Key Laboratory of Marine Genetics and Breeding (MGB), Ministry of Education, College of Marine Life Sciences, Ocean University of China, Qingdao, China.
PLoS One. 2013 Apr 19;8(4):e62432. doi: 10.1371/journal.pone.0062432. Print 2013.
The Peruvian scallop (Argopecten purpuratus) has been introduced to China and has successfully been hybridized with the bay scallop (A. irradians irradians). The F1 hybrids of these two scallops exhibited a large increase in production traits and some other interesting new characteristics. To understand the genetic basis of this heterosis, nuclear gene and partial mtDNA sequences, and genomic in situ hybridization (GISH) were employed to analyze the genomic organization of the hybrids. Amplification of the ribosomal DNA internal transcribed spacer (ITS) showed that the parental ITS sequences were present in all the hybrid individuals, illustrating that the hybrid offspring inherited nuclear DNA from both parents. Sequence analyses of the ITS region further confirmed that the hybrids harbored alleles from their parents; some recombinant variants were also detected, which revealed some alterations in the nuclear genetic material of the hybrids. The analysis of mitochondrial 16S rDNA showed that the hybrids possessed sequences that were identical to the 16S rDNA of the female parents, proving a matrilineal inheritance of mitochondrial genes in scallops. In addition, GISH clearly discriminated between the parental chromosomes and indicated a combination of haploid genomes of duplex parents in the hybrids. The genetic analyses in our study illustrated that the F1 hybrids inherited nuclear material from both parents and cytoplasmic genetic material maternally, and some variations occurred in the genome, which might contribute to a further understanding of crossbreeding and heterosis in scallop species.
秘鲁扇贝（Argopecten purpuratus）已引入中国，并成功与海湾扇贝（A. irradians irradians）杂交。这两种扇贝的 F1 杂种表现出生产性状的大幅增加和一些其他有趣的新特征。为了了解这种杂种优势的遗传基础，采用核基因和部分 mtDNA 序列以及基因组原位杂交（GISH）分析杂种的基因组组织。核糖体 DNA 内转录间隔区（ITS）的扩增表明，亲本 ITS 序列存在于所有杂种个体中，表明杂种后代从双亲遗传了核 DNA。ITS 区序列分析进一步证实杂种携带来自其父母的等位基因；还检测到一些重组变体，这揭示了杂种核遗传物质的一些改变。线粒体 16S rDNA 的分析表明，杂种具有与其母本 16S rDNA 相同的序列，证明了贝类中线粒体基因的母系遗传。此外，GISH 清楚地区分了亲本染色体，并表明杂种中存在双亲亲本单倍体基因组的组合。本研究的遗传分析表明，F1 杂种从双亲遗传了核物质和母系细胞质遗传物质，基因组发生了一些变异，这可能有助于进一步理解贝类的杂交和杂种优势。
