摘要:

Recent genetic work has suggested that abnormalities in serotonin biochemistry are directly causally linked to aggressive behavior, and there appears to be a consensus in the psychiatric literature that low levels of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid are specifically associated with impulsive violent behavior. We review the limitations of the genetic studies and conduct a meta-analysis of 39 studies linking 5-HIAA to aggression in humans. No differences in mean 5-HIAA levels were found between groups of violent impulsive psychiatric patients and groups of subjects diagnosed with other psychiatric or medical conditions not considered to involve violence once these levels had been corrected for three nonpsychiatric sources of variation (age, sex and height). However, mean 5-HIAA levels in both of these groups were lower than the mean corrected level in groups of normal healthy volunteers. The results confirm an association between low 5-HIAA levels and psychiatric disorders, but fail to support any specific relationship between low 5-HIAA levels and impulsive aggression or criminality. It is premature and misleading to speak of“mean genes”(Hen 1996) or a specific neurochemistry of aggressive behavior.

ISSN:0167-7063    

DOI:10.3109/01677069609107061

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Homozygous mutant mice such asstaggerer (sg/sg)orreeler (rl/rl)exhibit a marked ataxia associated with an atrophic cerebellum during the first postnatal weeks and a reduced number of Purkinje cells, the deficit reaching about 75% insg/sgand 50% inrl/rlas compared to age-and sex- matched mice from the same strain background. These two mutations are classically viewed as recessive, but we have recently shown that heterozygousstaggerer (+/sg)mice exhibit a progressive and age-related loss of Purkinje cells between 3 and 12 months of age, despite their apparent clinical normality (Shojaeian-Zanjaniet al, 1992). In the present study, we have investigated whether a similar cell loss exists in the cerebellum of heterozygous+/rlmice. The number of Purkinje cells was counted in serial parasagittal sections of the cerebellum of+/rland their +/+ littermates at 3, 16 and 26 months of age. Our results reveal a 16% deficit in the number of Purkinje cells in 3-month-old +/W and a 24% one in 16-month-old animals: surprisingly this deficit is only present in the+/rlmales, while the females are spared. These results suggest that thereelergene (D'Arcangeloet al., 1995) exerts its effect on Purkinje cell number in a gender-specific fashion in heterozygous mutant mice.

ISSN:0167-7063    

DOI:10.3109/01677069609107062

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

TheDrosophilareceptor oscillation A(rosA)mutations, which cause electroretinogram (ERG) defects, including oscillations, were localized to the 24F4-25A2 region of chromosome 2L. Genomic fragments from this region, isolated from bacteriophage PI clones, included those that detect transcriptional defects inrosAmutants in RNA blot experiments. One of these genomic fragments was used to screen a head cDNA library. The largest cDNA clone (3.6 kb) isolated was shown to rescue arosAmutant in P element-germline transformation experiments. The ROSA protein deduced from the open reading frame in the 3.6 kbrosAcDNA is 943 amino acids long and is 36-41% identical to members of the superfamily of Na+/Cl−-dependent neurotransmitter transporters, with no indication of higher sequence identity to any one subgroup within the superfamily. RNA blot experiments revealed multiple transcripts in various developmental stages, the most abundant one being a 3.7 kb transcript, particularly in the adult head. Tissuein situexperiments identified therosAtranscript to be localized to many tissues, with higher levels of hybridization in the nervous system and digestive tract. The results demonstrate that therosAgene encodes a novel Na+/Cl−-dependent transporter important for normal response properties of the photoreceptor.

ISSN:0167-7063    

DOI:10.3109/01677069609107063

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Conventional methods of gene cloning by complementing mutant defects is made difficult by the 800 ploidy of theParameciummacronucleus. However, this nucleus is some 30 nm in diameter and readily propagates exogenous DNA fragments as cells divide. These attributes allow for massive injection of engineered DNA fragments and their maintenance in the transformed descendant. If a genomic DNA fraction injected into a mutant macronucleus effects complementation, it should be possible to sort a fractional library to isolate the complementing gene. Here, we investigated four aspects of establishing this method for general use. First, using the clonedCAMgene as a test case, we further investigated transformation by macronu-clear injection and showed that phenotypic reversion is directly correlated with the copy number of the transgene, even when it is of a recessive allele,cam2, which has a missense mutation but produces a partially functional protein. Second, we examined the copy number of the transgene established in cells of older clonal age and discussed the likely dilution of the trans-gene in younger descendants of the injected cell. Third, we showed that the degree of phenotypic reversion is correlated with the transgene product, thecam2calmodulin protein in the cell. Fourth, we extended the investigation to very recessive mutants whose genes are to be cloned. We showed that size fractions of wild-type genomic DNA digests effect strong phenotypic reversions in severalpawnmutants, setting the stage for cloning these Ca2+-channel related genes. The general usefulness of this method in cloning genes that complement recessive alleles and current limitations of this method in dealing with dominant alleles are assessed and discussed.

ISSN:0167-7063    

DOI:10.3109/01677069609107064

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

The central complex (CC) is a prominent component of the adult insect brain. InDrosophila melanogaster, mutations which alter CC structure also impair adult locomotion. This has led to the suggestion that the CC functions as a higher organizer of adult locomotor patterns (Strauss and Heisenberg, 1993). In the present study, we describe altered larval behavior resulting from mutations in sixCCstructural genes. Differences from the control strain were found for larvae from eachCCmutant strain in at least one of three assays,central body defect1(cbd1), central complex deranged1(ccd1), central brain deranged1(ceb1)andcentral complex1(cex1)larvae all had general defects in locomotion (on a non-nutritive agar surface). Bothellipsoid body open2(ebo2)andno bridge1(nob1)had larval foraging behavior defects (on a nutritive yeast surface). Onlycex1larvae required significantly longer time in a roll over assay of muscle tone. Genetic analysis suggested thatnob1interacts additively with two other genes influencing larval foraging behavior,foraging (for)andChaser (Csr).foralso had an influence on adult foraging, whereas here we found thatCsrdid not. We did not include adult foraging behavior tests of the CC mutants due to general locomotion defects in these flies (Strauss and Heisenberg, 1993).

ISSN:0167-7063    

DOI:10.3109/01677069609107065

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Theperiodgene inDrosophila melanogastercontrols not only daily rhythms associated with adult emergence and behavior, but also a much higher frequency rhythm that accompanies the male's courtship song. This oscillation in the rate of sound production (normal period, ca. one minute) is either sped up (byper5), slowed down, or eliminated in the three classicpermutants. We have conducted a mosaic analysis in which both lovesong and cir-cadian locomotor cycles were examined in a series of flies that were each partper5and partper+.Consistent with previous studies, the focus forpercontrol of the adult's circadian rhythm of locomotion was found to be in the brain. However, several mosaic individuals were found to exhibit a mutant locomotor rhythm but a wild-type song cycle, or vice-versa, enabling us provisionally to map the song-rhythm focus to the thoracic ganglia. Thatperis expressed only in glial cells in the thoracic nervous system and, in general, mediates slow (hour-by-hour) fluctuations in the levels of its own products are discussed from the standpoint of the current mosaic mapping results and the renewed focus they bring to the gene's influence on an ultradian rhythm.

ISSN:0167-7063    

DOI:10.3109/01677069609107066

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor