Expression of a novel bHLH-Zip gene in human testis.
OBJECTIVE
To identify specifically expressed genes in the adult and fetal testes.


METHODS
A human testis cDNA microarray was established. Then the mRNA of adult and fetal testis was purified and probes were prepared by a reverse transcription reaction with the testis mRNA as template. The microarray was hybridized with probes of adult and fetal testes. The nucleic sequences of differentially expressed genes were determined and homologies were searched in the databases of the GenBank.


RESULTS
When hybridized with adult or fetal testis probes, the positive clones were 96.8 % and 95.4 %, respectively. Among these genes, one was a new testis-specific gene, which was named TSP1. TSP1 was highly expressed in human adult testis. The cDNA of TSP1 was 1,484 bp in length. The cDNA sequence of this clone was deposited in the Genbank (AF333098). TSP1 was also determined as Interim Gen Symbol (Unigene, No. Hs.98266). Protein analysis showed that TSP1 contained two functional domains: an N-terminal basic helix-loop-helix (bHLH) and a C-terminal leucine zipper (Zip). Homologous analysis showed that the 430 amino acid sequences deduced from the 1293 bp open reading frame (ORF) had a homology with the human gene FLJ2509 (AK098575). TSP1 had also a sequence homology with Spz 1 protein of mouse. Expression profiles showed that TSP1 was specifically and strongly expressed in the testis.


CONCLUSIONS
TSP1 is a gene highly expressed in adult testis. It may play an important role in spermatogenesis in the humans.
Sha
Jia-Hao
JH
Institute of Genetic Resources, Nanjing Normal University, Nanjing 210029, China.
Zhou
Zuo-Min
ZM
Li
Jian-Min
JM
Lin
Ming
M
Zhu
Hui
H
Zhu
Hu
H
Zhou
Ya-Dong
YD
Wang
Li-Long
LL
Wang
Yi-Quan
YQ
Zhou
Kai-Ya
KY
D000328:Adult; D000595:Amino Acid Sequence / Q000235:genetics; D001483:Base Sequence / Q000235:genetics; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D005333:Fetus / Q000378:metabolism; D015870:Gene Expression; D005796:Genes; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D017386:Sequence Homology, Amino Acid; D013737:Testis / Q000196:embryology / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; C481348:SPZ1 protein, human; D014157:Transcription Factors