Identification of LINE retrotransposons and long non-coding RNAs expressed in the octopus brain

Background

Transposable elements (TEs) widely contribute to the evolution of genomes allowing genomic innovations, generating germinal and somatic heterogeneity, and giving birth to long non-coding RNAs (lncRNAs). These features have been associated to the evolution, functioning, and complexity of the nervous system at such a level that somatic retrotransposition of long interspersed element (LINE) L1 has been proposed to be associated to human cognition. Among invertebrates, octopuses are fascinating animals whose nervous system reaches a high level of complexity achieving sophisticated cognitive abilities. The sequencing of the genome of the Octopus bimaculoides revealed a striking expansion of TEs which were proposed to have contributed to the evolution of its complex nervous system. We recently found a similar expansion also in the genome of Octopus vulgaris. However, a specific search for the existence and the transcription of full-length transpositionally competent TEs has not been performed in this genus.

Results

Here, we report the identification of LINE elements competent for retrotransposition in Octopus vulgaris and Octopus bimaculoides and show evidence suggesting that they might be transcribed and determine germline and somatic polymorphisms especially in the brain. Transcription and translation measured for one of these elements resulted in specific signals in neurons belonging to areas associated with behavioral plasticity. We also report the transcription of thousands of lncRNAs and the pervasive inclusion of TE fragments in the transcriptomes of both Octopus species, further testifying the crucial activity of TEs in the evolution of the octopus genomes.

Conclusions

The neural transcriptome of the octopus shows the transcription of thousands of putative lncRNAs and of a full-length LINE element belonging to the RTE class. We speculate that a convergent evolutionary process involving retrotransposons activity in the brain has been important for the evolution of sophisticated cognitive abilities in this genus.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-022-01303-5.

P368 PHYSICAL AND PSYCHOLOGICAL RECONDITIONING IN LONG COVID SYNDROME: RESULTS OF AN OUT–OF–HOSPITAL EXERCISED–BASED CARDIOVASCULAR REHABILITATION PROGRAM

Background

Long Covid Syndrome (LCS) is used to describe signs and symptoms that continue or develop after acute COVID–19 infection. Natural history and treatments of this syndrome are still poorly understood, even if evidence suggests the potential role of physical rehabilitation in improving symptoms in these subjects.

Aim

The aim of the present study was to evaluate safety, effectiveness and feasibility of a multidisciplinary, out–of–hospital, exercise–based cardiac rehabilitation (EBCR) program, of two months duration, in improving symptoms and physical and psychological parameters in patients with LCS Methods Thirty consecutive patients with LCS (18 males, mean age 58 years) underwent an accurate medical screening process including anthropometric and muscular strength evaluation, cardiopulmonary exercise test (CPET), quality of life (QoL) and psychological appraisal before and after an EBCR program.

Results

At baseline, all LCS patients were strongly symptomatic and showed severe impairments in physical performance, QoL and psychological parameters. No adverse effects and dropouts were observed during the exercise training sessions. After the EBCR program, COVID–19 residual symptoms significantly decreased and significant improvements in upper and lower limb muscular strength, CPET parameters, perceived physical and mental health, depression and anxiety were observed.

Conclusions

The present study confirms the severe physical and psychological impairment of patients with LCS and suggests that a multidisciplinary EBCR program could promote their physical and psychological recovery

Physical and psychological reconditioning in long covid syndrome patients: results of a structured physical exercise program

Funding Acknowledgements

Type of funding sources: None.

Background

Long Covid Syndrome (LCS) is used to describe signs and symptoms that continue or develop after acute COVID-19 infection. Natural history and treatments of this syndrome is still poorly understood. In literature there is currently a lack of data on the real effectiveness of a multidisciplinary rehabilitation program based on structured physical exercise (SPE) in these patients.

Purpose

To evaluate safety, effectiveness and feasibility of a structured individualized rehabilitation program in improving physical and psychological parameters in patients with LCS.

Methods

Twenty-eight patients with LCS (19 males, mean age 57 years) underwent an accurate medical screening process, body composition evaluation, cardiopulmonary exercise test (CPET), muscular strength assessment, quality of life (QoL), psychological assessment and counselling, before and after a 12-sessions SPE program.

Results

At baseline, all LCS patients showed severe impairments in physical performance, QoL and psychological parameters. No adverse effects and dropouts were observed during training session. After the rehabilitation program, significant improvement in CPET parameters, upper and lower limb muscular strength, perceived physical and mental health, body composition, depression and anxiety and Covid residual symptoms was observed.

Conclusions

The present study confirms severe impairment of patients with LCS and suggest that a multidisciplinary rehabilitation program based on SPE could promote their physical and psychological recovery.

Genus-level phylogeny of cephalopods using molecular markers: current status and problematic areas

Comprising more than 800 extant species, the class Cephalopoda (octopuses, squid, cuttlefish, and nautiluses) is a fascinating group of marine conchiferan mollusks. Recently, the first cephalopod genome (of Octopus bimaculoides) was published, providing a genomic framework, which will enable more detailed investigations of cephalopod characteristics, including developmental, morphological, and behavioural traits. Meanwhile, a robust phylogeny of the members of the subclass Coleoidea (octopuses, squid, cuttlefishes) is crucial for comparative and evolutionary studies aiming to investigate the group's traits and innovations, but such a phylogeny has proven very challenging to obtain. Here, we present the results of phylogenetic inference at the genus level using mitochondrial and nuclear marker sequences available from public databases. Topologies are presented which show support for (1) the monophyly of the two main superorders, Octobrachia and Decabrachia, and (2) some of the interrelationships at the family level. We have mapped morphological characters onto the tree and conducted molecular dating analyses, obtaining congruent results with previous estimates of divergence in major lineages. Our study also identifies unresolved phylogenetic relationships within the cephalopod phylogeny and insufficient taxonomic sampling among squids excluding the Loliginidae in the Decabrachia and within the Order Cirromorphida in the Octobrachia. Genomic and transcriptomic resources should enable resolution of these issues in the relatively near future. We provide our alignment as an open access resource, to allow other researchers to reconstruct phylogenetic trees upon this work in the future.

Rapid screening of glomerular slit diaphragm integrity in larval zebrafish

Gene array-type experiments have identified large numbers of genes thought to be important for the integrity of the glomerular slit diaphragm. Confirmation of individual proteins has been limited by the expenses and time involved in generating transgenic or knockout mice for each candidate. We present a functional screening assay based on the clearance of a 70-kDa fluorescent dextran in another vertebrate system that is rapid and low in cost. In the pronephric glomerulus of larval zebrafish, we have demonstrated quantifiable loss of slit diaphragm integrity in a zebrafish model of puromycin aminonucleoside (PA) toxicity. In addition, after knockdown of CD2-associated protein (CD2AP) and podocin, two well-characterized genetic contributors to podocyte differentiation in mammals, we observed glomerular loss of serum macromolecules similar to that seen in mammalian kidneys with inborn mutations in these genes. Increased filtration of 70-kDa FITC-labeled dextran correlates with effacement of podocyte foot processes in ultrastructural analysis. These findings document the value of the zebrafish model in genomics and pharmacological screening applications.