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The formation of diploid and triploid hybrids of female grass carp × male blunt snout bream and their 5S rDNA analysis.

He W, Xie L, Li T, Liu S, Xiao J, Hu J, Wang J, Qin Q, Liu Y - BMC Genet. (2013)

Bottom Line: Hybridization is a useful strategy to alter the genotypes and phenotypes of the offspring.And the offspring may exhibit advantages in growth rate, disease resistance, survival rate and appearance, which resulting from the combination of the beneficial traits from both parents.There was only one type of 5S rDNA (designated type I: 180 bp) in GC and one type of 5S rDNA (designated type II: 188 bp) in BSB.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Laboratory of Protein Chemistry and Fish Developmental Biology of Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha 410081, P R, China. lsj@hunnu.edu.cn.

ABSTRACT

Background: Hybridization is a useful strategy to alter the genotypes and phenotypes of the offspring. It could transfer the genome of one species to another through combing the different genome of parents in the hybrid offspring. And the offspring may exhibit advantages in growth rate, disease resistance, survival rate and appearance, which resulting from the combination of the beneficial traits from both parents.

Results: Diploid and triploid hybrids of female grass carp (Ctenopharyngodon idellus, GC, Cyprininae, 2n = 48) × male blunt snout bream (Megalobrama amblycephala, BSB, Cultrinae, 2n = 48) were successfully obtained by distant hybridization. Diploid hybrids had 48 chromosomes, with one set from GC and one set from BSB. Triploid hybrids possessed 72 chromosomes, with two sets from GC and one set from BSB.The morphological traits, growth rates, and feeding ecology of the parents and hybrid offspring were compared and analyzed. The two kinds of hybrid offspring exhibited significantly phenotypic divergence from GC and BSB. 2nGB hybrids showed similar growth rate compared to that of GC, and 3nGB hybrids significantly higher results. Furthermore, the feeding ecology of hybrid progeny was omnivorous.The 5S rDNA of GC, BSB and their hybrid offspring were also cloned and sequenced. There was only one type of 5S rDNA (designated type I: 180 bp) in GC and one type of 5S rDNA (designated type II: 188 bp) in BSB. However, in the hybrid progeny, diploid and triploid hybrids both inherited type I and type II from their parents, respectively. In addition, a chimera of type I and type II was observed in the genome of diploid and triploid hybrids, excepting a 10 bp of polyA insertion in type II sequence of the chimera of the diploid hybrids.

Conclusions: This is the first report of diploid and triploid hybrids being produced by crossing GC and BSB, which have the same chromosome number. The obtainment of two new hybrid offspring has significance in fish genetic breeding. The results illustrate the effect of hybridization and polyploidization on the organization and variation of 5S rDNA in hybrid offspring.

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Cytometric histograms of GC, BSB and their hybrid offspring. (A) The mean DNA content of GC (peak 1: 60.56). (B) The mean DNA content of BSB (peak 1: 74.55). (C) The mean DNA content of 2nGB (peak 1: 68.63). (D) The mean DNA content of 3nGB (peak 1: 98.19).
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Figure 3: Cytometric histograms of GC, BSB and their hybrid offspring. (A) The mean DNA content of GC (peak 1: 60.56). (B) The mean DNA content of BSB (peak 1: 74.55). (C) The mean DNA content of 2nGB (peak 1: 68.63). (D) The mean DNA content of 3nGB (peak 1: 98.19).

Mentions: The distribution of DNA content of all samples is given in Table 2 and Figures 3A–D. The mean DNA content of 2nGB hybrids was equal (P > 0.05) to the sum of half of GC and BSB, suggesting that 2nGB hybrids had one set of chromosomes from GC and BSB, respectively. The mean DNA content of 3nGB hybrids was equal (P > 0.05) to the sum of GC and half of BSB, suggesting that 3nGB hybrids had two sets of chromosomes from GC and one set of chromosomes from BSB.


The formation of diploid and triploid hybrids of female grass carp × male blunt snout bream and their 5S rDNA analysis.

He W, Xie L, Li T, Liu S, Xiao J, Hu J, Wang J, Qin Q, Liu Y - BMC Genet. (2013)

Cytometric histograms of GC, BSB and their hybrid offspring. (A) The mean DNA content of GC (peak 1: 60.56). (B) The mean DNA content of BSB (peak 1: 74.55). (C) The mean DNA content of 2nGB (peak 1: 68.63). (D) The mean DNA content of 3nGB (peak 1: 98.19).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4222567&req=5

Figure 3: Cytometric histograms of GC, BSB and their hybrid offspring. (A) The mean DNA content of GC (peak 1: 60.56). (B) The mean DNA content of BSB (peak 1: 74.55). (C) The mean DNA content of 2nGB (peak 1: 68.63). (D) The mean DNA content of 3nGB (peak 1: 98.19).
Mentions: The distribution of DNA content of all samples is given in Table 2 and Figures 3A–D. The mean DNA content of 2nGB hybrids was equal (P > 0.05) to the sum of half of GC and BSB, suggesting that 2nGB hybrids had one set of chromosomes from GC and BSB, respectively. The mean DNA content of 3nGB hybrids was equal (P > 0.05) to the sum of GC and half of BSB, suggesting that 3nGB hybrids had two sets of chromosomes from GC and one set of chromosomes from BSB.

Bottom Line: Hybridization is a useful strategy to alter the genotypes and phenotypes of the offspring.And the offspring may exhibit advantages in growth rate, disease resistance, survival rate and appearance, which resulting from the combination of the beneficial traits from both parents.There was only one type of 5S rDNA (designated type I: 180 bp) in GC and one type of 5S rDNA (designated type II: 188 bp) in BSB.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Laboratory of Protein Chemistry and Fish Developmental Biology of Education Ministry of China, College of Life Sciences, Hunan Normal University, Changsha 410081, P R, China. lsj@hunnu.edu.cn.

ABSTRACT

Background: Hybridization is a useful strategy to alter the genotypes and phenotypes of the offspring. It could transfer the genome of one species to another through combing the different genome of parents in the hybrid offspring. And the offspring may exhibit advantages in growth rate, disease resistance, survival rate and appearance, which resulting from the combination of the beneficial traits from both parents.

Results: Diploid and triploid hybrids of female grass carp (Ctenopharyngodon idellus, GC, Cyprininae, 2n = 48) × male blunt snout bream (Megalobrama amblycephala, BSB, Cultrinae, 2n = 48) were successfully obtained by distant hybridization. Diploid hybrids had 48 chromosomes, with one set from GC and one set from BSB. Triploid hybrids possessed 72 chromosomes, with two sets from GC and one set from BSB.The morphological traits, growth rates, and feeding ecology of the parents and hybrid offspring were compared and analyzed. The two kinds of hybrid offspring exhibited significantly phenotypic divergence from GC and BSB. 2nGB hybrids showed similar growth rate compared to that of GC, and 3nGB hybrids significantly higher results. Furthermore, the feeding ecology of hybrid progeny was omnivorous.The 5S rDNA of GC, BSB and their hybrid offspring were also cloned and sequenced. There was only one type of 5S rDNA (designated type I: 180 bp) in GC and one type of 5S rDNA (designated type II: 188 bp) in BSB. However, in the hybrid progeny, diploid and triploid hybrids both inherited type I and type II from their parents, respectively. In addition, a chimera of type I and type II was observed in the genome of diploid and triploid hybrids, excepting a 10 bp of polyA insertion in type II sequence of the chimera of the diploid hybrids.

Conclusions: This is the first report of diploid and triploid hybrids being produced by crossing GC and BSB, which have the same chromosome number. The obtainment of two new hybrid offspring has significance in fish genetic breeding. The results illustrate the effect of hybridization and polyploidization on the organization and variation of 5S rDNA in hybrid offspring.

Show MeSH
Related in: MedlinePlus