巴西橡胶树MADS-box基因家族6个成员的染色体物理定位

Research of Chromosomal Localization of Six Members of MADS-box Gene Family of Hevea brasiliensis

MADS-box基因家族广泛分布于真核生物中,巴西橡胶树的MADS-box基因家族主要参与花形态建成,对生殖生长起到重要的调节作用。目前,MADS-box基因家族的26个相关基因已被克隆分析,但它们在染色体上的具体位置还未确定。本研究以巴西橡胶树‘热研7-33-97’品种为材料,将MADS-box基因家族的6个成员(HbAGL8、HbAG15、HbAGL30、HbTT16、HbAP1和HbSVP1)定位在细胞核染色体上,通过双探针荧光原位杂交技术(FISH)对巴西橡胶树MADS-box基因家族的这6个成员在细胞核染色体上进行物理定位分析。结果表明:MADS-box基因家族的6个基因分别位于不同的染色体上,其中HbAGL15、HbAG8、HbAG30和HbSVP1基因定位在第4、5、7和8号染色体长臂上,其信号位点到着丝粒的平均百分距离是11.85、39.71、48.94和6.70;HbTT16和HbAP1基因定位在第1和13号染色体短臂上,其信号位点到着丝粒的平均百分距离是22.19和18.01。本研究结果揭示了巴西橡胶树MADS-box基因家族的6个成员在细胞核染色体上的实际位置,展现家族基因之间的分布特点和连锁遗传关系,不仅丰富了橡胶树分子细胞遗传学信息,也为橡胶树的分子辅助育种和比较基因组学研究提供了分子细胞遗传学的科学理论依据。

The MADS-box gene family is widely distributed in eukaryotes.The MADS-box gene family of Hevea brasiliensis is mainly involved in flower morphogenesis and plays an important role in regulating reproductive growth.At present,26 related genes of the MADS-box gene family have been cloned and analyzed,but the specific positions on the chromosome have not been determined.Six members of the MADS-box gene family(HbAGL8,HbAG15,HbAGL30,HbTT16,HbAP1 and HbSVP1)of‘Reyan 7-33-97’were localized on the nuclear chromosome.Physical localization analysis of the six genes on the nuclear chromosome was performed using dual-probe fluorescence in situ hybridization(FISH).The results showed that the six genes were located on different chromosomes.HbAGL15,HbAG8,HbAG30 and HbSVP1 genes were located on the long arm of chromosome 4,5,7 and 8 with PDCS(percent distance from centromere to the signal site)11.85,39.71,48.94 and 6.70,respectively.HbTT16 and HbAP1 gene were located on the short arm of chromosome 1 and 13 with PDCS 22.19 and 18.01,respectively.This study reveals the actual position of the six genes of H.brasiliensis on the nuclear chromosome,shows the distribution characteristics and linkage genetic relationship between family genes,which not only enriching molecular cytogenetics information,but also providing scientific theoretical basis for molecular assisted breeding and comparative genomics research of H.brasiliensis.