•确定目标基因的形态：DNA or RNA
•查找目标基因
•比对目标基因同源性和特点
•选取目标基因序列
•选取目标基因的目标区段
1、mRNA 序列的查询；
以查大鼠cort为例；
在Nucleotide中，搜索rat cort
在NCBI上搜索到目的基因，找到该基因的mRNA
把以下内容存成txt文件：
Rattus norvegicus cortistatin (Cort), mRNA
LOCUS NM_012835 438 bp mRNA linear ROD 11-FEB-2008
DEFINITION Rattus norvegicus cortistatin (Cort), mRNA.
ACCESSION NM_012835
VERSION NM_012835.1 GI:6978682
KEYWORDS .
SOURCE Rattus norvegicus (Norway rat)
ORGANISM Rattus norvegicus
Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
Mammalia; Eutheria; Euarchontoglires; Glires; Rodentia;
Sciurognathi; Muroidea; Muridae; Murinae; Rattus.
REFERENCE 1 (bases 1 to 438)
AUTHORS Xidakis,C., Mastrodimou,N., Notas,G., Renieri,E., Kolios,G.,
Kouroumalis,E. and Thermos,K.
TITLE RT-PCR and immunocytochemistry studies support the presence of
somatostatin, cortistatin and somatostatin receptor subtypes in rat
Kupffer cells
JOURNAL Regul. Pept. 143 (1-3), 76-82 (2007)
PUBMED 17481746
REMARK GeneRIF: RT-PCR and immunocytochemistry studies support the
presence of cortistatin in rat Kupffer cells.
REFERENCE 2 (bases 1 to 438)
AUTHORS Bourgin,P., Fabre,V., Huitron-Resendiz,S., Henriksen,S.J.,
Prospero-Garcia,O., Criado,J.R. and de Lecea,L.
TITLE Cortistatin promotes and negatively correlates with slow-wave sleep
JOURNAL Eur. J. Neurosci. 26 (3), 729-738 (2007)
PUBMED 17686045
REMARK GeneRIF: The capacity of CST-14 to increase SWA, together with
preprocortistatin's inverse correlation with time spent in SWS,
suggests a potential role in sleep homeostatic processes.
REFERENCE 3 (bases 1 to 438)
AUTHORS Deghenghi,R., Avallone,R., Torsello,A., Muccioli,G., Ghigo,E. and
Locatelli,V.
TITLE Growth hormone-inhibiting activity of cortistatin in the rat
JOURNAL J. Endocrinol. Invest. 24 (11), RC31-RC33 (2001)
PUBMED 11817718
REFERENCE 4 (bases 1 to 438)
AUTHORS de Lecea,L., Criado,J.R., Prospero-Garcia,O., Gautvik,K.M.,
Schweitzer,P., Danielson,P.E., Dunlop,C.L., Siggins,G.R.,
Henriksen,S.J. and Sutcliffe,J.G.
TITLE A cortical neuropeptide with neuronal depressant and
sleep-modulating properties
JOURNAL Nature 381 (6579), 242-245 (1996)
PUBMED 8622767
COMMENT PROVISIONAL REFSEQ: This record has not yet been subject to final
NCBI review. The reference sequence was derived from U51919.1.
Summary: inhibits growth hormone secretion; may act as a
neuropeptide to mediate signaling via a somatostatin receptor
subtype [RGD].
FEATURES Location/Qualifiers
source 1..438
/organism="Rattus norvegicus"
/mol_type="mRNA"
/strain="Sprague-Dawley"
/db_xref="taxon:10116"
/chromosome="5"
/map="5q36"
gene 1..438
/gene="Cort"
/note="cortistatin"
/db_xref="GeneID:25305"
/db_xref="RATMAP:41189"
/db_xref="RGD:2383"
CDS 30..368
/gene="Cort"
/note="Preprocortistatin"
/codon_start=1
/product="cortistatin"
/protein_id="NP_036967.1"
/db_xref="GI:6978683"
/db_xref="GeneID:25305"
/db_xref="RATMAP:41189"
/db_xref="RGD:2383"
/translation="MGGCSTRGKRPSALSLLLLLLLSGIAASALPLESGPTGQDSVQD
ATGGRRTGLLTFLAWWHEWASQDSSSTAFEGGTPELSKRQERPPLQQPPHRDKKPCKN
FFWKTFSSCK"
sig_peptide 30..110
/gene="Cort"
mat_peptide 324..365
/gene="Cort"
/product="cortistatin-14"
ORIGIN
1 aaagcacaga cttcaggtct ccaaggagga tgggtggctg cagcacaaga ggcaagcggc
61 cgtcagccct cagtctgctg ctgctgctgc tgctctcggg gatcgcagcc tctgccctcc
121 ccctggagag cggtcccacc ggccaggaca gtgtgcagga tgccacaggc gggaggagga
181 ccggccttct gactttcctt gcctggtggc atgagtgggc ttcccaagac agctccagca
241 ccgctttcga agggggtacc ccggagctgt ctaagcggca ggaaagacca cccctccagc
301 agcccccaca ccgggataaa aagccctgca agaacttctt ctggaaaacc ttctcctcgt
361 gcaagtagcc cgagcctgac cggagcctga ccggccaccc tgtgaatgca gccgtggcct
421 gaataaagag tgtcaagt
//
其中上面后origin后面的序列，是我们用来设计的序列。
要点：
1、种属判断不能有错：
Homo sapiens 代表人
Rattus norvegicus 代表大鼠
Mus musculus 代表小鼠
2、有别名，要判断是或者不是；
3、有受体，配体，名称中正好含这个关键词的，要判断是或者不是；
4、多个转录本时需要查找同源序列（即核酸序列相同区域）；
还有其他内容，可以向BioTNT 技术部垂询：
1、启动子序列的查询；
2、microRNA 序列的查询；
3、SNP 序列的查询；