title: Expression profiling of purified male germ cells: stage-specific expression patterns related to meiosis and postmeiotic development.
abstract: Gene expression profiling was performed using the National Institute on Aging 15,000-cDNA microarray to reveal the differential expression pattern of 160 genes between meiotic pachytene spermatocytes and postmeiotic round spermatids of the mouse. Our results indicate that more genes are expressed in spermatids than in spermatocytes. Genes participating in cell cycle regulation and chromatin structure and dynamics are preferentially expressed in spermatocytes, while genes for protein turnover, signal transduction, energy metabolism, and intracellular transport are prevalent in spermatids. This suggests that a switch of functional requirement occurs when meiotic germ cells differentiate into haploid spermatids. Concordant expression patterns were obtained when quantitative real-time polymerase chain reaction was performed to verify the microarray data. Interestingly, the majority of the differentially expressed genes were underrepresented in mitotic type A spermatogonia, and they were preferentially expressed in the testis. Our results suggest that an even higher proportion of the mouse genome is devoted to male gamete development from meiosis than was previously estimated. We also provide evidence that underscores the advantage of using purified germ cells over whole testes in profiling spermatogenic gene expression to identify transcripts that demonstrate stage-specific expression patterns.
authors.affiliation: Laboratory of Clinical Genomics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-4429, USA. panga@mail.nih.gov
authors.forename: Alan L Y
authors.initials: AL
authors.lastname: Pang
authors.forename: Warren
authors.initials: W
authors.lastname: Johnson
authors.forename: Neelakanta
authors.initials: N
authors.lastname: Ravindranath
authors.forename: Martin
authors.initials: M
authors.lastname: Dym
authors.forename: Owen M
authors.initials: OM
authors.lastname: Rennert
authors.forename: Wai-Yee
authors.initials: WY
authors.lastname: Chan
mesh_terms: D000818:Animals; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D008297:Male; D008540:Meiosis / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D013087:Spermatids / Q000166:cytology / Q000378:metabolism*; D013090:Spermatocytes / Q000166:cytology / Q000378:metabolism*; D013093:Spermatogonia / Q000166:cytology / Q000378:metabolism*