ABSTRACT
Platy-1 retroposons are short interspersed elements (SINEs) unique to platyrrhine primates. Discovered in the common marmoset (Callithrix jacchus) genome in 2016, these 100 bp mobile element insertions (MEIs) appeared to be novel drivers of platyrrhine evolution, with over 2200 full-length members across 62 different subfamilies, and strong evidence of ongoing proliferation in C. jacchus. Subsequent characterization of Platy-1 elements in Aotus, Saimiri and Cebus genera, suggested that the widespread mobilization detected in marmoset (family Callithrichidae) was perhaps an anomaly. Two additional Callithrichidae genomes are now available, a scaffold level genome assembly for Saguinus imperator (tamarin; SagImp_v1) and a chromosome-level assembly for Saguinus midas (Midas tamarin; ASM2_v1). Here, we report that each tamarin genome contains over 11,000 full-length Platy-1 insertions, about 1150 are shared by both Saguinus tamarins, 7511 are unique to S. imperator, and another 8187 are unique to S. midas. Roughly 325 are shared among the three callithrichids. We identified six new Platy-1 subfamilies derived from Platy-1-8, with the youngest new subfamily, Platy-1-8c_Saguinus, being the primary source of the Saguinus amplification burst. This constitutes the largest expansion of Platy-1 MEIs reported to date and the most extensive independent SINE amplification between two closely related species.
Subject(s)
Retroelements , Saguinus , Animals , Saguinus/genetics , Retroelements/genetics , Callithrix/genetics , Short Interspersed Nucleotide ElementsABSTRACT
This report describes a severe outbreak of the gill fluke Centrocestus formosanus in farm-raised platies Xiphophorus maculatus in Brazil, with mortality rate approaching 95%. Typical clinical signs of infection were observed, with microscopic examinations of fresh gills revealing multiple cysts containing a once-folded metacercaria with an X-shaped excretory bladder. The 18S subunit of the metacercariae (BR1) was amplified by PCR, sequenced and analyzed by BLAST. Subsequent phylogenetic analyses revealed that the BR1 isolate was closely related to C. formosanus from Thailand. This is the first report of C. formosanus in ornamental fish in Brazil. Our observations suggest that platies are highly sensitive to this digenetic parasite. Controlling population densities of the parasite's intermediate host, the snail Melanoides tuberculata, would help to reduce outbreaks.
Subject(s)
Cyprinodontiformes , Fish Diseases , Heterophyidae , Trematoda , Trematode Infections , Animals , Brazil , Disease Outbreaks , Farms , Phylogeny , Thailand , Trematode Infections/veterinaryABSTRACT
Well-defined plate and hollow disk of silica-dioctadecyldimethylammonium hybrid particles were obtained by the sol-gel reaction of tetraethoxysilane in the presence of dioctadecyldimethylammonium chloride, where synthetic condition was determined based on the Stöber synthesis for micron size silica sphere. The particle size was several hundreds of nm in the radius and several tens of nm in the thickness. X-ray powder diffraction patterns indicated that the products possess layered mesostructures, which were thought to be directed by the lamellar aggregates of dioctadecyldimethylammonium.
ABSTRACT
This work investigated the relationship between water characteristics and infestation of protozoan parasites, Icthyophthirius multifiliis and Trichodina sp., in swordtails (Xiphophorus helleri) and platy (Xiphophorus maculates) collected in an ornamental fish farm in São Paulo, Brazil. Fish were monthly collected from ponds and tanks for one year. The prevalence rates in fish from tanks and ponds were, respectively, 34.2 percent and 22.5 percent for I. multifiliis, and 13 percent and 54.2 percent for Trichodina sp. Increased electric conductivity and pH provoked reduction of I. multifiliis infestation. Low oxygen concentration increased Trichodina sp. infestation. The use of salt to increase the electric conductivity of water was a method to control I. multifiliis. Low dissolved oxygen and the addition of organic fertilizer favored the reproduction of Trichodina sp.
Investigou-se a relação entre as características da água e a infestação de protozoários parasitos, Icthyophthirius multifiliis e Trichodina sp., em peixe espada, Xiphophorus helleri e em plati, Xiphophorus maculatus, coletados em uma piscicultura de peixes ornamentais no Estado de São Paulo, Brasil. Os peixes foram coletados mensalmente, durante um ano, dos viveiros e das caixas de estocagem. A prevalência da infestação nos peixes das caixas e dos viveiros foram, respectivamente, 34,2 por cento e 22,5 por cento para I. multifiliis e 13 por cento e 54 por cento para Trichodina sp. A elevada condutividade elétrica e o pH da água reduziram a infestação por I. multifiliis. A baixa concentração de oxigênio resultou em aumento na infestação por Trichodina sp. O uso do sal, para aumentar a condutividade elétrica da água, consistiu em um método de controle de I. multifiliis. A redução do oxigênio dissolvido e a adição de fertilizante orgânico favoreceram a reprodução de Trichodina sp.
