This article is one of the serial studies oll the characteristics of the molecular structure for dystrophin gene in Chinese. By using the entire dystrophin cDNA (14 kb) as a probe- the number and RFLPs of Bgl Ⅱ exon-...This article is one of the serial studies oll the characteristics of the molecular structure for dystrophin gene in Chinese. By using the entire dystrophin cDNA (14 kb) as a probe- the number and RFLPs of Bgl Ⅱ exon-containing fragments of the dystrophin gene were analysed. Four new Bgl Ⅱ fragments were found, two of them (3.7 and 6.2 kb) detected by comparing the hybridization patterns with cDNA1-2a. 1a and 2a, one (9.3 kb) from the hybridization pattern with cDNA 9 by lengthening migrating distance of DNA fragments in electrophoresis. and another one (4.0 kb) by comparing the patterns with cDNA 11-14,11a- 11b’ 11c-12a and 14. The results indicated that the number of Bgl Ⅱ exon-containing fragments should be 59 rather than 55 reported previously, which laid the foundation of the Bgl Ⅱ partial restriction map for dystrophin gene. Three of the four RFLPs found in Caucacian appear in the hybridization patterns of three subclones, i.e.cDNA 2b-3. cDNA 4-5, and cDNA 5b-7.’ The values of expected heterozygote frequency (EHF) were 0.33, 0.33and 0.40 and the observed heterozygote frequency (OHF)were 0.40. 0.40 and 0.48 respectively. Meanwhile, two new rare allelic fragments (15 kb) were found in RFLPs from Bgl Ⅱ/2b-3 and Bgl Ⅱ/4-5a patterns respectively. These Bgl Ⅱ RFLPs and four XbaI RFLPs documented in our laboratory, have been used to detect the carrier in 7 DMDfamilies and 1 BMD family. Of the 69 individuals from the 8 families- 11 females were diagnosed as the carriers with DMD mutation, 4 females as the doubtful carriers, 12 females were defined as normal genotype and 2 females as probably normal. The results suggest that the carrier testing method based on dosage intensity analysis and genotype analysis by using dystrophin cDNA as a probe will be more sensitive and accurate.展开更多
Number and order of HindⅢ exon-containing fragments (Hd) at 3' region of DMD gene were studied systematically using 16 partly-overlapping cDNA subprobes which were produced from dystrophin cDNA 9- 14 with each of...Number and order of HindⅢ exon-containing fragments (Hd) at 3' region of DMD gene were studied systematically using 16 partly-overlapping cDNA subprobes which were produced from dystrophin cDNA 9- 14 with each of 9 restriction endonudeases. There are 25 Hd fragments corresponding to cDNA 9 -14 in DMD gene. Since then, the exact length and the new order of Hd fragments are established. A new 2.1 kb fragment (Hd 55) is revealed, a 5.2 kb fragment (formely designated as Hd 59) is excluded and the existence of a controversial 3.2 kb fragment (Hd 64) is confirmed. Besides, three new exons were revealed by comparing the PvuⅡ and the XbaⅠ hybridization patterns with the Hindlll hybridization patterns for these cDNA subprobes. It is concluded that there are at least 66 Hd fragments, or 79 exons in DMD gene basing on the discovery of three additional exons. The corresponding relationship between the 66 Hd fragments and the SfiⅠ large scale physical map has been studied, and at least 17 Hd fragments or 19 exons were shown to be distributed in the last fragment (LI fragment) of the SfiⅠ map of DMD gene.展开更多
文摘This article is one of the serial studies oll the characteristics of the molecular structure for dystrophin gene in Chinese. By using the entire dystrophin cDNA (14 kb) as a probe- the number and RFLPs of Bgl Ⅱ exon-containing fragments of the dystrophin gene were analysed. Four new Bgl Ⅱ fragments were found, two of them (3.7 and 6.2 kb) detected by comparing the hybridization patterns with cDNA1-2a. 1a and 2a, one (9.3 kb) from the hybridization pattern with cDNA 9 by lengthening migrating distance of DNA fragments in electrophoresis. and another one (4.0 kb) by comparing the patterns with cDNA 11-14,11a- 11b’ 11c-12a and 14. The results indicated that the number of Bgl Ⅱ exon-containing fragments should be 59 rather than 55 reported previously, which laid the foundation of the Bgl Ⅱ partial restriction map for dystrophin gene. Three of the four RFLPs found in Caucacian appear in the hybridization patterns of three subclones, i.e.cDNA 2b-3. cDNA 4-5, and cDNA 5b-7.’ The values of expected heterozygote frequency (EHF) were 0.33, 0.33and 0.40 and the observed heterozygote frequency (OHF)were 0.40. 0.40 and 0.48 respectively. Meanwhile, two new rare allelic fragments (15 kb) were found in RFLPs from Bgl Ⅱ/2b-3 and Bgl Ⅱ/4-5a patterns respectively. These Bgl Ⅱ RFLPs and four XbaI RFLPs documented in our laboratory, have been used to detect the carrier in 7 DMDfamilies and 1 BMD family. Of the 69 individuals from the 8 families- 11 females were diagnosed as the carriers with DMD mutation, 4 females as the doubtful carriers, 12 females were defined as normal genotype and 2 females as probably normal. The results suggest that the carrier testing method based on dosage intensity analysis and genotype analysis by using dystrophin cDNA as a probe will be more sensitive and accurate.
基金Project supported by Shanghai Joint Laboratory of Life Sciences, the Chinese Academy of Sciences, National Post-doctorate Science Foundation of China and the National Natural Sciences, Foundation of China.
文摘Number and order of HindⅢ exon-containing fragments (Hd) at 3' region of DMD gene were studied systematically using 16 partly-overlapping cDNA subprobes which were produced from dystrophin cDNA 9- 14 with each of 9 restriction endonudeases. There are 25 Hd fragments corresponding to cDNA 9 -14 in DMD gene. Since then, the exact length and the new order of Hd fragments are established. A new 2.1 kb fragment (Hd 55) is revealed, a 5.2 kb fragment (formely designated as Hd 59) is excluded and the existence of a controversial 3.2 kb fragment (Hd 64) is confirmed. Besides, three new exons were revealed by comparing the PvuⅡ and the XbaⅠ hybridization patterns with the Hindlll hybridization patterns for these cDNA subprobes. It is concluded that there are at least 66 Hd fragments, or 79 exons in DMD gene basing on the discovery of three additional exons. The corresponding relationship between the 66 Hd fragments and the SfiⅠ large scale physical map has been studied, and at least 17 Hd fragments or 19 exons were shown to be distributed in the last fragment (LI fragment) of the SfiⅠ map of DMD gene.
