Analysis of Drosophila proboscipedia mutant alleles

Genome ◽  
2004 ◽  
Vol 47 (3) ◽  
pp. 600-609 ◽  
Author(s):  
I Tayyab ◽  
H M Hallahan ◽  
A Percival-Smith
Keyword(s):  
Dna Sequence ◽  
Hox Genes ◽  
Genetic Interaction ◽  
Direct Interaction ◽  
Protein Product ◽  
Maxillary Palp ◽  
Phenotypic Analysis ◽  
Sex Combs Reduced ◽  
Important Region ◽  
Sex Combs

Proboscipedia (PB) is a HOX protein required for adult maxillary palp and proboscis formation. To identify domains of PB important for function, 21 pb point mutant alleles were sequenced. Twelve pb alleles had DNA sequence changes that encode an altered PB protein product. The DNA sequence changes of these 12 alleles fell into 2 categories: missense alleles that effect the PB homeodomain (HD), and nonsense or frameshift alleles that result in C-terminal truncations of the PB protein. The phenotypic analysis of the pb homeobox missense alleles suggests that the PB HD is required for maxillary palp and proboscis development and pb – Sex combs reduced (Scr) genetic interaction. The phenotypic analysis of the pb nonsense or frameshift alleles suggests that the C-terminus is an important region required for maxillary palp and proboscis development and pb–Scr genetic interaction. PB and SCR do not interact directly with one another in a co-immunoprecipitation assay and in a yeast two-hybrid analysis, which suggests the pb–Scr genetic interaction is not mediated by a direct interaction between PB and SCR.Key words: proboscipedia, Sex combs reduced, Hox genes, mutant analysis, Drosophila body plan, appendage development.

Sequence of the Tribolium castaneum Homeotic Complex: The Region Corresponding to the Drosophila melanogaster Antennapedia Complex

Genetics ◽  
2002 ◽  
Vol 160 (3) ◽  
pp. 1067-1074
Author(s):  
Susan J Brown ◽  
John P Fellers ◽  
Teresa D Shippy ◽  
Elizabeth A Richardson ◽  
Mark Maxwell ◽  
...  
Keyword(s):  
Tribolium Castaneum ◽  
Hox Genes ◽  
Transcription Unit ◽  
Sex Combs Reduced ◽  
Sex Combs ◽  
Selector Genes ◽  
Homeotic Selector Genes ◽  
Encoding Genes ◽  
Single Cluster ◽  
Homeotic Selector

Abstract The homeotic selector genes of the red flour beetle, Tribolium castaneum, are located in a single cluster. We have sequenced the region containing the homeotic selector genes required for proper development of the head and anterior thorax, which is the counterpart of the ANTC in Drosophila. This 280-kb interval contains eight homeodomain-encoding genes, including single orthologs of the Drosophila genes labial, proboscipedia, Deformed, Sex combs reduced, fushi tarazu, and Antennapedia, as well as two orthologs of zerknüllt. These genes are all oriented in the same direction, as are the Hox genes of amphioxus, mice, and humans. Although each transcription unit is similar to its Drosophila counterpart in size, the Tribolium genes contain fewer introns (with the exception of the two zerknüllt genes), produce shorter mRNAs, and encode smaller proteins. Unlike the ANTC, this region of the Tribolium HOMC contains no additional genes.

scholarly journals Novel patterns of homeotic protein accumulation in the head of the Drosophila embryo

Development ◽  
1989 ◽  
Vol 105 (1) ◽  
pp. 167-174 ◽  
Author(s):  
J.W. Mahaffey ◽  
R.J. Diederich ◽  
T.C. Kaufman
Keyword(s):  
Nerve Cord ◽  
Protein Product ◽  
Drosophila Embryo ◽  
Protein Accumulation ◽  
Homeotic Genes ◽  
Gene Products ◽  
Ventral Region ◽  
Sex Combs Reduced ◽  
Sex Combs ◽  
Dorsal Epidermis

Antibodies that specifically recognize proteins encoded by the homeotic genes: Sex combs reduced, Deformed, labial and proboscipedia, were used to follow the distribution of these gene products during embryogenesis. The position of engrailed-expressing cells was used as a reference and staining conditions were established that could distinguish, among cells expressing engrailed, one of the homeotic proteins or both. Our observations demonstrate two important facts about establishing identity in the head segments. First, in contrast to the overlapping pattern of homeotic gene expression in the trunk segments, we observe a non-overlapping pattern in the head for those homeotic proteins required during embryogenesis. In contrast, the spatial accumulation of the protein product of the non-vital proboscipedia locus overlaps partially with the distribution of the Deformed and Sex combs reduced proteins in the maxillary and labial segments, respectively. Second, two of the proteins, Sex combs reduced and Deformed, have different dorsal and ventral patterns of accumulation. Dorsally, these proteins are expressed in segmental domains while, within the ventral region, a parasegmental register is observed. The boundary where this change in pattern occurs coincides with the junction between the ventral neurogenic region and the dorsal epidermis. After contraction of the germ band, when the nerve cord has completely separated from the epidermis, the parasegmental pattern is observed only within the ventral nerve cord while a segmental register is maintained throughout the epidermis.

scholarly journals The TARANI/ UBIQUITIN SPECIFIC PROTEASE 14 destabilizes the AUX/IAA transcriptional repressors and regulates auxin response in Arabidopsis thaliana

2019 ◽  
Author(s):  
Parinita Majumdar ◽  
Premananda Karidas ◽  
Imran Siddiqi ◽  
Utpal Nath
Keyword(s):  
Arabidopsis Thaliana ◽  
Genetic Interaction ◽  
Leaf Shape ◽  
Protein Product ◽  
Auxin Signaling ◽  
Auxin Response ◽  
Phenotypic Analysis ◽  
Molecular Control ◽  
Specific Protease ◽  
Turn Over

ABSTRACTAuxin response is regulated by a group of AUX/IAA transcriptional inhibitors that suppress auxin signaling in the absence of the hormone. While the degradation of these proteins upon auxin signaling has been well studied, the molecular control of their rapid turn-over is not clearly understood. Here, we report that the TARANI/ UBIQUITIN PROTEASE 14 protein in Arabidopsis thaliana (Arabidopsis) is required for AUX/IAA degradation. The tni mutation was originally identified in a forward genetic screen to isolate mutants with altered leaf shape. Detailed phenotypic analysis revealed that tni displays pleiotropic phenotypic alterations that resemble auxin-related defects. The activity of auxin responsive reporters DR5::GUS, DR5::nYFP and IAA2::GUS was reduced in tni organs, implying that TNI is required for normal auxin response. Genetic interaction studies suggested that TNI acts along with TIR1, ARF7, AUX1 and PIN1 – molecules involved in auxin signaling or transport. A map-based cloning approach combined with next-generation sequencing identified TNI as UBIQUITIN SPECIFIC PROTEASE14 which is involved in ubiquitin recycling. In tni, the mutant primary transcript is spliced inefficiently, which is predicted to produce an aberrant protein product in addition to the normal protein, where a polypeptide corresponding to the 3rd intron in inserted in-frame within the Zn-finger domain of UBP14. The tni plants accumulated poly-ubiquitin chains and excess poly-ubiquitinated proteins due to reduced TNI activity. Improper ubiquitin recycling affected the degradation of DII:VENUS, IAA18:GUS and HS::AXR3-NT:GUS, resulting in their stabilization in the tni mutant. Thus, our study identified a function for TNI/UBP14 in regulating auxin response through ubiquitin recycling.

scholarly journals Direct interaction between Teashirt and Sex combs reduced proteins, via Tsh's acidic domain, is essential for specifying the identity of the prothorax in Drosophila

2007 ◽  
Vol 307 (1) ◽  
pp. 142-151 ◽  
Author(s):  
Ouarda Taghli-Lamallem ◽  
Armel Gallet ◽  
Fréderic Leroy ◽  
Pascale Malapert ◽  
Christine Vola ◽  
...  
Keyword(s):  
Direct Interaction ◽  
Sex Combs Reduced ◽  
Acidic Domain ◽  
Sex Combs

scholarly journals Hox genes mediate the escalation of sexually antagonistic traits in water striders

2019 ◽  
Vol 15 (2) ◽  
pp. 20180720 ◽  
Author(s):  
Antonin Jean Johan Crumière ◽  
Abderrahman Khila
Keyword(s):  
Sexual Conflict ◽  
Hox Genes ◽  
Complete Loss ◽  
Water Strider ◽  
Fitness Costs ◽  
Sex Combs Reduced ◽  
Hox Gene ◽  
Water Striders ◽  
Sex Combs ◽  
Sex Comb

Sexual conflict occurs when traits favoured in one sex impose fitness costs on the other sex. In the case of sexual conflict over mating rate, the sexes often undergo antagonistic coevolution and escalation of traits that enhance females' resistance to superfluous mating and traits that increase males' persistence. How this escalation in sexually antagonistic traits is established during ontogeny remains unclear. In the water strider Rhagovelia antilleana, male persistence traits consist of sex combs on the forelegs and multiple rows of spines and a thick femur in the rear legs. Female resistance traits consist of a prominent spike-like projection of the pronotum. RNAi knockdown against the Hox gene Sex Combs Reduced resulted in the reduction in both the sex comb in males and the pronotum projection in females. RNAi against the Hox gene Ultrabithorax resulted in the complete loss or reduction of all persistence traits in male rear legs. These results demonstrate that Hox genes can be involved in intra- and inter-locus sexual conflict and mediate escalation of sexually antagonistic traits.

scholarly journals Hox genes limit germ cell formation in the short germ insect Gryllus bimaculatus

2018 ◽  
Author(s):  
Austen A. Barnett ◽  
Taro Nakamura ◽  
Cassandra G. Extavour
Keyword(s):  
Hox Genes ◽  
Primordial Germ Cells ◽  
Cell Formation ◽  
Gryllus Bimaculatus ◽  
Sex Combs Reduced ◽  
Body Regions ◽  
Sex Combs ◽  
Hemimetabolous Insect ◽  
Encoding Genes ◽  
Germ Cell Formation

AbstractHox genes are conserved transcription factor-encoding genes that specify the identity of body regions in bilaterally symmetrical animals. In the cricket Gryllus bimaculatus, a member of the hemimetabolous insect group Orthoptera, the induction of a subset of mesodermal cells to form the primordial germ cells (PGCs) is restricted to the second through the fourth abdominal segments (A2-A4). In numerous insect species, the Hox genes Sex-combs reduced (Scr), Antennapedia (Antp), Ultrabithorax (Ubx) and abdominal-A (abd-A) jointly regulate the identities of middle and posterior body segments, suggesting that these genes may restrict PGC formation to specific abdominal segments in G. bimaculatus. Here we show that all of these Hox genes, either individually or in segment-specific combinations, restrict PGC formation. Our data provides evidence for a segmental Hox code used to regulate the placement of PGC formation, reminiscent of the segmental Hox codes used in other arthropod groups to establish other aspects of segmental identity. These data also provide, to our knowledge, the first evidence for this ancient group of genes in determining PGC placement within the context of axial patterning in any animal studied thus far.

Genetic characterization of the role of the two HOX proteins, Proboscipedia and Sex Combs Reduced, in determination of adult antennal, tarsal, maxillary palp and proboscis identities in Drosophila melanogaster

Development ◽  
1997 ◽  
Vol 124 (24) ◽  
pp. 5049-5062 ◽  
Author(s):  
A. Percival-Smith ◽  
J. Weber ◽  
E. Gilfoyle ◽  
P. Wilson
Keyword(s):  
Ectopic Expression ◽  
Maxillary Palp ◽  
Dominant Negative ◽  
Head Region ◽  
Hox Proteins ◽  
Sex Combs Reduced ◽  
Sex Combs ◽  
Identity Expression

Both Proboscipedia (PB) and Sex Combs Reduced (SCR) activities are required for determination of proboscis identity. Here we show that simultaneous removal of PB and SCR activity results in a proboscis-to-antenna transformation. Dominant negative PB molecules inhibit the activity of SCR indicating that PB and SCR interact in a multimeric protein complex in determination of proboscis identity. These data suggest that the expression pattern of PB and SCR and the ability of PB and SCR to interact in a multimeric complex control the determination of four adult structures. The absence of PB and SCR expression leads to antennal identity; expression of only PB leads to maxillary palp identity; expression of only SCR leads to tarsus identity; and expression of both PB and SCR, which results in the formation of a PB-SCR-containing complex, leads to proboscis identity. However, the PB-SCR interaction is not detectable in vitro and is not detectable genetically in the head region during embryogenesis, indicating the PB-SCR interaction may be regulated and indirect. This regulation may also explain why ectopic expression of SCR(Q50K) and SCR do not result in the expected transformation of the maxillary palp to an antennae and proboscis, respectively. Previous analysis of the requirements of SCR activity for adult pattern formation has shown that ectopic expression of SCR results in an antenna-to-tarsus transformation, but removal of SCR activity in a clone of cells does not result in a tarsus-to-arista transformation. Here we show in five independent assays the reason for this apparent contradictory requirement of SCR activity in tarsus determination. SCR activity is required cell nonautonomously for tarsus determination. Specifically, we propose that SCR activity is required in the mesodermal adepithelial cells of all leg imaginal discs at late second/early third instar larval stage for the synthesis of a mesoderm-specific, tarsus-inducing, signaling factor, which after secretion from the adepithelial cells acts on the overlaying ectodermal cells determining tarsus identity. This study characterizes a combinatorial interaction between two HOX proteins; a mechanism that may have a major role in patterning the anterior-posterior axis of other animals.

TheDrosophilaproboscis is specified by two Hox genes,proboscipediaandSex combs reduced, via repression of leg and antennal appendage genes

Development ◽  
2001 ◽  
Vol 128 (14) ◽  
pp. 2803-2814 ◽  
Author(s):  
Arhat Abzhanov ◽  
Stacy Holtzman ◽  
Thomas C. Kaufman
Keyword(s):  
Limb Development ◽  
Hox Genes ◽  
Distinct Type ◽  
Wild Type ◽  
Fate Map ◽  
Genetic Studies ◽  
Unique Type ◽  
Sex Combs Reduced ◽  
Sex Combs ◽  
Labial Disc

The proboscis is one of the most highly modified appendages in Drosophila melanogaster. However, the phenotypes of proboscipedia (pb) mutants, which transform the proboscis into leg or antenna, indicate a basic homology among these limbs. Recent genetic studies have revealed a developmental system for patterning appendages and identified several genes required for limb development. Among these are: extradenticle (exd), homothorax (hth), dachshund (dac), Distal-less (Dll) and spalt (sal). These limb genes have not been well studied in wild-type mouthparts and their role if any in this appendage is not well understood. Here we demonstrate that the homeotic gene products Proboscipedia (Pb) and Sex combs reduced (Scr) regulate the limb genes in the labial disc to give rise to a unique type of appendage, the proboscis. Pb inhibits exd, dac and sal expression and downregulates Dll. This observation explains the ability of Pb to inhibit the effects of ectopically expressed trunk Hox genes in the proboscis, to suppress leg identity in the trunk and to transform antenna to maxillary palp. Scr suppresses sal expression and also downregulates Dll in the labial discs; discs mutant for both pb and Scr give rise to complete antennae, further demonstrating appendage homology. In the labial disc, Pb positively regulates transcription of Scr, whereas in the embryo, Scr positively regulates pb. Additionally, our results suggests a revised fate map of the labial disc. We conclude that the proboscis constitutes a genetically distinct type of appendage whose morphogenesis does not require several important components of leg and/or antennal patterning systems, but retains distal segmental homology with these appendages.

scholarly journals The genome of a daddy-long-legs (Opiliones) illuminates the evolution of arachnid appendages

2021 ◽  
Vol 288 (1956) ◽  
pp. 20211168
Author(s):  
Guilherme Gainett ◽  
Vanessa L. González ◽  
Jesús A. Ballesteros ◽  
Emily V. W. Setton ◽  
Caitlin M. Baker ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Hox Genes ◽  
Genome Duplication ◽  
Draft Genome ◽  
Growth Factor Receptor ◽  
Loss Of Function ◽  
Sex Combs Reduced ◽  
Sex Combs ◽  
Dynamic Genome ◽  
Epidermal Growth

Chelicerate arthropods exhibit dynamic genome evolution, with ancient whole-genome duplication (WGD) events affecting several orders. Yet, genomes remain unavailable for a number of poorly studied orders, such as Opiliones (daddy-long-legs), which has hindered comparative study. We assembled the first harvestman draft genome for the species Phalangium opilio , which bears elongate, prehensile appendages, made possible by numerous distal articles called tarsomeres. Here, we show that the genome of P. opilio exhibits a single Hox cluster and no evidence of WGD. To investigate the developmental genetic basis for the quintessential trait of this group—the elongate legs—we interrogated the function of the Hox genes Deformed ( Dfd ) and Sex combs reduced ( Scr ), and a homologue of Epidermal growth factor receptor ( Egfr ). Knockdown of Dfd incurred homeotic transformation of two pairs of legs into pedipalps, with dramatic shortening of leg segments in the longest leg pair, whereas homeosis in L3 is only achieved upon double Dfd + Scr knockdown. Knockdown of Egfr incurred shortened appendages and the loss of tarsomeres. The similarity of Egfr loss-of-function phenotypic spectra in insects and this arachnid suggest that repeated cooption of EGFR signalling underlies the independent gains of supernumerary tarsomeres across the arthropod tree of life.

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