Extremely stable transcripts may compensate for the elimination of the gene fert-1 from all Ascaris lumbricoides somatic cells.
Extremely stable transcripts may compensate for the elimination of the gene fert-1 from all Ascaris lumbricoides somatic cells.
复制标题
极其稳定的转录本可以补偿所有蛔虫体细胞中 fert-1 基因的消除。
作者：
A. Spicher;A. Etter;V. Bernard;H. Tobler;F. Müller
在人蛔虫变种染色质减少的过程中，单拷贝基因fert-1从所有体细胞中消失。suum。通过北方杂交和原位杂交技术，我们分析了它的相当不寻常的表达模式。不同的剪接和3'末端形成事件以发育调节的方式产生各种poly（A）+和poly（A）- fert-1 RNA种类。在其大部分RNA产物中缺乏任何重要的开放阅读框架，表明fert-1可能作为结构RNA而不是编码蛋白质。Fert-1转录本在配子的前体中产生，但在减数分裂时降解，并且不传递给合子。一旦雌性细胞核完成减数分裂，fert-1的胚胎转录就开始了。因此，我们的数据表明，蛔虫转录装置是活跃的合子转录，我们认为发生在4至6细胞阶段的胚胎一般发病之前。在从体细胞中消除fert-1基因后，其大部分转录物消失。然而，两个短的fert-1 RNA产物在整个发育过程中稳定地维持，直到第二幼虫阶段，这是在其编码序列消除后1个多月。对fert-1的可能功能进行了讨论。
The single-copy gene fert-1 becomes eliminated from all somatic cells during the process of chromatin diminution in Ascaris lumbricoides var. suum. By using Northern blot and in situ hybridization techniques, we have analyzed its rather unusual expression pattern. Different splicing and 3' end formation events generate in a developmentally regulated manner various poly(A)+ and poly(A)- fert-1 RNA species. The lack of any significant open reading frame in most of its RNA products indicates that fert-1 may function as structural RNA rather than encoding a protein. Fert-1 transcripts are produced in the precursors of the gametes, but degraded at the time of meiosis and not passed on to the zygote. Embryonic transcription of fert-1 sets in as soon as the female nucleus has completed its meiosis. Our data thus demonstrate that the Ascaris transcription apparatus is active prior to the general onset of zygotic transcription, which we think takes place in the four- to six-cell-stage embryos. Upon elimination of fert-1 gene from the somatic cells, most of its transcripts disappear. Two short fert-1 RNA products, however, are stably maintained throughout development until the second larval stage, which is more than 1 month after the elimination of their coding sequences. Possible functions of fert-1 are discussed.