Temperature-sensitive periods and autonomy of pleiotropic effects of l(1)Nts1, a conditional notch lethal in Drosophila.

Analysis of temperature-shift experiments using strains homo- and/or hemizygous for a temperature-sensitive (ts) mutation of the Notch locus, l(1)N^ts1, has permitted us to localize temperature-sensitive periods (TSPs) both for lethality and for adult ectodermal morphology defects. Discrete TSPs for lethality are localized to the first half of the embryonic period, to the second larval instar, to the third larval instar, and to a 15 hr period immediately after pupation. TSPs for adult morphology defects are localized to the second and third larval instars for eyeless-headless and duplicated antenna, to the third larval instar for small and rough (spl-like) eye, eye scar, fused leg segments, shortened tarsal leg segments, Notch wings, and extra macrochaetae, and to the early pupal period for extra and missing microchaetae, fa^g-like rough eye and thick wing vein defects. Within the third larval instar, distinct patterns of eye, wing, and leg defects are observed. There is a striking similarity between the adult morphology defects and TSPs of l(1)N^ts1 and those of the larval and adult locomotor mutant, shi^ts1 (C. A. Poodry, L. Hall, and D. T. Suzuki, 1973, Develop. Biol.32, 373–386). Expression of l(1)N^ts1 also has been studied in genetic mosaics, in which we find that the pleiotropic effects of l(1)N^ts1 are autonomously expressed.     

Genetic and Developmental Analysis of a Temperature-Sensitive Minute Mutation of DROSOPHILA MELANOGASTER

A temperature-sensitive (ts) third chromosome Minute (M) mutation, designated Q-III, has been recovered and characterized. Q-III heterozygotes raised at 29° exhibit all of the dominant traits of M mutants including small bristles, rough eyes, prolonged development, reduced viability and interactions with several unrelated mutations. Q-III homozygotes raised at 29° are lethal; death occurs primarily during the first larval instar. When raised at 22°, Q-III heterozygotes are phenotypically normal and Q-III homozygotes display moderate M traits. In addition, Q-III elicits ts sterility and maternal-effect lethality. As it true of M lesions, the dominant traits of Q-III are not expressed in triploid females raised at 29°. Complementation tests suggest that Q-III is a ts allele of M(3)LS4, which is located in 3L near the centromere.—Reciprocal temperature-shift experiments revealed that the temperature-sensitive period (TSP) of Q-III lethality is polyphasic, extending from the first instar to the latter half of pupation. Heat-pulse experiments further resolved this into two post-embryonic TSPs: one occurring during the latter half of the second larval instar, and the other extending from the larval/pupal boundary to the second half of pupation. In addition, heat pulses elicited a large number of striking adult phenotypes in Q-III individuals. These included pattern alterations such as deficiencies and duplications and other morphological defects in structures produced by the eye-antennal, leg, wing and genital imaginal discs and the abdominal histoblasts. Each defect or pattern alteration is associated with a specific TSP during development.—We favor the interpretation that most of the major Q-III defects, particularly the structural duplications and deficiencies, result from temperature-induced cell death in mitotically active imaginal anlagen, while the small macrochaete phene probably results from the direct effects of Q-III on bristle synthesis. The hypothesis that the Q-III locus specifices a component required for protein synthesis is discussed, and it is concluded that this hypothesis can account for the pleiotropy of Q-III, and that perhaps it can be extended to M loci in general.     

黑果蝇dlts品系的温度敏感时期及dlts基因多效影响的自主性研究

本文采用D.T.Suzuki的方法,研究了黑果蝇Drosophila virilis Sturt dlts品系的温度敏感时期和致死时期的相互关系.选择了31℃为限制温度,25℃为许可温度.对于成虫盘缺损的研究用了12个小时为一个脉冲或24个小时为一个脉冲的热处理,用扫描电镜技术辅助对成虫形态缺损的研究.对于成虫盘缺失和重复的关系主要在48小时为一个脉冲的热处理盘中进行,对dlts基因的表达采用了遗传嵌合性的研究,其结果如下:1. 两个不连续的温度敏感时态对致死的影响是在第1龄幼虫、第2龄幼虫、第3龄幼虫和进入蛹期后的10个小时.温度敏感时态和致死时态并不一致,而是先于致死时态几个小时.2. 温度敏感时态对成虫形态的影响是:触角的重复和复眼的缺失发生在第2龄和第3龄幼虫期.足关节融合及跗节和腿节的缩短发生在第3龄幼虫期,翅脉硬化主要发生在第3龄幼虫期即将结束进入前蛹期的这段时间.第3龄幼虫期是成虫盘发生缺陷比较集中的时期,可以明显见到足、复眼、翅和刚毛的缺陷,同源异型突变体也在这个时期发生.同源突变体的变化主要是足、触角片段及刚毛和触角片段的相互转移.3. 每一个成虫盘缺陷部有自己明显的特征,根据它们成虫盘的形态缺陷和热处理的时间性,所有的成虫盘缺陷变化都可以分为这样三类:缺失,重复,缺失和重复并存.4. 遗传镶嵌测试表明:dlts基因是自主表达的,且具有一定的时间、环境和组织的特殊性.     

Larval RNAi in <Emphasis Type="Italic">Tribolium</Emphasis> (Coleoptera) for analyzing adult development

We report here on the use of RNA interference (RNAi) to create pupal and adult loss-of-function phenotypes in the red flour beetle, Tribolium castaneum, by injection of double-stranded RNA (dsRNA) into late instar larvae (we refer to this method as larval RNAi). RNAi is well-established as a useful method to mimic loss-of-function phenotypes in many organisms including insects. However, with a few exceptions (such as in the fruit fly Drosophila melanogaster), RNAi analysis has usually been limited to studies of embryogenesis. Here we demonstrate that injection of green fluorescent protein (GFP) dsRNA into the larval body cavity can inhibit GFP expression beginning shortly after injection and continuing through pupal and adult stages. RNAi analysis of the Tc-achaete-scute-homolog (Tc-ASH) revealed that larval RNAi can induce morphological defects in adult beetles, and also that larval RNAi affects the entire body rather than being localized near the site of injection. The larval RNAi technique will be useful to analyze gene functions in post-embryonic development, giving us the opportunity to study the molecular basis of adult morphological diversity in various organisms.Edited by D. Tautz     

Lethal(1)aberrant immune response mutations leading to melanotic tumor formation in Drosophila melanogaster

Using P element-mediated mutagenesis we have isolated 20 X-linked lethal mutations, representing at least 14 complementation groups, which exhibit melanotic tumor phenotypes. We present the systematic analysis of this interesting group of lethal mutations that were selected for their visible melanotic or immune response. The lethal and melanotic tumor phenotypes of each lethal(1) aberrant immune response (air) mutation are pleiotropic effects of single genetic lesions. Lethality occurs throughout the larval and early pupal periods of development and larval development is extended in some air mutants. The air mutant lethal syndromes include abnormalities associated with the brain, haematopoietic organs, gut, salivary glands, ring glands, and imaginal discs. Additional characterization of the melanotic tumor mutations Tum^l and tu(1)Sz^ts have indicated that the melanotic tumor phenotype is similar to that observed in the air mutants. These studies have led to the proposal that two distinct classes of melanotic tumor mutations exist. Class 1 includes mutants in which melanotic tumors result from “autoimmune responses” or the response of an apparently normal immune system to the presence of abnormal target tissues. The Class 2 mutants display obvious defects in the haematopoietic organs or haemocytes, manifested as overgrowth, and the resulting aberrant immune system behavior may contribute to melanotic tumor formation.     

Expression of phenotypes in a temperature-sensitive allele of the apterous mutation in Drosophila melanogaster

A temperature-sensitive allele of the apterous (ap) locus of Drosophila melanogaster has been used to examine the phenotypes produced by this mutation, which include wing, mesonotal, and haltere deficiencies, precocious adult death, and nonvitellogenic oocyte development. When raised at 15°C, homozygous ap^ts78j adults have nearly wild-type wing morphology except for patches of missing triple-row bristles and posterior wing margin deficiencies. With the exception of two missing bristles, the dorsal mesonotum and the haltere appear as wild-type. Increasing deficiency of structures derived from the wing and haltere imaginal discs results from increasing culture temperature, and at 29°C, the wing blade, many dorsal mesonotal bristles, and the haltere are absent. The temperature-sensitive period in development for these deficient phenotypes extends from late-second to mid-third instar. Despite extensive deficiencies seen after ap^ts78j larvae are heat-pulsed at 29°C, no duplication of the notal structures is evident, a common response of other mutants having extensive wing deficiencies. When raised at 29 or 25°C, ap^ts78j adults are short-lived, and females show nonvitellogenic oocyte development. At 22°C, however, adults are long-lived, and females are vitellogenic and lay fertile eggs. A sharp temperature-sensitive period for both phenotypes is located during the first 24 hr of pupal development. The application of a juvenile hormone mimic, ZR-515, restored vitellogenesis to ap^ts78j females raised at 25°C but was unable to rescue them from precocious death.     

Temperature-sensitive mutations in Drosophila melanogaster. 8. Temperature-sensitive periods of the lethal and morphological phenotypes of selected combinations of notch-locus mutations

Temperature-shift experiments were performed on five Notch-locus genotypes with temperature-sensitive phenotypes. The results show that temperature-sensitive periods (TSPs) for lethality may occur at any developmental stage: (1) $\text{N}{}^{\mathrm{g11}}\text{N}{}^{\mathrm{g11}}$;Dp^51b7 having a short embryonic TSP for lethality, (2) $\text{Ax}{}^{16172}\text{N}{}^{\mathrm{?40}}$ having a second-instar TSP for lethality, and (3) $\text{N}{}^{\mathrm{?103}}\text{fa}{}^{\mathrm{no}}$ with a long, possibly polyphasic, TSP, beginning in the embryonic stage and ending in the pupal stage. On the other hand, TSPs for adult morphological phenotypes appear to be restricted to the third larval instar: (1) $\text{Ax}{}^{16172}\text{N}{}^{\mathrm{?40}}$ having third-instar TSPs for wing vein gapping and ocellar bristle loss, and (2) $\text{N}{}^{\mathrm{?103}}\text{spl}$ having third-instar TSPs for eye facet disarray, wing notching, bristle number variation, and fusion of tarsal segments. The significance of these results is discussed in terms of the role of the Notch locus in development.     

Analysis of molting and metamorphosis in the ecdysteroid-deficient mutant L(3)3DTS of Drosophila melanogaster

The dominant temperature-sensitive mutation L(3)3^DTS (DTS-3) in Drosophila melanogaster causes lethality of heterozygotes during the third larval instar at the restrictive temperature (29°C). Temperature-shift experiments revealed two distinct temperature-sensitive periods, with lethal phases during the third larval instar (which may persist for 4 weeks) and during the late pupal stage. At 29°C mutant imaginal discs are unable to evert in situ, but did evert normally if cultured in the presence of exogenous ecdysterone or when implanted into wild-type larval hosts. The only morphologically abnormal tissue present in the lethal larvae is the ring gland, the prothoracic gland being greatly hypertrophied in third instar DTS-3 larvae. Injection of a single wild-type ring gland rescued these mutant larvae, indicating that the mutant gland is functionally, as well as morphologically, abnormal. Finally, the mutant larvae were shown to have less than 10% of the wild-type ecdysteroid levels. These results are all consistent with a proposed lesion in ecdysteroid hormone production in DTS-3 larvae. A comparison with the phenotypes of other “ecdysone-less” mutants is presented.     

Fine structure of flight muscles in different Notch mutants of Drosophila melanogaster reared at different temperatures

Summary The fine structure of the indirect flight muscles was studied by electron microscopy in the following Notch locus mutants of Drosophila melanogaster reared at 18° C or 29° C for 6 days after eclosion: Ax ¹⁶¹⁷²/Ax¹⁶¹⁷², Ax²⁸/ Ax²⁸, l(1)N^ts1/l(1)N^ts1,l(1)N^ts1/Y and in wild-type controls. The flies were raised up to eclosion at 25° C or 18° C. It was observed that the l(1)N^ts1 flies gradually became flightless within a few days if reared at 29° C as adults, and gross changes in the fine structure of the flight muscles were also observed in flies of this genotype. Peripheral myofilaments of myofibrils were disarranged and the mitochondria diminutive. At 18° C the flight muscles remained normal. In all of the Abruptex (Ax) combinations the flight muscles remained similar to the wild-type controls at both 18° C and 29° C, i.e. they were normal. The results suggest that the Notch gene is active in adult flies in addition to its activity during embryonic, larval and pupal stages, and is directly or indirectly involved in the adult development of the muscle tissue.     

Developmental changes of sepiapterin synthase activity associated with a variegated purple gene in Drosophila melanogaster

A variegated position effect on the autonomous gene, purple, has been studied enzymologically in Drosophila melanogaster. Sepiapterin synthase, the enzyme system associated with pr ⁺, was examined for activity in different developmental stages of the fly. The results indicate that T(Y:2) pr ^c5, cn/pr^c4 cn flies (flies in which pr ⁺ has been translocated and which exhibit variegation) have a reduced amount of enzyme activity as compared with both Oregon-R and pr ¹ flies. This reduction in activity was not found in larval stages, which suggests that the inactivation process probably occurs in late larval or early pupal stages. The phenotype of the variegated adult has white eyes with red-colored spots and patches where drosopterins occur. The phenotype of the fly carrying the translocation is modified by the presence of additional Y chromosomes. This extends the observation from other systems that extra heterochromatin acts to suppress the variegated position effect. The advantages of studying the variegation by measuring enzyme activity, as well as the phenotypic expression, are several; for example, the developmental time at which variegation occurs may be estimated even though drosopterin synthesis is not occurring.The Oak Ridge National Laboratory is operated by Union Carbide Corporation for the Department of Energy under Contract No. W-7405-eng-26.     

Recovery and Characterization of Temperature-Sensitive Mutations Affecting Adult Viability in DROSOPHILA MELANOGASTER

Temperature-sensitive (ts) autonomous cell-lethal mutations have been used extensively to study important developmental phenomena, such as pattern formation, in Drosophila. Their utility would be enhanced considerably if it were possible to establish which cell type is primarily affected by each lesion. To facilitate such an approach we have isolated and characterized 21 EMS- induced X-linked adult-lethal (adl) mutants, 16 of which are ts. Most of these lesions also elicit ts lethal effects during preimaginal development. They represent 19 different loci distributed randomly along the X chromosome. The general properties of these mutations are described. In addition, results of an in-depth analysis (focus mapping and, in some cases, temperature shift and heat-pulse studies) of four strains, adl-1^ts1, sesE, adl-2^{ts 1} and rex are reported. Two major temperature-sensitive periods (TSPs) of adl-1 lethality were resolved: one during the second half of embryogenesis and the other coinciding with pupariation. Mosaic analysis revealed separate mesodermal foci for leg paralysis. Developmental analysis of adl-1 embryos suggest that the adl-1 product may be required for maintenance of muscle tissue. Two discrete TSPs of sesE lethality exist: one during the second instar and the other extending from late third instar to early pupation. Mosaic analysis of sesE lethality resolved a pair of neural foci, each of which appears to incorporate three separate foci for leg paralysis. Mosaic analysis of adl-2^{ts 1} revealed the existence of paired lethal foci that appear to map to the vicinity of the subesophageal ganglion. Analysis of rex mosaics resolved separate mesodermal foci for leg paralysis.     

Isolation, characterization, and utilization of a temperature-sensitive allele of a Pseudomonas replicon

In order to facilitate genetic study of the opportunistic bacterial pathogen Pseudomonas aeruginosa, we isolated a conditional, temperature-sensitive plasmid origin of replication. We mutagenized the popular Pseudomonas stabilizing fragment from pRO1610 in vitro using the Taq thermostable DNA polymerase in a polymerase chain reaction (PCR). Out of approximately 23,000 potential clones, 48 temperature-sensitive mutants were isolated. One mutant was further characterized and the origin of replication was designated as mSF^ts1. The mutations that resulted in a temperature-sensitive phenotype in mSF^ts1 were localized to the 1.2 kb of minimum sequence required for replication in P. aeruginosa. The DNA sequence analysis revealed two mutations within the coding sequence of the Replication control (Rep) protein. Growth of P. aeruginosa carrying the temperature-sensitive plasmid at the non-permissive temperature of 42 °C resulted in loss of the plasmid by greater than 99.9999% of the cells after 16 h of growth. In order to facilitate its utilization, the mSF^ts1 was converted into a genetic cassette flanked by mirrored restriction endonuclease digestion sites of a pUC1918 derivative. We demonstrate utilization of the mSF^ts1 for genetic studies involving complementation and regeneration of a mutant in P. aeruginosa research.     

Cycloheximide-Resistant Temperature-Sensitive Lethal Mutations of Saccharomyces Cerevisiae

We describe the isolation and preliminary characterization of a set of pleiotropic mutations resistant to the minimum inhibitory concentration of cycloheximide and screened for ts (temperature-sensitive) growth. These mutations fall into 22 complementation groups of cycloheximide resistant ts lethal mutations (crl). None of the crl mutations appears to be allelic with previously isolated mutations. Fifteen of the CRL loci have been mapped. At the nonpermissive temperature (37°), these mutants arrest late in the cell cycle after several cell divisions. Half of these mutants are also unable to grow at very low temperatures (5°). Although mutants from all of the 22 complementation groups exhibit similar temperature-sensitive phenotypes, an extragenic suppressor of the ts lethality of crl3 does not relieve the ts lethality of most other crl mutants. A second suppressor mutation allows crl10, crl12, and crl14 to grow at 37° but does not suppress the ts lethality of the remaining crl mutants. We also describe two new methods for the enrichment of auxotrophic mutations from a wild-type yeast strain.     

Temperature sensitivity of muscle and neuron differentiation in embryonic cell cultures from the Drosophila mutant, shibire.

The sex-linked temperature-sensitive mutation, shibire^ts1, which causes, at the restrictive temperature, adult paralysis and pleiotropic morphological defects in embryonic, larval, and pupal development, has been shown to exhibit temperature-sensitive inhibition of differentiation in embryonic cultures in vitro. When shi cultures were incubated at 30°C for 24 hr, both muscle and neuron differentiation were inhibited more than 90% compared to control shi cultures incubated at 20°C. Heat shift experiments showed that the temperature-sensitive periods for neuron and muscle differentiation occurred at 11 to 18 and 14 to 16 hr, respectively, where zero time was the initiation of gastrulation in donor embryos. Short heat pulses (4 and 8 hr) which extended into the temperature-sensitive period resulted in moderate inhibition of differentiation; greater inhibition occurred as the duration of the pulses increased. In contrast, heating wild-type Oregon-R cultures at 30°C for 24 hr did not inhibit muscle cell differentiation and inhibited neuron differentiation relatively little. The temperature-sensitive period in shibire for muscle differentiation occurred well after myoblast division, during the period of myocyte elongation, aggregation, and fusion, whereas that for neuron differentiation took place during a period of enzyme synthesis (acetylcholinesterase and choline acetyltransferase) and axon elongation. Thus, the shi temperature-sensitive gene product affects at least two different cell types, in vitro, at different times during differentiation.     

Zygotic Lethals with Specific Maternal Effect Phenotypes in Drosophila Melanogaster. I. Loci on the X Chromosome

In order to identify all X-linked zygotic lethal loci that exhibit a specific maternal effect on embryonic development, germline clonal analyses of X-linked zygotic lethal mutations have been performed. Two strategies were employed. In Screen A germline clonal analysis of 441 mutations at 211 previously mapped X-linked loci within defined regions was performed. In Screen B germline clonal analysis of 581 larval and pupal mutations distributed throughout the entire length of the X chromosome was performed. These approaches provide an 86% level of saturation for X-linked late zygotic lethals (larval and pupal) with specific maternal effect embryonic lethal phenotypes. The maternal effect phenotypes of these mutations are described.     

黑果蝇dlts品系的温度敏感时期及dlts基因多效影响的自主性研究

本文采用D.T.Suzuki的方法,研究了黑果蝇Drosophila virilis Sturt dl^ts品系的温度敏感时期和致死时期的相互关系。选择了31℃为限制温度,25℃为许可温度。对于成虫盘缺损的研究用了12个小时为一个脉冲或24个小时为一个脉冲的热处理,用扫描电镜技术辅助对成虫形态缺损的研究。对于成虫盘缺失和重复的关系主要在48小时为一个脉冲的热处理盘中进行,对dlts基因的表达采用了遗传嵌合性的研究,其结果如下：1两个不连续的温度敏感时态对致死的影响是在第1龄幼虫、第2龄幼虫、第3龄幼虫和进入蛹期后的10个小时。温度敏感时态和致死时态并不一致,而是先于致死时态几个小时。2温度敏感时态对成虫形态的影响是：触角的重复和复眼的缺失发生在第2龄和第3龄幼虫期。足关节融合及跗节和腿节的缩短发生在第3龄幼虫期,翅脉硬化主要发生在第3龄幼虫期即将结束进入前蛹期的这段时间。第3龄幼虫期是成虫盘发生缺陷比较集中的时期,可以明显见到足、复眼、翅和刚毛的缺陷,同源异型突变体也在这个时期发生。同源突变体的变化主要是足、触角片段及刚毛和触角片段的相互转移。3每一个成虫盘缺陷部有自己明显的特征,根据它们成虫盘的形态缺陷和热处理的时间性,所有的成虫盘缺陷变化都可以分为这样三类：缺失,重复,缺失和重复并存。4遗传镶嵌测试表明：dl^ts基因是自主表达的,且具有一定的时间、环境和组织的特殊性。     

Temporal programming of epidermal cell protein synthesis during the larval-pupal transformation ofManduca sexta

Summary During the final larval instar the epidermis of the tobacco hornworm,Manduca sexta, synthesizes the larval cuticular proteins and the pigment insecticyanin. Then at the onset of metamorphosis the cells first become pupally-committed, then later produce the pupal cuticle. The changes in the pattern of epidermal protein synthesis during this period were followed by incubating the integument in vitro with either³H-leucine or³⁵S-methionine, then analyzing the proteins by 2-dimensional gel electrophoresis. Precipitation by larval and pupal cuticular antisera and by insecticyanin antibody identified these proteins. Three distinct changes in epidermal protein synthesis were noted: 1) Stage-specific proteins, some of which are larval cuticular proteins, appear just before and during the change of commitment on day 3. (2) By late the following day (wandering stage), synthesis of these and many other proteins including all the identified larval cuticular proteins and insecticyanin was undetectable. Several noncuticular proteins were transiently synthesized by this pupally committed cell during wandering and sometimes the following day. (3) During the production of pupal cuticle a new set of pupal-specific cuticular proteins as well as some common cuticular proteins (precipitated by both antisera) were synthesized. Some of the latter were also synthesized during the period between pupal commitment and pupal cuticle deposition.In spite of an apparent absence of methionine in both larval and pupal cuticle, many cuticular proteins incorporated³⁵S-methionine. Thus they may be synthesized as proproteins.Insecticyanin was shown to have two forms differing in isoelectric point, the cellular form being more acidic than the hemolymph form. Synthesis of the cellular form ceased before that of the hemolymph form.     

Increased levels of the Drosophila Abelson tyrosine kinase in nerves and muscles: subcellular localization and mutant phenotypes imply a role in cell-cell interactions.

Mutations in the Drosophila Abelson tyrosine kinase have pleiotropic effects late in development that lead to pupal lethality or adults with a reduced life span, reduced fecundity and rough eyes. We have examined the expression of the abl protein throughout embryonic and pupal development and analyzed mutant phenotypes in some of the tissues expressing abl. abl protein, present in all cells of the early embryo as the product of maternally contributed mRNA, transiently localizes to the region below the plasma membrane cleavage furrows as cellularization initiates. The function of this expression is not yet known. Zygotic expression of abl is first detected in the post-mitotic cells of the developing muscles and nervous system midway through embryogenesis. In later larval and pupal stages, abl protein levels are also highest in differentiating muscle and neural tissue including the photoreceptor cells of the eye. abl protein is localized subcellularly to the axons of the central nervous system, the embryonic somatic muscle attachment sites and the apical cell junctions of the imaginal disk epithelium. Evidence for abl function was obtained by analysis of mutant phenotypes in the embryonic somatic muscles and the eye imaginal disk. The expression patterns and mutant phenotypes indicate a role for abl in establishing and maintaining cell-cell interactions.     

Temperature-sensitive mutants of hsp82 of the budding yeast Saccharomyces cerevisiae

The budding yeast Saccharomyces cerevisiae has two HSP90-related genes per haploid genome, HSP82 and HSC82. Random mutations were induced in vitro in the HSP82 gene by treatment of the plasmid with hydroxylamine. Four temperature-sensitive (ts) mutants and one simultaneously is and cold-sensitivie (cs) mutant were then selected in a yeast strain in which HSC82 had previously been disrupted. The mutants were found to have single base changes in the coding region, which caused single amino acid substitutions in the HSP82 protein. All of these mutations occurred in amino acid residues that are well conserved among HSP90-related proteins of various species from Escherichia coli to human. Various properties including cell morphology, macromolecular syntheses and thermosensitivity were examined in each mutant at both the permissive and nonpermissive temperatures. The mutations in HSP82 caused pleiotropic effects on these properties although the phenotypes exhibited at the nonpermissive temperature varied among the mutants.     

Effect of plant oils on quality parameters of Bactrocera tryoni (Froggatt) reared on liquid larval diet

Liquid larval diets have been developed for several tephritid fruit flies including Queensland fruit fly, Bactrocera tryoni (Frogatt) (Q‐fly). In liquid diets, wheat germ oil (WGO) is usually added to improve performance in some quality parameters of reared flies, especially flight ability. However, for some flies, other plant oils may be more readily available, cheaper or produce flies of superior performance. In the present study, four alternative types of plant oils – rice bran, canola, vegetable, and sesame – were incorporated into a fruit fly liquid larval diet to replace the currently used wheat germ oil and their efficacy on the quality parameters of reared Q‐fly was compared to diets containing wheat germ oil or no oil. The quality parameters included: total pupal yield (N), pupal recovery (%), larval duration (days), pupal weight (mg), adult emergence (%), adult fliers (%), rate of fliers (%), sex ratio (%), F₁ egg/female/day and egg hatching (%). There were significant differences among treatments in performance of Q‐fly. Vegetable oil appeared better in terms of total pupal yield, percentage of pupal recovery, percentage of adult emergence, percentage of fliers, mean egg/female/day and % F₁ egg hatch compared with other oil treatments, especially from that of WGO treated diet. The result suggests that WGO can be substituted with rice bran and vegetable oil to improve the liquid larval diet for rearing of B. tryoni, with vegetable oil being the best replacement.