Efficient clofilium tosylate-mediated rescue of POLG-related disease phenotypes in zebrafish

The DNA polymerase gamma (Polg) is a nuclear-encoded enzyme involved in DNA replication in animal mitochondria. In humans, mutations in the POLG gene underlie a set of mitochondrial diseases characterized by mitochondrial DNA (mtDNA) depletion or deletion and multiorgan defects, named POLG disorders, for which an effective therapy is still needed. By applying antisense strategies, ENU- and CRISPR/Cas9-based mutagenesis, we have generated embryonic, larval-lethal and adult-viable zebrafish Polg models. Morphological and functional characterizations detected a set of phenotypes remarkably associated to POLG disorders, including cardiac, skeletal muscle, hepatic and gonadal defects, as well as mitochondrial dysfunctions and, notably, a perturbed mitochondria-to-nucleus retrograde signaling (CREB and Hypoxia pathways). Next, taking advantage of preliminary evidence on the candidate molecule Clofilium tosylate (CLO), we tested CLO toxicity and then its efficacy in our zebrafish lines. Interestingly, at well tolerated doses, the CLO drug could successfully rescue mtDNA and Complex I respiratory activity to normal levels, even in mutant phenotypes worsened by treatment with Ethidium Bromide. In addition, the CLO drug could efficiently restore cardio-skeletal parameters and mitochondrial mass back to normal values. Altogether, these evidences point to zebrafish as a valuable vertebrate organism to faithfully phenocopy multiple defects detected in POLG patients. Moreover, this model represents an excellent platform to screen, at the whole-animal level, candidate molecules with therapeutic effects in POLG disorders

ERBB2 in Cat Mammary Neoplasias Disclosed a Positive Correlation between RNA and Protein Low Expression Levels: A Model for erbB-2 Negative Human Breast Cancer

Human ERBB2 is a proto-oncogene that codes for the erbB-2 epithelial growth factor receptor. In human breast cancer (HBC), erbB-2 protein overexpression has been repeatedly correlated with poor prognosis. In more recent works, underexpression of this gene has been described in HBC. Moreover, it is also recognised that oncogenes that are commonly amplified or deleted encompass point mutations, and some of these are associated with HBC. In cat mammary lesions (CMLs), the overexpression of ERBB2 (27%–59.6%) has also been described, mostly at the protein level and although cat mammary neoplasias are considered to be a natural model of HBC, molecular information is still scarce. In the present work, a cat ERBB2 fragment, comprising exons 10 to 15 (ERBB2_10–15) was achieved for the first time. Allelic variants and genomic haplotype analyses were also performed, and differences between normal and CML populations were observed. Three amino acid changes, corresponding to 3 non-synonymous genomic sequence variants that were only detected in CMLs, were proposed to damage the 3D structure of the protein. We analysed the cat ERBB2 gene at the DNA (copy number determination), mRNA (expression levels assessment) and protein levels (in extra- and intra protein domains) in CML samples and correlated the last two evaluations with clinicopathological features. We found a positive correlation between the expression levels of the ERBB2 RNA and erbB-2 protein, corresponding to the intracellular region. Additionally, we detected a positive correlation between higher mRNA expression and better clinical outcome. Our results suggest that the ERBB2 gene is post-transcriptionally regulated and that proteins with truncations and single point mutations are present in cat mammary neoplastic lesions. We would like to emphasise that the recurrent occurrence of low erbB-2 expression levels in cat mammary tumours, suggests the cat mammary neoplasias as a valuable model for erbB-2 negative HBC.POCI/CVT/62940/2004 and by the PhD grants (SFRH/BD/23406/2005 and SFRH/BD/31754/2006, of the Science and Technology Foundation (FCT) from Portugal

Yellow belly as honest signal of female quality in Knipowitschia panizzae (Gobiidae)

Sexually dimorphic traits are common in fish species, and examples from both males and females have been described. The function of these traits has been widely investigated in males. On the contrary, female ornaments have been studied mainly in sex role reversed species, such as pipefish, while their role in species with \u2018conventional\u2019 sex roles remain to be investigated. This study focused on the presence, function, and possible role as indicator of female quality of a sexually dimorphic nuptial trait in the lagoon goby, Knipowitschia panizzae. In this species, that present conventional sex roles, females show a yellow spot on the belly. Aquarium spawning experiments demonstrated that the coloration on the belly is due to dermal pigments, is displayed only when female is ready to spawn and is switched off within few minutes from the end of egg deposition. This sexual trait presents variability in size among females and indicates female fecundity relatively to her own body size. As a consequence, female yellow belly appears to be an honest signal of female quality. Field data on natural nests highlighted that males perform parental cares mostly only on one egg batch at a time and the modality of egg deposition suggested that males are limited in their potential reproductive rates by environmental factors. Male limitation in egg care could constitute the basis for a female biased operational sex ratio, favouring male choosiness and the evolution of female nuptial displays

Egg size variability and mating system in the marbled goby, Pomatoschistus marmoratus (Pisces, Gobiidae)

The marbled goby Pomatoschistus marmoratus inhabits the Venetian lagoon, northern Adriatic Sea. We used both field and laboratory approaches to investigate the mating system and factors influencing egg size and number. Males nest in empty bivalve shells and provide parental care to eggs. Egg size showed wide variation (CV = 11.5%) and was positively correlated with female size and parental male size, but negatively with the progression of the spawning season. Field data showed that larger males occupied larger nests and obtained more and larger eggs than smaller males. Laboratory experiments showed that larger females produced both more and larger eggs than smaller ones. The relationship between egg size and male and female sizes suggested the presence of size-assortative mating in this species. The presence of high environmental variability could select for the peculiar pattern of egg size variability observed in this populatio

Il racconto delle Origini, dal Big Bang alla Vita

Tutto nell\u2019Universo \ue8 soggetto a cambiamenti continui, ora improvvisi e rapidi, altre volte infinitamente pi\uf9 lenti. Dalle maestose galassie composte da miliardi di stelle, alle catene montuose che sorgono dove prima esisteva un oceano, all\u2019invisibile virus che entra nel nostro corpo col respiro. Sono tutti cambiamenti che lasciano delle tracce. Alcune molto labili, destinate a scomparire presto, distrutte dal tempo, altre indelebili, capaci di attraversare intatte il fluire dei milioni e miliardi d\u2019anni. Sono proprio i cambiamenti dalle tracce indelebili a guidare il susseguirsi delle pagine di questo libro, mostrandoci uno dei possibili itinerari che ci collega alle origini. Quello che, per il momento, appare il pi\uf9 sostenibile dal culmine di quattrocento anni di Scienza. Questo \ue8 un percorso di conoscenza che, nei limiti imposti da una trattazione per immagini accompagnate da agili testi, cerca di cogliere l\u2019essenza del meraviglioso intreccio tra l\u2019evolversi dell\u2019universo inanimato e l\u2019affermarsi prorompente della vita, cos\uec come noi la conosciamo. Ma occorre prestare attenzione a non farsi ingannare dai limiti impliciti all\u2019esposizione, che presenta l\u2019evoluzione dell\u2019Universo fino alla comparsa della Terra, poi le modifiche del pianeta, ed infine la ricostruzione della folgorante storia della vita fino ai limiti della comparsa dell\u2019Umanit\ue0. Senz\u2019altro e\u2019 andata cos\uec, ma anche e\u2019 vero che mentre stiamo leggendo queste righe, in qualche parte dell\u2019Universo nuove galassie si stanno formando, e al loro interno nuove stelle stanno prendendo forma ed iniziano ad emettere la loro luce. Ora, proprio ora, nuovi pianeti appaiono attorno a queste nuove stelle e, forse, in qualcuno di questi, si sta ripetendo, lo far\ue0 fra poco o fra qualche miliardo di anni, il fenomeno della comparsa della vita. I nuovi organismi si adatteranno alle variazioni climatiche e alle modificazioni di territori in continuo mutamento, diventando parte di un complesso e mirabile intreccio di cause ed effetti. Il racconto delle origini, dunque, si svolge secondo le nostre conoscenze attuali. Certamente questa esposizione non \ue8 la risposta definitiva. La Scienza per prima, umilmente ma tenacemente, cercher\ue0 continuamente risposte, sempre pi\uf9 complete e precise. Domani altri, molti altri che lavorano ogni giorno per carpire alla natura i suoi segreti, forniranno materiale ed idee per poter scrivere un libro migliore. E\u2019 questa l\u2019affascinante missione della Scienza, anch\u2019essa in continuo, tenace cambiamento

Mechanisms enabling sperm economy in blenniid fishes.

Sperm competition, cost of spermatogenesis and spawning frequency are known to influence ejaculate expenditure. Accordingly, males, particularly those with high reproductive costs, are expected to have evolved mechanisms enabling them to prudently allocate sperm, such as the fractioning of ejaculate expenditure or the semicystic type of spermatogenesis, hypothesised to favour the production of small ejaculates. In this study, we investigate sperm competition risk, ejaculate size and mode of ejaculate release in seven polygynous blenniid fish where males provide sole paternal care of eggs. In addition, we estimated the relative size of the two parts composing the male gonad, the strictly testicular (testicular lobules or testis) and the glandular (testicular gland), as the development of the latter is indicative of the level of semi-cystic spermatogenesis. In all the examined species, eggs were laid one by one, and the sperm expenditure at mating, evaluated as the total number of sperm released per mating, was parcelled out in several successive ejaculations, allowing males to adjust the release of sperm to the duration of egg deposition. In accordance with sperm competition theory, species experiencing higher sperm competition risk allocated more in sperm, both considering ejaculate size and ejaculate expenditure per mating. An increase in sperm expenditure was paralleled by the development of the testis at the expense of the testicular gland. Smaller species, whose males do not face sperm competition risk and fecundity is low, produced smaller ejaculates and exhibited a more developed testicular gland, supporting the hypothesis that a semi-cystic type of spermatogenesis is a mechanism allowing sperm economy