Exclusion of the HLA locus from a large portion of the long arm of chromosome 6.

HLA antigens were determined in two infants with multiple congenital anomalies and in their healthy parents and one sibling. One infant had a deletion of a major portion of the long arm of chromosome 6. The other child had a translocation of a similar piece of chromosome 6 to the short arm of chromosome 3. The mother and the maternal grandmother showed this translocation in a balanced state. The HLA types of both children and their parents exclude the localization of the major histocompatibility locus from the deleted or translocated portion of the long arm of chromosome 6.     

Presumptive long arm deletion of chromosome 8: a new syndrome?

Summary This communication describes an infant with growth and psychomotor retardation and severe congenital malformations, who was found to have an interstitial deletion of the long arm of chromosome 8: 46,XY,del(8) (q13q22). Comparison with the only other previously reported patient with a deletion of a similar chromosomal segment suggested that deletion of the long arm of chromosome 8 may constitute a clinically recognizable syndrome.     

Physical characterization of the homoeologous group 5 chromosomes of wheat in terms of rice linkage blocks, and physical mapping of some important genes.

The wheat homoeologous Group 5 chromosomes were characterized physically in terms of rice linkage blocks using a deletion mapping approach. All three chromosomes, 5A, 5B, and 5D, were shown to have a similar structure, apart from the 4A-5A translocation on the distal end of chromosome arm 5AL. The physical mapping of rice markers on the deletion lines revealed that the whole of rice chromosome 9 is syntenous to a large block, proximal to the centromere, on the long arm. Likewise, a small segment of the distal end of the long arm showed conserved synteny with the distal one-third end of the long arm of rice chromosome 3. In between those conserved regions, there is a region on the long arm of the Group 5 chromosomes which shows broken synteny. The proximal part of the short arms of the Group 5 chromosomes showed conserved synteny with a segment of the short arm of rice chromosome 11 and the distal ends showed conserved synteny with a segment of rice chromosome 12. The physical locations of flowering time genes (Vrn and earliness per se) and the gene for grain hardness (Ha) on the Group 5 chromosomes were determined. These results indicate that comparative mapping using the deletion mapping approach is useful in the study of genome relationships, the physical location of genes, and can determine the appropriate gene cloning strategy.     

滇蜀豹子花核型及其变异研究

本文详细报道了滇蜀豹子花的核型,发现居群中存在两种细胞型,即A型和B型。A型参考核型为2n = 24＝2m(2SAT)+2sm+8st(4SAT)+12t(2SAT),其第3号两条同源染色体长臂均无居间随体：B型参考核型为2n=24＝2m(2SAT)+2sm+8st(2SAT)+12t(3SAT)+0—1b,其第3号一条同源染色体长臂紧靠着丝点处有一大而明显的居间随体,而另一条同源染色体则无,构成明显的3号染色体的结构杂合性。统计表明,居群中二者的比例近似为1A;2B。研究还发现了大量的体细胞染色体结构变异核型,表明滇蜀豹子花核型尚未趋于稳定,还处于强烈分化之中,高频率的体细胞染色体结构变异是其种内分化不可忽视的一种进化要素。     

A neocentromere derived from a supernumerary marker deleted from the long arm of chromosome 6

Parental chromosome studies were referred to us after initial finding of a balanced translocation involving chromosomes 4 and 15 in their phenotypically abnormal male child (cytogenetic analysis was done at another laboratory). In addition to the same 4;15 translocation, the father also had an interstitial deletion of the long arm of one chromosome 6 and a marker chromosome. In this article, we report a neocentromere on this marker, which was determined to be composed of chromosome 6 material by FISH. The child's karyotype was re-interpreted to be unbalanced due to the presence of the abnormal chromosome 6, but without the marker. The clinical phenotype associated with the interstitial deletion of chromosome 6 is also reported.     

Molecular cloning and mapping of 10 new probes on the human Y chromosome

We have developed a novel positive cloning vector whose use precludes the cloning of any fragments less than 0.8 kb as well as 3.4-kb EcoRI fragments of DYZ1, the largest repeating-DNA family on the long arm of the human Y chromosome. Using this vector, we subcloned inserts of a Y-chromosome-specific phage library constructed from EcoRI-digested flow-sorted Y-chromosome DNA. Ten novel Y-specific fragments were obtained. Their localization on the Y chromosome was determined by deletion mapping using clinical samples with structurally abnormal Y chromosomes. The long arm of the Y chromosome was divided into 12 segments by the novel probes in combination with established probes. The amelogenin-like sequence, mapped on the long arm in Human Gene Mapping 10, has been mapped on the short arm.     

黑麦6R抗白粉病基因向小麦的渗进与鉴定

为了将黑麦６Ｒ染色体上抗小麦白粉病的基因导入小麦,选用了一个６Ｒ／６Ｄ代换系Ｍ２４为亲本之一,分别与小麦栽培品种和第６部分同源群缺体系杂交,杂种出现６Ｒ或／或６Ａ,６Ｂ,６Ｄ单,双或三单体等各种情况,取其花药进行培养,共获得２４１个再生植株,对其中３２个抗白粉病的花粉植株经染色体计数,Ｃ－分带,基因组原位杂交,同工酶等电聚焦电泳和或／ＲＦＬＰ分子标记检测,发现有６株仍保持为６Ｒ／６Ｄ代换系,有１０     

Chromosome 1 in human colorectal tumors

Summary The significance of short and long arm anomalies of chromosome 1 was investigated in 55 colorectal tumors comprising 41 carcinomas and 14 adenomas. The tumors were at various stages of transformation from adenoma to carcinoma. Our investigation was prompted by the observation of a p32-pter deletion on the short arm of chromosome 1 in a case of benign tubulovillous adenoma with mild dysplasia, as well as by frequent reports that chromosome 1 is involved in many neoplastic processes. Long arm anomalies were found in seven of the 41 carcinomas, six of which were in stage B2, and short arm anomalies in ten carcinomas at various stages. Three of the adenomas exhibited chromosome 1 anomalies, which in one case comprised a 1p32-pter deletion only. Overall, short arm anomalies especially concerned the p32–36 region. These results suggest that the cytogenetic anomalies respectively located on the short and long arms of chromosome 1 should be considered separately. Damage to the long arm might constitute a late non-specific event, whereas damage to the p32-pter region of the short arm might be involved in triggering colorectal tumor development.     

Deletion mapping of H-Y antigen to the long arm of the human Y chromosome

A gene encoding or controlling the expression of the H-Y transplantation antigen was previously mapped to the human Y chromosome. We now report the sublocalization of this gene on the long arm of the human Y chromosome. Eight patients with Y-chromosomal abnormalities were examined with a series of existing and new DNA markers for the Y chromosome. The resulting deletion map was correlated with H-Y antigen expression. We conclude that the H-Y antigen gene maps to a portion of deletion interval 6 that is identified by specific DNA markers.     

The influence of the deletion on the long arm of the Y chromosome on sperm motility in mice

The multicopy region on the long arm of the mouse Y chromosome contains four known genes. There are evidences that deletions in this region lead to decrease of sperm quality in mutant mice. Male mice completely lacking this region are infertile. Here we report results obtained by using the computer assisted semen analysis system (CASA), describing the movement parameters of spermatozoa from mutant males with partial deletion on the long arm of the Y chromosome (B10. BR-Y(del)). First we have determined that genes necessary for spermiogenesis and located in this region are still active in mutants, than we have compared the sperm movement of mutants and control animals. This analysis revealed that the Yq deletion affects: velocity parameters (VAP, VCL, VSL), parameters describing sperm head activity during movement (ALH and BCF) and linearity (LIN) of movement. Our findings indicate that sperm movement is controlled by genes located in the long arm of the Y chromosome.     

Origin, structure, and behavior of a highly rearranged deletion chromosome 1BS-4 in wheat.

Wheat (Triticum aestivum L.) deletion (del) stocks are valuable tools for the physical mapping of molecular markers and genes to chromosome bins delineated by 2 adjacent deletion breakpoints. The wheat deletion stocks were produced by using gametocidal genes derived from related Aegilops species. Here, we report on the origin, structure, and behavior of a highly rearranged chromosome 1BS-4. The cytogenetic and molecular marker analyses suggest that 1BS-4 resulted from 2 breakpoints in the 1BS arm and 1 breakpoint in the 1BL arm. The distal segment from 1BS, except for a small deleted part, is translocated to the long arm. Cytologically, chromosome 1BS-4 is highly stable, but shows a unique meiotic pairing behavior. The short arm of 1BS-4 fails to pair with a normal 1BS arm because of lack of homology at the distal ends. The long arm of 1BS-4 only pairs with a normal 1BS arm within the distal region translocated from 1BS. Therefore, using the 1BS-4 deletion stock for physical mapping will result in the false allocation of molecular markers and genes proximal to the breakpoint of 1BS-4.     

The 4q-Syndrome

The 4q-Syndrome: Here we report four cases of interstitial and terminal deletions of the long arm of chromosome 4. Case 1 is a 16 month old boy with del(4)(q12q21) who has soft dysmorphic features, tetralogy of Fallot, and severe developmental delay. Case 2 is a male infant with the same deletion and congenital cardiomyopathy. He suffered severe birth asphyxia and died at the age of 6 months. His father was found to have a complex chromosome 4 rearrangement. Case 3 is a female infant with del(4)(q33) who died of aspiration pneumonia. She was mildly dysmorphic and presented with heart failure and hypercalcaemia. Case 4 is a 8 month old girl who has del(4)(q33) and Pierre-Robin sequence. So far about 70 patients with microscopically visible deletions of chromosome 4q have been described. Although they vary in their phenotypes, they have several features in common. We suggest to use the term 4q-syndrome for all macrodeletions of the long arm of chromosome 4.     

Occurrence and evolution of homogeneously staining regions may be due to breakage-fusion-bridge cycles following telomere loss

Chromosomes with homogeneously staining regions (HSR) were analysed in a subclone of the H4 rat hepatoma cell line, where they represent amplification of the ribosomal RNA (rRNA) genes. Detailed G-band analysis of the subclone revealed that an HSR on the short arm of chromosome 3 became unstable and changed its position within the chromosome. The evolution of this marker chromosome was associated with the terminal deletion of the normal long arm of the HSR-bearing chromosome 3 and may have involved ring formation as a result of fusion between the HSR on the short arm and the broken end of the long arm. Evidence was obtained for breakage at different sites within the ring, producing chromosomes with HSRs located terminally on either the long arms or both arms. The terminally located HSR underwent elongation in some cells presumably as a result of a breakage-fusion-bridge cycle characteristic of instability due to telomeric loss. It is suggested that terminally located HSRs may generally occur this way.     

Deletion mapping of stature determinants on the long arm of the Y chromosome

A gene contributing to human growth has previously been tentatively mapped to the long arm of the Y chromosome. In the present study, recently developed sequence-tagged site markers covering the entire Y chromosome were used to define deletion breakpoints in 15 males with partial deletions of Yq. By correlating the height of these individuals with their deletion breakpoints, we located a region whose presence or absence has a marked effect on stature. This critical region comprises the most proximal portion of the long arm, extending from marker sY78 in interval 4B to marker sY94 in interval 5G of the proximal long arm.     

Partial trisomy 13 as a result of de novo (6p;13q) translocation

Summary A newborn infant with the clinical features of the Patau syndrome was found to have excess chromosome 13 material present as a tandem translocation involving the short arm of chromosome 6 and the long arm of an extra chromosome 13: 46,XY,t(6;13)(p24;q12). The major part of the long arm of the extra chromosome 13 was attached linearly (tandem translocation) to the short arm of chromosome 6. Both parents were phenotypically and karyotypically normal.     

Prenatal diagnosis of an interstitial 12q chromosome deletion

Rearrangements involving long arm of chromosome 12 are rare events. To our knowledge, we present the first case of an interstitial deletion of the long arm of chromosome 12 in a prenatal diagnosis. A review of the literature is included in our report.     

Distal monosomy of the long arm of chromosome 6 (6q25----6qter) inherited by maternal translocation t(6q;17q)

Two half-sisters with distal monosomy of the long arm of chromosome 6 (q25----qter) inherited by maternal translocation t(6q;17q) were investigated. The clinical manifestations of these patients are compared with eight cases reported in the literature for further characterization of the 6q-syndrome. The cytogenetic diagnosis of alterations involving small chromosome fragments and the different origins of this type of deletion are also discussed.     

Identification and designation of telocentric chromosomes in barley by means of Giemsa N-banding technique

Summary Seven complete chromosomes and nine telocentric chromosomes in telotrisomics of barley (Hordeum vulgare L.) were identified and designated by an improved Giemsa N-banding technique. Karyotype analysis and Giemsa N-banding patterns of complete and telocentric chromosomes at somatic late prophase, prometaphase and metaphase have shown the following results: Chromosome 1 is a median chromosome with a long arm (Telo 1L) carrying a centromeric band, while short arm (Telo 1S) has a centromeric band and two intercalary bands. Chromosome 2 is the longest in the barley chromosome complement. Both arms show a centromeric band, an intercalary band and two faint dots on each chromatid at middle to distal regions. The banding pattern of Telo 2L (a centromeric and an intercalary band) and Telo 2S (a centromeric, two intercalary and a terminal band) corresponded to the banding pattern of the long and short arm of chromosome 2. Chromosome 3 is a submedian chromosome and its long arm is the second longest in the barley chromosome complement. Telo 3L has a centromeric (fainter than Telo 3S) and an intercalary band. It also shows a faint dot on each chromatid at distal region. Telo 3S shows a dark centromeric band only. Chromosome 4 is the most heavily banded one in barley chromosome complement. Both arms showed a dark centromeric band. Three dark intercalary bands and faint telomeric dot were observed in the long arm (4L), while two dark intercalary bands in the short arm (4S) were arranged very close to each other and appeared as a single large band in metaphase chromosomes. A faint dot was observed in each chromatid at the distal region in the 4S. Chromosome 5 is the smallest chromosome, which carries a centromeric band and an intercalary band on the long arm. Telo 5L, with a faint centromeric band and an intercalary band, is similar to the long arm. Chromosomes 6 and 7 are satellited chromosomes showing mainly centromeric bands. Telo 6S is identical to the short arm of chromosome 6 with a centromeric band. Telo 3L and Telo 4L were previously designated as Telo 3S and Telo 4S based on the genetic/linkage analysis. However, from the Giemsa banding pattern it is evident that these telocentric chromosomes are not correctly identified and the linkage map for chromosome 3 and 4 should be reversed. One out of ten triple 2S plants studied showed about 50% deficiency in the distal portion of the short arm. Telo 4L also showed a deletion of the distal euchromatic region of the long arm. This deletion (32%) may complicate genetic analysis, as genes located on the deficient segment would show a disomic ratio. It has been clearly demonstrated that the telocentric chromosomes of barley carry half of the centromere. Banding pattern polymorphism was attributed, at least partly, to the mitotic stages and differences in techniques.Contribution from the Department of Agronomy and published with the approval of the Director of the Colorado State University Experiment Station as Scientific Series Paper No. 2730. This research was supported in part by the USDA/SEA Competitive Research Grant 5901-0410-9-0334-0, USDA/ SEA-CSU Cooperative Research Grant 12-14-5001-265 and Colorado State University Hatch Project. This paper was presented partly at the Fourth International Barley Genetics Symposium, Edinburgh, Scotland, July 22–29, 1981     

A Y/15 translocation in a 45,X male with Prader-Willi syndrome

We report a male neonate with a 45 X karyotype; the long arm of a chromosome 15 was translocated onto the proximal long arm of the Y chromosome. Breakpoints were identified by in situ fluorescence hybridization (FISH) on the proximal 15q13 and Yq11.2. The derivative chromosome has no primary centromere. Clinical features were compatible with Prader-Willi syndrome. This is the first report case ofmonosomy 15q and Yq deletion with Prader-Willi syndrome.     

Localization of 616 human chromosome 3-specific cosmids using a somatic cell hybrid deletion mapping panel.

A total of 5700 human chromosome 3-specific cosmid clones was isolated from a series of cosmid libraries constructed from somatic cell hybrids whose only human component was an entire chromosome 3 or a chromosome 3 containing an interstitial deletion removing 50% of long arm sequences. Several unique sequence chromosome 3-specific hybridization probes were isolated from each of 616 of these cosmids. These probes were then used to localize the cosmids by hybridization to a somatic cell hybrid deletion mapping panel capable of resolving chromosome 3 into nine distinct subregions. All 616 of the cosmids were localized to either the long or short arm of chromosome 3 and 63% of the short arm cosmids were more precisely localized. We have identified a total of 87 cosmids that contain fragments that are evolutionarily conserved. Fragments from these cosmids should prove useful in the identification of new chromosome 3-specific genes as well as in comparative mapping studies. The localized cosmids should provide excellent saturation of human chromosome 3 and facilitate the construction of physical and genetic linkage maps to identify various disease loci including Von Hippel Lindau disease and renal and small cell lung carcinoma.