Abstract: Objective　To investigate the karyotypes and C bands of Triatoma rubrofasciata in China, so as to understand its chromosome number, morphology and C⁃band staining of T. rubrofasciata. Methods　The testis specimens were sampled from male T. rubrofasciata collected from Shunde City, Guangdong Province, prepared into slides of metaphase chromosomes and subjected to Giemsa staining and C⁃band staining. The morphology of metaphase chromosomes and the location of heterochromatin were observed using microscopy, and the long arm and short arm of each chromosome and total chromosome length were recorded to analyze the karyotypes and C bands of T. rubrofasciata. Results　The male T. rubrofasciata presented a chromosome number of 2n = 25, including 22 autosomes and 3 sex chromosomes. The relative length of chromosomes ranged from 3.59% to 12.76%, the arm ratio was 1.06 to 1.24, and the centromere index was 44.76% to 48.47%. All chromosomes were metacentric chromosomes and the karyotype formula was 2n = 22 metacentric + X1X2Y, and the C bands varied on different chromosomes. No heterochromatin was found in the X chromosome, and the overall staining appeared pale, while heterochromatin was detected in all regions of the Y chromosome, and the overall staining appeared dark. In addition, heterochromatin was present in both ends of the autosome. Conclusions　The male T. rubrofasciata presents a chromosome number of 2n = 25 in China, and the karyotype formula is 2n = 22 metacentric + X1X2Y. C⁃banding shows dark staining of the Y chromosome, pale staining of the X chromosome, and dark staining of both ends of the autosome. Our data may provide insights into the investigation on the origin, evolution and gene mapping of T. rubrofasciata in China.

Key words: Triatoma rubrofasciata, Chromosomal karyotype, C?band staining, Heterochromatin

摘要： 目的　对我国红带锥蝽进行核型及C带分析，了解其染色体数目、形态以及C带染色情况。方法　以采自广东顺德的雄性红带锥蝽精巢组织为实验样本，通过滴片法制备中期染色体玻片，进行Giemsa染色和C带染色，显微镜下观察中期染色体形态；同时观察异染色质所在位置，进行显微拍照并记录每条染色体长臂、短臂和全长，分析红带锥蝽染色体核型和C带特点。结果　雄性红带锥蝽染色体数目为2n = 25，其中22条为常染色体，3条为性染色体，所有染色体相对长度范围为3.59%～12.76%，臂比值为1.06～1.24，着丝粒指数为44.76%～48.47%，所有染色体均为中着丝粒染色体（m），核型公式为2n = 22m + X1X2Y。C带带型在不同染色体上分布有所不同：X染色体不含异染色质，整体呈淡染；Y染色体所有区域均含有异染色质，整体呈深染；常染色体两端存在异染色质区。结论　我国雄性红带锥蝽染色体数目为2n = 25，核型公式为2n = 22m + X1X2Y，其C带染色中Y染色体呈深染、X染色体淡染、常染色体两端呈深染。本研究相关结果可望为研究红带锥蝽起源、演化及基因定位等奠定基础。 　

关键词: 红带锥蝽, 染色体核型, C带技术, 异染色质