異育銀鯽“中科3號”是中國科學院水生生物研究所桂建芳研究員等在鑒定出可區(qū)分銀鯽不同克隆系的分子標記，證實銀鯽同時存在單性雌核生殖和有性生殖雙重生殖方式的基礎(chǔ)上,，利用銀鯽雙重生殖方式,，從D系銀鯽（♀）與A系銀鯽（♂）交配所產(chǎn)后代中篩選出少數(shù)優(yōu)良個體，再經(jīng)雌核生殖增殖擴群,，經(jīng)多代生長對比養(yǎng)殖試驗評價培育出來的水產(chǎn)新品種,。
最近，該實驗室研究人員進一步對異育銀鯽“中科3號”的遺傳特征進行了染色體計數(shù),、Cot-1 DNA熒光顯帶核型,、微衛(wèi)星DNA標記,、AFLP標記,、轉(zhuǎn)鐵蛋白等位基因序列以及線粒體DNA全序列等比較分析。研究結(jié)果表明,，異育銀鯽“中科3號”的核基因組與A系銀鯽的核基因組相同,，而線粒體DNA全序列與D系銀鯽的線粒體DNA相同。由此揭示異育銀鯽“中科3號”是一個新的核質(zhì)雜種克隆,，其形成的機制是A系銀鯽的精子在D系銀鯽的卵質(zhì)中經(jīng)雄核發(fā)育產(chǎn)生,。人工繁育實驗及其連續(xù)七代的微衛(wèi)星DNA和AFLP標記分析表明，異育銀鯽“中科3號”仍然保留了單性雌核生殖的能力,，產(chǎn)生遺傳性狀與其克隆繁殖用的核質(zhì)雜種母本完全一致的后代,，遺傳性狀穩(wěn)定。這一新的發(fā)現(xiàn)對開拓銀鯽的遺傳育種途徑具有重要意義,，因為由此產(chǎn)生的核質(zhì)雜種克隆避免了在人工誘導雄核發(fā)育和核移植中使用的輻射和物理休克所造成的遺傳和發(fā)育損傷,；其次,，這一發(fā)現(xiàn)還有助于了解單性脊椎動物克隆多樣性產(chǎn)生的原因，對研究其它單性動物的進化遺傳學和生態(tài)學也有重要意義,。
該研究得到國家大宗淡水魚類產(chǎn)業(yè)技術(shù)體系和國家基礎(chǔ)研究973計劃等項目的資助,，主要由王忠衛(wèi)副研究員等完成，通訊作者為桂建芳研究員,，相關(guān)論文已于近日以Research article在線發(fā)表在《BMC研究筆記》（BMC Research Notes） ,。（生物谷Bioon.com）
生物谷推薦原文出處：
BMC Research Notes 2011, 4:82
A novel nucleo-cytoplasmic hybrid clone formed via androgenesis in polyploid gibel carp
Zhong-Wei Wang , Hua-Ping Zhu , Da Wang , Fang-Fang Jiang , Wei Guo , Li Zhou and Jian-Fang Gui
Background
Unisexual vertebrates have been demonstrated to reproduce by gynogenesis, hybridogenesis, parthenogenesis, or kleptogenesis, however, it is uncertain how the reproduction mode contributes to the clonal diversity. Recently, polyploid gibel carp has been revealed to possess coexisting dual modes of unisexual gynogenesis and sexual reproduction and to have numerous various clones. Using sexual reproduction mating between clone D female and clone A male and subsequent 7 generation multiplying of unisexual gynogenesis, we have created a novel clone strain with more than several hundred millions of individuals. Here, we attempt to identify genetic background of the novel clone and to explore the significant implication for clonal diversity contribution.
Methods
Several nuclear genome markers and one cytoplasmic marker, the mitochondrial genome sequence, were used to identify the genetic organization of the randomly sampled individuals from different generations of the novel clone.
Results
Chromosome number, Cot-1 repetitive DNA banded karyotype, microsatellite patterns, AFLP profiles and transferrin alleles uniformly indicated that nuclear genome of the novel clone is identical to that of clone A, and significantly different from that of clone D. However, the cytoplasmic marker, its complete mtDNA genome sequence, is same to that of clone D, and different from that of clone A.
Conclusions
The present data indicate that the novel clone is a nucleo-cytoplasmic hybrid between the known clones A and D, because it originates from the offspring of gonochoristic sexual reproduction mating between clone D female and clone A male, and contains an entire nuclear genome from the paternal clone A and a mtDNA genome (cytoplasm) from the maternal clone D. It is suggested to arise via androgenesis by a mechanism of ploidy doubling of clone A sperm in clone D ooplasm through inhibiting the first mitotic division. Significantly, the selected nucleo-cytoplasmic hybrid female still maintains its gynogenetic ability. Based on the present and previous findings, we discuss the association of rapid genetic changes and high genetic diversity with various ploidy levels and multiple reproduction modes in several unisexual and sexual complexes of vertebrates and even other invertebrates.
