Discovery of germ cell-specific transcripts by expressed sequence tag database analysis.
OBJECTIVE
To identify transcripts whose expression is restricted to germ cells.


METHODS
Expressed sequence tags (ESTs) from unfertilized egg libraries were utilized to perform in silico subtraction and identify germ cell-specific transcripts.


METHODS
Baylor College of Medicine, Houston, Texas.


METHODS
C57BL/6J/129SvEv hybrid.


METHODS
Tissue harvesting from mice.


METHODS
Identification of germ cell-specific transcripts.


RESULTS
We have used the Unigene collection of mouse cDNA libraries to identify ESTs derived from unfertilized egg libraries. A total of 3,499 ESTs were identified from Knowles Solter and Ko unfertilized egg cDNA libraries. In silico subtraction identified 258 ESTs, which were found in these unfertilized egg libraries, but not in adult mouse tissue cDNA libraries. We performed reverse transcription polymerase chain reaction (RT-PCR) on multiple adult tissues with 43 selected ESTs and found 5 of them where expression was absent in heart, lung, liver, brain, spleen, stomach, intestines, kidneys, and uterus, but restricted to ovaries and testes. Three ESTs were further analyzed, and they were exclusively localized to the oocytes by in situ hybridization.


CONCLUSIONS
We have shown that utilization of publicly available ESTs from murine EST libraries is a simple and rapid in silico approach to the identification of transcripts preferentially expressed in germ cells.
Rajkovic
A
A
Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas 77030, USA.
Yan M S
C
C
Klysik
M
M
Matzuk
M
M
D000818:Animals; D016208:Databases, Factual; D020224:Expressed Sequence Tags; D005260:Female; D015723:Gene Library; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D020320:Oligoribonucleotides, Antisense; D009865:Oocytes / Q000502:physiology*; D009928:Organ Specificity; D010053:Ovary / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012984:Software; D014158:Transcription, Genetic
D020320:Oligoribonucleotides, Antisense