Liehr Thomas, Buleu Olesya, Karamysheva Tatyana, Bugrov Alexander, Rubtsov Nikolai
Institute of Human Genetics, Jena University Hospital, Am Klinikum 1, D-07747 Jena, Germany.
Novosibirsk State University, 630090 Novosibirsk, Russia.
Genes (Basel). 2017 Nov 17;8(11):327. doi: 10.3390/genes8110327.
Currently, approximately 3000 species of stick insects are known; however, chromosome numbers, which range between 21 and 88, are known for only a few of these insects. Also, centromere banding staining (C-banding) patterns were described for fewer than 10 species, and fluorescence in situ hybridization (FISH) was applied exclusively in two species. Interestingly, 10-25% of stick insects (Phasmatodea) are obligatory or facultative parthenogenetic. As clonal and/or bisexual reproduction can affect chromosomal evolution, stick insect karyotypes need to be studied more intensely. Chromosome preparation from embryos of five Phasmatodea species (, , , , and ) from four families were studied here by C-banding and FISH applying ribosomal deoxyribonucleic acid (rDNA) and telomeric repeat probes. For three species, data on chromosome numbers and structure were obtained here for the first time, i.e., , , and . Large C-positive regions enriched with rDNA were identified in all five studied, distantly related species. Some of these C-positive blocks were enriched for telomeric repeats, as well. Chromosomal evolution of stick insects is characterized by variations in chromosome numbers as well as transposition and amplification of repetitive DNA sequences. Here, the first steps were made towards identification of individual chromosomes in Phasmatodea.
目前，已知的竹节虫种类约有3000种；然而，这些昆虫中只有少数种类的染色体数目为21至88条。此外，着丝粒带染色（C带）模式仅在不到10种竹节虫中被描述过，荧光原位杂交（FISH）仅应用于两种竹节虫。有趣的是，10%至25%的竹节虫（竹节虫目）是 obligatory 或兼性孤雌生殖的。由于克隆和/或双性繁殖会影响染色体进化，因此需要更深入地研究竹节虫的核型。本文通过C带以及应用核糖体脱氧核糖核酸（rDNA）和端粒重复探针的FISH技术，对来自四个科的五种竹节虫（ 、 、 、 和 ）胚胎的染色体制备进行了研究。对于三种竹节虫，首次获得了其染色体数目和结构的数据，即 、 和 。在所有五个研究的远缘物种中都鉴定出了富含rDNA的大C阳性区域。其中一些C阳性块也富含端粒重复序列。竹节虫的染色体进化特征是染色体数目的变化以及重复DNA序列的转位和扩增。在此，朝着鉴定竹节虫的单个染色体迈出了第一步。
