scholarly journals There and Back Again: Hox Clusters Use Both DNA Strands

2021 ◽  
Vol 9 (3) ◽  
pp. 28
Author(s):  
Elena L. Novikova ◽  
Milana A. Kulakova

Bilaterian animals operate the clusters of Hox genes through a rich repertoire of diverse mechanisms. In this review, we will summarize and analyze the accumulated data concerning long non-coding RNAs (lncRNAs) that are transcribed from sense (coding) DNA strands of Hox clusters. It was shown that antisense regulatory RNAs control the work of Hox genes in cis and trans, participate in the establishment and maintenance of the epigenetic code of Hox loci, and can even serve as a source of regulatory peptides that switch cellular energetic metabolism. Moreover, these molecules can be considered as a force that consolidates the cluster into a single whole. We will discuss the examples of antisense transcription of Hox genes in well-studied systems (cell cultures, morphogenesis of vertebrates) and bear upon some interesting examples of antisense Hox RNAs in non-model Protostomia.

2021 ◽  
Author(s):  
Elena L. Novikova ◽  
Nadezhda I. Bakalenko ◽  
Milana A. Kulakova

AbstractTo date it is becoming more and more obvious that multiple non-coding RNAs, once considered to be transcriptional noise, play a huge role in gene regulation during animal ontogenesis. Hox genes are key regulators of embryonic development, growth and regeneration of all bilaterian animals. It was shown that mammalian Hox loci are transcribed in both directions and noncoding RNAs maintain and control the normal functioning of Hox clusters. We revealed antisense transcripts of most of Hox genes in two lophotrochozoans, errant annelids Alitta virens and Platynereis dumerilii. It is for the first time when non-coding RNAs associated with Hox genes are found in spiralian animals. All these asRNAs can be referred to as natural antisense transcripts (NATs). We analyzed the expression of all detected NATs using sense probes to their Hox mRNAs during larval and postlarval development and regeneration by whole mount in situ hybridization (WMISH). We managed to clone several asRNAs (Avi-antiHox4-1, Avi-antiHox4-2 and Avi-antiHox5) of these annelids and analyzed their expression patterns as well. Our data indicate variable and complicated interplay between sense and antisense Hox transcripts during development and growth of two annelids. The presence of Hox antisense transcription in the representatives of different bilaterian clades (mammals, myriapods and annelids) and similar expression relationships in sense-antisense pairs suggest that this can be the ancestral feature of Hox cluster regulation.


1973 ◽  
Vol 51 (24) ◽  
pp. 4152-4158 ◽  
Author(s):  
Albert Richard Norris ◽  
James William Lennox Wilson

The hydrogen peroxide oxidation of thiocyanate ion in cis- and trans-[Coen2NH3NCS]2+ leads to the formation of the corresponding cis- and trans-cyanoammine- and diamminebis(ethylenediamine)cobalt-(III) complexes. The spectral properties of the previously unreported trans-[Coe2NH3CN]2+ are reported and compared to the spectral properties of the cis-isomer.Observations are made concerning the reaction conditions which favor a high percent conversion of trans-[Coen2NH3NCS]2+ to trans-[Coen2NH3CN]2+.


Polyhedron ◽  
2000 ◽  
Vol 19 (26-27) ◽  
pp. 2565-2572 ◽  
Author(s):  
Ludmiła Szterenberg ◽  
Szczepan Roszak ◽  
Renata Matusiak ◽  
Antoni Keller

Development ◽  
1993 ◽  
Vol 117 (4) ◽  
pp. 1397-1407 ◽  
Author(s):  
H.G. Simon ◽  
C.J. Tabin

Adult urodele amphibians can regenerate their limbs and tail. Based on their roles in other developing systems, Hox genes are strong candidates for genes that play a role in regulating pattern formation during regeneration. There are four homologous clusters of Hox genes in vertebrate genomes. We isolated cDNA clones of two newt homeobox genes from homologous positions within two Hox clusters; Hox-4.5 and Hox-3.6. We used RNase protection on nonamputated (normal) and regenerating newt appendages and tissue to compare their transcriptional patterns. Both genes show increased expression upon amputation with similar kinetics. Hox-4.5 and Hox-3.6 transcription is limited to the mesenchymal cells in the regenerates and is not found in the epithelial tissue. In addition to regenerating appendages, both genes are transcriptionally active in adult kidney of the newt. Striking differences were found in the regulation of Hox-4.5 and Hox-3.6 when they were compared in unamputated limbs and in regenerating forelimbs versus regenerating hindlimbs. Hox-4.5 is expressed in the blastema of regenerating fore- and hindlimbs, but Hox-4.5 transcripts are not detectable in normal limbs. In contrast, Hox-3.6 transcripts are found exclusively in posterior appendages, but are present in normal as well as regenerating hindlimbs and tails. Hox-4.5 is also expressed at a higher level in proximal (mid-humerus) regenerates than in distal ones (mid-radius). When we proximalized the positional memory of a distal blastema with retinoic acid, we find that the early expression level of Hox-4.5 is also proximalized. When the expression of these genes is compared to the expression of two previously reported newt Hox genes, a consistent pattern emerges, which can be interpreted in terms of differential roles for the different Hox clusters in determining regenerative limb morphology.


1968 ◽  
Vol 46 (1) ◽  
pp. 21-24 ◽  
Author(s):  
W. W. Zajac Jr. ◽  
F. Sweet ◽  
R. K. Brown

Infrared spectra show both free and hydrogen bonded hydroxyl absorption in several trans-2-alkoxy-3-hydroxytetrahydrofurans. The extent of non-bonded hydroxyl is greater than that of bonded hydroxyl. Suggestions are made of possible conformations which might account for the infrared data.


1977 ◽  
Vol 50 (4) ◽  
pp. 704-713 ◽  
Author(s):  
M. A. Golub ◽  
M. L. Rosenberg ◽  
R. V. Gemmer

Abstract The microstructural changes which occur in cis- and trans-1,4-polyisoprenes and in squalene during photosensitized oxidation were investigated with the aid of infrared and proton and carbon-13 NMR spectroscopy. The singlet oxygenation of these isoprenic compounds resulted in allylic hydroperoxides with shifted double bonds, according to the expected “ene”-type process. In contrast to trans-1,4-polyisoprene and squalene, which displayed the three possible double bond shifts, cis-1,4-polyisoprene showed essentially two of the shifts (to di- and trisubstituted double bonds) and very little of the third (to exomethylene groups). A suitable measure of the extent of hydroperoxidation was afforded by the absorbance ratio, A3400/A1440≡A′. Similar correlations of A′ with oxygen uptake were obtained for the three isoprenic compounds, using chlorophyll or methylene blue as sensitizer. The use of rose bengal gave erratic results indicative of some autoxidation accompanying the hydroperoxide formation. The singlet oxygenation followed zero-order kinetics, the relative rates for cis- and trans-1,4-polyisoprenes being approximately 1.0:1.5.


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