Molecular characterization of embryonic gonads by gene expression profiling in Drosophila melanogaster.
In many animal species, germ-line progenitors associate with gonadal somatic cells to form the embryonic gonads (EGs) that later develop into functional organ producing gametes. To explore the genetic regulation of the germ-line development, we initiated a comprehensive identification and functional analysis of the genes expressed within the EGs. First, we generated a cDNA library from gonads purified from Drosophila embryos by FACS. Using this library, we catalogued the genes expressed in the gonad by EST analysis. A total of 17,218 high-quality ESTs representing 3,051 genes were obtained, corresponding to 20% of the predicted genes in the genome. The EG transcriptome is unexpectedly distinct from that of adult gonads and includes an extremely high proportion of retrotransposon-derived transcripts. We verified 101 genes preferentially expressed in the EGs by whole-mount in situ hybridization. Within this subset, 39 and 58 genes were expressed predominantly in germ-line and somatic cells, respectively, whereas four genes were expressed in the both cell lineages. The gonad-enriched genes encompassed a variety of predicted functions. However, genes implicated in SUMOylation and protein translation, including germ-line-specific ribosomal proteins, are preferentially expressed in the germ line, whereas the expression of various retrotransposons and RNAi-related genes are more prominent in the gonadal soma. These transcriptome data are a resource for understanding the mechanism of various cellular events during germ-line development.
Shigenobu
Shuji
S
Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Myodaiji, Okazaki 444-8787, Japan.
Kitadate
Yu
Y
Noda
Chiyo
C
Kobayashi
Satoru
S
D000818:Animals; D001483:Base Sequence; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics*; D004625:Embryo, Nonmammalian / Q000378:metabolism; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D006066:Gonads / Q000196:embryology* / Q000378:metabolism; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D034622:RNA Interference; D018626:Retroelements / Q000235:genetics; D025841:Small Ubiquitin-Related Modifier Proteins / Q000235:genetics / Q000378:metabolism; D020079:Terminal Repeat Sequences / Q000235:genetics; D014158:Transcription, Genetic
D018626:Retroelements; D025841:Small Ubiquitin-Related Modifier Proteins