scholarly journals Molecular Genetic Analysis of Drosophila ash2, a Member of the Trithorax Group Required for Imaginal Disc Pattern Formation

Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 621-633 ◽  
Author(s):  
Amy L Adamson ◽  
Allen Shearn

Abstract The ash2 gene is a member of the trithorax group of genes whose products function to maintain active transcription of homeotic selector genes. Mutations in ash2 cause the homeotic transformations expected for a gene in this group but, in addition, cause a variety of pattern formation defects that are not necessarily expected. The ash2 gene is located in cytogenetic region 96A17–19 flanked by slowpoke and tolloid and is included in a cosmid that contains part of slowpoke. The ash2 transcript is 2.0 kb and is present throughout development. The ASH2 protein predicted from the nucleotide sequence of the open reading frame has a putative double zinc-finger domain, called a PHD finger, that is present not only in the products of other trithorax group genes such as TRX and MH1, but also in the product of a Polycomb group gene, PCL. Polyclonal antibodies directed against ASH2 detect the protein in imaginal discs and in the nuclei of salivary gland and fat body cells. On immunoblots these affinity-purified antibodies detect a 70-kDa protein in larvae and a 53-kDa protein in pupae.

2021 ◽  
pp. jmedgenet-2021-108147
Author(s):  
Florentine Scharf ◽  
Rafaela Magalhaes Leal Silva ◽  
Monika Morak ◽  
Alex Hastie ◽  
Julia M A Pickl ◽  
...  

PurposeApproximately 20% of patients with clinical familial adenomatous polyposis (FAP) remain unsolved after molecular genetic analysis of the APC and other polyposis genes, suggesting additional pathomechanisms.MethodsWe applied multidimensional genomic analysis employing chromosomal microarray profiling, optical mapping, long-read genome and RNA sequencing combined with FISH and standard PCR of genomic and complementary DNA to decode a patient with an attenuated FAP that had remained unsolved by Sanger sequencing and multigene panel next-generation sequencing for years.ResultsWe identified a complex 3.9 Mb rearrangement involving 14 fragments from chromosome 5q22.1q22.3 of which three were lost, 1 reinserted into chromosome 5 and 10 inserted into chromosome 10q21.3 in a seemingly random order and orientation thus fulfilling the major criteria of chromothripsis. The rearrangement separates APC promoter 1B from the coding ORF (open reading frame) thus leading to allele-specific downregulation of APC mRNA. The rearrangement also involves three additional genes implicated in the APC–Axin–GSK3B–β-catenin signalling pathway.ConclusionsBased on comprehensive genomic analysis, we propose that constitutional chromothripsis dampening APC expression, possibly modified by additional APC–Axin–GSK3B–β-catenin pathway disruptions, underlies the patient’s clinical phenotype. The combinatorial approach we deployed provides a powerful tool set for deciphering unsolved familial polyposis and potentially other tumour syndromes and monogenic diseases.


Genetics ◽  
1996 ◽  
Vol 143 (2) ◽  
pp. 913-928 ◽  
Author(s):  
Nicholas Tripoulas ◽  
Dennis LaJeunesse ◽  
John Gildea ◽  
Allen Shearn

Abstract The determined state of Drosophila imaginal discs depends on stable patterns of homeotic gene expression. The stability of these patterns requires the function of the ash1 gene, a member of the trithorax group. The primary translation product of the 7.5-kb ash1 transcript is predicted to be a basic protein of 2144 amino acids. The ASHl protein contains a SET domain and a PHD finger. Both of these motifs are found in the products of some trithorax group and Polycomb group genes. We have determined the nucleotide sequence alterations in 10 ash1 mutant alleles and have examined their mutant phenotype. The best candidate for a null allele is ashl  22. The truncated protein product of this mutant allele is predicted to contain only 47 amino acids. The ASHl protein is localized on polytene chromosomes of larval salivary glands at >100 sites. The chromosomal localization of ASHl implies that it functions at the transcriptional level to maintain the expression pattern of homeotic selector genes.


2005 ◽  
Vol 83 (3) ◽  
pp. 322-331 ◽  
Author(s):  
Filippo M Cernilogar ◽  
Valerio Orlando

Polycomb group (PcG) and Trithorax group (TrxG) proteins work, respectively, to maintain repressed or active transcription states of developmentally regulated genes through cell division. Data accumulated in the recent years have increased our understanding of the mechanisms by which PcG and TrxG proteins regulate gene expression. The discovery that histone methylation can serve as a specific mark for PcG and TrxG complexes has provided new insight into the mechanistic function of this cell-memory system.Key words: Polycomb, Trithorax, RNAi, cell memory, noncoding RNA, epigenome.


2008 ◽  
Vol 29 (6) ◽  
pp. 1401-1410 ◽  
Author(s):  
Nara Lee ◽  
Hediye Erdjument-Bromage ◽  
Paul Tempst ◽  
Richard S. Jones ◽  
Yi Zhang

ABSTRACT JmjC domain-containing proteins have been shown to possess histone demethylase activity. One of these proteins is the Drosophila histone H3 lysine 4 demethylase Little imaginal discs (Lid), which has been genetically classified as a Trithorax group protein. However, contrary to the supposed function of Lid in gene activation, the biochemical activity of this protein entails the removal of a histone mark that is correlated with active transcription. To understand the molecular mechanism behind the function of Lid, we have purified a Lid-containing protein complex from Drosophila embryo nuclear extracts. In addition to Lid, the complex contains Rpd3, CG3815/Drosophila Pf1, CG13367, and Mrg15. Rpd3 is a histone deacetylase, and along with Polycomb group proteins, which antagonize the function of Trithorax group proteins, it negatively regulates transcription. By reconstituting the Lid complex, we demonstrated that the demethylase activity of Lid is not affected by its association with other proteins. However, the deacetylase activity of Rpd3 is greatly diminished upon incorporation into the Lid complex. Thus, our finding that Lid antagonizes Rpd3 function provides an explanation for the genetic classification of Lid as a positive transcription regulator.


2013 ◽  
Vol 20 (1-2) ◽  
pp. 1-8
Author(s):  
MM Rahman ◽  
L Rahman ◽  
SN Begum ◽  
F Nur

Random Amplified Polymorphic DNA (RAPD) assay was initiated for molecular genetic analysis among 13 F3 rice lines and their parents. Four out of 15 decamer random primers were used to amplify genomic DNA and the primers yielded a total of 41 RAPD markers of which 37 were considered as polymorphic with a mean of 9.25 bands per primer. The percentage of polymorphic loci was 90.24. The highest percentage of polymorphic loci (14.63) and gene diversity (0.0714) was observed in 05-6 F3 line and the lowest polymorphic loci (0.00) and gene diversity (0.00) was found in 05-12 and 05-15 F3 lines. So, relatively high level of genetic variation was found in 05-6 F3 line and it was genetically more diverse compared to others. The average co-efficient of gene differentiation (GST) and gene flow (Nm) values across all the loci were 0.8689 and 0.0755, respectively. The UPGMA dendrogram based on the Nei’s genetic distance differentiated the rice genotypes into two main clusters: PNR-519, 05-19, 05-14, 05-12 and 05-17 grouped in cluster 1. On the other hand, Baradhan, 05-9, 05-13, 05-11, 05-5, 05-6, 05-1, 05-4, 05-15 and 05-25 were grouped in cluster 2. The highest genetic distance (0.586) was found between 05-4 and 05-17 F3 lines and they remain in different cluster.DOI: http://dx.doi.org/10.3329/pa.v20i1-2.16839 Progress. Agric. 20(1 & 2): 1 – 8, 2009


2011 ◽  
Vol 7 (3) ◽  
pp. 225
Author(s):  
Gianfranco Sinagra ◽  
Michele Moretti ◽  
Giancarlo Vitrella ◽  
Marco Merlo ◽  
Rossana Bussani ◽  
...  

In recent years, outstanding progress has been made in the diagnosis and treatment of cardiomyopathies. Genetics is emerging as a primary point in the diagnosis and management of these diseases. However, molecular genetic analyses are not yet included in routine clinical practice, mainly because of their elevated costs and execution time. A patient-based and patient-oriented clinical approach, coupled with new imaging techniques such as cardiac magnetic resonance, can be of great help in selecting patients for molecular genetic analysis and is crucial for a better characterisation of these diseases. This article will specifically address clinical, magnetic resonance and genetic aspects of the diagnosis and management of cardiomyopathies.


Genetics ◽  
1986 ◽  
Vol 112 (2) ◽  
pp. 321-342
Author(s):  
Eugene M Rinchik ◽  
Liane B Russell ◽  
Neal G Copeland ◽  
Nancy A Jenkins

ABSTRACT Genes of the dilute-short ear (d-se) region of mouse chromosome 9 comprise an array of loci important to the normal development of the animal. Over 200 spontaneous, chemically induced and radiation-induced mutations at these loci have been identified, making it one of the most genetically well-characterized regions of the mouse. Molecular analysis of this region has recently become feasible by the identification of a dilute mutation that was induced by integration of an ecotropic murine leukemia virus genome. Several unique sequence cellular DNA probes flanking this provirus have now been identified and used to investigate the organization of wild-type chromosomes and chromosomes with radiation-induced d-se region mutations. As expected, several of these mutations are associated with deletions, and, in general, the molecular and genetic complementation maps of these mutants are concordant. Furthermore, a deletion break-point fusion fragment has been identified and has been used to orient the physical map of the d-se region with respect to the genetic complementation map. These experiments provide important initial steps for analyzing this developmentally important region at the molecular level, as well as for studying in detail how a diverse group of mutagens acts on the mammalian germline.


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