Integrative characterization of germ cell-specific genes from mouse spermatocyte UniGene library.
BACKGROUND
The primary regulator of spermatogenesis, a highly ordered and tightly regulated developmental process, is an intrinsic genetic program involving male germ cell-specific genes.


RESULTS
We analyzed the mouse spermatocyte UniGene library containing 2155 gene-oriented transcript clusters. We predict that 11% of these genes are testis-specific and systematically identified 24 authentic genes specifically and abundantly expressed in the testis via in silico and in vitro approaches. Northern blot analysis disclosed various transcript characteristics, such as expression level, size and the presence of isoform. Expression analysis revealed developmentally regulated and stage-specific expression patterns in all of the genes. We further analyzed the genes at the protein and cellular levels. Transfection assays performed using GC-2 cells provided information on the cellular characteristics of the gene products. In addition, antibodies were generated against proteins encoded by some of the genes to facilitate their identification and characterization in spermatogenic cells and sperm. Our data suggest that a number of the gene products are implicated in transcriptional regulation, nuclear integrity, sperm structure and motility, and fertilization. In particular, we found for the first time that Mm.333010, predicted to contain a trypsin-like serine protease domain, is a sperm acrosomal protein.


CONCLUSIONS
We identify 24 authentic genes with spermatogenic cell-specific expression, and provide comprehensive information about the genes. Our findings establish a new basis for future investigation into molecular mechanisms underlying male reproduction.
Department of Life Science and Research Center for BiomolecularNanotechnology, Gwangju Institute of Science and Technology, Gwangju, Korea. ibbnida@hotmail.com
Eunyoung
E
Choi
Jiae
J
Lee
Jungsu
J
Oh
Inju
I
Park
Cecil
C
Han
Chongil
C
Yi
Do Han
DH
Kim
Byung-Nam
BN
Cho
Edward M
EM
Eddy
Chunghee
C
Cho
D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002460:Cell Line; D005455:Fluorescent Antibody Technique; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013087:Spermatids / Q000166:cytology / Q000378:metabolism; D013090:Spermatocytes / Q000166:cytology / Q000378:metabolism*; D013091:Spermatogenesis / Q000235:genetics; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism; D013737:Testis / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection
D011506:Proteins; D049452:Green Fluorescent Proteins