Familial Site-specific Ovarian Cancer Is Linked to BRCA1 on 17q12-21

In a study of nine families with “site-specific” ovarian cancer (criterion: three or more cases of epithelial ovarian cancer and no cases of breast cancer diagnosed at age <50 years) we have obtained evidence of linkage to the breast-ovarian cancer susceptibility gene, BRCA1 on 17q12-21. If the risk of cancer in these families is assumed to be restricted to the ovary, the best estimate of the proportion of families linked to BRCA1 is .78 (95% confidence interval .32–1.0). If predisposition to both breast and ovarian cancer is assumed, the proportion linked is 1.0 (95% confidence interval .46–1.0). The linkage of familial site-specific ovarian cancer to BRCA1 indicates the possibility of predictive testing in such families; however, this is only appropriate in families where the evidence for linkage to BRCA1 is conclusive.     

CD and Fourier transform ir spectroscopic studies of peptides. II. Detection of β-turns in linear peptides

Comparative CD and Fourier transform ir (FTIR) spectroscopic data on N-Boc protected linear peptides with or without the (Pro-Gly) β-turn motif (e.g., Boc-Tyr-Pro-Gly-Phe-Leu-OH and Boc-Tyr-Gly-Pro-Phe-Leu-OH) are reported herein. The CD spectra, reflecting both backbone and aromatic contributions, were not found to be characteristic of the presence of β-turns. In the amide I region of the FTIR spectra, analyzed by self-deconvolution and curve-fitting methods, the β-turn band shewed up between 1639 and 1633 cm^?1 in trifluoroethanol (TFE) but only for models containing the (Pro-Gly) core. This band war-also present in the spectra in chloroform but absent in dimethylsulfoxide. These findings, in agreement with recent ir data on cyclic models and 3₁₀-helical polypeptides and protein in D₂O [see S. J. Prestrelski, D. M. Byler, and M. P. Thompson (1991), International Journal of Peptide and Protein Research, Vol. 37, pp. 508–512; H. H. Mantsch, A. Perczel. M. Hollósi, and G. D. Fasman (1992), FASEB Journal, Vol. 6, p. A341; H. H. Mantsch. A. Perczel, M. Hollósi, and G. Fasman (1992), Biopolymers. Vol. 33, pp. 201–207; S. M. Miick, G. V. Martinez, W. R. Fiori, A. P. Tedd, and G. L. Millhauser (1992). Nature, Vol. 359, pp. 653–655], suggest that the amide I band, with a major contribution from the acceptor C ? O of the 1 ← 4 intramolecular H bond of β-turns, appears near or below 1640 cm^?1, rather than above 1660 cm^?1. In TFE, bands between 1670 and 1660 cm^?1 are mainly due to “free” carbonyls, that is, C ? O's of amides that are solvated but not involved in the characteristic H bonds of periodic secondary structures or β-turns. © 1994 John Wiley & Sons, Inc.     

Interaction between the black yeast Aureobasidium pullulans and the gall midge Lasioptera ephedricola in gall formation on the desert shrub Ephedra trifurca

Galls produced by the cecidomynd Lastoptera ephedncola on Ephedia trifurca always have a black ring associated with them while galls produced by the congener L ephedrae never do Black ring material after microscopic examination and culture proved to be Aureobasidium pullulans In addition to lacking black ring material neither L ephedrae galls nor healthy stems consistently yielded Aureobasidium on culture Gall and larva size measurements indicated that continued larval presence is not necessary for gall development, suggesting fungus initiated gall formation However inoculation of healthy stems with Aureobasidium caused lesions hut not galls The mycelium m galls did not appear grazed and neither larvae nor pupae contained Aureobasidium propagules suggesting that larvae do not feed directly on fungi These data also suggest that there is no trans-pupal passage of fungus from larvae or pupae to adults Newly emerged females do not carry fungal propagules suggesting that thcy are not inoculated upon exiting the gall Gall position leaf culture and stem culture data suggest that the fungus is picked up from leaves prior to oviposition     

Physical mapping of inhibin β-A in domestic cattle

The gene for the -A subunit of inhibin (INHBA) was assigned to bovine syntenic group U13 by bovine x rodent hybrid somatic cells and the polymerase chain reaction (PCR). A 482-bp PCR fragment was used to clone a 37-kb cosmid. This cosmid was assigned to bovine Chromosome (Chr) 4 (BTA 4) by fluorescence in situ hybridization (FISH). This is the first assignment of a U13 marker to a bovine chromosome. A restriction fragment length polymorphism (RFLP) was detected with PstI within the INHBA cosmid.     

Media alternatives for the collection, culture and freezing of mouse and cattle embryos

The replacement of biological products in media for the collection, culture and freezing of mammalian embryos was studied. To test the hypothesis that chemically defined surfactants can replace bovine serum albumin (BSA) or serum in embryo media, morula-stage mouse and cattle embryos were collected, cultured, and/or frozen in the surfactant compound, VF5. Collection efficiency of mouse and cattle embryos did not differ whether the medium contained serum or surfactant. In addition, morula-stage mouse and cattle embryos developed and hatched at similar rates in culture media containing either BSA or surfactant. Although the freeze/thaw survival and development in culture of bovine embryos was not significantly different in any of the media, there was a significantly lower hatching rate of mouse embryos frozen with serum or surfactant than with cryoprotectant alone or with cryoprotectant plus albumin-free serum. However, the absence of serum or surfactant in embryo freezing media resulted in embryo loss, presumably due to stickiness. The data suggest that serum can be replaced by a chemically defined surfactant in mouse and cattle embryo transfer systems for the collection, culturing and freezing of embryos. It is likely that the beneficial effects of serum are due to its surfactant properties.     

The isolation of Ant1, a transposable element from Aspergillus niger

A transposable element has been isolated from the industrially important fungus Aspergillus niger (strain N402). The element was identified as an insertion sequence within the coding region of the nitrate reductase gene. It had inserted at a TA site and appeared to have duplicated the target site upon insertion. The isolated element was found to be 4798 by in length and contained 37-bp inverted, imperfect, terminal repeats (ITRs). The sequence of the central region of the element revealed an open reading frame (designated ORF1) which showed similarity, at the amino acid level, to the transposase of the Tc1/mariner class of DNA transposons. Another sequence within the central region of the element showed similarity to the 3 coding and downstream untranslated region of the amyA gene of A. niger. Sequence homology and structural features indicate that this element, which has been named Ant1 (A. niger transposon 1), is related to the Tc1/mariner group of DNA transposons. Ant1 is apparently present as a single copy in strain N402 of A. niger.     

Analysis of Orthologous Retrovirus-Like Elements in the White-Footed Mouse,Peromyscus leucopus

Three loci in the genome of the white-footed mouse, Peromyscus leucopus, were examined for the presence or absence of orthologous copies of the retrovirus-like element mys using polymerase chain reaction. We examined these loci in 28 mice collected throughout the P. leucopus species range. Mys insertions were present in only one of the individuals examined at the mys-1 and mys-7 loci. Conversely, the mys-6 element was found in several individuals, but the presence of this element was limited to northern latitudes. Because the long terminal repeats (LTRs) of a given element are expected to be identical at the time of retrotransposition into the genome, and to accumulate changes over evolutionary time, within-element LTR sequence comparisons can be used to estimate the relative age of insertions. Within-element LTR differences are greater in mys-6 than in mys-1 or mys-7. The LTRs from orthologous mys-6 elements of six mice were sequenced. The alignment revealed 13 of the 22 differences between the right and left LTRs that were shared by all orthologous mys-6 sites, suggesting that relative to its time of insertion into the genome, mys-6 has only recently spread across the northern part of the species range. Received: 23 January 1996 / Accepted: 24 April 1996     

Isolation of Race-and Cultivar-Specific Elicitors from Intercellular Fluids of Compatible Interactions of Pseudomonas syringae pv. pisi and Pea

Intercellular fluids obtained by an in vacuo infiltration technique from compatible race-cultivar interactions of five races of Pseudomonas syringae pv. pisi and pea induced extensive light brown necrotic (hypersensitive type of) lesions in resistant but not susceptible cultivars. In susceptible cultivars the intercellular fluids induced extetensive water soaking symptoms. The intercellular fluids elicited intermediate reactions in pea cultivars of moderate resistance. The intensity of the light brown necrotic reactions in pea appears to be positively correlated with the degree of resistance.