Evolutionary changes in the notochord genetic toolkit: a comparative analysis of notochord genes in the ascidian Ciona and the larvacean Oikopleura

<p>Abstract</p> <p>Background</p> <p>The notochord is a defining feature of the chordate clade, and invertebrate chordates, such as tunicates, are uniquely suited for studies of this structure. Here we used a well-characterized set of 50 notochord genes known to be targets of the notochord-specific Brachyury transcription factor in one tunicate, <it>Ciona intestinalis </it>(Class Ascidiacea), to begin determining whether the same genetic toolkit is employed to build the notochord in another tunicate, <it>Oikopleura dioica </it>(Class Larvacea). We identified <it>Oikopleura </it>orthologs of the <it>Ciona </it>notochord genes, as well as lineage-specific duplicates for which we determined the phylogenetic relationships with related genes from other chordates, and we analyzed their expression patterns in <it>Oikopleura </it>embryos.</p> <p>Results</p> <p>Of the 50 <it>Ciona </it>notochord genes that were used as a reference, only 26 had clearly identifiable orthologs in <it>Oikopleura</it>. Two of these conserved genes appeared to have undergone <it>Oikopleura</it>- and/or tunicate-specific duplications, and one was present in three copies in <it>Oikopleura</it>, thus bringing the number of genes to test to 30. We were able to clone and test 28 of these genes. Thirteen of the 28 <it>Oikopleura </it>orthologs of <it>Ciona </it>notochord genes showed clear expression in all or in part of the <it>Oikopleura </it>notochord, seven were diffusely expressed throughout the tail, six were expressed in tissues other than the notochord, while two probes did not provide a detectable signal at any of the stages analyzed. One of the notochord genes identified, <it>Oikopleura netrin</it>, was found to be unevenly expressed in notochord cells, in a pattern reminiscent of that previously observed for one of the <it>Oikopleura </it><it>Hox </it>genes.</p> <p>Conclusions</p> <p>A surprisingly high number of <it>Ciona </it>notochord genes do not have apparent counterparts in <it>Oikopleura</it>, and only a fraction of the evolutionarily conserved genes show clear notochord expression. This suggests that <it>Ciona </it>and <it>Oikopleura</it>, despite the morphological similarities of their notochords, have developed rather divergent sets of notochord genes after their split from a common tunicate ancestor. This study demonstrates that comparisons between divergent tunicates can lead to insights into the basic complement of genes sufficient for notochord development, and elucidate the constraints that control its composition.</p

Spider surgical system versus multiport laparoscopic surgery. Performance comparison on a surgical simulator

BACKGROUND: The rising interest towards minimally invasive surgery has led to the introduction of laparo-endoscopic single site (LESS) surgery as the natural evolution of conventional multiport laparoscopy. However, this new surgical approach is hampered with peculiar technical difficulties. The SPIDER surgical system has been developed in the attempt to overcome some of these challenges. Our study aimed to compare standard laparoscopy and SPIDER technical performance on a surgical simulator, using standardized tasks from the Fundamentals of Laparoscopic Surgery (FLS). METHODS: Twenty participants were divided into two groups based on their surgical laparoscopic experience: 10 PGY1 residents were included in the inexperienced group and 10 laparoscopists in the experienced group. Participants performed the FLS pegboard transfers task and pattern cutting task on a laparoscopic box trainer. Objective task scores and subjective questionnaire rating scales were used to compare conventional laparoscopy and SPIDER surgical system. RESULTS: Both groups performed significantly better in the FLS scores on the standard laparoscopic simulator compared to the SPIDER. Inexperienced group: Task 1 scores (median 252.5 vs. 228.5; p = 0.007); Task 2 scores (median 270.5 vs. 219.0; p = 0.005). Experienced group: Task 1 scores (median 411.5 vs. 309.5; p = 0.005); Task 2 scores (median 418.0 vs. 331.5; p = 0.007). Same aspects were highlighted for the subjective evaluations, except for the inexperienced surgeons who found both devices equivalent in terms of ease of use only in the peg transfer task. CONCLUSIONS: Even though the SPIDER is an innovative and promising device, our study proved that it is more challenging than conventional laparoscopy in a population with different degrees of surgical experience. We presume that a possible way to overcome such challenges could be the development of tailored training programs through simulation methods. This may represent an effective way to deliver training, achieve mastery and skills and prepare surgeons for their future clinical experience

Temporal Regulation of the Muscle Gene Cascade by Macho1 and Tbx6 Transcription Factors in Ciona Intestinalis

For over a century, muscle formation in the ascidian embryo has been representative of \u27mosaic\u27 development. The molecular basis of muscle-fate predetermination has been partly elucidated with the discovery of Macho1, a maternal zinc-finger transcription factor necessary and sufficient for primary muscle development, and of its transcriptional intermediaries Tbx6b and Tbx6c. However, the molecular mechanisms by which the maternal information is decoded by cis-regulatory modules (CRMs) associated with muscle transcription factor and structural genes, and the ways by which a seamless transition from maternal to zygotic transcription is ensured, are still mostly unclear. By combining misexpression assays with CRM analyses, we have identified the mechanisms through which Ciona Macho1 (Ci-Macho1) initiates expression of Ci-Tbx6b and Ci-Tbx6c, and we have unveiled the cross-regulatory interactions between the latter transcription factors. Knowledge acquired from the analysis of the Ci-Tbx6b CRM facilitated both the identification of a related CRM in the Ci-Tbx6c locus and the characterization of two CRMs associated with the structural muscle gene fibrillar collagen 1 (CiFCol1). We use these representative examples to reconstruct how compact CRMs orchestrate the muscle developmental program from pre-localized ooplasmic determinants to differentiated larval muscle in ascidian embryos

A Plea for Surgery in Pancreatic Metastases from Renal Cell Carcinoma: Indications and Outcome from a Multicenter Surgical Experience

Pancreatic metastases from renal-cell carcinoma (RCC-PMs) are rare. Surgery may play a role in improving overall (OS) and disease-free survival (DFS)

Effect of the αs1-casein genotype and its interaction with diet degradability on milk production, milk quality, metabolic and endocrinal response of Girgentana goats

We studied interaction between diet degradability and genotype at CSN1S1 locus in lactating goats.•We evaluated productive, metabolic and hormonal response of goats at different αs1-casein genotype.•Little effect of diet degradability and interaction with genotype on production and quality.•Higher milk yield, casein percentage and lower urea in goats with strong alleles at CSN1S1 locus.•Higher tyroid hormones in goats with strong alleles

Comparison of the biological effects of gadodiamide (Omniscan) and gadoteridol ({ProHance}) by means of multi-organ and plasma metabolomics

Gadolinium-based contrast agents (GBCAs) are massively employed in radiology to increase the diagnostic power of MRI. However, investigations aiming at detecting possible metabolic perturbations or adverse health effects due to gadolinium deposition are still lacking. In this work, aqueous organs extract and plasma samples were analyzed by GC-MS and H-1-NMR, respectively, to investigate the effects of multiple administrations of one linear (Omniscan) and one macrocyclic (ProHance) GBCA, on the main metabolic pathways in healthy mice. Multivariate analysis revealed that plasma metabolome was not differently perturbed by the two GBCAs, while, the multiorgan analysis displayed a clear separation of the Omniscan-treated from the control and the ProHance-treated groups. Interestingly, the most affected organs were the brain, cerebellum and liver. Thus, this work paves the way to both the safest use of the commercially available GBCAs and the development of new GBCAs characterized by lower general toxicity

Dynapenia is highly prevalent in older patients with advanced idiopathic pulmonary fibrosis

Body composition and muscle strength are emerging aspects in idiopathic pulmonary fibrosis (IPF) clinical assessment. We aimed to study the relationships of handgrip strength (HGS) with anthropometric variables, body composition, and disease staging, and to evaluate the prevalence of dynapenia in 102 clinically stable IPF patients (70&nbsp;M; mean age: 69.4&nbsp;years). Fat-free mass (FFM), skeletal muscle (SM) were estimated with bioimpedance analysis. HGS was measured with a digital handle dynamometer for both dominant and non-dominant body sides. Dynapenia was identified according to six recognized criteria sets. Mean body mass index (BMI) was 28.2 ± 4.7&nbsp;kg/m2, with a prevalence of overweight (BMI &gt; 25 and &lt; 30&nbsp;kg/m2) and obesity (BMI ≥ 30&nbsp;kg/m2) of 35% and 37%, respectively. FFM and SM were greater in males, whereas percentage body fat was higher in women. HGS was higher and declined with age slightly more rapidly in men, showing a stronger correlation with FFM and SM. Dynapenia prevalence ranged from 20.6 to 56.9%, depending on the criteria used, and was more frequent in older patients and advanced disease. Dynapenia is highly prevalent in IPF. HGS is a promising proxy marker of muscle function to be used in clinical evaluation and follow-up programs