An AI-based approach driven by genotypes and phenotypes to uplift the diagnostic yield of genetic diseases.

Identifying disease-causing variants in Rare Disease patients' genome is a challenging problem. To accomplish this task, we describe a machine learning framework, that we called "Suggested Diagnosis", whose aim is to prioritize genetic variants in an exome/genome based on the probability of being disease-causing. To do so, our method leverages standard guidelines for germline variant interpretation as defined by the American College of Human Genomics (ACMG) and the Association for Molecular Pathology (AMP), inheritance information, phenotypic similarity, and variant quality. Starting from (1) the VCF file containing proband's variants, (2) the list of proband's phenotypes encoded in Human Phenotype Ontology terms, and optionally (3) the information about family members (if available), the "Suggested Diagnosis" ranks all the variants according to their machine learning prediction. This method significantly reduces the number of variants that need to be evaluated by geneticists by pinpointing causative variants in the very first positions of the prioritized list. Most importantly, our approach proved to be among the top performers within the CAGI6 Rare Genome Project Challenge, where it was able to rank the true causative variant among the first positions and, uniquely among all the challenge participants, increased the diagnostic yield of 12.5% by solving 2 undiagnosed cases.

Evaluation of Intraoperative End-Tidal Carbon Dioxide Change Relates to Length Hospitalisation in Peridiaphragmatic Surgery: A Pilot Study.

Intraoperative evaluation is deeply changed using many new tools, both invasive and non-invasive. Peripheral oxygen saturation percentage (SpO2) is the more reliable method for a non-invasive monitoring of patient's blood oxygen concentration. Capnography (using end-tidal CO2 (EtCO2)) evaluation is an immediate and continuous non-invasive monitoring of carbon dioxide (CO2) in the breathing that provides important information on circulatory status and ventilation.Aim of this study is to perform a preliminary analysis of oxygen change during surgery exploring its possible influence on post-operative evolution. METHODS AND RESULTS: Intraoperative evaluation of SpO2 and EtCO2 was performed. Change in each parameter was categorised as 1 point for each five-point variation from baseline value (∆SpO2 as 1 point for each 5%, ∆EtCO2 as 1 point for each 5 mmHg). For each patient, the length of stay (LOS) in the intensive care unit (ICU), total hospitalisation, duration of intervention, surgical risk and complications were recorded. RESULTS: We analysed 93 consecutive patients (43 males and 40 females, aged 66.35 ± 9.79 years) that underwent peridiaphragmatic surgery. Forty patients (48.19%) presented complications after surgery. There was no statistically significant difference in age, duration of intervention and length of stay in ICU between complicated and non-complicated patients. As expected, patients with complications present an increased hospitalisation time compared to uncomplicated cases (14.69 ± 11.41 days vs 10.70 ± 6.28 days; p < 0.05). ∆EtCO2 was significantly increased (p < 0.05) in complicated compared to non-complicated. No differences were found in ∆SpO2 between the two groups. Considering the whole population, ∆EtCO2 presents a significant direct correlation to surgical risk, hospitalisation and duration of intervention. CONCLUSION: ∆EtCO2 may be related to possible complications after surgery and hospitalisation. An important comparison between SpO2 and EtCO2 and strict monitoring with an intraoperative arterial blood gas (ABG) sample during the main steps of surgery could bring some essential information to understand oxygen changes in intra- and post-operative evolution. However, a further validation analysis is needed before the approach can be used extensively in daily clinical settings.

Repatriation of a historical North Atlantic right whale habitat during an era of rapid climate change.

Climate change is affecting species distributions in space and time. In the Gulf of Maine, one of the fastest-warming marine regions on Earth, rapid warming has caused prey-related changes in the distribution of the critically endangered North Atlantic right whale (Eubalaena glacialis). Concurrently, right whales have returned to historically important areas such as southern New England shelf waters, an area known to have been a whaling ground. We compared aerial survey data from two time periods (2013-2015; 2017-2019) to assess trends in right whale abundance in the region during winter and spring. Using distance sampling techniques, we chose a hazard rate key function to model right whale detections and used seasonal encounter rates to estimate abundance. The mean log of abundance increased by 1.40 annually between 2013 and 2019 (p = 0.004), and the mean number of individuals detected per year increased by 2.23 annually between 2013 and 2019 (R2 = 0.69, p = 0.001). These results demonstrate the current importance of this habitat and suggest that management options must continually evolve as right whales repatriate historical habitats and potentially expand to new habitats as they adapt to climate change.

Impact of a large dam on reproduction of a non-migratory teleost species, Acestrorhynchus lacustris (Characiformes: Acestrorhynchidae) / Impacto de uma grande barragem na reprodução de uma espécie de teleósteo não migradora, Acestrorhynchus lacustris (Characiformes: Acestrorhynchidae)

The release of water from the reservoir hypolimnion, lower concentration of oxygen and the anthropogenic regulation of the river flow, could affect the reproduction of fish, especially migratory species. However, little is known about the effects of these changes in water on non-migratory species. In this sense, the reproduction of Acestrohynchus lacustris was evaluated in two sections of São Francisco River, Minas Gerais, Brazil. Section 1, located immediately downstream from Três Marias Dam (18°09'31.65"S and 45°13'36.00"W) and section 2, located at the confluence of the São Francisco and the Abaeté Rivers (18°02'47.78"S and 45°1057.95"W). For this, we obtained the physico-chemical parameters of water of each study section. Additionally, biometric data and biological indices ofall specimens were measured. Fecundity and follicles diameters were measured in females. Temperature, dissolvedoxygen and flow showed lower values in section 1. Fish captured in this section, had lower values of GSI in bothsexes, and females presented decreased values of fecundity and follicles diameter. This species showed reproductiveactivity in the two sections analyzed, however, in section 1 where the temperature and dissolved oxygen presentedsignificant lower values, the reproductive capacity of A. lacustris, was negatively affected.

A liberação de água do hipolímnio do reservatório, baixa concentração de oxigênio e a regulação antropogênica do fluxo do rio podem afetar a reprodução de peixes, principalmente espécies migradoras. No entanto, pouco se sabe sobre os efeitos dessas mudanças nas condições da água em espécies não migradoras. A reprodução de Acestrohynchus lacustris foi avaliada em duas seções do rio São Francisco. Seção 1, localizada imediatamente a jusante da barragem de Três Marias e seção 2, localizada na confluência dos rios São Francisco e Abaeté. Para isso, foram obtidos os parâmetros físico-químicos da água de cada seção do estudo. Além disso, dados biométricos e índices biológicos de todos os peixes capturados foram obtidos. Adicionalmente, nas fêmeas foram medidos os diâmetros dos folículos vitelogênicos e a fecundidade. Temperatura, oxigênio dissolvido e fluxo apresentaram valores mais baixos na seção 1. Os peixes capturados nesta seção apresentaram menores valores de IGS em ambos os sexos, e as fêmeas apresentaram menores valores de fecundidade e diâmetro dos folículos. Essa espécie apresentou atividade reprodutiva nas duas seções analisadas, porém, na seção 1, onde os parâmetros da água apresentam piores condições para o processo reprodutivo de peixes, a capacidade reprodutiva de A. lacustris foi afetada negativamente.

Impact of a large dam on reproduction of a non-migratory teleost species, Acestrorhynchus lacustris (Characiformes: Acestrorhynchidae)

Abstract The release of water from the reservoir hypolimnion, lower concentration of oxygen and the anthropogenic regulation of the river flow, could affect the reproduction of fish, especially migratory species. However, little is known about the effects of these changes in water on non-migratory species. In this sense, the reproduction of Acestrohynchus lacustris was evaluated in two sections of São Francisco River, Minas Gerais, Brazil. Section 1, located immediately downstream from Três Marias Dam (18°0931.65S and 45°1336.00W) and section 2, located at the confluence of the São Francisco and the Abaeté Rivers (18°0247.78S and 45°1057.95W). For this, we obtained the physico-chemical parameters of water of each study section. Additionally, biometric data and biological indices of all specimens were measured. Fecundity and follicles diameters were measured in females. Temperature, dissolved oxygen and flow showed lower values in section 1. Fish captured in this section, had lower values of GSI in both sexes, and females presented decreased values of fecundity and follicles diameter. This species showed reproductive activity in the two sections analyzed, however, in section 1 where the temperature and dissolved oxygen presented significant lower values, the reproductive capacity of A. lacustris, was negatively affected.

Resumo A liberação de água do hipolímnio do reservatório, baixa concentração de oxigênio e a regulação antropogênica do fluxo do rio podem afetar a reprodução de peixes, principalmente espécies migradoras. No entanto, pouco se sabe sobre os efeitos dessas mudanças nas condições da água em espécies não migradoras. A reprodução de Acestrohynchus lacustris foi avaliada em duas seções do rio São Francisco. Seção 1, localizada imediatamente a jusante da barragem de Três Marias e seção 2, localizada na confluência dos rios São Francisco e Abaeté. Para isso, foram obtidos os parâmetros físico-químicos da água de cada seção do estudo. Além disso, dados biométricos e índices biológicos de todos os peixes capturados foram obtidos. Adicionalmente, nas fêmeas foram medidos os diâmetros dos folículos vitelogênicos e a fecundidade. Temperatura, oxigênio dissolvido e fluxo apresentaram valores mais baixos na seção 1. Os peixes capturados nesta seção apresentaram menores valores de IGS em ambos os sexos, e as fêmeas apresentaram menores valores de fecundidade e diâmetro dos folículos. Essa espécie apresentou atividade reprodutiva nas duas seções analisadas, porém, na seção 1, onde os parâmetros da água apresentam piores condições para o processo reprodutivo de peixes, a capacidade reprodutiva de A. lacustris foi afetada negativamente.

Impact of a large dam on reproduction of a non-migratory teleost species, Acestrorhynchus lacustris (Characiformes: Acestrorhynchidae) / Impacto de uma grande barragem na reprodução de uma espécie de teleósteo não migradora, Acestrorhynchus lacustris (Characiformes: Acestrorhynchidae)

The release of water from the reservoir hypolimnion, lower concentration of oxygen and the anthropogenic regulation of the river flow, could affect the reproduction of fish, especially migratory species. However, little is known about the effects of these changes in water on non-migratory species. In this sense, the reproduction of Acestrohynchus lacustris was evaluated in two sections of São Francisco River, Minas Gerais, Brazil. Section 1, located immediately downstream from Três Marias Dam (18°09'31.65"S and 45°13'36.00"W) and section 2, located at the confluence of the São Francisco and the Abaeté Rivers (18°02'47.78"S and 45°10'57.95"W). For this, we obtained the physico-chemical parameters of water of each study section. Additionally, biometric data and biological indices of all specimens were measured. Fecundity and follicles diameters were measured in females. Temperature, dissolved oxygen and flow showed lower values in section 1. Fish captured in this section, had lower values of GSI in both sexes, and females presented decreased values of fecundity and follicles diameter. This species showed reproductive activity in the two sections analyzed, however, in section 1 where the temperature and dissolved oxygen presented significant lower values, the reproductive capacity of A. lacustris, was negatively affected.

A liberação de água do hipolímnio do reservatório, baixa concentração de oxigênio e a regulação antropogênica do fluxo do rio podem afetar a reprodução de peixes, principalmente espécies migradoras. No entanto, pouco se sabe sobre os efeitos dessas mudanças nas condições da água em espécies não migradoras. A reprodução de Acestrohynchus lacustris foi avaliada em duas seções do rio São Francisco. Seção 1, localizada imediatamente a jusante da barragem de Três Marias e seção 2, localizada na confluência dos rios São Francisco e Abaeté. Para isso, foram obtidos os parâmetros físico-químicos da água de cada seção do estudo. Além disso, dados biométricos e índices biológicos de todos os peixes capturados foram obtidos. Adicionalmente, nas fêmeas foram medidos os diâmetros dos folículos vitelogênicos e a fecundidade. Temperatura, oxigênio dissolvido e fluxo apresentaram valores mais baixos na seção 1. Os peixes capturados nesta seção apresentaram menores valores de IGS em ambos os sexos, e as fêmeas apresentaram menores valores de fecundidade e diâmetro dos folículos. Essa espécie apresentou atividade reprodutiva nas duas seções analisadas, porém, na seção 1, onde os parâmetros da água apresentam piores condições para o processo reprodutivo de peixes, a capacidade reprodutiva de A. lacustris foi afetada negativamente.

Impact of a large dam on reproduction of a non-migratory teleost species, Acestrorhynchus lacustris (Characiformes: Acestrorhynchidae).

The release of water from the reservoir hypolimnion, lower concentration of oxygen and the anthropogenic regulation of the river flow, could affect the reproduction of fish, especially migratory species. However, little is known about the effects of these changes in water on non-migratory species. In this sense, the reproduction of Acestrohynchus lacustris was evaluated in two sections of São Francisco River, Minas Gerais, Brazil. Section 1, located immediately downstream from Três Marias Dam (18°09'31.65"S and 45°13'36.00"W) and section 2, located at the confluence of the São Francisco and the Abaeté Rivers (18°02'47.78"S and 45°10'57.95"W). For this, we obtained the physico-chemical parameters of water of each study section. Additionally, biometric data and biological indices of all specimens were measured. Fecundity and follicles diameters were measured in females. Temperature, dissolved oxygen and flow showed lower values in section 1. Fish captured in this section, had lower values of GSI in both sexes, and females presented decreased values of fecundity and follicles diameter. This species showed reproductive activity in the two sections analyzed, however, in section 1 where the temperature and dissolved oxygen presented significant lower values, the reproductive capacity of A. lacustris, was negatively affected.

Heavy metals accumulation and endocrine disruption in Prochilodus argenteus from a polluted neotropical river.

Heavy metals are considered major pollutants of aquatic environments due to the difficulty of metabolization and the bioaccumulative potential in tissues of aquatic organisms, especially fish muscle that is often used as food worldwide. In addition to causing cell damage, some metals such as aluminium (Al), cadmium (Cd), copper (Cu), and lead (Pb) can act as endocrine disrupting chemicals in fish. The Paraopeba and Abaete Rivers are important tributaries of the upper São Francisco River basin, but the Paraopeba River receives, along its course, the discharge of many types of effluents that affect fish species, including widely consumed species such as Prochilodus argenteus. This study evaluated histological and molecular changes caused by chronic exposure to heavy metals in P. argenteus from the Paraopeba River and compared this to fish from the non-impacted Abaete River. Sampled fish from both rivers were used in histological analyses and immunohistochemical assays. The results showed increased incidence of histopathologies and changes in number and morphology of germline cells in both sexes. In addition, up-regulated expression of oestrogens-induced proteins in the liver of males were detected in polluted environment. All the alterations were related to the concentration of metals in water and fish. The high concentration of various metals observed in water and fish from Paraopeba River serves as an alert to the environmental and public health regulatory authorities.

Impact of chemotherapy in uterine sarcoma (UtS): review of 13 clinical trials from the EORTC Soft Tissue and Bone Sarcoma Group (STBSG) involving advanced/metastatic UtS compared to other soft tissue sarcoma (STS) patients treated with first line chemotherapy.

OBJECTIVE: UtS are a group of uncommon tumors representing 1% of malignant neoplasms of the female genital tract, and 7% of sarcomas. The objective of this study was to evaluate the factors associated with the clinical behavior UtS. METHODS: Information on 269 patients with advanced or metastatic first line UtS treated by chemotherapy was available in a database containing information on 3270 patients with advanced soft tissue sarcomas (STS) entered in EORTC-STBSG clinical trials between 1977 and 2010. The chemotherapy was aggregated in 4 categories: anthracyclines alone, ifosfamide alone, the combination of doxorubicin and ifosfamide, and CYVADIC. RESULTS: Among the 269 UtS pts, there were 231 deaths (median OS 10.4months, 95% CI: 9.1-11.9) and 257 progressions and/or deaths (median PFS 4.1months, 95% CI: 3.5-4.9). Multivariate analyses reported PS (p<0.001) only to be a statistically significant prognostic factor for OS in UtS; for PFS, LMS histology (p=0.025) is associated with a better outcome. There was no relationship between the 4 groups of chemotherapy regimens and impact on clinical outcomes. Histological subtype was significantly correlated with response to chemotherapy (RR: LMS 19% vs other 33%, p=0.026). Ifosfamide single agent yielded only 5% of RR. CONCLUSIONS: Clearly, UtS are very aggressive neoplasms with poor outcome when treated with chemotherapy consisting of anthracyclines with or without ifosfamide or cyclophosphamide. New strategies are urgently needed.

Genetic association of productive and reproductive traits with stayability in Nellore cattle: analysis using Bayesian models.

We evaluated the genetic association of growth traits [weight adjusted to 205 days of age (W205), 365 days of age (W365), and 550 days of age (W550); weight gain between 205 days of age and 365 days of age (WG1) and between 365 days of age and 550 days of age (WG2)] and reproductive traits [age at first calving (AFC); first calving interval (FCI)] with stayability in the herd (STAY), using Bayesian inference in linear and threshold models. We defined STAY as the probability of a cow calving three or more times before the age of 76 months, given that she had calved at least once. We assigned binary codes (0, failure; 1, success) to each female. We used a sire model for analysis and formed different contemporary groups for the investigated traits. We analyzed the results by applying a two-trait sire model that included STAY (threshold trait) and linear traits (W205, W365, W550, WG1, WG2, AFC, and FCI). We used Gibbs sampling to estimate variance components and heritabilities. In all the analyses, we found that the mean heritability estimates for STAY were of moderate magnitude (0.20-0.25). The mean heritabilities for W205, W365, W550, WG1, WG2, AFC, and FCI were 0.20, 0.23, 0.39, 0.08, 0.14, 0.12, and 0.11, respectively. We observed wide variation in the posterior distributions of genetic correlations; however, with the exception of those obtained for the reproductive traits, the mean estimates were of low magnitude. Selection for WG2 can results in favorable correlated response in STAY.

A new approach to integrate toxicity grade and repeated treatment cycles in the analysis and reporting of phase I dose-finding trials.

BACKGROUND: Safety assessment beyond the dose-limiting toxicity evaluation period provides relevant information to define the recommended phase II dose (RP2D) of a new treatment. We retrospectively analyzed three phase I trials to illustrate two indicators: per-cycle probability of graded toxicity and cumulative probability of severe toxicity over the treatment period. PATIENTS AND METHODS: Data were collected from two continual reassessment method (CRM) trials (T1: aviscumine in solid tumors with short time on treatment; T2: erlotinib + radiotherapy in brainstem gliomas with longer time on treatment) and one 3 + 3 design (T3: liposomal doxorubicin + cyclophosphamide combination in ovarian carcinoma). The probability of severe and moderate or severe toxicity per cycle was estimated at each dose level with mixed proportional odds model. The cumulative probability of severe toxicity was also estimated with the time-to-event CRM. RESULTS: Eighty-three patients were included in the three trials; 94, 96 and 72 treatment cycles were administered, in T1, T2 and T3, respectively. Moderate toxicities were at least twice as frequent as severe toxicities. An increased probability of toxicity over time was detected in T3 [P = 0.04; per-cycle probability of severe toxicity: 27% (cycle 1) to 59% (cycle 6) at the RP2D]. At the RP2D, 37% of patients experienced at least one severe toxicity over the first six cycles in T2, and 78% in T3. CONCLUSIONS: Dedicated methods can be used to analyze toxicities from all cycles of treatment. They do not delay accrual and should be integrated in the analysis and reporting of phase I dose-finding trials.

Salinity and temperature variations reflecting on cellular PCNA, IGF-I and II expressions, body growth and muscle cellularity of a freshwater fish larvae.

The present study assessed the influence of salinity and temperature on body growth and on muscle cellularity of Lophiosilurus alexaxdri vitelinic larvae. Slightly salted environments negatively influenced body growth of freshwater fish larvae and we observed that those conditions notably act as an environmental influencer on muscle growth and on local expression of hypertrophia and hypeplasia markers (IGFs and PCNA). Furthermore, we could see that salinity tolerance for NaCl 4gl(-)(1) diminishes with increasing temperature, evidenced by variation in body and muscle growth, and by irregular morphology of the lateral skeletal muscle of larvae. We saw that an increase of both PCNA and autocrine IGF-II are correlated to an increase in fibre numbers and fibre diameter as the temperature increases and salinity diminishes. On the other hand, autocrine IGF-I follows the opposite way to the other biological parameters assessed, increasing as salinity increases and temperature diminishes, showing that this protein did not participate in muscle cellularity, but participating in molecular/cellular repair. Therefore, slightly salted environments may provide adverse conditions that cause some obstacles to somatic growth of this species, suggesting some osmotic expenditure with a salinity increment.

In vitro, in vivo and in silico analysis of the anticancer and estrogen-like activity of guava leaf extracts.

Anticancer drug research based on natural compounds enabled the discovery of many drugs currently used in cancer therapy. Here, we report the in vitro, in vivo and in silico anticancer and estrogen-like activity of Psidium guajava L. (guava) extracts and enriched mixture containing the meroterpenes guajadial, psidial A and psiguadial A and B. All samples were evaluated in vitro for anticancer activity against nine human cancer lines: K562 (leukemia), MCF7 (breast), NCI/ADR-RES (resistant ovarian cancer), NCI-H460 (lung), UACC-62 (melanoma), PC-3 (prostate), HT-29 (colon), OVCAR-3 (ovarian) and 786-0 (kidney). Psidium guajava's active compounds displayed similar physicochemical properties to estradiol and tamoxifen, as in silico molecular docking studies demonstrated that they fit into the estrogen receptors (ERs). The meroterpene-enriched fraction was also evaluated in vivo in a Solid Ehrlich murine breast adenocarcinoma model, and showed to be highly effective in inhibiting tumor growth, also demonstrating uterus increase in comparison to negative controls. The ability of guajadial, psidial A and psiguadials A and B to reduce tumor growth and stimulate uterus proliferation, as well as their in silico docking similarity to tamoxifen, suggest that these compounds may act as Selective Estrogen Receptors Modulators (SERMs), therefore holding significant potential for anticancer therapy.

Self-potential monitoring of a crude oil-contaminated site (Trecate, Italy).

We present a multidisciplinary approach for characterization of a crude oil-contaminated site (Trecate, Italy), integrating geophysical data, such as subsoil electrical potential (in millivolts) and electrical resistivity (in ohm meters) distribution, with hydrogeological and bio-chemical data. Self-potential measurements have been evaluated together with active geoelectrical measurements and hydrological information, to provide spatial and temporal information about the self-potential sources and their possible correlations with the contamination state of the subsoil. Three self-potential surveys (March 2010, October 2010, and March 2011) were conducted at the site, both in the contaminated and uncontaminated regions. The obtained self-potential maps show large time-lapse differences in correspondence of the contaminated area, with positive electrical potential values (up to 50 mV) in spring surveys and an electrical potential dipolar distribution in October (2010) survey (amplitude from -15 to 25 mV). To understand the origin of the measured self-potential signals, a model using vertical dipolar electrical sources was built, taking into account the electrical resistivity distribution deduced from electrical resistivity tomography. The self-potential source identification allows the Trecate contamination state to be better delineated. In particular, two self-potential contributions are superimposed: the electrokinetic mechanism is predominant in spring, while the redox mechanism represents the most important contribution in autumn.

Reproduction and embryogenesis of the mandi-amarelo catfish, Pimelodus maculatus (Pisces, Pimelodidae), in captivity.

To study reproduction and embryogenesis, Pimelodus maculatus specimens were kept in captivity and captured bimonthly during 1 year. Gonads samples (211 specimens) were collected and submitted to routine histological techniques. Pimelodus maculatus prepared to reproduce when water temperature was high, and even reached advanced maturation but did not spawn in captivity. Spent fish gonads were not documented, and atretic follicles were frequent (60%) in late maturation females. When then submitted to hypophysation, 70% of the females responded positively to hormonal treatment. Oocyte extrusion occurred 8 h after a second hormonal injection at 26°C. The fertilisation rate was 65.1 ± 9.2% at 24°C. Recently spawned oocytes of P. maculatus were spherical, non-adhesive, yellow in colour, with an average diameter of 1113.92 ± 37.02 µm and covered by a thick gelatinous layer. Blastopore closure occurred 7 h and 30 min after fertilisation. Embryonic development was completed within 18 h after fertilisation. The results of this work provide important knowledge for the handling and cultivation of not only P. maculatus, but other species of potential value for fish culture.

Comparative analysis of the oocytes and early development of two species of curimatidae teleost fish.

Curimatella lepidura and Steindachnerina elegans are small forage fish, constituting an important link in the food chain, serving as food for larger commercial fish. In this study, characteristics of the eggs, of the oocyte's surface ultrastructure and of the embryogenesis are first described for these species. Absolute fecundity was 40864 ± 8769 oocytes for C. lepidura and 22089 ± 8710 oocytes for S. elegans. Oocytes of both species are yellowish, weakly adhesive and with a post-fertilization diameter of 1019.5 ± 20.6 µm and 978.75 ± 29.16 µm for C. lepidura and S. elegans, respectively. The ultrastructural analysis, using scanning electron microscopy, showed that the oocyte's surface of both species has pore canals over the entire surface and a funnel-shaped micropyle. At 24°C, the embryonic development of C. lepidura was completed 25 h after fertilization, and blastopore closure occurred in 7 h 30 min. In S. elegans, larvae hatched 20 h after fertilization, and blastopore closure occurred in 7 h 15 min. The fertilization rate was 74.5 ± 7.96 and 71.2 ± 10.8% for C. lepidura and S. elegans, respectively. This study provides important support for clarifying phylogenetic relationships and in ecological and zoological understanding of Neotropical Curimatidae fish.

Autophagy and apoptosis interplay during follicular atresia in fish ovary: a morphological and immunocytochemical study.

Follicular atresia in fish ovary provides an interesting model for studying autophagy and apoptosis. In order to improve knowledge of the mechanisms regulating ovarian regression, we investigated the immunolocalisation of various proteins involved in the complex network of autophagy and apoptosis. Females of three species of freshwater fish maintained in captivity were sampled after the reproductive period and the main events of follicular atresia were assessed by histology: splits in the zona radiata, yolk degradation and reabsorption, hypertrophy of the follicular cells, accumulation of autophagic vacuoles, closing of the follicular lumen and thickening of the theca. The interplay of apoptosis and autophagy was analysed by TUNEL in situ and by immunocytochemistry for caspase-3, bax, bcl-2, beclin-1 and cathepsin-D. During early and advanced stages of follicular regression, the actin cytoskeleton was well developed and labelling for bcl-2 and cathepsin-D were pronounced in the follicular cells at a stage when they were intensively involved in yolk phagocytosis. Immunofluorescence for beclin-1 was prevalent in the follicular cells, punctate labelling often surrounding autophagic vacuoles during the advanced stage of follicular regression, a critical step towards cell death. TUNEL-positive reaction and immunostaining for bax and caspase-3 demonstrated the participation of apoptosis in late follicular regression. Overall, this study provides evidence that autophagic and apoptotic proteins are activated in a coordinated fashion depending on the stage of follicular regression, with interplay between autophagy and apoptosis being essential in determining the fate of the cell during follicular atresia in fish ovary.

Apoptosis, cell proliferation and vitellogenesis during the folliculogenesis and follicular growth in teleost fish.

Aiming to better understand folliculogenesis, this study evaluated cell death and proliferation of ovarian cells, besides cathepsin-D expression in Prochilodus argenteus captured in two sites of the São Francisco River downstream from the Três Marias Dam, Brazil. In the site immediately following the Dam (S1), low levels of dissolved oxygen were registered in the rainy period. The water temperature was higher in the São Francisco River immediately after the confluence with the Abaeté River (S2), regardless of the period. In S1, the ovaries showed smaller oocytes, high caspase-3 enzymatic activity and apoptosis, lower cells in proliferation and GSI, as well as a lesser quantity of cathepsin-D when compared to females captured from S2. Regarding relative frequency of ovarian structures, in the dry period, only oogonia and perinucleolar oocytes were found in fish ovaries from both sites. On the other hand, in the rainy period, the relative frequency of oogonia and perinucleolar oocytes decreased and the vitellogenic oocytes increased in S2. Postovulatory follicles were observed only in S2, whereas atretic follicles occurred at a higher frequency in S1. Our results showed that apoptosis, cell proliferation and cathepsina-D evaluation can be used as biomarkers of environmental impact.

Eggs ultrastructure and early development of Franciscodoras marmoratus (Pisces: Doradidae).

This study presents, for the first time, information on the eggs and early development of Franciscodoras marmoratus, fish of São Francisco river, Brazil. To analyse the egg ultrastructure and morphological events of embryogenesis, a total of 36 F. marmoratus specimens (18 males and 18 females) were captured and subjected to spawning induction. Gametes were collected by manual extrusion, and fertilization was conducted using the dry method. After fertilization, eggs were kept in incubators with water temperature of 24°C. The embryonic development was monitored using a stereomicroscope until hatching. There was a 67% positive response to hypophysation by the females and the fertilization rate was 73.8 ± 6.2%. The oocytes are discoid, yellow, adhesive and covered by a thick jelly coat. Under the electron scanning microscope, the oocytes presented a surface with pore canals and funnel-shaped micropyle with a smooth vestibule. Recently extruded oocytes had a mean diameter of 1.27 ± 0.4 mm and after hydration was 1.91 ± 0.05 mm. The jelly coat was 0.34 ± 0.03 mm thickness, and the perivitelline space was 0.19 ± 0.04 mm. Eight phases of the embryonic development were identified, and embryogenesis was completed at 47 h after fertilization, at 24°C water temperature. The recently hatched larvae had 2.76 ± 0.57 mm of total length. These results provide useful information for the successful breeding and reproductive strategies of fishes.