A high-resolution cytogenetic map of human chromosome 3: localization of 291 new cosmid markers by direct R-banding fluorescence in situ hybridization

Silencing of CT120 by antisense oligonucleotides could inhibit the lung cancer cells growth

BACKGROUND AND AIMS

The CT120 gene had been proven to be a novel gene closely related to pulmonary carcinogenesis and cancer progression. Our aim was to explore the mechanism of growth suppression caused by silencing CT120.

METHODS

CT120 was detected in lung cancer tissues and the cell line A549, and the cell clones for silencing CT120 were obtained. Then the target genes were detected and the downstream proteins from the silencing of CT120 were separated and identified.

RESULTS

The expression of CT120 was higher in lung cancer tissues and A549 cells. Silencing of CT120 was shown to inhibit cell growth, reduce the expression of cyclin D1 and Cdk4, and increase the expression of p53 and caspase-3. The differential proteins were related to carcinogenesis, invasiveness, and metastasis.

CONCLUSION

CT120 may play an important role in tumor progression, and the down-regulation of CT120 expression could be a new drug target candidate in the treatment of lung cancer.

Translocation t(2;3)(p15-23;q26-27) in myeloid malignancies: report of 21 new cases, clinical, cytogenetic and molecular genetic features

Chromosomal rearrangements involving 3q26 either due to inversion or translocation with various partner chromosomes are a recurrent finding in malignant myeloid disorders. Typically, these chromosome aberrations contribute to ectopic expression of or to the formation of fusion genes involving the EVI1 proto-oncogene. Chromosomal translocations involving the short arm of chromosome 2 (p15-p23) and the distal part of the long arm of chromosome 3 (q26-q27) are a rare but recurrent finding in patients with myeloid malignancies, and are assumed to be part of this spectrum of disorders. Thus far, however, these translocations have been poorly studied. Here, we present 21 new cases with myelodysplasia, acute myeloid leukemia or CML in blast crisis, which upon karyotyping showed the presence of a t(2;3). Furthermore, an extensive literature review disclosed 29 additional cases. Morphological, clinical and cytogenetic assessment revealed the typical hallmarks of 3q26/EVI1 rearrangements, that is, trilineage dysplasia and dysmegakaryopoiesis, poor prognosis and additional monosomy 7. Molecular cytogenetic analysis and PCR in selected samples indicated that in most cases the translocation indeed targets the EVI1 locus. Mapping of the chromosome 2 breakpoints confirmed the initially suspected cytogenetic breakpoint heterogeneity at the 2p arm.

Simultaneous detection of high-resolution R-banding and fluorescence in situ hybridization signals after fluorouracil-induced cellular synchronization

A method for simultaneous detection of fluorescence in situ hybridization of DNA probes and high resolution fluorescent R banding is described. Human lymphocytes were stimulated with phytohemagglutinin and synchronized using a fluorouracil block followed by exposure to bromodeoxyuridine and Hoechst 33258 prior to harvest. Metaphase preparations were treated with Hoechst 33258 and exposed to UV light. Thereafter they were incubated in sodium phosphate buffer and dried prior to in situ hybridization with a biotin-labelled centromere-specific alpha-satellite DNA probe for chromosome 1 (pUCl.77) and two digoxigenin-labelled probes, i.e., a PCR-generated chromosome 8-specific alphoid probe (#8) and a cosmid probe for FLT4 gene on 5q33-qter (class III receptor tyrosine kinase). Hybridization signals were detected by an indirect immunofluorescence method using fluorescein isothiocyanate. The chromosomes were counterstained with propidium iodide and 4',6-diamidino-2-phenylindole dihydrochloride. This simple method allows unambiguous chromosome band identification simultaneously with detection of the hybridized probes.

A new chromosome banding technique, spectral color banding (SCAN), for full characterization of chromosomal abnormalities

We have developed spectral color banding (SCAN) as a new chromosome banding technique based on spectral analysis of differentially labeled chromosome band-specific painting probes. In this study, we succeeded in displaying a multicolor banding pattern for chromosome 3, which was almost identical to the pattern obtained with the corresponding G-banding. We applied this method to metaphase cells from different normal male donors with various levels of G-banding resolution, ranging from 250 to 850 bands per haploid set. The same multicolor banding pattern was observed in all samples regardless of the length of the chromosomes or the quality of the G-banding. We then used SCAN in a diffuse large B-cell lymphoma case for a complete analysis of the intrachromosomal change for chromosome 3, which could not be fully characterized by G-banding or even by spectral karyotyping (SKY). SCAN could detect the duplicated segment and identify the origin of the chromosome band on the basis of the specific spectral color of each band. This study demonstrates that SCAN is a useful tool for full characterization of chromosomal abnormalities not identified by SKY.

A new case of dup(3q) syndrome due to a pure duplication of 3qter

The characteristic clinical features of the dup(3q) syndrome include typical facial features, mental and growth retardation, and (often) congenital heart anomalies. However, pure duplication of 3qter is rare because most of the reported cases are patients who carry an unbalanced translocation and, in addition to the duplication for 3qter, have a deletion for another chromosomal segment. A new case with a pure duplication of 3q detected in a 2-month-old boy is presented here. Extensive cytogenetic analysis revealed an inverted duplication of the distal part of 3q (chromosomal band 3q26.3 up to the telomere), with no (detectable) loss of the original telomeric sequences. Clinical evaluation revealed several phenotypic hallmarks characteristic for the dup(3q) syndrome. By comparing the duplicated region of this patient with the duplicated regions of the other patients with a pure duplication of 3q, we were able to localize the critical region for the dup(3q) phenotype to band 3q26.3. Alongside this new case with a pure duplication of 3q, an overview of six previous cases is given.

Integrated karyotyping of sorghum by in situ hybridization of landed BACs

The reliability of genome analysis and proficiency of genetic manipulation are increased by assignment of linkage groups to specific chromosomes, placement of centromeres, and orientation with respect to telomeres. We have endeavored to establish means to enable these steps in sorghum (Sorghum bicolor (L.) Moench), the genome of which contains ca. 780 Mbp spread across n = 10 chromosomes. Our approach relies on fluorescence in situ hybridization (FISH) and integrated structural genomic resources, including large-insert genomic clones in bacterial artificial chromosome (BAC) libraries. To develop robust FISH probes, we selected sorghum BACs by association with molecular markers that map near the ends of linkage groups, in regions inferred to be high in recombination. Overall, we selected 22 BACs that encompass the 10 linkage groups. As a prelude to development of a multiprobe FISH cocktail, we evaluated BAC-derived probes individually and in small groups. Biotin- and digoxygenin-labeled probes were made directly from the BAC clones and hybridized in situ to chromosomes without using suppressive unlabelled C0t-1 DNA. Based on FISH-signal strength and the relative degree of background signal, we judged 19 BAC-derived probes to be satisfactory. Based on their relative position, and collective association with all 10 linkage groups, we chose 17 of the 19 BACs to develop a 17-locus probe cocktail for dual-color detection. FISH of the cocktail allowed simultaneous identification of all 10 chromosomes. The results indicate that linkage and physical maps of sorghum allow facile selection of BAC clones according to position and FISH-signal quality. This capability will enable development of a high-quality molecular cytogenetic map and an integrated genomics system for sorghum, without need of chromosome flow sorting or microdissection. Moreover, transgeneric FISH experiments suggest that the sorghum system might be applicable to other Gramineae.

Comparative FISH mapping of the ancestral fusion point of human chromosome 2

It is known that human chromosome 2 originated from the fusion of two ancestral primate chromosomes. This has been confirmed by chromosome banding and fluorescence in-situ hybridization (FISH) with human chromosome-2-specific DNA libraries. In this study, the order of 38 cosmid clones derived from the human chromosome region 2q12-q14 was exactly determined by high-resolution FISH in human chromosome 2 and its homologous chromosomes in chimpanzees (Pan trogrodydes, 2n=48) and cynomolgus monkeys (Macacafascicularis, 2n = 42). This region includes the telomere-to-telomere fusion point of two ancestral ape-type chromosomes. As a result of comparative mapping, human chromosome region 2q12-q14 was found to correspond to the short arms of chimpanzee chromosomes 12 and 13 and cynomolgus monkey chromosomes 9 and 15. It is noted that no difference was detected in the relative order of the cosmid clones between human and chimpanzee chromosomes. This suggests that two ancestral ape-type chromosomes fused tandemly at telomeres to form human chromosome 2, and the genomic organization of this region is thought to be considerably conserved. In the cynomolgus monkey, however, the order of clones in each homologue was inverted. In addition to cosmid mapping, two chromosome-2-specific yeast artificial chromosome (YAC) clones containing the fusion point were identified by FISH.

Dual-color fish analysis of breakpoints on Robertsonian translocations

We investigated six Robertsonian translocations, including two cases of rob(13q14q); one of rob(14q21q), one of rob (13q22q), and two of rob(21q21q), by means of fluorescence in situ hybridization (FISH) using five repetitive DNA probes: two alpha-satellite DNAs (D21Z1/D13Z1 and D14Z1/D22Z1), satellite III DNA, beta-satellite DNA, and ribosomal DNA. Single color FISH successfully defined the breakpoints in four cases of the six. Since the remaining two cases, rob(13q22q) and rob(21q21q), revealed to retain rDNA, we tried to define the breakpoints in detail by dual color FISH in these rare types. In the rob(13q22q) the chromosomal breakage on chromosome 22 was likely to have occurred within the rDNA region and that the chromosome 13 breakpoint was within the alpha-satellite region. In one rob(21q21q) case we defined the breakpoint on one chromosome distal to, or within, the beta-satellite region distal to the rDNA, and the other chromosome breakage had occurred within alpha-satellite DNA. Our results underscored the power of dual-color FISH for defining the precise locations of breakpoints in Robertsonian translocations.

Assignment of Alzheimer's presenilin-2 (PS-2) gene to 1q42.1 by fluorescence in situ hybridization

Presenilin-2 (PS-2) was suggested to be localized on 1q31-42 based on linkage analysis and cDNA cloning. The final identification of PS-2 as the causal gene for early-onset familial Alzheimer's disease in Voga-German pedigrees was concluded based on the point mutation found in the candidate cDNA isolated from this familial AD. We present evidence of its physical genome mapping of PS-2 on chromosome 1q42.1 by fluorescence in situ hybridization method.

Loss of heterozygosity on chromosome arm 3p in nasopharyngeal carcinoma

We have examined 17 primary undifferentiated nasopharyngeal carcinoma biopsies for allelic loss on 3p, comparing the findings in tumors with those in normal lymphocyte DNA from the same patients. Ten polymorphic microsatellite markers were used between 3p13 and 3p26. Allelic loss was observed in 12 samples (70%). Two loci were most frequently affected: D3S1067 (3p21.1-14.3) in 60% and D3S1217 (3p14.2-14.1) in 58%. One tumor seemed to have a homozygous deletion at 3p26, detected by the D3S1297 marker. Analysis of the clinical data showed that an increased number of aberrations in 3p was correlated with more advanced tumor stages.

The Japan Society of Human Genetics Award Lecture. Application of DNA markers to clinical genetics

DNA technology using DNA sequence polymorphisms has brought a new system to the fields of medicine and forensic science, especially for the studies of genetic diseases and tumor suppressor genes, and for identification of individuals for forensic purpose. Linkage analysis based on segregation of polymorphic alleles in affected families has contributed to identification of many genetic disease. We isolated a large number of polymorphic DNA markers, called VNTR (variable number of tandem repeat) markers and identified the APC gene that is responsible for familial adenomatous polyposis (FAP) by means of a so-called "positional cloning" and characterized germline and somatic mutations of the APC gene in colorectal cancer patients. In addition, we have applied genetic information during colorectal carcinogenesis to sensitive diagnosis of lymph-node metastasis of colorectal cancer.

Major role for a 3p21 region and lack of involvement of the t(3;8) breakpoint region in the development of renal cell carcinoma suggested by loss of heterozygosity analysis

In a loss of heterozygosity analysis of 3p, we examined 44 sporadic cases of renal cell carcinoma (RCC) and matched normal tissue with 18 markers distributed over the whole p-arm. The majority of these markers clustered in three regions that have been suggested to be involved in the development of RCC, namely the p25 region, where the von Hippel Lindau (VHL) gene is located; the p21 region, which has been identified as a common region of overlap (SRO) of heterozygous deletions; and the p14 region, which is the location of the constitutional t(3;8) breakpoint occurring in an RCC family. Thirty-one out of these 44 tumors were analyzed with 9 additional markers from the 3p12-14 region to further delimit the SRO in this region. Our analysis shows that when deletions were detected the 3p21 region was always included. The 3p21 markers D3F15S2 and UBEIL were always contained within these 3p21 deletions. The t(3;8) breakpoint region showed the lowest percentage of loss of heterozygosity. Moreover, in three cases the t(3;8) breakpoint region retained heterozygosity, whereas a region more proximal to the breakpoint showed allelic losses. This supports exclusion of the t(3;8) region from a role in the development of sporadic RCC. In a number of tumors, two or three 3p regions with allelic losses were present separated by a region of retention of heterozygosity. In these tumors, deletions at 3p21 occurred in combination with deletions of either the VHL region, or the region proximal to the t(3;8), or both, suggestive of multiple gene involvement in the development of sporadic RCC with a primary role of the 3p21 region.

Cosmids and transcribed sequences from chromosome 11q23

To obtain cosmid markers and transcribed sequences from a specific chromosome region, a series of radiation-reduced hybrids (RHs) containing various regions of human chromosome 11 was prepared from microcell hybrid A9 (neo11) cells containing a normal human chromosome 11 tagged with pSV2neo at 11p11.2. Among 15 radiation hybrid clones isolated, RH(11)-9 which contains a q23 fragment in addition to the neo integration site, was used for the construction of a cosmid library. Cosmid clones having human DNA sequences were screened, and localized by Southern hybridization with the radiation hybrid panel. Fifty-nine cosmids were assigned to 11q23 and 6 cosmids to 11p11.2. Exon amplification proceeded with 23 of the 59 cosmids and 16 putative exons were cloned. Three of them were identical to those constituting a known gene which locates on q23 (ATDC), and the others were unknown. Thus, the RHs containing various subchromosomal fragments of chromosome 11 were useful for constructing region-specific DNA markers. The RH(11)-9 cells and putative exons also facilitate the positional cloning of genes in the 11q23 region.

Fluorescent in situ hybridization of a bacterial artificial chromosome

Fluorescent in situ hybridization (FISH) of a 130 kilobase cotton (Gossypium hirsuitum L.) bacterial artificial chromosome (BAC) clone containing a high proportion of single-copy DNA produced a large pair of FISH signals on the distal end of the long arm of a pair of chromosomes of the D-genome species G. raimondii Ulbr. and produced a fainter pair of signals on a small submetacentric pair of chromosomes of the A-genome species G. herbaceum L. The signals were synthetic with a nucleolar organizer region in G. raimondii and G. herbaceum. Signal pairs were easily recognized in interphase and metaphase cells either with or without suppression of repetitive sequences with unlabeled G. hirsutum C0t-1 DNA. High quality FISH results were consistently obtained and image analysis was not required for viewing or photography. Results indicate that FISH of BAC clones is an excellent tool for the establishment of new molecular cytogenetic markers in plants and will likely prove instrumental in the development of useful physical maps for many economically important crop species.

Physical and linkage mapping of the bovine genome with cosmids

We have initiated a mapping strategy using cosmid clones to chromosomally anchor a high-resolution bovine genetic linkage map. Ten cosmids containing microsatellites were assigned to bovine chromosomes by fluorescence in situ suppression hybridization (FISH). Four cosmid clones, three of which contain an informative microsatellite, were assigned to autosomes 5, 13, 24, and 28. The assignment to autosome 13 anchors bovine syntenic group U11. Two additional cosmid clones, each containing informative microsatellites, are assigned to autosomes 9 and 29, anchoring bovine linkage groups U2 and U8, respectively. Four cosmid clones, three of which contain informative microsatellites, also provide the first assignment to autosome 25, anchoring bovine syntenic group U7 and orienting the corresponding linkage group relative to the centromere.

Cloning of breakpoints in 3q21 associated with hematologic malignancy

Rearrangements of band 3q21 have been well documented in leukemia. To analyze the region involved, we have isolated a normal genomic P1 clone that spans the 3q21 breakpoints derived from two leukemia patients carrying t(3;3)(q21;q26). Both breakpoints are contained within a 50-kb NotI restriction fragment, but are not identical. They are separated by 9-11 kb and may disrupt genes associated with either the proximal or distal NotI sites. We further show that one patient carried a small insertion of material from chromosome 2 in the 3q- derivative. The P1 clone will allow isolation of candidate genes for these breakpoints and investigations into the clustering of other 3q21 leukemia breakpoints.

Application of fluorescence in situ hybridization in genome analysis of the mouse

Fluorescence in situ hybridization (FISH) is an effective technique for localizing cloned DNA probes directly onto metaphase chromosomes. Human genome mapping using FISH has been significantly enhanced by the development of new techniques, especially high-resolution gene mapping with direct R-banding FISH and physical gene ordering with multi-color FISH. By contrast, FISH techniques have not been put to practical use for the analysis of the mouse genome compared with the human. We have developed and modified FISH techniques for use in mouse genome analysis. In this article we summarize and review our recent results with FISH analyses in the following studies: (i) high-resolution gene mapping with the direct R-banding FISH, (ii) analysis of chromosomal rearrangement with multi-color FISH, (iii) establishment of centromere mapping with the major satellite DNA probe, (iv) analysis of chromatin structure in meiotic cells, and (v) application of FISH in cytogenetic studies of genetic variation in the mouse, showing that these applications of FISH are very useful for mouse genome analysis.

The detection of subtelomeric chromosomal rearrangements in idiopathic mental retardation

A major challenge for human genetics is to identify new causes of mental retardation, which, although present in about 3% of individuals, is unexplained in more than half of all cases. We have developed a strategy to screen for the abnormal inheritance of subtelomeric DNA polymorphisms in individuals with mental retardation and have detected three abnormalities in 99 patients with normal routine karyotypes. Pulsed-field gel electrophoresis and reverse chromosome painting showed that one case arose from an interstitial or terminal deletion and two from the de novo inheritance of derivative translocation chromosomes. At least 6% of unexplained mental retardation is accounted for by these relatively small chromosomal abnormalities, which will be an important resource in the characterization of the genetic basis of neurodevelopment.

Duplication 3q syndrome: molecular delineation of the critical region

The phenotype of dup(3q) syndrome partially overlaps with Brachmann-de Lange phenotype. Convulsions and eye, palate renal, and cardiac anomalies are more frequent in dup(3q) syndrome, while limb deficiencies, hirsutism, and synophrys are more characteristic of Brachmann-de Lange syndrome. Whether the two syndromes have a biological relationship has yet to be demonstrated. Using two patient translocation cell lines, each involving distal 3q, we have narrowed the critical region of the dup(3q) syndrome to the interval 3q26.31-q27.3 and initiated its molecular characterization. We have mapped in this region 6 cosmid clones spanning approximately 3-5 Mb. The critical region appears to overlap with the region where a balanced translocation was found in a Brachmann-de Lange patient. This work provides the mapping framework for finer molecular analysis of dup(3q) syndrome.

High-resolution cytogenetic mapping of the short arm of chromosome 1 with newly isolated 411 cosmid markers by fluorescence in situ hybridization: the precise order of 18 markers on 1p36.1 on prophase chromosomes and "stretched" DNAs

A high-resolution cytogenetic map of the short arm of chromosome 1 with newly isolated 411 cosmid markers was constructed by fluorescence in situ hybridization (FISH). These markers were scattered throughout chromosome 1p, but they were preferentially concentrated on R-band dominant regions such as 1p36, 1p34, 1p32, 1p22, and 1p13. Among these markers, 197 were localized on chromosome band 1p36, a region frequently deleted in neuroblastoma. Of these, 18 were precisely ordered on 1p36.1 by multicolor FISH of prophase chromosomes and "stretched" DNAs as follows: 1pter-163-41-11-1-226-586-568-614-631-665-451-199-190-561-241-74-1 76-652-1cen. The high-density map of chromosome 1p constructed here can provide useful landmarks for constructing a contig map of the short arm of chromosome 1 with YACs and cosmid clones and will expedite the identification of breakpoints and/or tumor suppressor gene(s) associated with several types of malignant tumors that frequently exhibit chromosomal aberrations or deletions of chromosome 1p.

Cloning, characterization, and chromosomal mapping of human aquaporin of collecting duct

We recently cloned a cDNA of the collecting duct apical membrane water channel of rat kidney, which is important for the formation of concentrated urine (Fushima, K., S. Uchida, Y. Hara, Y. Hirata, F. Marumo, and S. Sasaki. 1993. Nature [Lond.]. 361:549-552). Since urine concentrating ability varies among mammalian species, we examined whether an homologous protein is present in human kidney. By screening a human kidney cDNA library, we isolated a cDNA clone, designated human aquaporin of collecting duct (hAQP-CD), that encodes a 271-amino acid protein with 91% identity to rat AQP-CD. mRNA expression of hAQP-CD was predominant in the kidney medulla compared with the cortex, immunohistochemical staining of hAQP-CD was observed only in the collecting duct cells, and the staining was dominant in the apical domain. Functional expression study in Xenopus oocytes confirmed that hAQP-CD worked as a water channel. Western blot analysis of human kidney medulla indicated that the molecular mass of hAQP-CD is 29 kD, which is the same mass expected from the amino acid sequence. Chromosomal mapping of the hAQP-CD gene assigned its location to chromosome 12q13. These results could be important for future studies of the pathophysiology of human urinary concentration mechanisms in normal and abnormal states.

Physical map of small cell lung cancer deletion region on short arm of human chromosome 3 (3p13-22) based on radiation fusion hybrid analysis

Deletion of DNA sequences from various regions of the short arm of human chromosome 3 (3p13-14, 3p21, and 3p25) has been observed during the development of a variety of solid tumors, including lung and renal cell carcinomas. In this study we have used a set of radiation fusion hybrids to generate a physical map of chromosome 3p to orient the search for putative tumor suppressor genes. Eighty-six human-hamster radiation fusion hybrids were screened on Southern blots for the retention of 55 human chromosome 3p DNA markers. The high marker density enabled us to identify a set of successively overlapping chromosome fragments in the 3p13-22 area guided by eight markers with previously known order. Twenty-four map intervals were suggested using breakpoints determined by partial fragment overlaps. The final order between the markers derived is consistent with previous information about localizations for 26 of the markers to three larger cytogenetic intervals.

A high-resolution cytogenetic map of human chromosome 12: localization of 195 new cosmid markers by direct R-banding fluorescence in situ hybridization

We have constructed a high-resolution cytogenetic map of human chromosome 12 with 195 newly isolated cosmids by direct R-banding fluorescence in situ hybridization. The fluorescent signals of 195 clones were evenly distributed throughout chromosome 12, but sublocalized preferentially to R-positive bands. This high-resolution cytogenetic map with an average map distance of 0.73 Mb on bands can, in conjunction with a genetic linkage map, facilitate the analysis of chromosomal and molecular aberrations in genetic diseases and cancers. Moreover, the cytogenetic mapping data provide starting points for establishing contig maps with cosmid clones and yeast artificial chromosomes.

Physical ordering of three polymorphic DNA markers spanning the regions containing a tumor suppressor gene of renal cell carcinoma by three-color fluorescent in situ hybridization

Fluorescent in situ hybridization (FISH) is a powerful technique for gene mapping and multi-color FISH allows us to determine directly the order of two or more probes on both metaphase and interphase chromosomes. We report the physical ordering of three DNA markers by three-color FISH using two fluorochrome dyes, fluorescein isothiocyanate (FITC; green) and rhodamine (red). The third color was visualized as a pseudo-color (yellow) generated by optical interference with FITC and rhodamine. Using this system we could rapidly determine the order of three polymorphic DNA markers located on the 3p23-p21.2 bands which span a tumor suppressor gene for renal cell carcinoma, lung carcinoma, and several other types of tumors.

Detailed mapping around the breakpoint of (3;8) translocation in familial renal cell carcinoma and FRA3B

As a critical step toward cloning the breakpoint of the (3;8) translocation observed in familial renal cell carcinoma and a common fragile site on chromosome 3p (FRA3B), we have characterized the 3p14 region containing the breakpoint and FRA3B by fluorescence in situ hybridization (FISH), pulsed-field gel electrophoresis (PFGE), and genetic linkage analysis. Of 23 cosmids mapped by FISH, 14 cosmids were distal to the breakpoint of t(3;8) and 9 were proximal. Analyses of FRA3B by FISH were identical to those for the (3;8) breakpoint and indicated that the breakpoint of t(3;8) occurred at or very close to the fragile site. We have also constructed a genetic linkage map and a preliminary long-range restriction map using PFGE of the 3p14 region. The linkage results were consistent with the physical data. The combined results of FISH, PFGE, and linkage analysis establish a basis for further experiments to clone the (3;8) breakpoint and FRA3B.