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modern single-cell tools significantly advances our knowledge in this field. We used stable isotope tracers, isotope ratio mass spectrometry and nanoscale secondary ion mass spectrometry (NanoSIMS) to investigate concurrent uptake of nitrate and urea by dinoflagellates Prorocentrum minimum at the population and single-cell levels. Although bulk and averaged single-cell measurements revealed similar relationships between the urea and nitrate uptake, NanoSIMS disclosed significant heterogeneity in nutritional activity of individual cells. Dinoflagellates readily consumed urea even if this nutrient was new to the cells, but some cells took it up at a 9-folds higher rate than others. Furthermore, sudden urea input resulted in overall 30-40% suppression ofthe nitrate uptake. However, a closer look with NanoSIMS showed that in 30% of cells nitrate consumption was completely inhibited, whereas in other cells it might be not suppressed. We conclude that even sporadic inputs of urea to coastal ecosystems are likely to have a prominent effect on P. minimum populations. Physiological heterogeneity among individual dinoflagellate cells can represent a so far overlooked strategy towards ecological success. Funded by the Russian Science Foundation, project 16-14-10116 (to OM, SS) and Federal Ministry of Education and Research, grant BMBF 03F0626A (to AV, MV).
TRENDS IN ENDOSYMBIOTIC GENE TRANSFER ON PLASTID METABOLIC PATHWAYS IN DINOFLAGELLATES WITH NON-CANONICAL PLASTIDS Matsuo E.1, Inagaki Y.12
1 - Graduate School of Life and Environmental Sciences, University of Tsukuba
2 - Center for Computational Sciences, University of Tsukuba
The major photosynthetic dinoflagellates possess red algal-derived plastids, but some minor lineages established non-canonical plastids derived from phylogenetically diverse eukaryotic algae. Dinoflagellates Karlodinium veneficum and Lepidodinium chlorophorum, which bear non-canonical plastids derived from haptophyte- and green algal endosymbionts, respectively, and their nuclear genomes contain genes encoding plastidal proteins that are likely transferred from the genomes ofthe endosymbiont algae (endosymbiotic gene transfer, EGT). Although EGT is generally considered to be an essential step in transforming an endosymbiotic alga into a plastid, it has yet to be fully understood to what extent metabolic functions in the Karlodinium and Lepidodinium plastids rely
on endosymbiotically acquired proteins. We here surveyed nucleus-encoded plastidal proteins in Karlodinium and Lepidodinium, and investigated the origins of the proteins involved in two metabolic pathways localized in the plastid. Chlorophyll a biosynthetic pathway in the two species appeared to be reorganized in different ways. The pathway in Karlodinium was found to be occupied by proteins acquired from the haptophyte endosymbiont, while 'laterally derived' proteins, which were acquired from diverse eukaryotes rather than the green algal endosymbiont, comprise the pathway in Lepidodinium. In contrast, the majority of proteins which were detected in isoprene biosynthetic pathway in Karlodinium or Lepidodinium were derived from host dinoflagellate, suggesting that switch from the canonical to non-canonical plastids barely triggered reorganization of this particular pathway in the two species. In this talk, we discuss biological reasons for the marked difference in the impact of gene transfer between the two metabolic pathways in Karlodinium and Lepidodinium.
LAGENOPHRYS PATINA (CILIOPHORA: PERITRICHIA: LAGENOPHRYIDAE) ATTACHED TO TWO MEXICAN POPULATIONS OF HYALELLA AZTECA (CRUSTACEA: AM-PHIPODA): STATISTICAL APPROACH TO PROBE SITE PATTERN PREFERENCE ON HOST
Mayén-Estrada R.1, Macip-Ríos R.2, Hermoso-Salazar M.3, Romero-Niembro V.M.1
1 - Lab. Protozoología, Depto. Biol. Comparada, Fac. Ciencias, Universidad Nacional Autónoma de México, Circuito Ext. s/núm. Ciudad Universitaria, C. P. 04510, Ciudad de México, Mexico
2 - ENES Morelia, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No.8701, Col. Ex Hacienda de San José de la Huerta, C.P. 58190 Morelia, Michoacán, Mexico
3 - Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Circuito Ext. s/núm. Ciudad Universitaria, C. P. 04510, Ciudad de México, Mexico [email protected]
Members of genus Lagenophrys are obligate symbiotic peritrichs of crustaceans, however the pattern of distribution on corporal surface varies according to involved species. To demonstrate with statistical tests the preference for an amphipod body region or appendage to attach, two Hyalella azteca populations were collected in two Mexican lakes, Xochimilco Lake and Cuitzeo Lake, and density and prevalence of Lagenophrys patina on host surface were calculated. We used a contingency table and
46 • "PROTIST—2016
correspondance analysis to identify a microhabitat preference. Except for the head, pleopods and telson, lagenophryid ciliates were attached to 2-9 amphipod body regions, and greatest prevalence was found on coxae, followed by pereiopods. For Cuitzeo Lake individuals the total L. patina loricae abundance was from 617-1165, being the coxae with the highest values (626), and for Xochimilco Lake L. patina showed a highly significative preference for coxae for their attachment (X2=1752.01, P<0.0001); we also obtained the same highly significant result for Cuitzeo Lake symbiotic system (with X2=1317.8, P < 0.0001). These results could be explained by the shape and function of appendages of amphipods, providing the water flow derived by host movements and swimming, carrying food and oxygen for symbiotic ciliate.
Acknowledgements. To Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica (PAPIIT-DGAPA-UNAM), for the funds to project IN229811 for Cuitzeo Lake samples collection. To all participants of PAPIIT IN229811 project for their support in samples collection, especially to Biól. M. Reyes and M. C. Maricela Vicencio, Facultad de Ciencias, UNAM, for technical procedures.
COMPARATIVE MORPHOMETRY OF LEIDY-ANA SP. (EUGREGARINORIDA) AND ITS FIRST RECORD IN CONOCEPHALUS ICTUS (ORTHOPTERA: ENSIFERA: TETTIGO-NIIDAE) FROM MEXICO Medina-Durán J.H.1, Mayén-Estrada R.1, Mariño-Pérez R.2, Song H.2
1 - Laboratorio de Protozoología, Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, Av. Universidad 3000, C.P. 04510, Ciudad de México, México
2 - DepartmentofEntomology, TexasA&M University, College Station, Texas, USA [email protected]
Leidyana is a genus of apicomplexan eugregarine inhabiting the digestive tract of insects, mainly lepidopterans and orthopterans. Its classification is mainly based on the shape of their epimerite, protomerite, deuteromerite and oocyst, and also on their gametocyst dehiscence. Nevertheless, morphometrical data of the species belonging to this genus have been also considered in order to establish reliable descriptions but is not a main criterion for its identification. In the present work we compared the morphometric attributes of Leidyana sp. a parasite of Conocephalus ictus collected in Tlanchinol, Hidalgo, Mexico, with
two species that also infect orthopterans belonging to the same suborder (Ensifera) but different families and infraorder (Gryllidea) and belonging to the Old World. These species of Leidyana also possess epimerites resembling the ones found of Leidyana sp. The three species measurements comparison was made using a one-way ANOVA and a correspondence analysis (n=20 each sample). We found significative differences in the epimerite length and width, considered as an important character for the eugregarines taxonomy to genus and species level identification. Additionally we show the first record of a species of genus Leidyana parasitizing the gut lumen of an orthopteran of the infraorder Tettigoniidea, family Tettigonidae, as well for Mexico. Key words: eugregarines, Mexico, Leidyana.
Acknowledgments: To Biol. Margarita Reyes Santos for her advice in the stain techniques.
SOME NOTES ON THE MORPHOLOGY, GEOGRAPHIC DISTRIBUTION AND 18S rRNA GENE SEQUENCE OF A FRESHWATER OXY-TRICHID CILIATE (HYPOTRICHIA: OXY-TRICHIDAE) FROM MEXICO Méndez-Sánchez Daniel1, Mayén-Estrada Rosaura1, Hu Xiaozhong2, Luo Xiaotian2, Song Weibo2
1 - Laboratorio de Protozoología, Facultad de Ciencias, Universidad Nacional Autónoma de México, Av. Universidad 3000 Ciudad Universitaria, 04510 Coyoacán, Ciudad de México, México
2 - Laboratory ofProtozoology, Institute of Evolution and Marine Biodiversity, Ocean University ofChina, Qingdao 266003, China [email protected]
Species of genus Oxytricha are characterized by 18 frontal-ventral-transverse cirri, one right and one left row of marginal cirri, undulating membranes and dorsal kineties usually in Oxytricha-pattern, and also the presence of caudal cirri. We collected some samples from a Mexican freshwater lake and we isolated Oxytricha granulifera (Foissner & Adam, 1981). Our individuals presented six dorsal kineties compared with the Austrian population (with five dorsal kineties) collected in a terrestrial environment. All available records of O. granulifera were plotted and obtained a broad geographic distribution. Considering the 18S rRNA gene sequence, our species grouped with other O. granulifera strains and populations available in GenBank. Due to the number of dorsal kineties we propose that Mexican population could be considered like a subspecies of O. granulifera.
Acknowledgements: To Posgrado en Ciencias Biolygica UNAM and CONACyT for the grant to
