Strashnyuk Volodymyr Yu, Shakina Lyubov A, Skorobagatko Daria A
Department of Genetics and Cytology, VN Karazin Kharkiv National University, Svobody sq., 4, Kharkiv, 61022, Ukraine.
Laboratory "Applied Genetics and Plant Biotechnologies", Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Acad. G. Bonchev str., B. 21, Sofia, 1113, Bulgaria.
Genetica. 2023 Feb;151(1):75-86. doi: 10.1007/s10709-022-00168-4. Epub 2022 Sep 26.
Polyteny is an effective mechanism for accelerating growth and enhancing gene expression in eukaryotes. The purpose of investigation was to study the genetic variability of polyteny degree of giant chromosomes in the salivary glands of Drosophila melanogaster Meig. in relation to the differential fitness of different genotypes. 16 strains, lines and hybrids of fruit flies were studied. This study demonstrates the significant influence of hereditary factors on the level of polytenization of giant chromosomes in Drosophila. This is manifested in the differences between strains and lines, the effect of inbreeding, chromosome isogenization, hybridization, adaptively significant selection, sexual differences, and varying degrees of individual variability of a trait in different strains, lines, and hybrids. The genetic component in the variability of the degree of chromosome polyteny in Drosophila salivary glands was 45.3%, the effect of sex was 9.5%. It has been shown that genetic distances during inbreeding, outbreeding or hybridization, which largely determine the selective value of different genotypes, also affect polyteny patterns. Genetic, humoral, and epigenetic aspects of endocycle regulation, which may underlie the variations in the degree of chromosome polyteny, as well as the biological significance of the phenomenon of endopolyploidy, are discussed.
多线化是真核生物中加速生长和增强基因表达的一种有效机制。本研究的目的是研究黑腹果蝇（Drosophila melanogaster Meig.）唾液腺中巨大染色体多线化程度的遗传变异性，以及不同基因型的差异适应性。研究了16个果蝇品系、品系间杂种。本研究证明了遗传因素对果蝇巨大染色体多线化水平有显著影响。这体现在品系间的差异、近亲繁殖的影响、染色体同型化、杂交、适应性显著选择、性别差异以及不同品系、品系间杂种和杂种中该性状个体变异程度的不同。果蝇唾液腺染色体多线化程度变异中的遗传成分占45.3%，性别效应占9.5%。研究表明，近亲繁殖、远亲繁殖或杂交过程中的遗传距离在很大程度上决定了不同基因型的选择价值，同时也影响多线化模式。本文还讨论了内复制周期调控的遗传、体液和表观遗传方面，这些方面可能是染色体多线化程度变化的基础，以及内多倍体现象的生物学意义。
