Molecular genetic analysis of the Drosophila melanogaster gene absent, small or homeotic discs1 (ash1).

Genetics ◽  
1994 ◽  
Vol 137 (4) ◽  
pp. 1027-1038 ◽  
Author(s):  
N A Tripoulas ◽  
E Hersperger ◽  
D La Jeunesse ◽  
A Shearn

Abstract The absent, small or homeotic discs1 gene (ash1) is one of the trithorax set of genes. Recessive loss of function mutations in ash1 cause homeotic transformations of imaginal disc derived tissue which resemble phenotypes caused by partial loss or gain of function mutations in genes of the Antennapedia Complex and bithorax Complex. F2 screens were used to isolate P element insertion alleles and EMS-induced alleles of ash1, including one temperature-sensitive allele, and an F1 screen was used to isolate gamma-ray-induced alleles. Analysis of ash1 mutant flies that survive until the adult stage indicates that not only imaginal disc- and histoblast-derived tissues are affected but also that oogenesis requires ash1 function. Mutations in the gene brahma (brm) which also is one of the trithorax set of genes interact with mutations in ash1 such that non-lethal ash1 +/+ brm double heterozygotes have a high penetrance of homeotic transformations in specific imaginal disc- and histoblast-derived tissues. The cytogenetic location of ash1 was determined to be 76B6-11 by the breakpoint of a translocation recovered in the F1 screen. The gene Shal, which is located cytogenetically nearby ash1, was used to initiate an 84-kb genomic walk within which the ash1 gene was identified. The ash1 gene encodes a 7.5-kb transcript that is expressed throughout development but is present at higher levels during the embryonic and pupal stages than during the larval stages. During the larval stages the transcript accumulates primarily in imaginal discs. During oogenesis the transcript accumulates in the nurse cells of developing egg chambers.

Medicina ◽  
2021 ◽  
Vol 57 (2) ◽  
pp. 123
Author(s):  
Cigdem Yuce Kahraman ◽  
Ali Islek ◽  
Abdulgani Tatar ◽  
Özlem Özdemir ◽  
Adil Mardinglu ◽  
...  

Wilson disease (WD) (OMIM# 277900) is an autosomal recessive inherited disorder characterized by excess copper (Cu) storage in different human tissues, such as the brain, liver, and the corneas of the eyes. It is a rare disorder that occurs in approximately 1 in 30,000 individuals. The clinical presentations of WD are highly varied, primarily consisting of hepatic and neurological conditions. WD is caused by homozygous or compound heterozygous mutations in the ATP7B gene. The diagnosis of the disease is complicated because of its heterogeneous phenotypes. The molecular genetic analysis encourages early diagnosis, treatment, and the opportunity to screen individuals at risk in the family. In this paper, we reported a case with a novel, hotspot-located mutation in WD. We have suggested that this mutation in the ATP7B gene might contribute to liver findings, progressing to liver failure with a loss of function effect. Besides this, if patients have liver symptoms in childhood and/or are children of consanguineous parents, WD should be considered during the evaluation of the patients.


Development ◽  
1996 ◽  
Vol 122 (7) ◽  
pp. 2283-2294 ◽  
Author(s):  
P. Manfruelli ◽  
N. Arquier ◽  
W.P. Hanratty ◽  
M. Semeriva

Inactivation of the lethal(2)giant larvae (l(2)gl) gene results in malignant transformation of imaginal disc cells and neuroblasts of the larval brain in Drosophila. Subcellular localization of the l(2)gl gene product, P127, and its biochemical characterization have indicated that it participates in the formation of the cytoskeletal network. In this paper, genetic and phenotypic analyses of a temperature-sensitive mutation (l(2)glts3) that behaves as a hypomorphic allele at restrictive temperature are presented. In experimentally overaged larvae obtained by using mutants in the production of ecdysone, the l(2)glts3 mutation displays a tumorous potential. This temperature-sensitive allele of the l(2)gl gene has been used to describe the primary function of the gene before tumor progression. A reduced contribution of both maternal and zygotic activities in l(2)glts3 homozygous mutant embryos blocks embryogenesis at the end of germ-band retraction. The mutant embryos are consequently affected in dorsal closure and head involution and show a hypertrophy of the midgut. These phenotypes are accompanied by an arrest of the cell shape changes normally occurring in lateral epidermis and in epithelial midgut cells. l(2)gl activity is also necessary for larval fife and the critical period falls within the third instar larval stage. Finally, l(2)gl activity is required during oogenesis and mutations in the gene disorganize egg chambers and cause abnormalities in the shape of follicle cells, which are eventually internalized within the egg chamber. These results together with the tumoral phenotype of epithelial imaginal disc cells strongly suggest that the l(2)gl product is required in vivo in different types of epithelial cells to control their shape during development.


2017 ◽  
Vol 98 (6) ◽  
pp. 1435-1453 ◽  
Author(s):  
Elena S. Kornienko ◽  
Darya D. Golubinskaya ◽  
Olga M. Korn ◽  
Svetlana N. Sharina

The complete larval development of the lobster shrimpLeonardsaxius amurensis(Kobjakova, 1937) (Decapoda: Axiidea: Axiidae) is described and illustrated for the first time. The first zoeae of this species were collected from the plankton samples and reared in the laboratory before moulting to the megalopa. A molecular genetic analysis based on comparison of partial mitochondrial COI, 12S rDNA and 16S rDNA sequence data confirmed the identity of axiid larvae found in the plankton andL. amurensisadults collected in the same area. The larval development ofL. amurensisincludes five zoeal stages and a single megalopa. Zoeae I ofL. amurensisare characterized by the presence of one short posterodorsal spine on the fifth pleonite in contrast to the larvae of related sympatric speciesBoasaxius princepshaving four posterodorsal spines on the pleonites 2–5.Leonardsaxius amurensisoccupies an intermediate position between lobster shrimps with abbreviated pelagic development (2–3 zoeal stages) and species with long development (up to eight zoeal stages). Thus, the number of zoeal stages in the family Axiidae varies widely, similarly to that in the families Callianassidae and Upogebiidae.


1999 ◽  
Vol 19 (3) ◽  
pp. 2389-2399 ◽  
Author(s):  
Jennifer Hei-Ngam Ho ◽  
Arlen W. Johnson

ABSTRACT A mutation in NMD3 was found to be lethal in the absence of XRN1, which encodes the major cytoplasmic exoribonuclease responsible for mRNA turnover. Molecular genetic analysis of NMD3 revealed that it is an essential gene required for stable 60S ribosomal subunits. Cells bearing a temperature-sensitive allele of NMD3 had decreased levels of 60S subunits at the nonpermissive temperature which resulted in the formation of half-mer polysomes. Pulse-chase analysis of rRNA biogenesis indicated that 25S rRNA was made and processed with kinetics similar to wild-type kinetics. However, the mature RNA was rapidly degraded, with a half-life of 4 min. Nmd3p fractionated as a cytoplasmic protein and sedimented in the position of free 60S subunits in sucrose gradients. These results suggest that Nmd3p is a cytoplasmic factor required for a late cytoplasmic assembly step of the 60S subunit but is not a ribosomal protein. Putative orthologs of Nmd3p exist inDrosophila, in nematodes, and in archaebacteria but not in eubacteria. The Nmd3 protein sequence does not contain readily recognizable motifs of known function. However, these proteins all have an amino-terminal domain containing four repeats of Cx2C, reminiscent of zinc-binding proteins, implicated in nucleic acid binding or protein oligomerization.


2018 ◽  
Vol 14 (2) ◽  
pp. 64-71
Author(s):  
Nina A. Makretskaya ◽  
Olga B. Bezlepkina ◽  
Anna A. Kolodkina ◽  
Alexey V. Kiyaev ◽  
Evgeny V. Vasilyev ◽  
...  

Congenital hypothyroidism is a heterogeneous group of diseases, which is manifested by loss of function of the thyroid gland that affects infants from birth. 80–85% of cases are due to different types of thyroid dysgenesis. 5 genes have been described that are involved in the pathogenesis of thyroid dysgenesis: TSHR, PAX8, FOXE1, NKX2-1, NKX2-5. Aims. To evaluate the prevalence of mutations in the genes TSHR, PAX8, FOXE1, NKX2-1, NKX2-5 among patients with severe congenital hypothyroidism. Materials and methods. 161 patients (64 boys, 97 girls) with congenital hypothyroidism (TSH levels at neonatal screening or retesting greater than 90 mU/l) were included in the study. 138 subjects had different variants of thyroid dysgenesis, and 23 patients had normal volume of the gland. A next generation sequencing was used for molecular-genetic analysis. Sequencing was performed using PGM semiconductor sequencer (Ion Torrent, Life Technologies, USA) and a panel “Hypothyroidism” (Custom DNA Panel). Assessment of the pathogenicity of sequence variants were carried out according to the latest international guidelines (ACMG, 2015). Results. 13 patients had variants in thyroid dysgenesis genes (8,1%, 13/161): TSHR, n = 6; NKX2-1, n = 3; NKX2-5, n = 1; PAX8, n = 3; FOXE1, n = 0. Conclusions. Mutations in thyroid dysgenesis genes are a rare pathology. The majority of variants among our patients were identified in TSHR.


Development ◽  
1993 ◽  
Vol 117 (4) ◽  
pp. 1287-1297 ◽  
Author(s):  
W.J. Brook ◽  
L.M. Ostafichuk ◽  
J. Piorecky ◽  
M.D. Wilkinson ◽  
D.J. Hodgetts ◽  
...  

When imaginal disc fragments from Drosophila are cultured in adult female hosts, they either duplicate the part of the pattern specified by the fate map, or regenerate to replace the missing part. The new tissue is added by proliferation of a small number of cells from the cut edge, brought together when the wound heals to form a regeneration blastema. Specification of the new pattern has been explained by assuming interactions among cells of different positional value in the regeneration blastema. In order to identify genes which might mediate these events, we screened over eight hundred independently isolated autosomal insertions of an enhancer-sensitive P-element, for altered lac-z expression in regenerating discs following cell death induced by a temperature-sensitive cell-lethal mutation. Two further screens divided the positive lines into four groups based on appropriate timing of the lac-z response in the cell-lethal mutant background and the expected response to an alternate source of cell death. Expression in wing disc fragments cultured in vivo was most frequent in the target class defined by the screens. In this direct test, lac-z expression was found in 23 lines and in most cases was spatially and temporally correlated with the formation of the regeneration blastema. Our results suggest a very substantial transcriptional response during the early stages of imaginal disc regeneration. lac-z expression in control imaginal discs, embryos and adult ovaries of the positive lines was also assayed. The selected insertions included: a small class expressed only in discs undergoing regeneration and apparently not at any other stage, possibly representing genes active exclusively in regeneration; a larger class expressed in the embryo or during oogenesis, but not normally in imaginal discs, as expected for functions recruited from earlier stages of the developmental program; and finally a class with spatially patterned expression in normal discs. This class included several insertions with expression associated with compartment boundaries, including one at the decapentaplegic (dpp), and one at the crumbs (crb) locus, a growth factor homologue, and an EGF-repeat gene respectively. Some of the expression patterns observed in cultured disc fragments provide evidence for cell communication in the regeneration blastema.


Author(s):  
Asburce Olgac ◽  
Çiğdem Seher Kasapkara ◽  
Betül Derinkuyu ◽  
Deniz Yüksel ◽  
Semra Çetinkaya ◽  
...  

Abstract Objectives X-linked adrenoleukodystrophy (X-ALD), is a peroxisomal inborn error of metabolism caused due to the loss of function variants of ABCD1 gene that leads to accumulation of very long chain fatty acids (VLCFAs) in several tissues including the neurological system. Childhood cerebral X-ALD (CCALD) is the most common and severe form of X-ALD, if left untreated. Allogenic hematopoietic stem cell transplantation (HSCT) is the only available therapy that halts neurological deterioration in CCALD. We present 12 patients with several subtypes of X-ALD that were followed-up in a single center. Methods Data of 12 patients diagnosed with X-ALD were documented retrospectively. Demographics, age of onset, initial symptoms, endocrine and neurological findings, VLCFA levels, neuroimaging data, molecular genetic analysis of ABCD1 gene, and disease progress were documented. Results Mean age of initiation of symptoms was 7.9 years and mean age of diagnosis was 10.45 years. Eight patients had the CCALD subtype, while two had the cerebral form of AMN, one had the adult form of cerebral ALD, and one patient had the Addison only phenotype. The most common initial symptoms involved the neurological system. Loes scores varied between 0 and 12. Seven patients with CCALD underwent HSCT, among them three patients died. The overall mortality rate was 25%. Conclusions Patients with X-ALD should be carefully followed up for cerebral findings and progression, since there is no genotype–phenotype correlation, and the clinical course cannot be predicted by family history. HSCT is the only available treatment option for patients with neurological deterioration.


Genetics ◽  
1993 ◽  
Vol 135 (2) ◽  
pp. 489-505 ◽  
Author(s):  
D H Castrillon ◽  
P Gönczy ◽  
S Alexander ◽  
R Rawson ◽  
C G Eberhart ◽  
...  

Abstract We describe 83 recessive autosomal male-sterile mutations, generated by single P element mutagenesis in Drosophila melanogaster. Each mutation has been localized to a lettered subdivision of the polytene map. Reversion analyses, as well as complementation tests using available chromosomal deficiencies, indicate that the insertions are responsible for the mutant phenotypes. These mutations represent 63 complementation groups, 58 of which are required for spermatogenesis. Phenotypes of the spermatogenesis mutants were analyzed by light microscopy. Mutations in 12 loci affect germline proliferation, spermatocyte growth, or meiosis. Mutations in 46 other loci disrupt differentiation and maturation of spermatids into motile sperm. This collection of male-sterile mutants provides the basis for a molecular genetic analysis of spermatogenesis.


1997 ◽  
Vol 200 (2) ◽  
pp. 237-245 ◽  
Author(s):  
J A Dow ◽  
S A Davies ◽  
Y Guo ◽  
S Graham ◽  
M E Finbow ◽  
...  

V-ATPases are phylogenetically widespread, highly conserved, multisubunit proton pumps. Originally characterised in endomembranes, they have been found to energise transport across plasma membranes in a range of animal cells and particularly in certain epithelia. While yeast is the model of choice for the rapid generation and identification of V-ATPase mutants, it does not allow their analysis in a plasma membrane context. For such purposes, Drosophila melanogaster is a uniquely suitable model. Accordingly, we have cloned and characterised genes encoding several V-ATPase subunits in D. melanogaster and, using P-element technology, we have succeeded in generating multiple new alleles. Reporter gene constructs reveal ubiquitous expression, but at particularly high levels in those epithelial thought to be energised by V-ATPases, and several of the alleles have lethal recessive phenotypes characterised by epithelial dysfunction. These results, while providing the first gene knockouts of V-ATPases in animals, also illustrate the general utility of D. melanogaster as a model for the genetic analysis of ion transport and its control in epithelia.


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