Waller M S, Angus R B
School of Biological Sciences, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK.
Genetica. 2005 Sep;125(1):17-25. doi: 10.1007/s10709-005-1468-6.
C-banded karyotypes are provided for the five west European species of Corixa Geoffroy. All have 2n = 22 autosomes + sex chromosomes which are XY (male symbol), XX (female symbol). Some specimens of C. punctata have a small B-chromosome, while some C. panzeri have a fairly large one. The karyotypes of C. punctata, C. dentipes, C. affinis and C. panzeri are all distinctive, but the karyotypes of C. punctata and C. iberica appear indistinguishable. The Scottish material of C. punctata and C. iberica used in this study shows morphological intergradation between the two, suggesting that they hybridise where their ranges overlap. Meiosis shows very fine even pachytene bands in C. punctata, and that the autosomes form true bivalents during diplotene in C. affinis and C. panzeri, while the sex chromosomes appear closely associated. At first metaphase the sex chromosomes may appear either closely associated or may have separated. There is no evidence of the presence of m-chromosomes.
本文提供了西欧冠划蝽属（Corixa Geoffroy）5个物种的C带核型。所有物种均具有2n = 22条常染色体 + 性染色体，雄性为XY，雌性为XX。一些斑背冠划蝽（C. punctata）标本有一条小的B染色体，而一些潘氏冠划蝽（C. panzeri）有一条相当大的B染色体。斑背冠划蝽、齿背冠划蝽（C. dentipes）、近缘冠划蝽（C. affinis）和潘氏冠划蝽的核型都很独特，但斑背冠划蝽和伊比利亚冠划蝽（C. iberica）的核型似乎难以区分。本研究中使用的苏格兰斑背冠划蝽和伊比利亚冠划蝽材料显示，二者之间存在形态渐变，这表明它们在分布范围重叠处杂交。减数分裂显示，斑背冠划蝽在粗线期有非常细的均匀带，在终变期，近缘冠划蝽和潘氏冠划蝽的常染色体形成真正的二价体，而性染色体似乎紧密相连。在第一次中期，性染色体可能紧密相连，也可能已经分离。没有证据表明存在m染色体。
