粗糙脉孢菌的同宗配合、拟同宗配合和异宗配合物种之间的DNA同源性。

DNA homologies among homothallic, pseudo-homothallic and heterothallic species of Neurospora.

作者信息

Dutta S K, Sheikh I, Choppala J, Aulakh G S, Nelson W H

出版信息

Mol Gen Genet. 1976 Sep 23;147(3):325-30. doi: 10.1007/BF00582884.

Abstract

Highly purified DNAs from three homothallic species Neurospora africana, N. dodgei and N. lineolata; three reference strains representing authentic heterothallic species, N. crassa, N. intermedia and N. sitophila; and two strains of pseudo-homothallic species N. tetrasperma were characterized by spectrophotometry and DNA reassociation using hydroxyapatite chromatography. All of these known species are closely related on the basis of DNA characteristics such as base composition and thermal denaturation profiles of major DNA components. Minor components of ascospore DNA was, however, only 5-7% of total DNA instead of 15-20% minor component DNA shown by mycelial DNA. Species belonging to same group were not distinguishable morphologically, but all of these species were distinguishable by DNA:DNA homology studies. Greater DNA homology was noticed between DNAs of heterothallic species and DNAs of pseudohomothallic species than DNA of true homothallic species. Difference on DNA-nucleotide sequences among homothallic species was very little. Pseudo-homothallic species N. tetrasperma was found to be distinctly different from homothallic species but closer to heterothallic species based on such studies.

摘要

对来自三个同宗配合物种非洲脉孢菌、多吉脉孢菌和线条脉孢菌；三个代表正宗异宗配合物种的参考菌株，即粗糙脉孢菌、间脉孢菌和嗜坐脉孢菌；以及两株假同宗配合物种四孢脉孢菌的高度纯化DNA，通过分光光度法和使用羟基磷灰石色谱法的DNA复性进行了表征。基于DNA特征，如主要DNA成分的碱基组成和热变性图谱，所有这些已知物种都密切相关。然而，子囊孢子DNA的次要成分仅占总DNA的5-7%，而不是菌丝体DNA所显示的15-20%的次要成分DNA。属于同一组的物种在形态上无法区分，但所有这些物种都可以通过DNA:DNA同源性研究来区分。与真正同宗配合物种的DNA相比，异宗配合物种的DNA与假同宗配合物种的DNA之间具有更高的DNA同源性。同宗配合物种之间的DNA核苷酸序列差异非常小。基于此类研究发现，假同宗配合物种四孢脉孢菌与同宗配合物种明显不同，但更接近异宗配合物种。