The basis for modern genetics was laid by Gregor Mendel. He proposed that traits belonging to the intraspecific variability class be studied. However, individuals of one species possess traits of another class. They are related to intraspecific similarity. Individuals never differ from each other in these traits. By analogy with traits varying within a species and determined by genes, it is conjectured that intraspecific similarity is determined by genes, too. If so, mutations in these genes can be obtained. This paper provides a review of works published in 2000-2014 that: (1) propose breeding methods for detection of mutations in Drosophila melanogaster genes that lead intraspecific similarity; these mutations were called conditional; (2) describe collections of conditional mutations in chromosomes X, 2, and 3 of Drosophila; (3) show unusual features of epigenetic nature in the mutants; and (4) analyze these features of the mutants. Based on the peculiarities of manifestation it is supposed that the recognized conditional mutations occur in genes responsible for intraspecific similarity. The genes presumably belong to the so-called regulatory network of the Drosophila genome. This approach expands the scope of breeding analysis introduced by G. Mendel for heredity studies 150 years ago.

中文翻译：

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果蝇中的条件突变：在孟德尔（G. Mendel）在布吕恩（Brünn）发表报告150周年之际。

现代遗传学的基础是格雷戈尔·孟德尔（Gregor Mendel）奠定的。他建议研究属于种内变异性类别的性状。但是，一个物种的个体具有另一类的特征。它们与种内相似性有关。在这些特征上，个人永远不会彼此不同。通过与一个物种内变化并由基因决定的性状进行类比，推测种内相似性也由基因决定。如果是这样，则可以获得这些基因的突变。本文综述了2000年至2014年发表的工作：（1）提出了检测果蝇果蝇基因突变的育种方法，这些突变导致种内相似性；这些突变称为条件突变；（2）描述了果蝇X，2和3号染色体中条件性突变的集合；（3）在突变体中表现出表观遗传特性的异常特征；（4）分析突变体的这些特征。根据表现的特殊性，假定公认的条件突变发生在负责种内相似性的基因中。这些基因大概属于果蝇基因组的所谓调节网络。这种方法扩展了G. Mendel于150年前为遗传研究引入的育种分析的范围。