The Amusic Brain: Lost in Music,but Not in Space

Congenital amusia is a neurogenetic disorder of music processing that is currently ascribed to a deficit in pitch processing. A recent study challenges this view and claims the disorder might arise as a consequence of a general spatial-processing deficit. Here, we assessed spatial processing abilities in two independent samples of individuals with congenital amusia by using line bisection tasks (Experiment 1) and a mental rotation task (Experiment 2). Both amusics and controls showed the classical spatial effects on bisection performance and on mental rotation performance, and amusics and controls did not differ from each other. These results indicate that the neurocognitive impairment of congenital amusia does not affect the processing of space.     

Basal autophosphorylation of insulin receptor occurs preferentially on the receptor conformation exhibiting high affinity for insulin and stabilizes this conformation

Insulin signal transmission through the plasma membrane was studied in terms of relationship between basal autophosphorylation of the β-subunit and the ability by bind insulin by the -subunit of the insulin receptor. In a cell free system, receptors phosphorylated on tyrosine residues in the absence of insulin were separated from non-phosphorylated receptors using antiphosphotyrosine antibodies. Insulin binding assays were then performed on basally autophosphorylated and on non-phosphorylated receptors. We found that the tyrosine phosphorylated receptors, which corresponded to 25% of the total number of receptors, were accountable for 60–80% of insulin binding. Scatchard representation of binding data has shown that the plot corresponding to tyrosine phosphorylated receptors was localized above, and was steeper than the plot corresponding to non-phosphorylated receptors. These data make it likely that the conformation of -subunit which favours ligand binding is connected to the conformation of β-subunit which favours phosphate reception on tyrosine residues. Reciprocally, the high-affinity conformation of insulin receptor seems to become stabilized by basal autophosphorylation.     

New chromosome 21 DNA markers isolated by pulsed field gel electrophoresis from an ETS2-containing Down syndrome chromosomal region

To generate new chromosome 21 markers in a region that is critical for the pathogenesis of Down syndrome (D21S55-MX1), we used pulsed field gel electrophoresis (PFGE) to isolate a 600-kb NruI DNA fragment from the WA17 hybrid cell line, which has retained chromosome 21 as the only human material. This fragment, which contains the oncogene ETS2, was used to construct a partial genomic library. Among the 14 unique sequences that were isolated, 3 were polymorphic markers and contained sequences that are conserved in mammals. Five of these markers mapped on the ETS2-containing NruI fragment and allowed us to define an 800-kb high-resolution PFGE map.     

Variants of the anti-Müllerian hormone gene in a compound heterozygote with the persistent Müllerian duct syndrome and his family

Summary The human genome contains a large number of interspersed simple repeat sequences that are variable in length and can therefore serve as highly informative, polymorphic markers. Typing procedures include conventional multilocus and single locus probing, and polymerase chain reaction aided analysis. We have identified simple sequences in a cosmid clone stemming from the human Y chromosome and consisting of (gata)_n repeats. We have compared these with two equivalent simple repeat loci from chromosome 12. After amplifying the tandemly repeated motifs, we detected between four and eight different alleles at each of the three loci. Codominant inheritance of the alleles was established in family studies and the informativity of the simple repeat loci was determined by typing unrelated individuals. The polymorphisms are suitable for application in linkage studies, practical forensic case work, deficiency cases in paternity determination, and for studying ethnological questions. The mutational mechanisms that bring about changes in simple repeats located both on the autosomes and on the sex chromosomes, are discussed.Professor Dr. Otto Prokop (Humboldt-Universität Berlin) on the occasion of his 70th birthday     

Influence of menstrual cycle on shivering, skin blood flow, and sweating responses measured at night

In 10 women, external cold and heat exposures were performed both in the middle of luteal phase (L) and in the early follicular phase (F) of the menstrual cycle. Serum progesterone concentrations in L and F averaged 46.0 and 0.9 nmol X l-1, respectively. The experiments took place between 3:00 and 4:30 A.M., when the L-F core temperature difference is maximal. At neutral ambient temperature, esophageal (Tes), tympanic (Tty), rectal (Tre), and mean skin (Tsk) temperatures averaged 0.59 degrees C higher in L than in F. The thresholds for shivering, chest sweating, and cutaneous vasodilation (heat clearance technique) at the thumb and forearm were increased in L by an average of 0.47 degrees C, related to mean body temperature [Tb(es) = 0.87Tes + 0.13 Tsk] and to Tes, Tty, Tre, or Tsk. The above-threshold chest sweat rate and cutaneous heat clearances at the thumb and forearm were also enhanced in L, when related to Tb(es) or time. The metabolic rate, arm blood flow, and heart rate at thermoneutral conditions were increased in L by 5.0%, 1.1 ml X 100 ml-1 X min-1, and 4.6 beats X min-1, respectively. The concomitant increase in threshold temperatures for all autonomic thermoregulatory responses in L supports the concept of a resetting of the set point underlying the basal body temperature elevation in L. The effects of the increased threshold temperatures are counteracted by enhanced heat loss responses.     

Effect of Nitrogen Fertilization and Growth Suppression on Pitch Canker Development on Loblolly Pine Seedlings

One-yr-old loblolly pine seedlings of two half-sib families, grown in sand, were fertilized three times per week with nutrient solution containing 20 μg/ml (low) or 80 μg/ml (high) nitrogen. Nitrogen concentration in the nutrient solution was either constant throughout the experiment, or interehanged after the inoculation of stems or shoots with Fusarium subglutinans, 55 days after initiation of fertilization. Growth was suppressed by a weekly excision of shoots branching from the stem apex. Either high nitrogen nutrition or shoot excision generally enhanced canker elongation on stem inoculated plants; the combination of both was extremely conducive for disease development. With intact plants of family 8–68, interchange of pre-inoculation low nitrogen nutrition with high nitrogen after inoculation enhanced canker elongation and rate of wilt. Nitrogen content varied in wood, bark and needles, as well as with time intervals, but was consistently in accordance with nitrogen level in the nutrient solution. In shoot excised plants, nitrogen content was higher than in the respective treatment without shoot excision. The higher nitrogen nutrient accelerated disease development on inoculated shoots, compared to low nitrogen, on both pine families. With respective treatments, stem cankers were larger and rates of shoots exhibiting lesions or wilt were higher on plants of family 8–68 than on 8–61. It is postulated that the disease enhancing effect associated with higher nitrogen content in stem tissues results from an increased nitrogen availability to the pathogen.     

A new gene coding for an antigen recognized by autologous cytolytic T lymphocytes on a human renal carcinoma

Previous reports have described antigens that are recognized on human melanoma cells by autologous cytolytic T lymphocytes (CTL). The genes coding for a number of these antigens have been identified. Here we report the cloning of a gene that codes for an antigen recognized by autologous CTL on a human renal carcinoma cell line. This antigen is presented byHLA-B7 and is encoded by a new gene that we have namedRAGE1. No expression ofRAGE1 was found in normal tissues other than retina. RAGE1 expression was found in only one of 57 renal cell carcinoma samples, and also in some sarcomas, infiltrating bladder carcinomas, and melanomas. This represents the first identification of an antigen recognized by autologous CTL on a renal tumor.     

Yeast proteins can activate expression through regulatory sequences of the amdS gene of Aspergillus nidulans

The upstream regulatory region of the amdS gene of Aspergillus nidulans contains a CCAAT sequence known to be important in setting both basal and derepressed levels of expression. We have investigated whether the CCAAT-binding HAP2/3/4 complex of the yeast Saccharomyces cerevisiae can recognise this sequence in an amdS context. Sequences from the 5′ region of amdS were cloned in front of the CYCI-lacZ fusion gene bearing a minimal promoter and transformed into wild-type and hap2 strains of yeast. This study has indicated that amdS sequences are capable of promoting regulated expression of the fusion gene in response to carbon limitation. The yeast HAP2/3/4 complex can recognise the amdS CCAAT sequence and activate expression from this sequence. In addition, the results indicate that other yeast proteins can also regulate expression from the A. nidulans amdS 5′ sequences under carbon-limiting conditions.