Developmental regulatory mechanisms in the evolution of insect diversity

Development ◽  
1994 ◽  
Vol 1994 (Supplement) ◽  
pp. 217-223
Author(s):  
Sean B. Carroll
Keyword(s):  
Genetic Basis ◽  
Target Genes ◽  
Genetic Regulation ◽  
Morphological Diversity ◽  
Fruit Fly ◽  
Color Pattern ◽  
Fruit Flies ◽  
Distinct Pattern ◽  
Homeotic Genes ◽  
Appendage Formation

The major architectural differences between most Arthropod classes and orders involve variations in the number, type and pattern of body appendages. We have utilized the emerging knowledge of appendage formation in fruit flies to begin to address the developmental and genetic basis of morphological diversity among insects. Butterflies, for example, differ from fruit flies in possessing larval abdominal limbs, two pairs of adult wings, and a sophisticated system of wing color pattern formation. We have found that the genetic bases for these three major morphological features involve differences between flies and butterflies at three levels of genetic regulation during development. First, we show that the presence of abdominal limbs in butterflies is associated with striking changes in the regulation of specific homeotic genes in the abdominal segments of the butterfly embryo. Second, we suggest that the two-winged state of the fruit fly and the distinct pattern of the butterfly hindwing are the consequence of many accurrulated changes in the target genes regulated by the Ultrabithorax homeotic gene. And finally, we demonstrate that a new genetic program, involving many of the same genes that specify the conserved global patterning coordinates of fruit fly and butterfly wings, has been superimposed onto the butterfly wing to create their unique color patterning system. These findings demonstrate how morphological diversity arises from the different ways in which conserved sets of regulatory genes are deployed during development.

scholarly journals Mutant Alleles of the Drosophila trithorax Gene Produce Common and Unusual Homeotic and Other Developmental Phenotypes

Genetics ◽  
1999 ◽  
Vol 152 (1) ◽  
pp. 319-344
Author(s):  
Thomas R Breen
Keyword(s):  
Target Gene ◽  
Target Genes ◽  
Protein Isoforms ◽  
Homeotic Genes ◽  
Set Domain ◽  
Human Homologue ◽  
Terminal Set ◽  
Hypomorphic Alleles ◽  
Different Levels ◽  
Target Gene Transcription

Abstract trithorax (trx) encodes chromosome-binding proteins required throughout embryogenesis and imaginal development for tissue- and cell-specific levels of transcription of many genes including homeotic genes of the ANT-C and BX-C. trx encodes two protein isoforms that contain conserved motifs including a C-terminal SET domain, central PHD fingers, an N-terminal DNA-binding homology, and two short motifs also found in the TRX human homologue, ALL1. As a first step to characterizing specific developmental functions of TRX, I examined phenotypes of 420 combinations of 21 trx alleles. Among these are 8 hypomorphic alleles that are sufficient for embryogenesis but provide different levels of trx function at homeotic genes in imaginal cells. One allele alters the N terminus of TRX, which severely impairs larval and imaginal growth. Hypomorphic alleles that alter different regions of TRX equivalently reduce function at affected genes, suggesting TRX interacts with common factors at different target genes. All hypomorphic alleles examined complement one another, suggesting cooperative TRX function at target genes. Comparative effects of hypomorphic genotypes support previous findings that TRX has tissue-specific interactions with other factors at each target gene. Some hypomorphic genotypes also produce phenotypes that suggest TRX may be a component of signal transduction pathways that provide tissue- and cell-specific levels of target gene transcription.

Linking mango infestation by fruit flies to fruit maturity and fly pressure: A prerequisite to improve fruit fly damage management via harvest timing optimization

2021 ◽  
Vol 146 ◽  
pp. 105663
Author(s):  
Isabelle Grechi ◽  
Anne-Laure Preterre ◽  
Aude Caillat ◽  
Frédéric Chiroleu ◽  
Alain Ratnadass
Keyword(s):  
Fruit Fly ◽  
Fruit Flies ◽  
Timing Optimization ◽  
Fruit Maturity ◽  
Harvest Timing

scholarly journals Host Suitability Index for Polyphagous Tephritid Fruit Flies

2021 ◽  
Author(s):  
Peter A Follett ◽  
Fay E M Haynes ◽  
Bernard C Dominiak
Keyword(s):  
Fruit Fly ◽  
Fruit Production ◽  
General Purpose ◽  
Fruit Flies ◽  
Host Suitability ◽  
Bactrocera Dorsalis ◽  
Infestation Rate ◽  
Suitability Index ◽  
Host Status ◽  
Tephritid Fruit Flies

Abstract Tephritid fruit flies are major economic pests for fruit production and are an impediment to international trade. Different host fruits are known to vary in their suitability for fruit flies to complete their life cycle. Currently, international regulatory standards that define the likely legal host status for tephritid fruit flies categorize fruits as a natural host, a conditional host, or a nonhost. For those fruits that are natural or conditional hosts, infestation rate can vary as a spectrum ranging from highly attractive fruits supporting large numbers of fruit flies to very poor hosts supporting low numbers. Here, we propose a Host Suitability Index (HSI), which divides the host status of natural and conditional hosts into five categories based on the log infestation rate (number of flies per kilogram of fruit) ranging from very poor (<0.1), poor (0.1–1.0), moderately good (1.0–10.0), good (10–100), and very good (>100). Infestation rates may be determined by field sampling or cage infestation studies. We illustrate the concept of this index using 21 papers that examine the host status of fruits in five species of polyphagous fruit flies in the Pacific region: Bactrocera tryoni Froggatt, Bactrocera dorsalis (Hendel), Bactrocera latifrons (Hendel), Zeugodacus cucurbitae (Coquillett), and Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). This general-purpose index may be useful in developing systems approaches that rely on poor host status, for determining surveillance and detection protocols for potential incursions, and to guide the appropriate regulatory response during fruit fly outbreaks.

scholarly journals Establishing criteria for the management of tephritid fruit fly outbreaks

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Michael D. Ormsby
Keyword(s):  
Cost Benefit ◽  
Fruit Fly ◽  
Economic Benefits ◽  
Fruit Flies ◽  
International Standards ◽  
Trade Restrictions ◽  
Export Restriction ◽  
Fly Control ◽  
Financial Impacts ◽  
Tephritid Fruit Flies

AbstractTephritid fruit flies (Diptera; Tephritidae) represent a group of insects that include some of the most economically important pests in horticulture. Because of their economic importance, the financial impacts of an incursion of tephritid fruit flies into a new area can often result in restrictions to trade. The economic impacts of any trade restrictions imposed by importing countries are confounded by the current absence of consistent and accepted criteria for the strength and extent of any trade restrictions and declaring the end of an incursion. The author has developed models that can be used to establish criteria for the management of tephritid fruit fly outbreaks as outlined in international standards. A model enables criteria on when to recognise an incursion has occurred and establish export restrictions. Another model determines what area or radius an export restriction zone (ERZ) should cover. And a third model establishes criteria for the conditions required to enable an ERZ to be rescinded and the area’s pest free status reinstated. The models rely primarily on fruit fly biology and the effectiveness of surveillance trapping systems. The adoption of these proposed criteria internationally for establishing a control system and responding to fruit fly outbreaks would provide considerable economic benefits to international trade. Additionally, these criteria would enable countries to make more informed cost–benefit decisions on the level of investment in fruit fly control systems that better reflects the economic risks fruit flies represent to their economy.

Non-host status of papaya cultivars to the oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae), in relation to the degree of fruit ripeness

2016 ◽  
Vol 37 (01) ◽  
pp. 19-29 ◽  
Author(s):  
Domingos Cugala ◽  
João Jone Jordane ◽  
Sunday Ekesi
Keyword(s):  
Fruit Ripening ◽  
Market Access ◽  
Fruit Fly ◽  
Fruit Flies ◽  
Bactrocera Dorsalis ◽  
Laboratory Evaluation ◽  
Ripening Stage ◽  
Field Cage ◽  
Major Barrier ◽  
Ripening Stages

AbstractPhytosanitary measures are a major barrier to trade in papaya. We assessed the infestation of tephritid fruit flies on different stages of maturity of papaya, to determine its non-host stage of maturity, for market access. Papaya fruits were collected from Kilifi and Embu counties, Kenya from March 2013 to December 2014, to assess the level of infestation by fruit flies according to the degree of fruit ripening. In all locations, no fruit fly infestation was recorded on papaya when fruits were at the 0, 25 and 50% yellow fruit ripening stage.Bactrocera dorsalis(Hendel) was, however, observed attacking fruits when papaya fruits were at 75 and 100% all yellow (fully ripe fruit ripening stage) with infestations of 0.19−0.51B. dorsalis/kg fruit and 0.24−1.24B. dorsalis/kg fruit, respectively, in all locations. Field cage exposure ofB. dorsalisto fruits of five papaya cultivars—‘Papino’, ‘Neo Essence’, ‘Sunrise Solo’, ‘Tainung No. 1’ and ‘Tainung No. 2’ in Manica Province, Mozambique—showed thatB. dorsalisdid not infest fruits at 0, 25 and 50% yellow ripening stages at the densities of 50 and 100 flies per cage. However, at 75% yellow ripening stage, up to 13.1 pupae/kg of fruits was recorded at a density of 150 flies per cage in Tainung No. 1, and infestation ranged from 4.5 to 136 pupae/kg fruits at 100% yellow ripening stage across all the cultivars and infestation densities. Laboratory evaluation of volatiles emanating from freshly crushed papaya pulp of four cultivars: ‘Sunrise Solo’, ‘Red Lady’, ‘Papayi’ and ‘Apoyo’ on egg viability ofB. dorsalisshowed that at 0, 25 and 50% yellow, egg hatchability was inhibited, suggesting that semiochemical compounds present in green tissues of papaya prevent egg development, although this effect was variable across the four cultivars and ripening stages. Export papaya is harvested at less than 40% yellow ripening stage. Our results, therefore, suggest that quarantine treatment for fruits at this ripening stage is inconsequential, asB. dorsalisdoes not infest papaya fruits at this stage; thus, authorities should permit entry of these papaya cultivars of less than 40% yellow ripening stage to quarantine-sensitive markets.

scholarly journals Diversity and seasonality of fruit flies (Diptera: Tephritidae and Lonchaeidae) and their parasitoids (Hymenoptera: Braconidae and Figitidae) in orchards of guava, loquat and peach

2009 ◽  
Vol 69 (1) ◽  
pp. 31-40 ◽  
Author(s):  
MF. Souza-Filho ◽  
A. Raga ◽  
JA. Azevedo-Filho ◽  
PC. Strikis ◽  
JA. Guimarães ◽  
...  
Keyword(s):  
Population Density ◽  
Ceratitis Capitata ◽  
Fruit Fly ◽  
Fruit Flies ◽  
Parasitoid Species ◽  
Seasonal Behavior ◽  
Leptopilina Boulardi ◽  
Torula Yeast ◽  
Tephritid Species

This work was carried out in orchards of guava progenies, and loquat and peach cultivars, in Monte Alegre do Sul, SP, Brazil, in 2002 and 2003. Guavas and loquats were bagged and unbagged bi-weekly and weekly, respectively, for assessment of the infestation period. Peach was only bagged weekly. The assays started when the fruits were at the beginning of development, but still green. Ripe fruits were taken to the laboratory and placed individually into plastic cups. McPhail plastic traps containing torula yeast were hung from January 2002 to January 2004 to assess the fruit fly population in each orchard, but only the Ceratitis capitata population is here discussed. Five tephritid species were reared from the fruits: Anastrepha bistrigata Bezzi, A. fraterculus (Wiedemann), A. obliqua (Macquart), A. sororcula Zucchi, and C. capitata, in addition to six lonchaeid species: Neosilba certa (Walker), N. glaberrima (Wiedemann), N. pendula (Bezzi), N. zadolicha McAlpine and Steyskal, Neosilba sp. 4, and Neosilba sp. 10 (both species are in the process of being described by P. C. Strikis), as well as some unidentified Neosilba species. Ten parasitoid species were obtained from fruit fly puparia, of which five were braconids: Asobara anastrephae (Muesebeck), Doryctobracon areolatus (Szépligeti), D. brasiliensis (Szépligeti), Opius bellus Gahan, and Utetes anastrephae (Viereck), and five figitids: Aganaspis pelleranoi (Brèthes), Dicerataspis grenadensis Ashmead, Lopheucoila anastrephae (Rhower), Leptopilina boulardi (Barbotin, Carlton and Kelner-Pillaut), and Trybliographa infuscata Diaz, Gallardo and Uchôa. Ceratitis capitata showed a seasonal behavior with population density peaking at the second semester of each year. Anastrepha and Neosilba species remained in the orchards throughout both years.

scholarly journals The trithorax Group Genemoira Encodes a Brahma-Associated Putative Chromatin-Remodeling Factor in Drosophila melanogaster

1999 ◽  
Vol 19 (2) ◽  
pp. 1159-1170 ◽  
Author(s):  
Madeline A. Crosby ◽  
Chaya Miller ◽  
, Tamar Alon ◽  
Kellie L. Watson ◽  
C. Peter Verrijzer ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Chromatin Remodeling ◽  
Leucine Zipper ◽  
Genetic Relationships ◽  
Fruit Fly ◽  
Protein Product ◽  
Homeotic Genes ◽  
Trithorax Group ◽  
Functional Relationships

ABSTRACT The genes of the trithorax group (trxG) inDrosophila melanogaster are required to maintain the pattern of homeotic gene expression that is established early in embryogenesis by the transient expression of the segmentation genes. The precise role of each of the diverse trxG members and the functional relationships among them are not well understood. Here, we report on the isolation of the trxG gene moira(mor) and its molecular characterization. morencodes a fruit fly homolog of the human and yeast chromatin-remodeling factors BAF170, BAF155, and SWI3. mor is widely expressed throughout development, and its 170-kDa protein product is present in many embryonic tissues. In vitro, MOR can bind to itself and it interacts with Brahma (BRM), an SWI2-SNF2 homolog, with which it is associated in embryonic nuclear extracts. The leucine zipper motif of MOR is likely to participate in self-oligomerization; the equally conserved SANT domain, for which no function is known, may be required for optimal binding to BRM. MOR thus joins BRM and Snf5-related 1 (SNR1), two known Drosophila SWI-SNF subunits that act as positive regulators of the homeotic genes. These observations provide a molecular explanation for the phenotypic and genetic relationships among several of the trxG genes by suggesting that they encode evolutionarily conserved components of a chromatin-remodeling complex.

Species composition and host range of fruit-infesting flies (Diptera: Tephritidae) in northern Ghana

2015 ◽  
Vol 35 (03) ◽  
pp. 137-151 ◽  
Author(s):  
K.B. Badii ◽  
M.K. Billah ◽  
K. Afreh-Nuamah ◽  
D. Obeng-Ofori
Keyword(s):  
Host Range ◽  
Plant Species ◽  
Host Plants ◽  
Management Strategies ◽  
Fruit Fly ◽  
Fruit Flies ◽  
Northern Ghana ◽  
Accurate Information ◽  
Wild Host ◽  
Fruit Samples

An important aspect of fruit fly management is accurate information on the species and their host spectrum. Studies were conducted between October 2011 and September 2013 to determine the host range and species diversity of pest fruit flies in the northern savannah ecology of Ghana. Fruit samples from 80 potential host plants (wild and cultivated) were collected and incubated for fly emergence; 65 (81.5%) of the plant species were positive to fruit flies. From records in Africa, 11 plant species were reported to be new hosts to the African invader fly,Bactrocera invadens(Drew, Tsuruta and White, 2005). This study documented the first records ofDacus ciliatus(Loew) andTrirhithrum nigerrimum(Bezzi) in northern Ghana although both species have been previously reported in other parts of the country. Infestation byB. invadenswas higher in the cultivated fruits;Ceratitis cosyradominated in most wild fruits. Cucurbitaceae were mainly infested by three species ofDacusandBactroceracucurbitae, a specialized cucurbit feeder. Among the commercial fruit species, the highest infestations were observed in mango, tomato, sweet pepper and watermelon, whereas marula plum, soursop, tropical almond, sycamore fig, African peach, shea nut, persimmon, icacina and albarillo dominated the wild host flora. The widespread availability of host plants and the incidence of diverse fly species in the ecology call for particular attention to their impact on commercial fruits and the development of sustainable management strategies against these economically important pests in Ghana.

Homeotic complex and teashirt genes co-operate to establish trunk segmental identities in Drosophila

Development ◽  
1994 ◽  
Vol 120 (8) ◽  
pp. 2287-2296 ◽  
Author(s):  
P. de Zulueta ◽  
E. Alexandre ◽  
B. Jacq ◽  
S. Kerridge
Keyword(s):  
Heat Shock ◽  
Target Genes ◽  
Homeotic Genes ◽  
Sex Combs Reduced ◽  
Downstream Target ◽  
Functional Aspects ◽  
Sex Combs ◽  
Head Segment ◽  
Posterior Trunk ◽  
Segmental Identity

Homeotic genes determine the identities of metameres in Drosophila. We have examined functional aspects of the homeotic gene teashirt by ectopically expressing its product under the control of a heat-shock promoter during embryogenesis. Our results confirm that the gene is critical for segmental identity of the larva. Under mild heat-shock conditions, the Teashirt protein induces an almost complete transformation of the labial to prothoracic segmental identity, when expressed before 8 hours of development. Positive autoregulation of the endogenous teashirt gene and the presence of Sex combs reduced protein in the labium explain this homeosis. Patterns in the maxillary and a more anterior head segment are partly replaced with trunk ones. Additional Teashirt protein has no effect on the identity of the trunk segments where the gene is normally expressed; teashirt function is overridden by some homeotic complex acting in the posterior trunk. Strong heat-shock regimes provoke novel defects: ectopic sense organs differentiate in posterior abdominal segments and trunk pattern elements differentiate in the ninth abdominal segment. Teashirt acts in a partially redundant way with certain homeotic complex proteins but co-operates with them for the establishment of specific segment types. We suggest that Teashirt and HOM-C proteins regulate common sets of downstream target genes.

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