scholarly journals The transformer-2 and fruitless characterisation with developmental expression profiles of sex-determining genes in Bactrocera dorsalis and B. correcta

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kamoltip Laohakieat ◽  
Siriwan Isasawin ◽  
Sujinda Thanaphum
Keyword(s):  
Splice Variants ◽  
Expression Profiles ◽  
Bactrocera Dorsalis ◽  
Developmental Expression ◽  
Alternative Promoters ◽  
Downstream Effector ◽  
Effector Genes ◽  
Early Embryos ◽  
Alternatively Spliced ◽  
Tephritid Fruit Flies

Abstract Sex determination in tephritid fruit flies involves a signaling cascade of alternatively spliced genes. The Transformer (TRA) and Transformer-2 (TRA-2) complex establishes an autoregulatory loop switching sex-specific splicing of tra pre-mRNA in females. The TRA/TRA-2 complex also regulates the sex-specific splicing of downstream effector genes, doublesex (dsx) and fruitless (fru). In Ceratitis capitata, a Maleness-on the-Y (MoY) gene modulates sex-specifically spliced Cctra pre-mRNA and results in the breakdown of the Cctra autoregulatory loop in males. In this study, the tra-2 and fru genes were characterised in two key pests, Bactrocera dorsalis and B. correcta. The tra-2 genes showed high degrees of conservation among tephritids. The complex gene organisation for each of Bdfru and Bcfru were identified. There are sex-specific and non sex-specific transcripts generated by alternative promoters as found in Drosophila melanogaster and other insects. RNAi knockdown of Bdtra transcripts showed that BdTRA controls the sex-specific splicing of Bddsx and Bdfru pre-mRNAs. Developmental expression analysis shows that multiple splice variants of Bdtra and Bctra RNAs are present before and during cellular blastoderm formation and that the mature sex-specific variants become fixed later in embryogenesis. Furthermore, the BddsxM splice variants are found in early embryos at the beginning of gastulation, but BdfruM does not appear until the larval stage. We proposed that the zygotic tra loop is initiated in both female and male embryos before becoming automatised or abolished by MoY, respectively.

Isolation and developmental expression of the amphioxus Pax-6 gene (AmphiPax-6): insights into eye and photoreceptor evolution

Development ◽  
1998 ◽  
Vol 125 (14) ◽  
pp. 2701-2710 ◽  
Author(s):  
S. Glardon ◽  
L.Z. Holland ◽  
W.J. Gehring ◽  
N.D. Holland
Keyword(s):  
Lamellar Body ◽  
General Rule ◽  
Developmental Expression ◽  
Paired Domain ◽  
Early Embryos ◽  
Alternatively Spliced ◽  
Cerebral Vesicle ◽  
Anterior Neural Plate ◽  
Dependent Mechanism

Pax-6 genes have been identified from a broad range of invertebrate and vertebrate animals and shown to be always involved in early eye development. Therefore, it has been proposed that the various types of eyes evolved from a single eye prototype, by a Pax-6-dependent mechanism. Here we describe the characterization of a cephalochordate Pax-6 gene. The single amphioxus Pax-6 gene (AmphiPax-6) can produce several alternatively spliced transcripts, resulting in proteins with markedly different amino and carboxy termini. The amphioxus Pax-6 proteins are 92% identical to mammalian Pax-6 proteins in the paired domain and 100% identical in the homeodomain. Expression of AmphiPax-6 in the anterior epidermis of embryos may be related to development of an olfactory epithelium. Expression is also detectable in Hatschek's left diverticulum as it forms the preoral ciliated pit, part of which gives rise to the homolog of the vertebrate anterior pituitary. A zone of expression in the anterior neural plate of early embryos is carried into the cerebral vesicle (a probable diencephalic homolog) during neurulation. This zone includes cells that will differentiate into the lamellar body, a presumed homolog of the vertebrate pineal eye. In neurulae, AmphiPax-6 is also expressed in ventral cells at the anterior tip of the nerve cord; these cells are precursors of the photoreceptive neurons of the frontal eye, the presumed homolog of the vertebrate paired eyes. However, AmphiPax-6 expression was not detected in two additional types of photoreceptors, the Joseph cells or the organs of Hesse, which are evidently relatively recent adaptations (ganglionic photoreceptors) and appear to be rare exceptions to the general rule that animal photoreceptors develop from a genetic program triggered by Pax-6.

Expression of laminin and of a laminin-related antigen during early development of Drosophila melanogaster

Development ◽  
1989 ◽  
Vol 106 (1) ◽  
pp. 17-27
Author(s):  
V. Garzino ◽  
H. Berenger ◽  
J. Pradel
Keyword(s):  
Expression Profiles ◽  
Cell Sheet ◽  
Cell Formation ◽  
Basal Membrane ◽  
Developmental Expression ◽  
Paraffin Sections ◽  
Early Embryos ◽  
Related Proteins ◽  
Blastoderm Cell

This paper reports the characterization of two immunologically related proteins that may be involved in cell adhesion during Drosophila development. These proteins, laminin chain A and a 240K component, share the epitope recognized by monoclonal antibody RD3 (Mab RD3). The two antigens show different developmental expression profiles. Laminin is detected only from 6 to 8 h of development onwards; its concentration increases during embryogenesis to reach steady-state value in larvae, pupae and adult flies. By contrast, the 240K antigen, not found in oocytes, is present before blastoderm stages; its concentration increases during gastrulation, decreases at the end of organogenesis and the antigen is no longer detected in third instar larvae. Light and electron microscope immunolocalization in imaginal discs indicates that laminin is distributed apically in the lumen and basally in the basal membrane that surrounds the nonevaginated disc. During morphogenesis laminin is detected at the basal side of the evaginating part of the disc epithelium. Immunolocalization on paraffin sections of early embryos suggests that the 240K antigen is related to (1) cell formation and polarization in association with cytoskeleton components, (2) establishment of cell-extracellular substratum interactions during the blastoderm cell sheet organization and (3) basement membrane deposition during embryonic germ cell layer segregation. This 240K protein is poorly or not glycosylated, is resistant to chondroitinase ABC and collagenase and appears therefore as a new extracellular component that might be specifically involved in early processes of morphogenesis.

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 Identification of Autosomal Regions Involved in Drosophila Raf Function

Genetics ◽  
2000 ◽  
Vol 156 (2) ◽  
pp. 763-774 ◽  
Author(s):  
Willis Li ◽  
Elizabeth Noll ◽  
Norbert Perrimon
Keyword(s):  
Limb Development ◽  
Target Gene ◽  
Biological Function ◽  
Genetic Interaction ◽  
Ectopic Expression ◽  
Tor Signaling ◽  
Downstream Effector ◽  
Early Embryos ◽  
Genomic Regions

Abstract Raf is an essential downstream effector of activated p21Ras (Ras) in transducing proliferation or differentiation signals. Following binding to Ras, Raf is translocated to the plasma membrane, where it is activated by a yet unidentified “Raf activator.” In an attempt to identify the Raf activator or additional molecules involved in the Raf signaling pathway, we conducted a genetic screen to identify genomic regions that are required for the biological function of Drosophila Raf (Draf). We tested a collection of chromosomal deficiencies representing ∼70% of the autosomal euchromatic genomic regions for their abilities to enhance the lethality associated with a hypomorphic viable allele of Draf, DrafSu2. Of the 148 autosomal deficiencies tested, 23 behaved as dominant enhancers of Draf  Su2, causing lethality in Draf  Su2 hemizygous males. Four of these deficiencies identified genes known to be involved in the Drosophila Ras/Raf (Ras1/Draf) pathway: Ras1, rolled (rl, encoding a MAPK), 14-3-3ϵ, and bowel (bowl). Two additional deficiencies removed the Drosophila Tec and Src homologs, Tec29A and Src64B. We demonstrate that Src64B interacts genetically with Draf and that an activated form of Src64B, when overexpressed in early embryos, causes ectopic expression of the Torso (Tor) receptor tyrosine kinase-target gene tailless. In addition, we show that a mutation in Tec29A partially suppresses a gain-of-function mutation in tor. These results suggest that Tec29A and Src64B are involved in Tor signaling, raising the possibility that they function to activate Draf. Finally, we discovered a genetic interaction between Draf  Su2 and Df(3L)vin5 that revealed a novel role of Draf in limb development. We find that loss of Draf activity causes limb defects, including pattern duplications, consistent with a role for Draf in regulation of engrailed (en) expression in imaginal discs.

scholarly journals Comparison of gene expression in fresh and frozen–thawed human preimplantation embryos

Reproduction ◽  
2012 ◽  
Vol 144 (5) ◽  
pp. 569-582 ◽  
Author(s):  
Lisa Shaw ◽  
Sharon F Sneddon ◽  
Daniel R Brison ◽  
Susan J Kimber
Keyword(s):  
Gene Expression ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Developmental Expression ◽  
Preimplantation Embryos ◽  
Human Embryos ◽  
Molecular Events ◽  
Reliable Source ◽  
Human Preimplantation Embryos ◽  
Early Human

Identification and characterisation of differentially regulated genes in preimplantation human embryonic development are required to improve embryo quality and pregnancy rates in IVF. In this study, we examined expression of a number of genes known to be critical for early development and compared expression profiles in individual preimplantation human embryos to establish any differences in gene expression in fresh compared to frozen–thawed embryos used routinely in IVF. We analysed expression of 19 genes by cDNA amplification followed by quantitative real-time PCR in a panel of 44 fresh and frozen–thawed human preimplantation embryos. Fresh embryos were obtained from surplus early cleavage stage embryos and frozen–thawed embryos from cryopreserved 2PN embryos. Our aim was to determine differences in gene expression between fresh and frozen–thawed human embryos, but we also identified differences in developmental expression patterns for particular genes. We show that overall gene expression among embryos of the same stage is highly variable and our results indicate that expression levels between groups did differ and differences in expression of individual genes was detected. Our results show that gene expression from frozen–thawed embryos is more consistent when compared with fresh, suggesting that cryopreserved embryos may represent a reliable source for studying the molecular events underpinning early human embryo development.

The Drosophila Hrb98DE locus encodes four protein isoforms homologous to the A1 protein of mammalian heterogeneous nuclear ribonucleoprotein complexes

1990 ◽  
Vol 10 (1) ◽  
pp. 316-323
Author(s):  
S R Haynes ◽  
G Raychaudhuri ◽  
A L Beyer
Keyword(s):  
Protein A ◽  
Protein Isoforms ◽  
Alternative Promoters ◽  
Splice Acceptor ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Rich Domain ◽  
Ribonucleoprotein Complexes ◽  
Early Embryos ◽  
Protein Components ◽  
Nuclear Ribonucleoprotein

The Drosophila Hrb98DE locus encodes proteins that are highly homologous to the mammalian A1 protein, a major component of heterogeneous nuclear ribonucleoprotein (RNP) particles. The Hrb98DE locus is transcribed throughout development, with the highest transcript levels found in ovaries, early embryos, and pupae. Eight different transcripts are produced by the use of combinations of alternative promoters, exons, and splice acceptor sites; the various species are not all equally abundant. The 3'-most exon is unusual in that it is completely noncoding. These transcripts can potentially generate four protein isoforms that differ in their N-terminal 16 to 21 amino acids but are identical in the remainder of the protein, including the RNP consensus motif domain and the glycine-rich domain characteristic of the mammalian A1 protein. We suggest that these sequence differences could affect the affinities of the proteins for RNA or other protein components of heterogeneous nuclear RNP complexes, leading to differences in function.

Field response of three Tephritid fruit flies to three food-based attractants and suppression of Bactrocera zonata (Saunders) using Mazoferm–Spinosad in guava ecosystem in Sudan

2021 ◽  
Author(s):  
Mohammed E. E. Mahmoud ◽  
Mohammed ◽  
Fathya M. Khamis and ◽  
Sunday Ekesi ◽  
Keyword(s):  
Fruits And Vegetables ◽  
Fruit Flies ◽  
Bactrocera Dorsalis ◽  
Economic Losses ◽  
Horticultural Crops ◽  
Torula Yeast ◽  
Bactrocera Zonata ◽  
Male Annihilation ◽  
Environmentally Friendly Approach ◽  
Tephritid Fruit Flies

Abstract Fruit flies of the genus Bactrocera are the most damaging pests of horticultural crops, leading to severe economic losses hindered exportation. Bactrocera dorsalis (Hendel) and Bactrocera zonata (Saunders) were reported in Sudan in 2005 and 2011 respectively affecting most of the fruits and vegetables in Sudan threatening income of poor farmers. Only Male Annihilation Technique (MAT) is applied in Sudan to manage the two Bactrocera species. A filed experiment was conducted to evaluate the response of B. dorsalis, B. zonata and Zeugodacus cucurbitae to three food-based attractants using McPhail traps in two sites in Gezira state, Sudan. Also, other trial was undertaken to determine the effect of spray of Mazoferm and Spinosad combination to control B. zonata. The results showed that food-based attractants lured both sexes of the above mentioned fruit flies and females represented (55-86%). At the first site, B. zonata responded in high numbers to Mazoferm followed by Torula yeast and GF-120 respectively while it responded equally to the Mazoferm and Torula yeast in the second site. B. dorsalis responded positively to Mazoferm followed by Torula yeast and GF-120 while Z. cucurbitae was attracted to Mazoferm, GF-120 and Torula for each attractant respectively. Spray of Mazoferm combined with Spinosad significantly reduced population of B. zonata (FTD) population and suppressed infestation level of guava fruits (fruit flies/Kg of fruits) when compared to unsprayed orchard. Bait Application Technique is an environmentally friendly approach that reduces infestation levels, lessen contamination and safeguard produce.

scholarly journals Promoter-mediated diversification of transcriptional bursting dynamics following gene duplication

2018 ◽  
Vol 115 (33) ◽  
pp. 8364-8369 ◽  
Author(s):  
Edward Tunnacliffe ◽  
Adam M. Corrigan ◽  
Jonathan R. Chubb
Keyword(s):  
Gene Duplication ◽  
Expression Profiles ◽  
Single Cells ◽  
Family Members ◽  
Gene Families ◽  
Developmental Expression ◽  
Upstream Sequence ◽  
Genomic Context ◽  
Entire Family ◽  
Transcriptional Bursting

During the evolution of gene families, functional diversification of proteins often follows gene duplication. However, many gene families expand while preserving protein sequence. Why do cells maintain multiple copies of the same gene? Here we have addressed this question for an actin family with 17 genes encoding an identical protein. The genes have divergent flanking regions and are scattered throughout the genome. Surprisingly, almost the entire family showed similar developmental expression profiles, with their expression also strongly coupled in single cells. Using live cell imaging, we show that differences in gene expression were apparent over shorter timescales, with family members displaying different transcriptional bursting dynamics. Strong “bursty” behaviors contrasted steady, more continuous activity, indicating different regulatory inputs to individual actin genes. To determine the sources of these different dynamic behaviors, we reciprocally exchanged the upstream regulatory regions of gene family members. This revealed that dynamic transcriptional behavior is directly instructed by upstream sequence, rather than features specific to genomic context. A residual minor contribution of genomic context modulates the gene OFF rate. Our data suggest promoter diversification following gene duplication could expand the range of stimuli that regulate the expression of essential genes. These observations contextualize the significance of transcriptional bursting.

259. Pluripotency genes in a marsupial, the tammar wallaby

2008 ◽  
Vol 20 (9) ◽  
pp. 59
Author(s):  
S. Frankenberg ◽  
A. J. Pask ◽  
M. B. Renfree
Keyword(s):  
Expression Profiles ◽  
Genomic Analysis ◽  
Tammar Wallaby ◽  
Early Embryo ◽  
Lineage Specification ◽  
Signalling Molecules ◽  
Early Embryos ◽  
Genes Encoding ◽  
Morphological Differences ◽  
Pluripotency Genes

Markers of pluripotency and early differentiation in the early embryo have been extensively characterised in eutherian species, most notably the mouse. By comparison, mechanisms controlling pluripotency and early lineage specification have received surprisingly little attention in marsupials, which represent the second major infraclass of mammals. Early marsupial embryogenesis exhibits overt morphological differences to that of eutherians, however the underlying developmental mechanisms may be conserved. In order to characterise early marsupial development at the molecular level, we have identified, cloned and analysed expression of orthologueues of several eutherian genes encoding transcription factors and signalling molecules involved in regulating pluripotency and early lineage specification. These genes include POU5F1 (OCT4), SOX2, NANOG, FGF4, FGFR2, CDX2, EOMES, TEAD4, GATA6 and KITL and are all expressed at early stages of development in the tammar. In addition, we have identified and cloned tammar POU2, which has orthologueues in non-mammalian vertebrates. POU2 is a paralogue of POU5F1 – a master regulator of pluripotency in eutherians. Genomic analysis indicates that POU5F1 arose via gene duplication of POU2 before the monotreme-therian divergence. Both genes have persisted in marsupials and monotremes, while POU2 was lost early during eutherian evolution. Similar expression profiles of tammar POU5F1 and POU2 in early embryos and gonadal tissues suggest possible overlapping roles in the maintenance of pluripotency.

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