Evidence has accumulated that there is a trade-off between benefits and costs associated with rapid growth. A trade-off between growth rates and critical swimming speed (Ucrit) had been also reported to be common in t...Evidence has accumulated that there is a trade-off between benefits and costs associated with rapid growth. A trade-off between growth rates and critical swimming speed (Ucrit) had been also reported to be common in teleost fish. We hypothesize that growth acceleration in the F3 generation of "all-fish" growth hormone gene (GH) transgenic common carp (Cyprinus carpio L.) would reduce the swimming abilities. Growth and swimming performance between transgenic fish and non-transgenic controls were compared. The results showed that transgenic fish had a mean body weight 1.4―1.9-fold heavier,and a mean specific growth rate (SGR) value 6%―10% higher than the controls. Transgenic fish,however,had a mean absolute Ucrit (cm/s) value 22% or mean relative Ucrit (BL/s) value 24% lower than the controls. It suggested that fast-growing "all-fish" GH-transgenic carp were inferior swimmers. It is also supported that there was a trade-off between growth rates and swimming performance,i.e. faster-growing individuals had lower critical swimming speed.展开更多
Nematoda is a metazoan group with extremely high diversity only next to Insecta. Caenorhabditis elegans is now a favorable experimental model animal in modern de-velopmental biology, genetics and genomics studies. How...Nematoda is a metazoan group with extremely high diversity only next to Insecta. Caenorhabditis elegans is now a favorable experimental model animal in modern de-velopmental biology, genetics and genomics studies. However, the phylogeny of Nematoda and the phylogenetic position of the phylum within animal kingdom have long been in debate. Recent molecular phylogenetic studies gave great challenges to the traditional nematode classification. The new phylog-enies not only placed the Nematoda in the Ecdysozoan and divided the phylum into five clades, but also provided new insights into animal molecular identification and phyloge-netic biodiversity studies. The present paper reviews major progress and remaining problems in the current molecular phylogenetic studies of Nematoda, and prospects the devel-opmental tendencies of this field.展开更多
基金Supported by the National Natural Science Foundation of China (Grant Nos. 30400056 and 30130050)the Development Plan of the State Key Fundamental Research of China (Grant No. 2001CB109006)the ‘863’ High Technology Project (Grant No. 2004AA213120)
文摘Evidence has accumulated that there is a trade-off between benefits and costs associated with rapid growth. A trade-off between growth rates and critical swimming speed (Ucrit) had been also reported to be common in teleost fish. We hypothesize that growth acceleration in the F3 generation of "all-fish" growth hormone gene (GH) transgenic common carp (Cyprinus carpio L.) would reduce the swimming abilities. Growth and swimming performance between transgenic fish and non-transgenic controls were compared. The results showed that transgenic fish had a mean body weight 1.4―1.9-fold heavier,and a mean specific growth rate (SGR) value 6%―10% higher than the controls. Transgenic fish,however,had a mean absolute Ucrit (cm/s) value 22% or mean relative Ucrit (BL/s) value 24% lower than the controls. It suggested that fast-growing "all-fish" GH-transgenic carp were inferior swimmers. It is also supported that there was a trade-off between growth rates and swimming performance,i.e. faster-growing individuals had lower critical swimming speed.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 30000020) the doctoral Foundation of Shanghai.
文摘Nematoda is a metazoan group with extremely high diversity only next to Insecta. Caenorhabditis elegans is now a favorable experimental model animal in modern de-velopmental biology, genetics and genomics studies. However, the phylogeny of Nematoda and the phylogenetic position of the phylum within animal kingdom have long been in debate. Recent molecular phylogenetic studies gave great challenges to the traditional nematode classification. The new phylog-enies not only placed the Nematoda in the Ecdysozoan and divided the phylum into five clades, but also provided new insights into animal molecular identification and phyloge-netic biodiversity studies. The present paper reviews major progress and remaining problems in the current molecular phylogenetic studies of Nematoda, and prospects the devel-opmental tendencies of this field.
