Neitzel H, Kalscheuer V, Henschel S, Digweed M, Sperling K
Institute of Human Genetics, Charité of the Humboldt University Berlin, Germany.
Cytogenet Cell Genet. 1998;80(1-4):165-72. doi: 10.1159/000014974.
The heterochromatin of Microtus agrestis contains two retroposons, one L1 and one non-L1, which were cloned and analyzed with respect to their structure and genomic organization. These sequences have accumulated in the heterochromatin and exhibit a complex interspersed organization of relatively recent origin. In contrast, the pericentromeric heterochromatin is composed of simple, repetitive, tandemly organized elements. From the underlying sequences, the dinucleotide frequencies, the sequence organization, and its transcriptional activity, the heterochromatin of M. agrestis strongly resembles the beta-heterochromatin first described by Heitz and well characterized in Drosophila. This is evidence that this class of heterochromatin, presumably with its own distinct physiological and functional role, is indeed also present in the mammalian genome.
草甸田鼠的异染色质包含两个逆转座子，一个L1和一个非L1，对其结构和基因组组织进行了克隆和分析。这些序列在异染色质中积累，并呈现出相对较新起源的复杂散布组织。相比之下，着丝粒周围的异染色质由简单的、重复的、串联组织的元件组成。从基础序列、二核苷酸频率、序列组织及其转录活性来看，草甸田鼠的异染色质与Heitz首次描述并在果蝇中充分表征的β-异染色质非常相似。这证明这类异染色质可能具有其独特的生理和功能作用，确实也存在于哺乳动物基因组中。
