Expression pattern in a modified equalized kidney cDNA library of hypertensive rat.
BACKGROUND
Genes with important functions and rarely expressed would probably more easily be cloned from a modified equalized kidney cDNA library for further investigation.


METHODS
A kidney cDNA library of a spontaneously hypertensive rat was synthesized by a modified equalization method. Inserts of random clones were amplified by PCR and sequenced. Sequences were compared against a nonredundant database in GenBank. The cDNA profile was compared with an expression profile of a mouse renal proximal tubule cDNA library. Seven clones were analyzed by Northern blot analysis. The cDNA ends of two novel genes were amplified by PCR, sequenced and analyzed.


RESULTS
336 cDNA clones were analyzed and grouped into 323 species of transcript with 77 species similar to previously reported genes. Northern blot analysis identified one kidney-specific, one rarely expressed and lung-specific, and another relatively testis-specific gene. Two novel genes were cloned. One was 4.1 kb in length and encoded a 390-amino acid zinc-finger protein. Another was 2.5 kb and encoded a 474-amino acid protein of unknown function. Compared with the expression profile of a mouse renal proximal tubule cDNA library, this kidney library had a lower proportion of ribosomal genes and had a greater proportion of genes for signal transduction and DNA or RNA binding.


CONCLUSIONS
Rare or novel genes could be more easily isolated from this library for molecular study of hypertension and renal pathophysiology.
Chern
T H
TH
Institute of Clinical Medicine, National Yang-Ming University, School of Medicine, Taipei, Taiwan.
Chiang
F T
FT
Wu
K D
KD
Hsu
K L
KL
Lo
H M
HM
Tseng
C D
CD
Tseng
Y Z
YZ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics*; D015870:Gene Expression; D015723:Gene Library; D006801:Humans; D006973:Hypertension / Q000235:genetics*; D007668:Kidney / Q000378:metabolism*; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D051381:Rats; D011918:Rats, Inbred SHR; D016335:Zinc Fingers / Q000235:genetics
D017931:DNA Primers; D018076:DNA, Complementary