Ansari H A, Pearce P D, Maher D W, Malcolm A A, Broad T E
Gene Mapping Unit, Grasslands Research Centre, NZ Pastoral Agriculture Research Institute Ltd., Palmerston North, New Zealand.
Chromosoma. 1993 May;102(5):340-7. doi: 10.1007/BF00661277.
The unambiguous identification of ovine chromosomes has become essential for the mapping of the sheep genome, which predominantly consists of telocentric chromosomes of gradually decreasing size. Nucleolus organizer regions (NORs) and Robertsonian fusions have been used here as the cytological and morphological markers, respectively, to define the banding pattern of eight paris of sheep telocentric chromosomes that have an ambiguous identification status. Five Robertsonian chromosomes involving most of the ambiguous chromosomes as well as normal prometaphase chromosomes were stained sequentially and separately by QFQ, GTG, and Ag-NOR methodologies. The prometaphase banding patterns of the ambiguous chromosomes 4, 6, 8, 9, 21, 24, 25 and 26 are represented schematically. For providing an accurate image of the banding pattern, a system of shading has been employed to show the relative intensity of bands in a given chromosome. The results presented here will facilitate the regional mapping of the sheep genome, extend the information on cytogenetic homology with other bovids, and substantially accelerate the comparative mapping studies in Bovidae.
绵羊染色体的明确鉴定对于绵羊基因组图谱绘制至关重要，绵羊基因组主要由大小逐渐减小的端着丝粒染色体组成。核仁组织区（NORs）和罗伯逊融合分别作为细胞学和形态学标记，用于确定八对鉴定状态不明确的绵羊端着丝粒染色体的带型。五条涉及大部分不明确染色体以及正常早中期染色体的罗伯逊染色体，依次分别用QFQ、GTG和Ag-NOR方法进行染色。示意性地展示了不明确染色体4、6、8、9、21、24、25和26的早中期带型。为了提供带型的准确图像，采用了一种阴影系统来显示给定染色体中带的相对强度。本文给出的结果将有助于绵羊基因组的区域图谱绘制，扩展与其他牛科动物细胞遗传学同源性的信息，并大幅加速牛科动物的比较图谱研究。
