Karyotyp-Phenotyp-Lorrelation bei einem 46,Xdel(X)(p22)-Befund

Summary In a patient with a height of 1.46 m, short neck and cubitus valgus the unbalanced karyotype 46,Xdel(X)(p22) was found. The mother of the proband has the balanced karyotype 46,Xt(X;15)(p22;p1). The mother is 1.56 m tall and has a short neck and cubitus valgus too. For this reason the deletion of the Xp22 band seems to cause the short stature of Turner patients. Our proband has had 2 pregnancies which ended as abortions in the 2nd and 4th month.As Giraud et al. (1974) have shown the deletion of the dark middle bande of the short X chromosome arm induces a slight dysgenesie of the gonade.     

Partial deletion of the X chromosome in gonadal dysgenesis 46,X,del(X)(p22) identified by BUdR treatment

Summary In this report we describe a deletion of the short arm of the X chromosome in a 16-year-old female with gonadal dysgenesis.The breakpoint was localized by BUdR treatment and acridine orange staining in region 2, band 2.Of the examined cells, 3% showed an early replication of the deleted X chromosome.     

Trinucleotide repeats (CGG)22TGG(CGG)43TGG(CGG)21 from the fragile X gene remain stable in transgenic mice

Unstable premutation alleles in fragile X contain CGG repeats ranging from 34 to about 200. To study the mechanism of formation and the behavior of dynamic mutations, we constructed and cloned 88 trinucleotide repeats including 43 uninterrupted CGGs and injected them into mouse fertilized oocytes. We analyzed 342 transgenic animals obtained from 6 different founders after one to four generations, and found that the repeats remained stable regardless of the sex of the transmitting mouse. Therefore, we may need to consider factors other than trinucleotide repeat length alone to explain CGG instability and create an animal model. Received: 17 January 1997 / Accepted: 14 April 1997     

Molecular studies of a translocated (X;22) DiGeorge patient using somatic cell hybridization.

In order to better characterize the chromosomic rearrangement of an unbalanced 45XX t(X;22) (q28;q11) DiGeorge patient, a somatic hybrid clone segregating the translocated chromosome was constructed and investigated using X and 22 linked markers. Our study demonstrated that this de novo translocation was from paternal origin. The breakpoint was assigned between DXS296 and IDS loci at Xq28 and between D22S9 and BCRL2 at 22q11. This observation and published data allow to locate a "critical region" for DiGeorge syndrome between these two last loci on 22q11. Our hybrid clone may be a useful tool for mapping new probes arising in this region.     

Fragile site (16) (q22)

Summary The rare autosomal fragile site, fra (16)(q22), is the most common of all rare autosomal fragile sites and has a heterozygote frequency of about 5%. Evidence for it was found following the segregation expected from a simple codominant trait with complete penetrance; this is in contrast to a variety of other rare autosomal fragile sites. Based on the analysis of 12 families in which fra (16)(q22) is segregating, we found that, whereas complete penetrance could be confirmed, the transmitting parent was significantly more likely to be of the female sex. On the other hand, there was no evidence for preferential transmission to offspring of either sex.     

The fragile site (16) (q22)

Summary The rare fragile site at 16q22 was experimentally induced in lymphocyte cultures with various AT-specific, non-intercalating DNA-ligands. The optimum conditions for the induction of fra (16)(q22) were determined. The best expression of fra (16)(q22) was found with the aromatic diamidine berenil which is recommended for further studies on this fragile site. The results indicate that fra (16)(q22) is a region with AT-rich, late replicating DNA. The simultaneous treatment of lymphocytes with berenil and aphidicolin (inhibitor of DNA polymerase ) induces both the rare fra (16) (q22) and the common fra (16) (q23) within the same chromosome. A population study on 350 unselected individuals showed that fra (16)(q22) is the most common of all rare autosomal fragile sites in man. The frequency of individuals heterozygous for fra (16)(q22) is 5.1% no homozygosity for fra (16) (q22) was detected. Statistical analysis indicates that the population is in Hardy-Weinberg equilibrium with respect to the fragile and non-fragile chromosomes 16.     

Tertiary trisomy (22q11q),47,+der(22),t(11;22)

Summary We describe a case of tertiary trisomy (22q11q) 47,XX,+der(22),(22pter22q13: : 11q2511qter) in a child with mental retardation, cleft palate, and congenital heart disease resulting from 3: 1 meiotic nondisjunction in a maternal (11;22) translocation carrier. The clinical findings in previously reported cases are reviewed and compared with the features of reported patients with partial trisomy 11q and trisomy 22 syndromes. Half of the ten reported families had additional balanced translocation carriers who may have an increased risk of having a liveborn child with an MCA/MR syndrome, although none have been reported to date.     

Blätteralkohol (X)

Durch Erhitzen von 3-cis-Hexen-l-ol (Blätteralkohol) mit Natrium wurde die aromatische Verbindung (2-Propyl-5-äthyl-benzylalkohol) hergestellt und auch aus 3-trans-, 2-cis-oder 2-trans-Hexen-l-ol, oder aus 2-trans-Hexen-l-al (Blätteraldehyd) wurde die gleiche Verbindung erhalten. Durch eine gleiche Reaktion, wurde aus 3-Penten-l-ol die aromatische Verbindung (2-Äthyl-5-methyl-benzylalkohol) und aus 2-trans -Buten-l-ol wurde 2-Methyl-benzylalkohol erhalten.

Wir möchten besonders diese interessante Reaktion, bei der aus αβ- oder βγ-ungesättigten, n-primären Alkoholen oder Aldehyden Benzylalkohole mit verschiedenen Substitutionen hergestellt werden, als “Blätteralkohol-Reaktion” bezeichnen.     

Monoclonal antibodies specific for poly(dG) X poly(dC) and poly(dG) X poly(dm5C)

Most duplex DNAs that are in the "B" conformation are not immunogenic. One important exception is poly(dG) X poly(dC), which produces a good immune response even though, by many criteria, it adopts a conventional right-handed helix. In order to investigate what features are being recognized, monoclonal antibodies were prepared against poly(dG) X poly(dC) and the related polymer poly(dG) X poly(dm5C). Jel 72, which is an immunoglobulin G, binds only to poly(dG) X poly(dC), while Jel 68, which is an immunoglobulin M, binds approximately 10-fold more strongly to poly(dG) X poly(dm5C) than to poly(dG) X poly(dC). For both antibodies, no significant interaction could be detected with any other synthetic DNA duplexes including poly[d(Gm5C)] X poly[d(Gm5C)] in both the "B" and "Z" forms, poly[d(Tm5Cm5C)] X poly[d(GGA)], and poly[d(TCC)] X poly[d(GGA)], poly(dI) X poly(dC), or poly(dI) X poly(dm5C). The binding to poly(dG) X poly(dC) was inhibited by ethidium and by disruption of the DNA duplex, confirming that the antibodies were not recognizing single-stranded or multistranded structures. Furthermore, Jel 68 binds significantly to phage XP-12 DNA, which contains only m5C residues and will precipitate this DNA in the absence of a second antibody. The results suggest that (dG)n X (dm5C)n sequences in natural DNA exist in recognizably distinct conformations.     

Supernumerary chromosome der(22)t(11;22): Emanuel syndrome associates with novel features

Emanuel syndrome results from +der(22)t(11q23;22q11). Cleft palate, ear anomalies, heart defects, genital anomalies, hypotonia, and mental retardation are the main features of the syndrome. We report a nine-year-old boy with the t(11;22)(q23;q11) chromosome, transmitted in an unbalanced fashion from his mother, and originated in the maternal grandmother's meiosis. In addition to mental retardation, hypotonia, craniofacial anomalies, and cryptorchidism, he has novel findings such as, joint hyperextensibility, left liver lobe agenesis, left sided malposition of the gallbladder and pancreas hypoplasia. This is the first report associating these features with Emanuel syndrome.     

fra(1) (p11), fra(1) (q22) and r(1) (p11q22) in a retarded girl.

A mentally retarded girl with a 46,XX/47, XX+r(1) (p11q22q22p11)/47, XX+r(1) (p11q22) fra(1) (p31) fra(1) (p11) fra(1) (q22) karyotype who inherited the fragile sites from the normal mother was studied. The conicidence of fra(1) (p11) and fra(1) (q22) with the ring chromosome breakpoints strongly suggests a cause-effect relationship. This finding agrees with other reported associations between fragile sites and structural chromosome abnormalities and constitutes the fourth reported of a de novo structurally abnormal chromosome as a consequence of presumed in vivo fragile sites instability. Although risk figures for chromosome anomalies and cancer associated with fragile sites are lacking, carriers of fra (1) (p11) may have a higher risk for abnormalities of chromosome 1 in somatic and gonadal cells than the general population.     

A linkage map of sheep chromosome X (OARX) aligned to human chromosome X (HSAX)

We have constructed a genetic linkage map of the sheep X chromosome (OARX) containing 22 new gene loci from across the human X chromosome (HSAX). The female OARX linkage map has a total length of 152.6 cM with average gene spacing of 5.5 cM. Comparison with HSAX confirms one previously reported major breakpoint and inversion, and other minor rearrangements between OARX and HSAX. Comparison of the linkage map with sheep sequence data OAR 1.0 reveals a different arrangement of markers on the q arm, which may more accurately reflect the genuine arrangement of this region.     

中国苦苣苔科的研究(十)

<正> 多年生草本。根状茎,粗。叶约10枚,均基生,具长或短柄;叶片纸质,卵形或卵状菱形,长2—3.4厘米,宽1.6—2.9厘米,顶端钝或圆形,基部宽楔形或圆形,边缘有钝重牙齿,上面多少泡状,在细脉形成的小空间中密被短柔毛,下面脉上密被白色短柔毛,在隆起的中脉和侧脉上还被暗褐色长柔毛,侧脉每侧4—5条;叶柄长1—3厘米,密被暗褐色长     

Multiple sex chromosome system of X1X1X2X2/X1X2)Y type in lutjanid fish, Lutjanus quinquelineatus (Perciformes)

The karyotype and other chromosomal markers as revealed by C-banding and Ag-staining were studied in Lutjanus quinquelineatus and L. kasmira (Lutjanidae, Perciformes). While in latter species, the karyotype was invariably composed of 48 acrocentric chromosomes in both sexes, in L. quinquelineatus the female karyotype had exclusively 48 acrocentric chromosomes (2n = 48) but that of the male consisted of one large metacentric and 46 acrocentric chromosomes (2n = 47). The chromosomes in the first meiotic division in males showed 22 bivalents and one trivalent, which was formed by an end-to-end association and a chiasmatic association. Multiple sex chromosome system of X₁X₁X₂X₂/X₁X₂Y type resulting from single Robertsonian fusion between the original Y chromosome and an autosome was hypothesized to produce neo-Y sex chromosome. The multiple sex chromosome system of L. quinquelineatus appears to be at the early stage of the differentiation. The positive C-banded heterochromatin was situated exclusively in centromeric regions of all chromosomes in both species. Similarly, nucleolus organizer region sites were identified in the pericentromeric region of one middle-sized pair of chromosomes in both species. The cellular DNA contents were the same (3.3 pg) between the sexes and among this species and related species.