Twelve loci form a continuous linkage map for human chromosome 18

We have constructed a primary genetic map of human chromosome 18 consisting of 11 DNA markers and one serological marker (JK). Two of these loci define highly polymorphic VNTR systems. The markers define a continuous genetic linkage map of 97 cM in males and 205 cM in females; female genetic distances in a panel of 59 three-generation families were consistently about twice those observed in males. The high odds in support of the linear order of the markers on this recombination map, and the extent of coverage of chromosome 18, indicate that this map will permit efficient linkage studies of human genetic diseases that may be segregating on chromosome 18 and will provide anchor points for development of high-resolution maps for this chromosome.     

Detection by DGGE of a new polymorphism closely linked to the adenomatous polyposis coli region

Summary The EF5.44 locus is in close proximity to the chromosome 5 region to which the genetic defect responsible for familial adenomatous polyposis has been mapped. We have devised two oligonucleotides that promote the specific polymerase chain reaction (PCR) amplificiation of a 365-bp sequence in this region. Analysis by denaturing gradient gel electrophoresis of the resulting fragment has unravelled individual differences that could be identified as a single base pair change in aMnlI restriction site. This PCR assayable polymorphism increases the informativeness at this locus, and should be useful in the presymptomatic diagnosis of familial adenomatous polyposis.     

Identification of 57 conventional RFLP and 6 VNTR systems with 32 DNA clones on chromosome 11p15

Fifty-four clones containing human inserts were selected from a cosmid library constructed from a somatic cell hybrid containing chromosome 11p15.3-p15.5 as its only human complement. In 32 of these clones, 63 polymorphic systems were identified with a panel of restriction enzymes: 57 conventional RFLP systems and 6 highly polymorphic VNTR systems. Although we examined the cosmid with only seven enzymes, 18 clones (including 6 VNTRs) were polymorphic with three or more enzymes. The results suggested that DNA sequences on the peritelomeric region of chromosome 11p tend to be highly variable. Because these markers are highly informative, they will be excellent resources for investigations of hereditary diseases and tumor suppressor genes in this region of chromosome 11.     

The influence of experimentally produced oligohydramnios on lung growth and pulmonary surfactant content in fetal rabbits.

To study the effect of oligohydramnios on lung growth and biochemical lung development in fetal rabbits, amniotic fluid was drained through a tube inserted into the maternal peritoneal cavity on the 23 day of gestation. Littermate fetuses without an amniotic shunt were used as controls. The fetuses were delivered abdominally on the 28 day of gestation. In a total of 8 pregnant does, 17 fetuses underwent amniotic shunting and 22 fetuses were used as controls. The amniotic shunt produced a significant reduction in the amniotic fluid volume. There were no differences in the wet weights of the fetal body, liver or brain between the two groups. However, the amniotic shunt significantly decreased the wet weight of the fetal lung, fetal lung wet weight/body weight ratio, and protein concentration per lung as compared to the control fetuses. In the fetal liver and brain tissues, no changes were found in the concentrations of total phospholipids, phosphatidylcholine (PC) or disaturated phosphatidylcholine (DSPC, the main component of lung surfactant) per g of wet tissue and per mg of protein. However, the lungs of the fetuses with amniotic shunts contained significantly more PC and DSPC, and the L/S ratio was higher than in the control fetuses. These results suggest that the oligohydramnios produced by an amniotic shunt causes pulmonary hypoplasia, but raises the pulmonary surfactant content of fetal rabbit lung.     

Xenopus M phase MAP kinase: isolation of its cDNA and activation by MPF.

MAP kinase is activated and phosphorylated during M phase of the Xenopus oocyte cell cycle, and induces the interphase-M phase transition of microtubule dynamics in vitro. We have carried out molecular cloning of Xenopus M phase MAP kinase and report its entire amino acid sequence. There is no marked change in the MAP kinase mRNA level during the cell cycle. Moreover, studies with an anti-MAP kinase antiserum indicate that MAP kinase activity may be regulated posttranslationally, most likely by phosphorylation. We show that MAP kinase can be activated by microinjection of MPF into immature oocytes or by adding MPF to cell-free extracts of interphase eggs. These results suggest that MAP kinase functions as an intermediate between MPF and the interphase-M phase transition of microtubule organization.     

Contra-IL 2; a suppressor lymphokine that inhibits IL 2 activity

Suppressive activity of culture supernatant of AS-9 (AS-9 CS), a T cell hybridoma line that was derived from fusion of BW5147 thymoma and splenic T cells of anti-lymphocyte serum-treated C3H mice, was analyzed. AS-9 CS inhibited allogeneic cytotoxic T lymphocyte (CTL) generation as well as T cell proliferation to alloantigens and mitogens, but failed to inhibit B cell response to lipopolysaccharide or growth of tumor and fibroblast cells. Although addition of AS-9 CS to the allogeneic sensitization culture as late as on day 2 of incubation resulted in maximal inhibiton of CTL generation, removal of AS-9 CS on day 3 of incubation abolished its inhibitory effect. Addition of purified IL 2 together with AS-9 CS to the allogeneic sensitization cultures only partially abrogated the suppression. Experiments with IL 2-dependent cytotoxic T cell line (CTLL) showed that AS-9 CS suppressed the IL 2-induced proliferation of CTLL. Preincubation of AS-9 CS with CTLL removed its inhibitory effect on CTL generation. These results indicate that AS-9 CS interferes with the mechanism of T cell activation by IL 2. On this basis, AS-9 CS was named contra-IL 2.     

Amino acid sequence of polypeptide chain IIB of extracellular hemoglobin from the polychaete Tylorrhynchus heterochaetus

The giant extracellular hemoglobin from the polychaete Tylorrhynchus heterochaetus consists of two types of subunits: a "monomeric" chain (chain I) and a disulfide-bonded trimer of chains IIA, IIB, and IIC. The complete amino acid sequence of chain IIB was determined. This chain has 148 amino acid residues and a molecular weight of 17,236 including a heme group. Of the residues in chain IIB, 74 (50%) and 34 (30%) were found to be identical with those in the corresponding positions in Tylorrhynchus chains IIC and I, respectively (Suzuki, T., Furukohri, T., and Gotoh, T. (1985) J. Biol. Chem. 260, 3145-3154). Marked differences were found between the chains of Tylorrhynchus and Lumbricus in the COOH-terminal regions. Significant differences were predicted between the monomeric chain I and the "trimeric" chains (IIB and IIC) in the hydropathy profiles and alpha-helical contents.     

Nucleotide sequence of a functional cDNA for human thymidylate synthase.

We have determined the nucleotide sequence of a cDNA clone, pcHTS-1, encoding human thymidylate synthase (5,10-methylenetetrahydrofolate: dUMP C-methyltransferase, EC 2.1.1.45) which was previously isolated from a human fibroblast expressible cDNA library and functional in mouse cells. The 1.6 kilobase cDNA insert of pcHTS-1 encodes a subunit protein of 313 amino acid (Mr = 35,706) and its predicted amino acid sequence is highly conserved in many regions including folylpolyglutamate and 5-fluoro-2'-deoxyuridylate binding sites, when compared with those of Lactobacillus casei, Escherichia coli, and bacteriophage T4. The cDNA contains in its 5'-untranslated region a triple tandemly repeated sequence consisting of 90 nucleotides, which starts immediately upstream of the ATG initiator codon, is very high in G+C content (80%), and can form three possible interconvertible stem-loop structures.     

Restriction fragment length polymorphism detected by human salivary amylase cDNA

Summary The plasmid clone which contains human salivary amylase cDNA was used to detect restriction fragment length polymorphisms (RFLPs). After double digestion with Pst 1 and Bam H1, a polymorphism with two alleles was observed. In Japanese, frequencies of these alleles, tentatively called 5.7kb and 6.5kb fragment alleles, are 0.55 and 0.45, respectively.     

Life-cycle variation inPanonychus akitanus Ehara (Acarina:Tetranychidae)

The life history ofPanonychus akitanus Ehara was studied in two Hokkaido populations on dwarf bamboos. The Sapporo population overwintered both as egg and female adult onSasa senanensis, and the Tomakomai population overwintered as egg onSasa apoiensis. Mites of the Sapporo population produced four or five generations from late April to late November or early December. The eggs that had overwintered began to hatch in mid-May, and this hatching period overlapped with that of eggs laid in late April by females that had overwintered. Therefore, mites with different overwintering stages would interbreed. Most eggs that had overwintered in the Tomakomai population hatched in mid-May, and about four generations were produced before early December, when only eggs were found. The density of mites per leaf of the Sapporo population reached a maximum in early May on old leaves and in late June on new leaves, and thereafter gradually decreased. The Tomakomai population initially decreased in density after hatching in the spring, but rapidly dispersed to new leaves, reached a peak in early September, and then gradually decreased. The maximal density was about 10 times higher and the distribution was less clumped (lower values of the aggregation index,m/m) than that of the Sapporo population. This was probably because the Sapporo mites could utilize only the underside of sporadically distributed leaves which were curled by spiders, whereas the Tomakomai mites inhabited any part of the leaf undersurface of the hairy host plant. Predators observed were phytoseiid mites and larvae of gall midges. The predatory effect on the Sapporo population was not clear. In the Tomakomai population, the number of gall midges correlated with the number of spider mites better than that of phytoseiid mites.