDNA probes showed six positive fluorescence signals on six chromosomes of all the analysed metaphases from the three tilapia samples. Subsequently, 45S rDNA probes were also prepared, and six positive fluorescence signals were observed on three chromosome pairs in all analysed metaphases of the three tilapia samples. The correlation between 45 rDNA localization and nucleolar organizer regions (NORs) was confirmed by silver nitrate staining in tilapia fishes. Further, different chromosomal localizations of 5S rDNA and 45S rDNA were verified by two different colour FISH probes. Briefly, the current data provide an insights for hybridization projects and breeding improvement of tilapias.
英文摘要:
In this study, classical and molecular cytogenetic analyses were performed in tilapia fishes, Oreochromis mossambicus (XX/XY sex determination system), O urolepis hornorum (WZ/ZZ sex determination system) and their hybrid by crossing O mossambicus female x O. u hornorum male. An identical karyotype ((2n = 44, NF (total number of chromosomal arms) = 50) was obtained from three examined tilapia samples. Genomic organization analysis of 5S rDNA revealed two different types of 5S rDNA sequences, 5S type I and 5S type II. Moreover, fluorescence in situ hybridization (FISH) with 5S rDNA probes showed six positive fluorescence signals on six chromosomes of all the analysed metaphases from the three tilapia samples. Subsequently, 45S rDNA probes were also prepared, and six positive fluorescence signals were observed on three chromosome pairs in all analysed metaphases of the three tilapia samples. The correlation between 45 rDNA localization and nucleolar organizer regions (NORs) was confirmed by silver nitrate staining in tilapia fishes. Further, different chromosomal localizations of 5S rDNA and 45S rDNA were verified by two different colour FISH probes. Briefly, the current data provide an insights for hybridization projects and breeding improvement of tilapias.
Chromosomal localization of rDNA genes and genomic organization of 5S rDNA in Oreochromis mossambicus, O. urolepis hornorum and their hybrid.pdf（566KB）
1.Chinese Acad Fishery Sci, Pearl River Fisheries Res Inst, Guangzhou 510380, Guangdong, Peoples R China 2.Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Peoples R China
Recommended Citation:
Zhu, Hua Ping; Lu, Mai Xin; Gao, Feng Ying; Huang, Zhang Han; Yang, Li Ping; Gui, Jian Fang.Chromosomal localization of rDNA genes and genomic organization of 5S rDNA in Oreochromis mossambicus, O. urolepis hornorum and their hybrid,JOURNAL OF GENETICS,2010,89(2):163-171
