Structure, organization and expression of common carp (Cyprinus carpio L.) SLP-76 gene

SLP-76 is an important member of the SLP-76 family of adapters, and it plays a key role in TCR signaling and T cell function. Partial cDNA sequence of SLP-76 of common carp (Cyprinus carpio L.) was isolated from thymus cDNA Library by the method of suppression subtractive hybridization (SSH). Subsequently, the full length cDNA of carp SLP-76 was obtained by means of 3' RACE and 5' RACE, respectively. The full Length cDNA of carp SLP-76 was 2007 bp, consisting of a T-terminal untranslated region (UTR) of 285 bp, a T-terminal. UTR of 240 bp, and an open reading frame of 1482 bp. Sequence comparison showed that the deduced amino acid sequence of carp SLP-76 had an overall similarity of 34-73% to that of other species homotogues, and it was composed of an NH2-terminal domain, a central proline-rich domain, and a C-terminal SH2 domain. Amino acid sequence analysis indicated the existence of a Gads binding site R-X-X-K, a 10-aa-long sequence which binds to the SH3 domain of LCK in vitro, and three conserved tyrosine-containing sequence in the NH2-terminal domain. Then we used PCR to obtain a genomic DNA which covers the entire coding region of carp SLP-76. In the 9.2 k-long genomic sequence, twenty one exons and twenty introns were identified. RT-PCR results showed that carp SLP-76 was expressed predominantly in hematopoietic tissues, and was upregulated in thymus tissue of four-month carp compared to one-year old carp. RT-PCR and virtual northern hybridization results showed that carp SLP-76 was also upregulated in thymus tissue of GH transgenic carp at the age of four-months. These results suggest that the expression level of SLP-76 gene may be related to thymocyte development in teleosts. (c) 2007 Published by Elsevier Ltd.

利用Γ－X混合在AlAs/GaAs异质结构实现光生电子、空穴对的持久存储

利用GaAs量子阱中Γ谷速缚态与AlAs层中X谷束缚态在异质结界面处的共振Γ－X混合，使得光生电子不仅在实空间而且在K空间与光生空穴分离开来，从而在结构中形成了持久的电荷极化。这一效应已被C－V特性上所观察到的电容阶跃和正反方向扫描时所出现的双稳滞迟现象所证实。如果将我们的器件用作存储单元，预期可以获得很长的存储时间T_s。同时，由于Γ－X混合隧穿速率很快，光子“读出”仍可以保持很快。