Characterization of an autosomal rudimentary-shaped wing mutation in Drosophila melanogaster that affects pyrimidine synthesis.

A new autosomal mutation, rudimental (ral), which causes rudimentary-shaped wings in Drosophila melanogaster, has been isolated following ethyl methanesulfonate (EMS) mutagenesis. The wing phenotype of rudimental is identical to that of the X-linked rudimentary (r) mutation, which affects the first three enzymes in the pyrimidine biosynthetic pathway. The autosomal mutant maps very close to ebony (3-70.7) at 70.42 on the right arm of chromosome 3. Analysis of the enzyme activities of orotate phosphoribosyltransferase (OPRTase) and orotidylate decarboxylase (ODCase) indicates that the rala26a allele has less than wild-type activity for both enzymes. This result is discussed in light of the fact that the OPRTase and ODCase activities are part of an enzyme complex, as are the carbamyl phosphate synthetase (CPSase), aspartate transcarbamylase (ATCase) and dihydroorotase (DHOase) activities, which are encoded by the complex rudimentary locus. We suggest that rudimental is also a complex lucus.

Sex-linked auxotrophic and putative auxotrophic mutants of Drosophila melanogaster.

Thirty-two mutants with improved growth response on a yeast-sucrose compared with a defined medium have been characterized with respect to ribonucleoside supplementability. Twenty mutants respond to either pyrimidine ribonucleoside. Four mutants respond to one or both purine ribonucleosides. Eight mutants ("putative" auxotrophs) do not respond to dietary RNA supplementation. Mapping and complementation studies suggest that eleven loci are represented: one, rudimentary, probably accounts for all pyrimidine requirers; there are three purine loci and seven at which the putative auxotrophs are found.

A genetic and biochemical analysis of the temperature sensitive, normal-winged alleles of the rudimentary locus of Drosophila melanogaster.

The genetic and biochemical characteristics of a particular class of mutants at the rudimentary locus are described. The mutants are pyrimidine auxotrophs, like classical rudimentary alleles, but they are unique in that they do not alter the size or shape of the wing (Falk and Nash 1974b). Aspartate transcarbamylase and dihydroorotase activities have been measured in seven different normal-winged mutants, and the results indicate that these strains are enzymologically "leaky" mutants. Previous studies have shown that three genetic functions (corresponding to the first three enzymes of pyrimidine synthesis) are associated with the rudimentary locus. Four of the seven mutants appear to affect all three of these functions. Each of the four is temperature sensitive, and a biochemical analysis of the temperature sensitivity of one of these mutants, (r)pyr1-3, suggests that a process affecting the synthesis or assembly of these enzymes is altered at high temperatures.

The genetic analysis of achiasmate segregation in Drosophila melanogaster. III. The wild-type product of the Axs gene is required for the meiotic segregation of achiasmate homologs.

The regular segregation of achiasmate chromosomes in Drosophila melanogaster females is ensured by two distinct segregational systems. The segregation of achiasmate homologs is assured by the maintenance of heterochromatic pairing; while the segregation of heterologous chromosomes is ensured by a separate mechanism that may not require physical association. AxsD (Aberrant X segregation) is a dominant mutation that specifically impairs the segregation of achiasmate homologs; heterologous achiasmate segregations are not affected. As a result, achiasmate homologs frequently participate in heterologous segregations at meiosis I. We report the isolation of two intragenic revertants of the AxsD mutation (Axsr2 and Axsr3) that exhibit a recessive meiotic phenotype identical to that observed in AxsD/AxsD females. A third revertant (Axsr1) exhibits no meiotic phenotype as a homozygote, but a meiotic defect is observed in Axsr1/Axsr2 females. Therefore mutations at the AxsD locus define a gene necessary and specific for homologous achiasmate segregation during meiosis. We also characterize the interactions of mutations at the Axs locus with two other meiotic mutations (ald and ncd). Finally, we propose a model in which Axs+ is required for the normal separation of paired achiasmate homologs. In the absence of Axs+ function, the homologs are often unable to separate from each other and behave as a single segregational unit that is free to segregate from heterologous chromosomes.

The characterization of chromosome breaks in Drosophila melanogaster. II. Molecular analysis of gamma-ray-induced deficiencies in the 14F-15A region.

In the previous paper of this series, a total of 446 mutations of the para gene were isolated following gamma- or X-irradiation. Of these, 180 were shown to be chromosome deficiencies. In this analysis we examine the molecular distribution of breakpoints in a subset of strains [38] which have an endpoint in the 14F-15A5 region. We find that although the breakpoints are distributed throughout the entire region, there is some regional specificity to the distribution of those endpoints.

The characterization of chromosome breaks in Drosophila melanogaster. I. Mass isolation of deficiencies which have an end point in the 14A-15A region.

A total of 2.7 X 10(6) chromosomes have been screened for deficiencies that extend into some portion of the 14A-15A segment of the X-chromosome. Mutants have been identified on the basis of their paralysis at high temperature (the para ts phenotype) in a stock which contains a para ts allele on the X-chromosome and a para+ allele on the Dp(1;4)r+f+ chromosome. Several hundred mutants have been genetically characterized and a large percentage are deficiencies. Cytological characterization of a sub-set suggests that breakpoints are distributed throughout the 14B-15A region, but in a non-random fashion.

Produtividade de genótipos de trigo duplo propósito submetidos ao pastejo com vacas em lactação / Productivity of dual-purpose wheat genotypes under grazing with lactating cows

Esta pesquisa foi conduzida com o objetivo de avaliar a produtividade de dois genótipos de trigo de duplo propósito, BRS Tarumã e BRS Umbu, submetidos ao pastejo com vacas em lactação. O delineamento experimental foi o inteiramente ao acaso, com dois tratamentos (genótipos), três repetições (piquetes) e medidas repetidas no tempo (pastejos). Avaliaram-se a precocidade, a composição estrutural dos trigos, as produções de forragem e de biomassa de lâminas foliares, as taxas de acúmulo diário de forragem e de lâminas foliares, a taxa de lotação, as ofertas de forragem e de lâminas foliares, a eficiência de pastejo, o consumo aparente e a produção de grãos. O trigo mais precoce para produção de forragem foi o BRS Umbu. Houve diferença para a produção de forragem (3196 vs. 4143kg MS/ha) e de lâminas foliares (2281 vs. 3205kg MS/ha) para os genótipos BRS Umbu e BRS Tarumã, respectivamente. Valores similares foram encontrados para taxa de lotação (2,26UA/ha); eficiência de pastejo (52,26%), consumo aparente (2,91%) e produção de grãos (1716kg/ha). O genótipo BRS Tarumã é o mais indicado para o manejo de duplo propósito em condições de pastejo com vacas em lactação.(AU)

The objective of this research was to evaluate the productivity of two dual-purpose wheat genotypes BRS Tarumã and BRS Umbu under grazing with lactating cows. The experimental design was completely randomized, with two treatments, three replications (paddocks) and repeated measures (grazing cycles). Studied variables were early growth, the structural composition of wheat, forage production, leaf blade biomass, the stocking rate, the herbage and leaf blade allowance, the grazing efficiency, the herbage intake and grain yield. The earliest genotype for forage production was the BRS Umbu. Differences in herbage yield between BRS Umbu and BRS Tarumã genotypes (3196 vs. 4143kg DM/ha) and leaf blade production (2281 vs. 3205kg DM/ha), respectively, were detected. Similar values between cultivars were found in stocking rate (2,26AU/ha); grazing efficiency (52,26%), herbage intake (2,91 %) and grain yield (1716kg/ha). The BRS Tarumã genotype is the most suitable for dual-purpose under grazing with dairy cows.(AU)

Pyrimidine auxotrophy and the complementation map of the rudimentary locus of Drosophila melanogaster.

The complementation pattern of twelve rudimentary mutations have been analyzed at two different levels. When analyzed on the basis of complementation for a wing abnormality the mutations can be divided into three groups, each of which is believed to affect the activity of one of the first three enzymes of pyrimidine synthesis (Norby, 1973; Jarry and Falk, 1974; Rawls and Fristrom, 1975). However, when the mutants are analyzed for complementation on the basis of a second phenotype, pyrimidine auxotrophy, the distinction between two of these three groups is not evident. The disparity in the two patterns probably reflects a different threshold of gene activity required for the detection of an auxotrophic phenotype as compared to that at which a wing abnormality is detectable. The biochemical basis of these results is interpreted in light of recent data suggesting that at least the first two enzymes of pyrimidine synthesis are contained within a single multifunctional protein complex (Soderholm et al., 1975).

Public health nurses' responses to domestic violence: a report from the Enhanced Domestic Abuse Intervention Project.

Public health nurses (PHNs) can play an important role in the detection of domestic violence. This study examines whether the introduction of a domestic violence assessment protocol by public health nurses in a maternal and child health visiting program increases the identification and referral rates of women experiencing domestic violence. Data collected from case files during the baseline year prior to the initiation of the protocol were compared to case file information after the protocol had been implemented. When the protocol was used, there was a higher rate of identification, although the difference was not statistically significant. Significantly more women, however, were provided with information about domestic violence resources after the protocol was in place, and significantly more women were referred to services in the second year after the protocol had been implemented. This study provides support for the use of a domestic violence protocol to improve the public health nursing response to domestic violence.