Almstrup Kristian, Nielsen John E, Hansen Martin A, Tanaka Masami, Skakkebaek Niels E, Leffers Henrik
University Department of Growth and Reproduction, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark.
Biol Reprod. 2004 Jun;70(6):1751-61. doi: 10.1095/biolreprod.103.026575. Epub 2004 Feb 11.
In rodents, changes in gene expression during spermatogenesis can be monitored by sampling testis from each day during postnatal development. However, changes in gene expression at the tissue level can reflect changes in the concentration of an mRNA in a specific cell type, changes in volume of specific cells, or changes in the cell-type composition. This reflects the cellularity of the tissue. Here we have combined techniques that assess the expression profiles of genes at the whole-tissue level, differential display and DNA array, and, at the level of cellularity, in situ hybridization. Combining results from these techniques allows determination of the cell-type-specific gene-expression patterns of many genes during spermatogenesis. Differential display was used to determine expression profiles with high sensitivity and independent of prior knowledge of the sequence, whereas DNA arrays quickly assess the expression profiles of all the genes. This identified three groups of gene-expression profiles. The major group corresponds to genes that are upregulated in spermatocytes during either the mid- or late- pachytene phase of spermatogenesis (stages VII-XI). This pachytene cluster was gradually extinguished in the later spermatid stages but was followed by another cluster of genes expressed in spermatids. Finally, a group of genes was downregulated during spermatogenesis and probably expressed in nongerm cells. We believe that expression of most genes can be described by a combination of these cell-type-specific expression patterns.
在啮齿动物中，精子发生过程中的基因表达变化可以通过在出生后发育的每一天对睾丸进行采样来监测。然而，组织水平上的基因表达变化可能反映特定细胞类型中mRNA浓度的变化、特定细胞体积的变化或细胞类型组成的变化。这反映了组织的细胞构成。在这里，我们结合了在全组织水平评估基因表达谱的技术，即差异显示和DNA阵列，以及在细胞构成水平上的原位杂交技术。综合这些技术的结果，可以确定精子发生过程中许多基因的细胞类型特异性基因表达模式。差异显示用于以高灵敏度确定表达谱，且不依赖于序列的先验知识，而DNA阵列则可快速评估所有基因的表达谱。这确定了三组基因表达谱。主要的一组对应于在精子发生的粗线期中期或后期（VII - XI阶段）精母细胞中上调的基因。这个粗线期簇在后期精子细胞阶段逐渐消失，但随后是另一组在精子细胞中表达的基因。最后，一组基因在精子发生过程中下调，可能在非生殖细胞中表达。我们认为大多数基因的表达可以通过这些细胞类型特异性表达模式的组合来描述。
