Exploring the Sublethal Impacts of Cu and Zn on Daphnia magna: a transcriptomic perspective.

Metal contamination of aquatic environments remains a major concern due to their persistence. The water flea Daphnia magna is an important model species for metal toxicity studies and water quality assessment. However, most research has focused on physiological endpoints such as mortality, growth, and reproduction in laboratory settings, as well as neglected toxicogenomic responses. Copper (Cu) and zinc (Zn) are essential trace elements that play crucial roles in many biological processes, including iron metabolism, connective tissue formation, neurotransmitter synthesis, DNA synthesis, and immune function. Excess amounts of these metals result in deviations from homeostasis and may induce toxic responses. In this study, we analyzed Daphnia magna transcriptomic responses to IC5 levels of Cu (120 µg/L) and Zn (300 µg/L) in environmental water obtained from a pristine lake with adjusted water hardness (150 mg/L CaCO3). The study was carried out to gain insights into the Cu and Zn regulated stress response mechanisms in Daphnia magna at transcriptome level. A total of 2,688 and 3,080 genes were found to be differentially expressed (DEG) between the control and Cu and the control and Zn, respectively. There were 1,793 differentially expressed genes in common for both Cu and Zn, whereas the number of unique DEGs for Cu and Zn were 895 and 1,287, respectively. Gene ontology and KEGG pathways enrichment were carried out to identify the molecular functions and biological processes affected by metal exposures. In addition to well-known biomarkers, novel targets for metal toxicity screening at the genomic level were identified.

Clinging on the brink: Whole genomes reveal human-induced population declines and severe inbreeding in the Critically Endangered Emirati Leaf-toed Gecko (Asaccus caudivolvulus).

Human-mediated habitat destruction has had a profound impact on increased species extinction rates and population declines worldwide. The coastal development in the United Arab Emirates (UAE) over the last two decades, serves as an example of how habitat transformation can alter the landscape of a country in just a few years. Here, we study the genomic implications of habitat transformation in the Critically Endangered Emirati Leaf-toed Gecko (Asaccus caudivolvulus), the only endemic vertebrate of the UAE. We generate a high-quality reference genome for this gecko, representing the first reference genome for the family Phyllodactylidae, and produce whole-genome resequencing data for 23 specimens from 10 different species of leaf-toed geckos. Our results show that A. caudivolvulus has consistently lower genetic diversity than any other Arabian species of Asaccus, suggesting a history of ancient population declines. However, high levels of recent inbreeding are recorded among populations in heavily developed areas, with a more than 50% increase in long runs of homozygosity within a 9-year period. Moreover, results suggest that this species does not effectively purge deleterious mutations, hence making it more vulnerable to future stochastic threats. Overall, results show that A. caudivolvulus is in urgent need of protection, and habitat preservation must be warranted to ensure the species' survival.

The Database of European Forest Insect and Disease Disturbances: DEFID2.

Insect and disease outbreaks in forests are biotic disturbances that can profoundly alter ecosystem dynamics. In many parts of the world, these disturbance regimes are intensifying as the climate changes and shifts the distribution of species and biomes. As a result, key forest ecosystem services, such as carbon sequestration, regulation of water flows, wood production, protection of soils, and the conservation of biodiversity, could be increasingly compromised. Despite the relevance of these detrimental effects, there are currently no spatially detailed databases that record insect and disease disturbances on forests at the pan-European scale. Here, we present the new Database of European Forest Insect and Disease Disturbances (DEFID2). It comprises over 650,000 harmonized georeferenced records, mapped as polygons or points, of insects and disease disturbances that occurred between 1963 and 2021 in European forests. The records currently span eight different countries and were acquired through diverse methods (e.g., ground surveys, remote sensing techniques). The records in DEFID2 are described by a set of qualitative attributes, including severity and patterns of damage symptoms, agents, host tree species, climate-driven trigger factors, silvicultural practices, and eventual sanitary interventions. They are further complemented with a satellite-based quantitative characterization of the affected forest areas based on Landsat Normalized Burn Ratio time series, and damage metrics derived from them using the LandTrendr spectral-temporal segmentation algorithm (including onset, duration, magnitude, and rate of the disturbance), and possible interactions with windthrow and wildfire events. The DEFID2 database is a novel resource for many large-scale applications dealing with biotic disturbances. It offers a unique contribution to design networks of experiments, improve our understanding of ecological processes underlying biotic forest disturbances, monitor their dynamics, and enhance their representation in land-climate models. Further data sharing is encouraged to extend and improve the DEFID2 database continuously. The database is freely available at https://jeodpp.jrc.ec.europa.eu/ftp/jrc-opendata/FOREST/DISTURBANCES/DEFID2/.

Systematic molecular analysis of the human secretome and membrane proteome in gastrointestinal adenocarcinomas.

The human secretome and membrane proteome are a large source of cancer biomarkers. Membrane-bound and secreted proteins are promising targets for many clinically approved drugs, including for the treatment of tumours. Here, we report a deep systematic analysis of 957 adenocarcinomas of the oesophagus, stomach, colon and rectum to examine the cancer-associated human secretome and membrane proteome of gastrointestinal tract adenocarcinomas (GIACs). Transcriptomic data from these GIACs were applied to an innovative majority decision-based algorithm. We quantified significantly expressed protein-coding genes. Interestingly, we found a consistent pattern in a small group of genes found to be overexpressed in GIACs, which were associated with a cytokine-cytokine interaction pathway (CCRI) in all four cancer subtypes. These CCRI associated genes, which spanned both one secretory and one membrane isoform were further analysed, revealing a putative biomarker, interleukin-1 receptor accessory protein (IL1RAP), which indicated a poor overall survival, a positive correlation with cancer stemness and a negative correlation with several kinds of T cells. These results were further validated in vitro through the knockdown of IL1RAP in two human gastric carcinoma cell lines, which resulted in a reduced indication of cellular proliferation, migration and markers of invasiveness. Following IL1RAP silencing, RNA seq results showed a consistent pattern of inhibition related to CCRI, proliferation pathways and low infiltration of regulatory T cells (Tregs) and CD8 naive cells. The significance of the human secretome and membrane proteome is elucidated by these findings, which indicate IL1RAP as a potential candidate biomarker for cytokine-mediated cancer immunotherapy in gastric carcinoma.

Carbapenemase-producing Aeromonas species isolated from the urban-impacted Akaki river in Ethiopia.

Carbapenemase-producing Aeromonas species are an emerging health threat. This study aimed to determine carbapenemase-mediated resistance among Aeromonas isolates from the Akaki river, Ethiopia during the dry and wet seasons in 2019-2020. Antimicrobial susceptibility to carbapenems and cephalosporins was determined and carbapenemase production was confirmed. Of 163 isolates, the majority were human pathogens Aeromonas caviae (62), Aeromonas hydrophila (33) and Aeromonas veronii (49). These isolates were resistant to carbapenem and cephalosporin antibiotics, with the highest resistance to cefotaxime 86 (59.7%), ertapenem 71 (49.3%) and imipenem 65 (45.1%). Resistance to carbapenem antibiotics varied between species, where most A. veronii 37 (75.5%) and A. hydrophila 28 (84.8%) were resistant to imipenem and all A. caviae were sensitive. A. veronii, A. caviae and A. hydrophila resistance to meropenem was 31 (63.3%), 3 (4.8%) and 19 (57.6%), respectively. Of isolates resistant to carbapenem, 82.1% A. hydrophila and 94.4% A. veronii were carbapenemase producers. Cephalosporin resistance also varied among the different species. The highest resistance to carbapenem antibiotics was in isolates collected during the wet season (p<0.05); however, it was not consistent across all classes of antibiotics tested. The rivers in megacities could be reservoirs of carbapenemase-producing Aeromonas spp.

Influence of water hardness on zinc toxicity in Daphnia magna.

Zinc is an essential trace metal required for the maintenance of multiple physiological functions. Due to this, organisms can experience both zinc deficiency and toxicity. Hardness is recognized as one of the main modifying physiochemical factors regulating zinc bioavailability. Therefore, the present study analyzed the effect of hardness on zinc toxicity using Daphnia magna. Endpoint parameters were acute-toxicity, development, reproduction, and expression data for genes involved in metal regulation and oxidative stress. In addition, the temporal expression profiles of genes during the initiation of reproduction and molting were investigated. Water hardness influenced the survival in response to exposures to zinc. A zinc concentration of 50 µg/l in soft water (50 mg CaCO3 /L) caused 73% mortality after 96 h exposure, whereas the same zinc concentration in the hardest water did not cause any significant mortality. Moreover, increasing water hardness from 100 to 200 mg CaCO3 /L resulted in a reduced number of offspring. Fecundity was higher at first brood for groups exposed to higher Zn concentrations. The survival data were used to assess the precision of the bioavailability models (Bio-met) and the geochemical model (Visual MINTEQ). As the Bio-met risk predictions overestimated the Zn toxicity, a competition-based model to describe the effects of hardness on zinc toxicity is proposed. This approach can be used to minimize differences in setting environmental quality standards. Moreover, gene expression data showed that using the toxicogenomic approach was more sensitive than the physiological endpoints. Therefore, data presented in the study can be used to improve risk assessment for zinc toxicity.

Transcriptional responses of Daphnia magna exposed to Akaki river water.

Pollution of the aquatic environment is a global problem, with industrial waste, farming effluents, sewage, and wastewater as the main contributors. Many pollutants are biologically active at low concentrations, resulting in sublethal effects, which makes it a highly complex situation and difficult to assess. In many places, such as the Akaki river in Ethiopia, the pollution situation has resulted in streams with minimal presence of invertebrates or vertebrates. As it is difficult to perform a complete chemical analysis of the waters, the present study focused on using gene expression analysis as a biological end point to determine the effects of Akaki river contaminants. The present study was conducted using the small planktonic crustacean Daphnia magna with toxicogenomic molecular markers. Daphnia magna neonates were exposed to Akaki water samples collected from two different sites on the river and analyzed for mortality and expression of genes involved in different biological pathways. Despite the poor quality of Akaki river water, 48 h acute toxicity tests showed no mortality. Interestingly, analysis of sublethal toxicogenomic responses showed that exposure to Akaki water altered the expression of 25 out of 37 genes involved in metal regulation, immune response, oxidative stress, respiration, reproduction, and development. The toxicogenomic data gives insight into the mechanisms involved in causing potential adverse effects to aquatic biota harboring the Akaki river system.

Sustainability transformations: socio-political shocks as opportunities for governance transitions.

Faced with accelerating environmental challenges, research on social-ecological systems is increasingly focused on the need for transformative change towards sustainable stewardship of natural resources. This paper analyses the potential of rapid, large-scale socio-political change as a window of opportunity for transformative change of natural resources governance. We hypothesize that shocks at higher levels of social organization may open up opportunities for transformation of social-ecological systems into new pathways of development. However, opportunities need to be carefully navigated otherwise transformations may stall or lead the social-ecological system in undesirable directions. We investigate (i) under which circumstances socio-political change has been used by actors as a window of opportunity for initiating transformation towards sustainable natural resource governance, (ii) how the different levels of the systems (landscape, regime and niche) interact to pave the way for initiating such transformations and (iii) which key features (cognitive, structural and agency-related) get mobilized for transformation. This is achieved through analyzing natural resource governance regimes of countries that have been subject to rapid, large-scale political change: water governance in South Africa and Uzbekistan and governance of coastal fisheries in Chile. In South Africa the political and economic change of the end of the apartheid regime resulted in a transformation of the water governance regime while in Uzbekistan after the breakdown of the Soviet Union change both at the economic and political scales and within the water governance regime remained superficial. In Chile the democratization process after the Pinochet era was used to transform the governance of coastal fisheries. The paper concludes with important insight on key capacities needed to navigate transformation towards biosphere stewardship. The study also contributes to a more nuanced view on the relationship between collapse and renewal.

Zebrafish cyp17a1 knockout reveals that androgen-mediated signaling is important for male brain sex differentiation.

Brain sex differentiation is a complex process, wherein genes and steroid hormones act to induce specific gender brain differentiation. Testosterone (T) derived from the gonads has been linked to neural circuit modeling in a sex-specific manner. Previously, we have shown that cyp17a1 knockout (KO) zebrafish have low plasma androgen levels, and display compromised male-typical mating behaviors. In this study, we demonstrated that treatment of cyp17a1 KO males with T or 11-ketotestosterone (11-KT) is sufficient to rescue mating impairment by restoring the male-typical secondary sex characters (SSCs) and mating behaviors, confirming an essential role of androgen in maintaining SSCs and mating behaviors. Brain steroid hormone analysis revealed that cyp17a1 KO fish have reduced levels of T and 11-KT. We performed RNA sequencing on brain samples of control and cyp17a1 KO male zebrafish to get insights regarding the impact of cyp17a1 KO on gene expression pattern, and to correlate it with the observed disruption of male-typical mating behaviors. Transcriptome analysis of cyp17a1 KO males showed a differential gene expression when compared to control males. In total, 358 genes were differentially regulated between control males and KO males. Important genes including brain aromatase (cyp19a1b), progesterone receptor (pgr), deiodinase (dio2), and insulin-like growth factor 1 (igf1) that are involved in brain functions, as well as androgen response genes including igf1, frem1a, elovl1a, pax3a, mmp13b, hsc70, ogg1 were regulated. RT-qPCR analysis following rescue of cyp17a1 KO with T and 11-KT further suggested that androgen-mediated signaling is disrupted in the cyp17a1 KO fish. Our results indicated that cyp17a1 KO fish have an incomplete masculinization and altered brain gene expression, which could be due to decreased androgen levels.

Distinct transcriptional response of Caenorhabditis elegans to different exposure routes of perfluorooctane sulfonic acid.

Although people are exposed daily to per- and polyfluorinated alkyl substances (PFASs), the biological consequences are poorly explored. The health risks associated with PFAS exposure are currently based on chemical analysis with a weak correlation to potential harmful effects in man and animals. In this study, we show that perfluorooctane sulfonic acid (PFOS), often the most enriched PFAS in the environment, can be transferred via bacteria to higher organisms such as Caenorhabditis elegans. C. elegans nematodes were exposed to PFOS directly in buffer or by feeding on bacteria pretreated with PFOS, and this led to distinct gene expression profiles. Specifically, heavy metal and heat shock associated genes were significantly, although inversely, expressed following the different PFOS exposures. The innate immunity receptor for microbial pathogens, clec-60, was shown for the first time to be down-regulated by PFOS. This is in line with a previous study indicating that PFOS is associated with children's susceptibility to certain infectious diseases. Furthermore, bar-1, a gene associated with various cancers was highly up-regulated only when C. elegans were exposed to PFOS pretreated live bacteria. Furthermore, dead bacterial biomass had higher binding capacity for linear and isomeric PFOS than live bacteria, which correlated to the higher levels of PFOS detected in C. elegans when fed the treated E. coli, respectively. These results reveal new aspects concerning trophic chain transport of PFOS.

Germ cell depletion in zebrafish leads to incomplete masculinization of the brain.

Zebrafish sex differentiation is under the control of multiple genes, but also relies on germ cell number for gonadal development. Morpholino and chemical mediated germ cell depletion leads to sterile male development in zebrafish. In this study we produced sterile males, using a dead end gene morpholino, to determine gonadal-brain interactions. Germ cell depletion following dnd inhibition downregulated the germ cell markers, vasa and ziwi, and later the larvae developed as sterile males. Despite lacking proper testis, the gonadal 11-ketotestosterone (11-KT) and estradiol (E2) levels of sterile males were similar to wild type males. Qualitative analysis of sexual behavior of sterile males demonstrated that they behaved like wild type males. Furthermore, we observed that brain 11-KT and E2 levels in sterile males remained the same as in the wild type males. In female brain, 11-KT was lower in comparison to wild type males and sterile males, while E2 was higher when compared to wild type males. qRT-PCR analysis revealed that the liver transcript profile of sterile adult males was similar to wild type males while the brain transcript profile was similar to wild type females. The results demonstrate that proper testis development may not be a prerequisite for male brain development in zebrafish but that it may be needed to fully masculinize the brain.

Adaptive governance, ecosystem management, and natural capital.

To gain insights into the effects of adaptive governance on natural capital, we compare three well-studied initiatives; a landscape in Southern Sweden, the Great Barrier Reef in Australia, and fisheries in the Southern Ocean. We assess changes in natural capital and ecosystem services related to these social-ecological governance approaches to ecosystem management and investigate their capacity to respond to change and new challenges. The adaptive governance initiatives are compared with other efforts aimed at conservation and sustainable use of natural capital: Natura 2000 in Europe, lobster fisheries in the Gulf of Maine, North America, and fisheries in Europe. In contrast to these efforts, we found that the adaptive governance cases developed capacity to perform ecosystem management, manage multiple ecosystem services, and monitor, communicate, and respond to ecosystem-wide changes at landscape and seascape levels with visible effects on natural capital. They enabled actors to collaborate across diverse interests, sectors, and institutional arrangements and detect opportunities and problems as they developed while nurturing adaptive capacity to deal with them. They all spanned local to international levels of decision making, thus representing multilevel governance systems for managing natural capital. As with any governance system, internal changes and external drivers of global impacts and demands will continue to challenge the long-term success of such initiatives.

TBECH, 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane, alters androgen receptor regulation in response to mutations associated with prostate cancer.

Point mutations in the AR ligand-binding domain (LBD) can result in altered AR structures leading to changes of ligand specificity and functions. AR mutations associated to prostate cancer (PCa) have been shown to result in receptor activation by non-androgenic substances and anti-androgenic drugs. Two AR mutations known to alter the function of anti-androgens are the ART877A mutation, which is frequently detected mutation in PCa tumors and the ARW741C that is rare and has been derived in vitro following exposure of cells to the anti-androgen bicalutamide. AR activation by non-androgenic environmental substances has been suggested to affect PCa progression. In the present study we investigated the effect of AR mutations (ARW741C and ART877A) on the transcriptional activation following exposure of cells to an androgenic brominated flame retardant, 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane (TBECH, also named DBE-DBCH). The AR mutations resulted in higher interaction energies and increased transcriptional activation in response to TBECH diastereomer exposures. The ART877A mutation rendered AR highly responsive to low levels of DHT and TBECH and led to increased AR nuclear translocation. Gene expression analysis showed a stronger induction of AR target genes in LNCaP cells (ART877A) compared to T-47D cells (ARWT) following TBECH exposure. Furthermore, AR knockdown experiments confirmed the AR dependency of these responses. The higher sensitivity of ART877A and ARW741C to low levels of TBECH suggests that cells with these AR mutations are more susceptible to androgenic endocrine disrupters.

Zebrafish sexual behavior: role of sex steroid hormones and prostaglandins.

BACKGROUND: Mating behavior differ between sexes and involves gonadal hormones and possibly sexually dimorphic gene expression in the brain. Sex steroids and prostaglandin E2 (PGE2) have been shown to regulate mammalian sexual behavior. The present study was aimed at determining whether exposure to sex steroids and prostaglandins could alter zebrafish sexual mating behavior. METHODS: Mating behavior and successful spawning was recorded following exposure to 17ß-estradiol (E2), 11-ketotestosterone (11-KT), prostaglandin D2 (PGD2) and PGE2 via the water. qRT-PCR was used to analyze transcript levels in the forebrain, midbrain, and hindbrain of male and female zebrafish and compared to animals exposed to E2 via the water. RESULTS: Exposure of zebrafish to sex hormones resulted in alterations in behavior and spawning when male fish were exposed to E2 and female fish were exposed to 11-KT. Exposure to PGD2, and PGE2 did not alter mating behavior or spawning success. Determination of gene expression patterns of selected genes from three brain regions using qRT-PCR analysis demonstrated that the three brain regions differed in gene expression pattern and that there were differences between the sexes. In addition, E2 exposure also resulted in altered gene transcription profiles of several genes. CONCLUSIONS: Exposure to sex hormones, but not prostaglandins altered mating behavior in zebrafish. The expression patterns of the studied genes indicate that there are large regional and gender-based differences in gene expression and that E2 treatment alter the gene expression pattern in all regions of the brain.

Inhibition of retinoic acid synthesis disrupts spermatogenesis and fecundity in zebrafish.

Timing of germ cell entry into meiosis is sexually dimorphic in mammals. However it was recently shown that germ cells initiate meiosis at the same time in male and female zebrafish. Retinoic acid (RA) has been shown to be critical for mammalian spermatogenesis. Inhibition of RA synthesis by WIN 18,446 has been reported to inhibit spermatogenesis in a wide variety of animals including humans and was once used as a contraceptive in humans. In this study we explored the role of RA in zebrafish spermatogenesis. In silico analysis with Internal coordinate mechanics docking software showed that WIN 18,446 can bind to the rat, human and zebrafish Aldh1a2 catalytic domain with equivalent potency. RA exposure resulted in up-regulation of the RA metabolizing enzyme genes cyp26a1, cyp26b1 and cyp26c1 in vitro and in vivo. Exposure to WIN 18,446 resulted in down-regulation of Aldh1a2, cyp26a1 and cyp26b1 in vivo. WIN 18,446 was effective in disrupting spermatogenesis and fecundity in zebrafish but the reduction in sperm count and fecundity was only observed when zebrafish were maintained on a strict Artemia nauplii diet which is known to contain low levels of vitamin A. This study shows that RA is involved in spermatogenesis as well as oocyte development in zebrafish. As the zebrafish Aldh1a2 structure and function is similar to the mammalian counterpart, Aldh1a2 inhibitor screening using zebrafish as a model system may be beneficial in the discovery and development of new and safe contraceptives for humans.

Lessons for resource conservation from two contrasting small-scale fisheries.

Small-scale fisheries present challenges to management due to fishers' dependency on resources and the adaptability of management systems. We compared social-ecological processes in the sea cucumber fisheries of Zanzibar and Mayotte, Western Indian Ocean, to better understand the reasons for resource conservation or collapse. Commercial value of wild stocks was at least 30 times higher in Mayotte than in Zanzibar owing to lower fishing pressure. Zanzibar fishers were financially reliant on the fishery and increased fishing effort as stocks declined. This behavioral response occurred without adaptive management and reinforced an unsustainable fishery. In contrast, resource managers in Mayotte adapted to changing fishing effort and stock abundance by implementing a precautionary fishery closure before crossing critical thresholds. Fishery closure may be a necessary measure in small-scale fisheries to preserve vulnerable resources until reliable management systems are devised. Our comparison highlighted four poignant lessons for managing small-scale fisheries: (1) diagnose the fishery regularly, (2) enable an adaptive management system, (3) constrain exploitation within ecological limits, and (4) share management responsibility.

Juvenile ovary to testis transition in zebrafish involves inhibition of ptges.

The sex differentiation mechanisms in zebrafish (Danio rerio) remains elusive, partly because of the absence of sex chromosomes but also because the process appears to depend on the synchrony of multiple genes and possibly environmental factors. Zebrafish gonadal development is initiated through the development of immature oocytes. Depending on multiple signaling cues, in about half of the individuals, the juvenile ovaries degenerate or undergo apoptosis to initiate testes development while the other half maintains the oogenic pathway. We have previously shown that activation of NFκB and prostaglandin synthase 2 (ptgs2) results in female-biased sex ratios. Prostaglandin synthase and prostaglandins are involved in multiple physiological functions, including cell survival and apoptosis. In the present study, we show that inhibition of ptgs2 by meloxicam results in male-biased sex ratios. On further evaluation, we observed that exposure with the prostaglandin D2 (PGD2) analogue BW-245C induced SRY-box containing gene 9a (sox9a) and resulted in male-biased sex ratios. On the other hand, prostaglandin E2 (PGE2) treatment resulted in female-biased sex ratios and involved activation of NFκB and the ß-catenin pathway as well as inhibition of sox9. Exposure to the ß-catenin inhibitor PNU-74654 resulted in up-regulation of ptgds and male-biased sex ratios, further confirming the involvement of ß-catenin in the female differentiation pathway. In this study, we show that PGD2 and PGE2 can program the gonads to either the testis or the ovary differentiation pathways, indicating that prostaglandins are involved in the regulation of zebrafish gonadal differentiation.

Positional identification of TNFSF4, encoding OX40 ligand, as a gene that influences atherosclerosis susceptibility.

Ath1 is a quantitative trait locus on mouse chromosome 1 that renders C57BL/6 mice susceptible and C3H/He mice resistant to diet-induced atherosclerosis. The quantitative trait locus region encompasses 11 known genes, including Tnfsf4 (also called Ox40l or Cd134l), which encodes OX40 ligand. Here we report that mice with targeted mutations of Tnfsf4 had significantly (P

Temporal sex specific brain gene expression pattern during early rat embryonic development.

Background: The classical concept of brain sex differentiation suggests that steroid hormones released from the gonads program male and female brains differently. However, several studies indicate that steroid hormones are not the only determinant of brain sex differentiation and that genetic differences could also be involved. Methods: In this study, we have performed RNA sequencing of rat brains at embryonic days 12 (E12), E13, and E14. The aim was to identify differentially expressed genes between male and female rat brains during early development. Results: Analysis of genes expressed with the highest sex differences showed that Xist was highly expressed in females having XX genotype with an increasing expression over time. Analysis of genes expressed with the highest male expression identified three early genes, Sry2, Eif2s3y, and Ddx3y. Discussion: The observed sex-specific expression of genes at early development confirms that the rat brain is sexually dimorphic prior to gonadal action on the brain and identifies Sry2 and Eif2s3y as early genes contributing to male brain development.

Iatrogenic transmission of Trypanosoma evansi infection in camels and its consequences.

Trypanosoma evansi infection has started to become a wide spread phenomena around the camel-rearing areas of North Africa and the Middle East. The disease caused by trypanosomes is locally known as "Surra" and it can seriously impact not only the health of domestic animals but the local economy as well. After taking over the management of a farm containing approximately 700 camels, it was found that a large number were suffering from trypanosome infection and it was of the utmost importance to find the source of this infection. An extensive dive into the records and observations were initially made to identify the infected population. Under closer inspection it was found that the infection was limited mostly to female individuals that had undergone extended reproductive analysis or treatment. Blood samples were taken from each of the individuals for buffy coat test and blood smears. Among the total number of tested camels (n = 590), almost 40% were infected with trypanosomes. The number and percentage of infection correlate with the number of fertility and pregnancy treatments that the camels had undergone. The most severely infected group, underwent between 17 and 20 instances of treatment or tests, had an infection rate of almost 90%. The devastating effect of trypanosomiasis on camel pregnancy and birth were also verified with 61% of all abortions and 82% of all neonatal deaths coming from trypanosome infected individuals. These results clearly demonstrate how damaging iatrogenic infections of T. evansi can be and how simply they could have been prevented.