Distribución y cambios del sistema sbGnRH en machos de Rastrelliger brachysoma durante el período reproductivo

Rastrelliger brachysoma is a mariculture candidate species, but reproduction in captive fish has been problematic. This report examines the difference in the HPG axis, the neuroendocrine system and the development of reproductive tissues between captive vs. wild male R. brachysoma. The gonadosomatic index (GSI) of sexually mature male wild R. brachysoma was 1.12±0.34 and 1.94±0.26 during the non-breeding and breeding seasons, respectively. Captive R. brachysoma had a GSI of 1.88±0.17. All wild R. brachysoma were in the late spermatogenic stage irrespective of seasons. Immunostaining results showed that sbGnRH-immunoreactive neurons were distributed in three areas of the brain, namely the nucleus periventricularis, nucleus preopticus and nucleus lateralis tuberis. Follicle stimulating hormone and luteinizing hormone immunoreactivities were also observed in the pituitary gland. The levels of brain sbGnRH and GtH mRNA were not significantly different between the non-breeding and breeding seasons, but captive fish displayed (times or percent difference) lower mRNA levels than wild fish. These results suggest that these hormones control the testicular development in R. brachysoma and that the impaired reproduction in captivity may be due to their relative lower expression levels of follicle stimulating hormone and luteinizing hormone genes.Rastrelliger brachysoma es una especie candidata para la piscicultura marina, pero la reproducción de individuos cautivos de esta especie ha sido problemática. Este estudio examina las diferencias en el eje hipotálamo-hipófisis-gónada (eje HPG), junto con el desarrollo de tejidos reproductivos, entre machos cautivos y salvajes de R. brachysoma. El índice gonadosomático (IGS) de machos salvajes de R. brachysoma sexualmente maduros fue de 1.12±0.34 y 1.94±0.26 durante la estación no-reproductiva y reproductiva, respectivamente. Los R. brachysoma cautivos mostraron un IGS de 1.88±0.17. Todos los R. brachysoma salvajes se encontraban en un estado de espermatogénesis tardío, independientemente de la estación. Los resultados de inmunotinción mostraron que las neuronas sbGnRH-inmunoreactivas se distribuían en tres áreas del cerebro, nucleus periventricularis, nucleus preopticus y nucleus lateralis tuberis. Se detectó inmunoreactividad para Fsh y Lh también en la hipófisis. Los niveles de mRNA de sbgnrh y gths en cerebro no fueron significativamente diferentes entre las estaciones de reproducción y no-reproducción, aunque se observaron niveles de mRNA menores (diferencia en nivel o porcentaje) en individuos cautivos que en salvajes. Estos resultados sugieren que las hormonas analizadas controlan el desarrollo testicular en R. brachysoma y que la inhibición de la reproducción en cautividad podría ser debida a unos menores niveles de expresión relativa de los genes de Fsh y Lh

Spermatozoon of the wild scalloped perchlet, Ambassis nalua (Hamilton, 1822): Ultrastructure and morphometric analysis

The description of sperm morphology is fundamental in the reproductive biology of fishes, but this information is limited in the family Ambassidae. Our report hence focused on the ultrastructure and morphometric analysis of spermatozoa in a pelagic fish Ambassis nalua. All fish (n = 75) were obtained during January and March 2017 from the Estuarine Pranburi River, Thailand. The standard length of fish used in this study was 3.4 ± 0.12 cm (mean ± standard deviation). All specimens were considered mature based on the abundance of spermatozoa in the testis. The testicular organs were collected and observed using standard histology and transmission electron microscopy (TEM). Ultrastructural observation associated with morphometric analysis showed that spermatozoa are structurally long cells of approximately 51.17 ± 4.54 µm total length, composed of a head, a midpiece and a tail. The head had no acrosome, and the granular structure of condensed chromatin was observed within the ovoid nucleus. The midpiece consisted of a short cylindrical region with the length of 1.29 ± 0.87 µm in diameter, having the centriolar complex organization and eight mitochondria (approx. 0.32 ± 0.02 µm each). The uniflagellar tail was clearly identified with a classical 9+2 arrangements of microtubules. Based on these characteristics, the spermatozoon of wild scalloped perchlet are considered as uniflagellate anacrosomal aquqsperm. The morphological features, including the number of mitochondria, may be used for further cryopreservation and in the evolutionary biology of this species

Characterization of Plasmodium vivax Proteins in Plasma-Derived Exosomes From Malaria-Infected Liver-Chimeric Humanized Mice

Exosomes are extracellular vesicles of endocytic origin containing molecular signatures implying the cell of origin; thus, they offer a unique opportunity to discover biomarkers of disease. Plasmodium vivax, responsible for more than half of all malaria cases outside Africa, is a major obstacle in the goal of malaria elimination due to the presence of dormant liver stages (hypnozoites), which after the initial infection may reactivate to cause disease. Hypnozoite infection is asymptomatic and there are currently no diagnostic tools to detect their presence. The human liver-chimeric (FRG huHep) mouse is a robust P. vivax infection model for exo-erythrocytic development of liver stages, including hypnozoites. We studied the proteome of plasma-derived exosomes isolated from P. vivax infected FRG huHep mice with the objective of identifying liver-stage expressed parasite proteins indicative of infection. Proteomic analysis of these exosomes showed the presence of 290 and 234 proteins from mouse and human origin, respectively, including canonical exosomal markers. Human proteins include proteins previously detected in liver-derived exosomes, highlighting the potential of this chimeric mouse model to study plasma exosomes derived unequivocally from human hepatocytes. Noticeably, we identified 17 parasite proteins including enzymes, surface proteins, components of the endocytic pathway and translation machinery, as well as uncharacterized proteins. Western blot analysis validated the presence of human arginase-I and an uncharacterized P. vivax protein in plasma-derived exosomes. This study represents a proof-of-principle that plasma-derived exosomes from P. vivax infected FRG-huHep mice contain human hepatocyte and P. vivax proteins with the potential to unveil biological features of liver infection and identify biomarkers of hypnozoite infection

The Micronemal Plasmodium Proteins P36 and P52 Act in Concert to Establish the Replication-Permissive Compartment Within Infected Hepatocytes

Within the liver, Plasmodium sporozoites traverse cells searching for a “suitable” hepatocyte, invading these cells through a process that results in the formation of a parasitophorous vacuole (PV), within which the parasite undergoes intracellular replication as a liver stage. It was previously established that two members of the Plasmodium s48/45 protein family, P36 and P52, are essential for productive invasion of host hepatocytes by sporozoites as their simultaneous deletion results in growth-arrested parasites that lack a PV. Recent studies point toward a pathway of entry possibly involving the interaction of P36 with hepatocyte receptors EphA2, CD81, and SR-B1. However, the relationship between P36 and P52 during sporozoite invasion remains unknown. Here we show that parasites with a single P52 or P36 gene deletion each lack a PV after hepatocyte invasion, thereby pheno-copying the lack of a PV observed for the P52/P36 dual gene deletion parasite line. This indicates that both proteins are equally important in the establishment of a PV and act in the same pathway. We created a Plasmodium yoelii P36mCherry tagged parasite line that allowed us to visualize the subcellular localization of P36 and found that it partially co-localizes with P52 in the sporozoite secretory microneme organelles. Furthermore, through co-immunoprecipitation studies in vivo, we determined that P36 and P52 form a protein complex in sporozoites, indicating a concerted function for both proteins within the PV formation pathway. However, upon sporozoite stimulation, only P36 was released as a secreted protein while P52 was not. Our results support a model in which the putatively glycosylphosphatidylinositol (GPI)-anchored P52 may serve as a scaffold to facilitate the interaction of secreted P36 with the host cell during sporozoite invasion of hepatocytes

Structural classifications in the digestive tract of short mackerel, Rastrelliger brachysoma (Bleeker, 1865) from Upper Gulf of Thailand

This study was the first attempt on the classification of the gross anatomy with histological structures of the digestive tract in the Rastrelliger brachysoma. Based on gross anatomical analysis, the digestive tract (65.68±7.06 cm, n = 25) is distinctly composed of four parts; oesophagus, stomach, pyloric caeca and intestine, respectively. Base on the histological analysis of the digestive tract, it is composed of four layers: mucosa, submucosa, muscularis and serosa. The epithelial lining of anterior oesophagus was shown to be a simple squamous epithelium whereas posterior oesophagus, stomach and intestine were simple columnar epithelium. The surface of this epithelium positively stained with both Periodic Acid Schiff (PAS) and alcian blue (AB). The posterior oesophagus exclusively showed high longitudinal fold with numerous gastric glands in the mucosal layer, which is similar to the stomach structure (cariac and pylorus). Numerous pyloric caeca about 220-225 pieces, were detected between the stomach and intestine regions. Finally, the intestinal coefficient (IC) was 3.69±0.47 cm. The anterior intestine presented either various longitudinal folds or various goblet cells. The short longitudinal folds of posterior intestine were in the higher number of goblet cell than the previous part

Cytotoxicity Screening of Anionic Dye Removal by Bio-Natural Adsorbent: Egg Shell and Peanut Shell

Synthetic dye is produced by chemical compound that can be harmful to living microorganisms and human. Textile dye industry is inadequate dye effluent to the environment that can lead to water pollution. Therefore, the  releasing dye effluent should be minimized. Eggshell and peanut shell adsorbent are recycled from solid agro-waste and household food waste. They are wildly used in adsorption process to dye effluent before releasing into natural water bodies. However, the toxic reduction of dye after dye removal is unknown. The aim of this study was to investigate the toxicity of eosin dye and its removal by adsorbent. Moreover, the cytotoxicity of dye is evaluated by brine shrimp lethality bioassay. The results showed that the dye after removal by eggshell had the lower mortality rate when compared to those of eosin dye and penut shell adsorption. The histopathological lesions such as abnormal appearance of enterocyte, blebing cell and coagulation necrosis were found. Therefore, these bio-natural adsorbents might be the alternative substances for the adsorption process in wastewater treatment and they might decrease the toxicity of dye pollution

Identification of a PH domain-containing protein which is localized to crystalloid bodies of Plasmodium ookinetes

Abstract Background For the success of the malaria control and eradication programme it is essential to reduce parasite transmission by mosquito vectors. In the midguts of mosquitoes fed with parasite-infected blood, sexual-stage parasites fertilize to develop into motile ookinetes that traverse midgut epithelial cells and reside adjacent the basal lamina. Therefore, the ookinete is a promising target of transmission-blocking vaccines to break the parasite lifecycle in mosquito vectors. However, the molecular mechanisms of ookinete formation and invasion of epithelial cells have not been fully elucidated. A unique structure called the crystalloid body has been identified in the ookinete cytoplasm by electron microscopy, but its biological functions remain unclear. Methods A recombinant protein of a novel molecule, designated as crystalloid body specific PH domain-containing protein of Plasmodium yoelii (PyCryPH), was synthesized using a wheat germ cell-free system. Specific rabbit antibodies against PyCryPH were obtained to characterize the expression and localization of PyCryPH during sexual-stage parasite development. In addition, PyCryPH knockout parasites were generated by targeted gene disruption to examine PyCryPH function in mosquito-stage parasite development. Results Western blot and immunofluorescence assays using specific antibodies showed that PyCryPH is specifically expressed in zygotes and ookinetes. By immunoelectron microscopy it was demonstrated that PyCryPH is localized within crystalloid bodies. Parasites with a disrupted PyCryPH gene developed normally into ookinetes and formed oocysts on the basal lamina of midguts. In addition, the number of sporozoites residing in salivary glands was comparable to that of wild-type parasites. Conclusions CryPH, containing a signal peptide and PH domain, is predominantly expressed in zygotes and ookinetes and is localized to crystalloid bodies in P. yoelii. CryPH accumulates in vesicle-like structures prior to the appearance of typical crystalloid bodies. Unlike other known crystalloid body localized proteins, CryPH does not appear to have a multiple domain architecture characteristic of the LAP/CCp family proteins. Although CryPH is highly conserved among Plasmodium, Babesia, Theileria, and Cryptosporidium, PyCryPH is dispensable for the development of invasive ookinetes and sporozoites in mosquito bodies

Synthesis and Immunological Studies of the Lipomannan Backbone Glycans Found on the Surface of <i>Mycobacterium tuberculosis</i>

Investigations into novel bacterial drug targets and vaccines are necessary to overcome tuberculosis. Lipomannan (LM), found on the surface of <i>Mycobacterium tuberculosis</i> (<i>Mtb</i>), is actively involved in the pathogenesis and survival of <i>Mtb</i>. Here, we report for the first time a rapid synthesis and biological activities of an LM glycan backbone, α(1–6)­mannans. The rapid synthesis is achieved via a regio- and stereoselective ring opening polymerization to generate multiple glycosidic bonds in one simple chemical step, allowing us to finish assembling the defined polysaccharides of 5–20 units within days rather than years. Within the same pot, the polymerization is terminated by a thiol-linker to serve as a conjugation point to carrier proteins and surfaces for immunological experiments. The synthetic glycans are found to have adjuvant activities <i>in vivo</i>. The interactions with DC-SIGN demonstrated the significance of α(1–6)­mannan motif present in LM structure. Moreover, surface plasmon resonance (SPR) showed that longer chain of synthetic α(1–6)­mannans gain better lectin’s binding affinity. The chemically defined components of the bacterial envelope serve as important tools to reveal the interactions of <i>Mtb</i> with mammalian hosts and facilitate the determination of the immunologically active molecular components