A thyroid hormone regulated asymmetric responsive centre is correlated with eye migration during flatfish metamorphosis

Flatfish metamorphosis is a unique post-embryonic developmental event in which thyroid hormones (THs) drive the development of symmetric pelagic larva into asymmetric benthic juveniles. One of the eyes migrates to join the other eye on the opposite side of the head. Developmental mechanisms at the basis of the acquisition of flatfish anatomical asymmetry remain an open question. Here we demonstrate that an TH responsive asymmetric centre, determined by deiodinase 2 expression, ventrally juxtaposed to the migrating eye in sole (Solea senegalensis) correlates with asymmetric cranial ossification that in turn drives eye migration. Besides skin pigmentation that is asymmetric between dorsal and ventral sides, only the most anterior head region delimited by the eyes becomes asymmetric whereas the remainder of the head and organs therein stay symmetric. Sub-ocular ossification is common to all flatfish analysed to date, so we propose that this newly discovered mechanism is universal and is associated with eye migration in all flatfish.Fundacao para a Ciencia e Tecnologia (FCT) [SFRH/BPD/66808/2009, IF/01274/2014]; FCT [SFRH/BPD/79105/2011, SFRH/BPD/89889/2012, PTDC/MAR/115005/2009, PEst-C/MAR/LA0015/2011, UID/Multi/04326/2013, Pest-OE/EQB/LA0023/2013, UID/BIM/04773/2013]; European Regional Development Fund through COMPETE; INIA; EU [RTA2013-00023-C02-01

Troponin T isoform expression is modulated during Atlantic Halibut metamorphosis

<p>Abstract</p> <p>Background</p> <p>Flatfish metamorphosis is a thyroid hormone (TH) driven process which leads to a dramatic change from a symmetrical larva to an asymmetrical juvenile. The effect of THs on muscle and in particular muscle sarcomer protein genes is largely unexplored in fish. The change in <it>Troponin T </it>(<it>TnT</it>), a pivotal protein in the assembly of skeletal muscles sarcomeres and a modulator of calcium driven muscle contraction, during flatfish metamophosis is studied.</p> <p>Results</p> <p>In the present study five cDNAs for halibut <it>TnT </it>genes were cloned; three were splice variants arising from a single <it>fast TnT </it>(<it>fTnT</it>) gene; a fourth encoded a novel teleost specific fTnT-like cDNA (<it>AfTnT</it>) expressed exclusively in slow muscle and the fifth encoded the teleost specific <it>sTnT2</it>. THs modified the expression of halibut <it>fTnT </it>isoforms which changed from predominantly basic to acidic isoforms during natural and T4 induced metamorphosis. In contrast, expression of red muscle specific genes, <it>AfTnT </it>and <it>sTnT2</it>, did not change during natural metamorphosis or after T4 treatment. Prior to and after metamorphosis no change in the dorso-ventral symmetry or temporal-spatial expression pattern of <it>TnT </it>genes and muscle fibre organization occurred in halibut musculature.</p> <p>Conclusion</p> <p>Muscle organisation in halibut remains symmetrical even after metamorphosis suggesting TH driven changes are associated with molecular adaptations. We hypothesize that species specific differences in <it>TnT </it>gene expression in teleosts underlies different larval muscle developmental programs which better adapts them to the specific ecological constraints.</p

Maternal thyroid hormones are essential for neural development in Zebrafish

Teleost eggs contain an abundant store of maternal thyroid hormones (THs), and early in zebrafish embryonic development, all the genes necessary for TH signaling are expressed. Nonetheless the function of THs in embryonic development remains elusive. To test the hypothesis that THs are fundamental for zebrafish embryonic development, an monocarboxilic transporter 8 (Mct8) knockdown strategy was deployed to prevent maternal TH uptake. Absence of maternal THs did not affect early specification of the neural epithelia but profoundly modified later dorsal specification of the brain and spinal cord as well as specific neuron differentiation. Maternal THs acted upstream of pax2a, pax7, and pax8 genes but downstream of shha and fgf8a signaling. The lack of inhibitory spinal cord interneurons and increased motoneurons in the mct8 morphants is consistent with their stiff axial body and impaired mobility. The mct8 mutations are associated with X-linked mental retardation in humans, and the cellular and molecular consequences of MCT8 knockdown during embryonic development in zebrafish provides new insight into the potential role of THs in this condition.Portuguese Science Foundation (FCT) [PTDC/MAR/115005/2009]; FCT [SFRH/BPD/66808/2009, SFRH/BPD/67008/2009, Pest-OE/EQB/LA0023/2013]info:eu-repo/semantics/publishedVersio

Thyroid hormone receptor expression during metamorphosis of Atlantic halibut (Hippoglossus hippoglossus)

Flatfish such as the Atlantic halibut (Hippoglossus hippoglossus) undergo a dramatic metamorphosis that transforms the pelagic, symmetric larva into a benthic, cranially asymmetric juvenile. In common with amphibian metamorphosis, flatfish metamorphosis is under endocrine control with thyroid hormones being particularly important. In this report we confirm that tri-iodothyronine (T3) levels peak at metamorphic climax during halibut metamorphosis. Moreover we have isolated cDNA clones of TR and TR genes and confirmed the presence in halibut of two TR isoforms (representing the products of distinct genes) and two TR isoforms (generated from a single gene by alternative splicing). Real time PCR was used to assess expression of these genes during metamorphosis. TR shows the most dramatic expression profile, with a peak occurring during metamorphic climax.This work has been carried out within the project “Arrested development: The Molecular and Endocrine Basis of Flatfish Metamorphosis” (Q5RS-2002-01192) with financial support from the Commission of the European Communities. However, it does not necessarily reflect the Commission’s views and in no way anticipates its future policy in this area. We thank Heiddis Smáradóttir (Fiskeldi Eyjafjarðar, IS-600 Akureyri, Iceland) for collecting and providing the Atlantic halibut samples, and Karin Pittman and Øystein Sæle (both from the Department of Biology, University of Bergen, Norway) for analysing samples to determine developmental stage. We are also grateful to Marco Campinho for preparing the RNA used in the study

Active wetting of epithelial tissues

Development, regeneration and cancer involve drastic transitions in tissue morphology. In analogy with the behavior of inert fluids, some of these transitions have been interpreted as wetting transitions. The validity and scope of this analogy are unclear, however, because the active cellular forces that drive tissue wetting have been neither measured nor theoretically accounted for. Here we show that the transition between 2D epithelial monolayers and 3D spheroidal aggregates can be understood as an active wetting transition whose physics differs fundamentally from that of passive wetting phenomena. By combining an active polar fluid model with measurements of physical forces as a function of tissue size, contractility, cell-cell and cell-substrate adhesion, and substrate stiffness, we show that the wetting transition results from the competition between traction forces and contractile intercellular stresses. This competition defines a new intrinsic lengthscale that gives rise to a critical size for the wetting transition in tissues, a striking feature that has no counterpart in classical wetting. Finally, we show that active shape fluctuations are dynamically amplified during tissue dewetting. Overall, we conclude that tissue spreading constitutes a prominent example of active wetting --- a novel physical scenario that may explain morphological transitions during tissue morphogenesis and tumor progression

Avaliação do desempenho sexual após cirurgias corretivas de genitália ambígua

This study evaluated the sexual performance of patients with genital ambiguity that had been submitted to corrective genitalsurgery. It was done a survey among the patients with genital ambiguity, undergone surgical correction, now aged 16 years oldor older and who had already initiated a sex life of a university clinic of intersexuality. Later, it was applied the Golombok RustInventory of Sexual Satisfaction (GRISS). Twenty patients who fulfilled the inclusion criteria: age older than or equal to 15 yearsold and submitted to surgical correction were selected. Of those, only four patients had begun their sex life. Several problemsrelating to sexuality were identified: Low frequency of relations, inappropriate sexual communication, sexual dissatisfaction,and sexual avoidance, lack of expression of sensuality, Vaginism and anorgasmia. Among those difficulties, the “low frequencyof relations” has been detected in all patients. It was detected that sexual function is altered in patients undergoing correctivegenital surgery. However, we can not say whether this is due to the basic pathology or if it is a sole consequence of the surgicalcorrection. This survey asks whether there is a negative effect resulting from corrective surgery of the genitalia, no sexual futureperformance of these patients. It questions also what the most propitious time to perform the surgery is: if in early childhoodor during adolescence.A ambiguidade genital atinge em torno de 1/20000 nascidos vivos na América Latina, e as repercussões psicossexuaisdesse evento ressaltam a necessidade de aprofundamento nesse tema. Este trabalho teve por objetivo avaliar odesempenho sexual de pacientes intersexuais com ambiguidade genital, submetidos à cirurgia genital corretiva.Participaram da pesquisa quinze pacientes femininas, portadoras de ambiguidade genital, submetidas à clitoroplastiaredutora, atualmente com idade igual ou superior a dezesseis anos, de um serviço universitário especializado emintersexualidade. Foi aplicado o GRISS, um questionário de avaliação da função sexual, às quatro pacientes que haviaminiciado vida sexual, das quinze pacientes contatadas. Foram notificados diversos problemas relativos à sexualidade.Todas as pacientes tinham pouca frequência do intercurso sexual e evitação sexual, e três delas expressaram falta deexpressão do desejo sexual e insatisfação sexual. Observou-se que a função sexual está alterada em pacientes submetidasà correção genital cirúrgica, porém não se pode afirmar se isso é consequência exclusiva da correção cirúrgica, ou decorrenteda patologia de base

Revista de Vertebrados de la Estación Biológica de Doñana

The Osteology of Barbus bocagei (Steindachner, 1866) (Pisces: Cyprinidae).El crecimiento del Cacho (Leuciscus cephalus pyraenaicus Günther, 1862) en el rio Jarama (cuenca del Tajo)Contribución al estudio de la bermejuela, Rutilus arcasi, Steindachner 1866 de la cuenca del Júcar (Osteichthyes: Cyprinidae) 1. MorfometríaDimensiones, estructura, forma y disposición en la cavidad de los nidos de Corvus monedula.Variaciones altitudinales en la composición de las comunidades nidificantes de aves de Sierra Nevada (Sur de España)Ecomorfología de una comunidadde Passeriformes en la Sierra de Cazorla, SE de EspañaLa Distribución del pez-sol (Lepolllis gibbostlS L.) en la Península IbéricaSobre la distribución de Barbus haasi (OSTARIOPHYSI: CYPRINIDAE)La Distribución de Barbus bocagei STEINDACHNER, 1865 (OSTARIOPHYSI: CYPRINIDAE) en la Península IbéricaLighy effects on circadian locomotor activity of Lacerta lepida under constant temperatureEvaluación de diferentes métodos para estimar el área de campeo de dos especies de iguánidos.Un Casal de Cartaxo-Nottenho (Saxicola rubetra) a criar em Portugal.Nidificación de Passer hispaniolensis en antiguos nidos de Dendrocopos major thanneri.Observación de un lince ibérico (Lynx pardina) en la provincia de Lugo. Norte de España.El Visón americano, Mustela vison SCHREBER, 1777 (MAMMALIA, MUSTELIDAE) en Cataluña, N.E. de la Península Ibérica.Peer reviewe

The genome and transcriptome of Japanese flounder provide insights into flatfish asymmetry

Flatfish have the most extreme asymmetric body morphology of vertebrates. During metamorphosis, one eye migrates to the contralateral side of the skull, and this migration is accompanied by extensive craniofacial transformations and simultaneous development of lopsided body pigmentation(1-5). The evolution of this developmental and physiological innovation remains enigmatic. Comparative genomics of two flatfish and transcriptomic analyses during metamorphosis point to a role for thyroid hormone and retinoic acid signaling, as well as phototransduction pathways. We demonstrate that retinoic acid is critical in establishing asymmetric pigmentation and, via cross-talk with thyroid hormones, in modulating eye migration. The unexpected expression of the visual opsins from the phototransduction pathway in the skin translates illumination differences and generates retinoic acid gradients that underlie the generation of asymmetry. Identifying the genetic underpinning of this unique developmental process answers long-standing questions about the evolutionary origin of asymmetry, but it also provides insight into the mechanisms that control body shape in vertebrates.National Natural Science Foundation of China [31130057, 31461163005, 31530078, 31472269, 31472262, 31472273]; State 863 High Technology R&D Project of China [2012AA092203, 2012AA10A408, 2012AA10A403-2]; Education and Research of Guangdong Province [2013B090800017]; Taishan Scholar Climb Project Fund of Shandong of China; Taishan Scholar Project Fund of Shandong of China for Young Scientists; Shanghai Universities First-class Disciplines Project of Fisheries; Program for Professor of Special Appointment (Eastern Scholar) at the Shanghai Institutions of Higher Learning; Shanghai Municipal Science, Special Project on the Integration of Industryinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/publishedVersio

Transient up- and down-regulation of expression of myosin light chain 2 and myostatin mRNA mark the changes from stratified hyperplasia to muscle fiber hypertrophy in larvae of gilthead sea bream (Sparus aurata L.)

Hyperplasia and hypertrophy are the two mechanisms by which muscle develops and grows. We study these two mechanisms, during the early development of white muscle in Sparus aurata, by means of histology and the expression of structural and regulatory genes. A clear stage of stratified hyperplasia was identified early in the development of gilthead sea bream but ceased by 35 dph when hypertrophy took over. Mosaic recruitment of new white fibers began as soon as 60 dph. The genes mlc2a and mlc2b were expressed at various levels during the main phases of hyperplasia and hypertrophy. The genes myog and mlc2a were significantly up-regulated during the intensive stratified formation of new fibers and their expression was significantly correlated. Expression of mstn1 and igf1 increased at 35 dph, appeared to regulate the hyperplasia-to-hypertrophy transition, and may have stimulated the expression of mlc2a, mlc2b and col1a1 at the onset of mosaic hyperplasia. The up-regulation of mstn1 at transitional phases in muscle development indicates a dual regulatory role of myostatin in fish larval muscle growth