The aromatic amino acid hydroxylase genes AAH1 and AAH2 in Toxoplasma gondii contribute to transmission in the cat

The Toxoplasma gondii genome contains two aromatic amino acid hydroxylase genes, AAH1 and AAH2 encode proteins that produce L-DOPA, which can serve as a precursor of catecholamine neurotransmitters. It has been suggested that this pathway elevates host dopamine levels thus making infected rodents less fearful of their definitive Felidae hosts. However, L-DOPA is also a structural precursor of melanins, secondary quinones, and dityrosine protein crosslinks, which are produced by many species. For example, dityrosine crosslinks are abundant in the oocyst walls of Eimeria and T. gondii, although their structural role has not been demonstrated, Here, we investigated the biology of AAH knockout parasites in the sexual reproductive cycle within cats. We found that ablation of the AAH genes resulted in reduced infection in the cat, lower oocyst yields, and decreased rates of sporulation. Our findings suggest that the AAH genes play a predominant role during infection in the gut of the definitive feline host

Ultrastructure of Sarcocystis bertrami sarcocysts from a naturally infected donkey (Equus asinus) from Egypt

There is considerable confusion concerning Sarcocystis species in equids. Little is known of Sarcocystis infections in donkeys (Equus asinus). Here we describe the structure of Sarcocystis bertrami-like from the donkey by light microscopy (LM) and transmission electron microscopy (TEM). Nineteen sarcocysts from the tongue of a donkey from Egypt were studied both by LM and TEM. By LM, all sarcocysts had variably shaped and sized projections on the sarcocyst walls, giving it a thin-walled to thick-walled appearance, depending on individual sarcocyst and plane of section. By TEM, sarcocysts walls had villar protrusions (vp) of type 11. The sarcocyst wall had conical to slender vp, up to 6 µm long and 1 µm wide; the vp were folded over the sarcocyst wall. The total thickness of the sarcocyst wall with ground substance layer (gs) was 1-3 µm. The vp had microtubules (mt) that originated deeper in the gs and continued up to the tip. The apical part of the vp had electron dense granules. The mt were configured into 3 types: a tuft of electron dense mt1 extending the entire length of the vp with a tuft of medium electron dense mt2 appearing in parallel, and fine mt3 present only in the villar tips. The gs was mainly smooth with few indistinct granules. All sarcocysts were mature and contained metrocytes and bradyzoites. Bradyzoites were approximately 11-15 × 2-3 µm in size with typical organelles.http://journals.cambridge.org/action/displayJournal?jid=PAR2016-07-30hb201

Endogenous kisspeptin tone is a critical excitatory component of spontaneous GnRH activity and the GnRH response to NPY and CART

BACKGROUND / AIMS : Kisspeptin is the major excitatory regulator of gonadotropin-releasing hormone (GnRH) neurons and is responsible for basal GnRH/LH release and the GnRH/LH surge. Although it is widely assumed, based on mutations in kisspeptin and Kiss1R, that kisspeptin acts to sustain basal GnRH neuronal activity, there have been no studies to investigate whether endogenous basal kisspeptin tone plays a direct role in basal spontaneous GnRH neuronal excitability. It is also of interest to examine possible interactions between endogenous kisspeptin tone and other neuropeptides that have direct effects on GnRH neurons, such as neuropeptide Y (NPY) or cocaine- and amphetamine-regulated transcript (CART), since the activity of all these neuropeptides changes during states of negative energy balance. METHODS : Loose cell-attached and whole-cell current patch-clamp recordings were made from GnRH-GFP neurons in hypothalamic slices from female and male rats. RESULTS : Kisspeptin activated GnRH neurons in a concentration-dependent manner with an EC 50 of 3.32 ± 0.02 n M . Surprisingly, a kisspeptin an-endogenous kisspeptin tone. Furthermore, inhibition of endogenous kisspeptin tone blocked the direct activation of GnRH cells that occurs in response to antagonism of NPY Y5 receptor or by CART. CONCLUSIONS : Our electrophysiology studies suggest that basal endogenous kisspeptin tone is not only essential for spontaneous GnRH neuronal firing, but it is also required for the net excitatory effects of other neuropeptides, such as CART or NPY antagonism, on GnRH neurons. Therefore, endogenous kisspeptin tone could serve as the linchpin in GnRH activation or inhibition.NIH grants HD014643, HD014643 (ARRA Supplement),OD011092.http://www.karger.com/Journal/Home/223855hb201

Input Utilization for Sustainable Yields in Dryland Areas

ABSTRACT India's population touched 1.198 98, 96, 85, 80, 79, 71, 66 an

A review of sarcocystosis in camels and redescription of Sarcocystis cameli and Sarcocystis ippeni sarcocysts from the one-humped camel (Camelus dromedarius)

There is considerable confusion concerning Sarcocystis species in camels. Five species: Sarcocystis cameli, S. ippeni, S. camelicanis, S. camelocanis, and S. miescheri were named with inadequate descriptions and no type specimens. Here, we review literature on sarcocystosis in camels worldwide and redescribe structure of S. cameli and S. ippeni sarcocysts by light and transmission electron microscopy (LM, TEM). Eight sarcocysts from the esophagi of two camels (Camelus dromedarius) from Egypt were studied. By LM all sarcocysts were thin walled with barely visible projections on the cyst walls. By TEM, two structurally distinct sarcocysts were recognized by unique villar protrusions (vp) not found in sarcocysts from any other host. Sarcocysts of S. cameli had vp of type 9j. The sarcocyst wall had upright slender vp, up to 3.0 μm long and 0.5 μm wide; the total thickness of the sarcocyst wall with ground substance layer (gs) was 3.5 μm. On each vp there were rows of knob-like protrusions that appeared to be interconnected. The vp had microtubules that originated at mid point of the gs and continued up to the tip; microtubules were smooth, without any granules or dense areas. Bradyzoites were approximately 14-15 x 3-4 μm in size with typical organelles. Sarcocystis ippeni sarcocysts had type 32 sarcocyst wall characterized by conical villar protrusions with an electron dense knob. The total thickness of the sarcocyst wall (from the base of gs to vp tip) was 2.3-3.0 μm. The vp were up to 1.2 μm wide at the base and 0.25 μm at the tip. Microtubules in vp originated at midpoint of gs and continued up to tip; microtubules were criss-crossed, smooth and without granules or dense areas. Bradyzoites were 12.0-13.5 x 2.0-3.0 μm in size. Sarcocystis camelicanis, S. camelocanis, and S. miescheri are considered invalid.R. Calero-Bernal is a postdoctoral fellow (ref. PO12010) funded by the Department of Employment and Innovation of the Regional Government of Extremadura (Spain) and the European Social Fund.http://journals.cambridge.org/action/displayJournal?jid=PAR2016-01-31hb201

Redescription of Sarcocystis fusiformis sarcocysts from the water buffalo (Bubalus bubalis)

Four valid species of Sarcocystis have been reported from the water buffalo (Bubalus bubalis): Sarcocystis fusiformis, Sarcocystis buffalonis, Sarcocystis levinei and Sarcocystis dubeyi. Here, we redescribe structure of S. fusiformis sarcocysts by scanning and transmission electron microscopy (SEM, TEM). Twenty-one macroscopic sarcocysts from oesophagus of the water buffalo in Egypt were examined by light microscopy, SEM and TEM. The sarcocyst wall was up to 9 μm thick, depending on the section and the technique. In 5 μm paraffin-embedded sections, the sarcocyst wall was indistinct, 2–5 μm thick and appeared smooth. In 1 μm plastic-embedded sections stained with toluidine blue, the sarcocyst wall was 2·5–5·2 μm thick and had branched villar protrusions (vp)-like branches of a dead tree. By SEM, the sarcocyst wall had a mesh-like structure with irregularly shaped vp that were folded over the sarcocyst wall. On each vp there were uniform papillomatous structures that were 100 nm wide. By TEM, vp were up to 6 μm long and contained filamentous tubular structures, most of which were parallel to the long axis of the projections; granules were absent from these tubules. By TEM, bradyzoites within the same cyst varied from 11·2 to 16·8 μm in length. By TEM, bradyzoites had a very long (10 μm) convoluted mitochondrion, up to 12 dense granules, but only 2 rhoptries. This redescription should help to differentiate the sarcocysts of S. fusiformis from similar sarcocysts in domestic and wild ruminants.R. Calero-Bernal is a postdoctoral fellow (ref. PO12010) funded by the Department of Employment and Innovation of the Regional Government of Extremadura (Spain) and the European Social Fund.http://journals.cambridge.org/action/displayJournal?jid=PARhb201

Sarcocystis cymruensis: discovery in Western Hemisphere in the Brown rat (Rattus norvegicus) from Grenada, West Indies: redescription, molecular characterization, and transmission to IFN-γ gene knockout mice via sporocysts from experimentally infected domestic cat (Felis catus)

Rodents are intermediate hosts for many species of Sarcocystis. Little is known of Sarcocystis cymruensis that uses the Brown rat (Rattus norvegicus) as intermediate hosts and the domestic cat (Felis catus) as experimental definitive host. Here, we identified and described Sarcocystis cymruensis in naturally infected R. norvegicus from Grenada, West Indies. Rats (n = 167) were trapped in various locations in two parishes (St. George and St. David). Microscopic, thin (\u3c 1 μm) walled, slender sarcocysts were found in 11 of 156 (7.0%) rats skeletal muscles by squash examination. A laboratory-raised cat fed naturally infected rat tissues excreted sporocysts that were infectious for interferon gamma gene knockout (KO) mice, but not to Swiss Webster outbred albino mice. All inoculated mice remained asymptomatic, and microscopic S. cymruensis-like sarcocysts were found in the muscles of KO mice euthanized on day 70, 116, and 189 post inoculation (p.i.). Sarcocysts from infected KO mice were infective for cats at day 116 but not at 70 days p.i. By transmission electron microscopy, the sarcocyst wall was Btype 1a.^ Detailed morphological description of the cyst wall, metrocytes, and bradyzoites is given for the first time. Additionally, molecular data on S. cymruensis are presented also for the first time. Molecular characterization of sarcocysts 18S rDNA and 28S rDNA, ITS-1, and cox1 loci showed the highest similarity with S. rodentifelis and S. muris. In conclusion, the present study described the natural infection of S. cymruensis in Brown rat for the first time in a Caribbean country and provided its molecular characteristics

Sarcocystis oreamni, n. sp. (Apicomplexa : Sarcocystidae) from the mountain goat (Oreamnos americanus)

Numerous species of Sarcocystis have been reported from wild ruminants but none has been named from the Rocky Mountain goat (Oreamnos americanus). Mature sarcocysts were found in frozen muscle samples of three of seven mountain goats from Alaska, USA. Two morphological types of sarcocysts were found; one had Sarcocystis cornagliai-like sarcocysts, previously named from the Alpine ibex (Capra ibex) from Europe. Two other goats were infected with a new species, Sarcocystis oreamni. Sarcocystis oreamni sarcocysts were microscopic with 2 μm-thick sarcocyst wall. By transmission electron microscopy, the sarcocyst wall had 1.7 μm-thick with unusual molar tooth-like villar protusions (vp), type 29. The vp had electron dense core and two disc-shaped plaques at the tip with fine microtubules. Bradyzoites were 8.6-9.1 μm long. Single nucleotide polymorphism (SNP) identified in 18S rRNA, and 28S rRNA loci of rDNA regions that suggested S. oreamni molecularly apart from related species. The phylogenetic analysis based on 18S rRNA, and 28S rRNA sequences suggested S. oreamni is related with Sarcocystis species that employ members of Canidae family as their definitive host.R. Calero-Bernal is a postdoctoral fellow (ref. PO12010) funded by the Department of Employment and Innovation of the Regional Government of Extremadura (Spain) and the European Social Fund.http://link.springer.com/journal/4362016-11-11hb201

Sarcocystis cafferi n. sp. (Protozoa : Apicomplexa) from the African Buffalo (Syncerus caffer)

Sarcocystis infections have been reported from the African buffalo (Syncerus caffer), but the species have not been named. Here we propose a new name Sarcocystis cafferi from the African buffalo. Histological examination of heart (92), skeletal muscle (36), and tongue (2) sections from 94 buffalos from the Greater Kruger National Park, South Africa, and a review of the literature revealed only 1 species of Sarcocystis in the African buffalo. Macrocysts were up to 12 mm long and 6 mm wide and were located in the neck muscles and overlying connective tissue. They were pale yellow; shaped like a lychee fruit stone or cashew nut; turgid or flaccid and oval to round (not fusiform). By light microscopy (LM) the sarcocyst wall was relatively thin. By scanning electron microscopy (SEM), the sarcocyst wall had a mesh-like structure with irregularly shaped villar protrusions (vp) that were of different sizes and folded over the sarcocyst wall. The entire surfaces of vp were covered with papillomatous structures. By transmission electron microscopy (TEM), the sarcocyst wall was up to 3.6 lm thick and had highly branched villar protrusions that were up to 3 lm long. The villar projections contained filamentous tubular structures, most of which were parallel to the long axis of the projections, but some tubules criss-crossed, especially at the base. Granules were absent from these tubules. Longitudinally cut bradyzoites were 12.132.7 lm in size, had a long convoluted mitochondrion, and only 2 rhoptries. Phylogenetic analysis of 18S rRNA and cytochrome C oxidase subunit 1 (cox1) gene sequences indicated that this Sarcocystis species is very closely related to, but distinct from, Sarcocystis fusiformis and Sarcocystis hirsuta. Thus, morphological findings by LM, SEM, and TEM together with molecular phylogenetic data (from 18S rRNA and cox1) confirm that the Sarcocystis species in the African buffalo is distinct from S. fusiformis and has therefore been named Sarcocystis cafferi.http://digitalcommons.unl.edu/jrnlparasitology/hb201

Sarcocystis mehlhorni n. sp. (Apicomplexa : Sarcocystidae) from the black-tailed deer (Odocoileus hemionus columbianus)

Infection with Sarcocystis is common in many species of wild cervids but none is reported from the black-tailed deer (Odocoileus hemionus columbianus). Here, we report Sarcocystis infection in two black-tailed deer from northwest USA for the first time. Sarcocysts were microscopic, up to 556 μm long and mature. The sarcocyst wall was up to 1.39 μm thick, and had rectangular 1.17 μm long villar protrusions, type 17, with thin (230 nm) electron dense ground substance layer. Molecular characterization and phylogenetic analysis indicated that Sarcocystis in the black-tailed deer is related to structurally distinct Sarcocystis species in cervids. A new name, Sarcocystis mehlhorni, is proposed for the Sarcocystis species in black-tailed deer.http://link.springer.com/journal/4362016-12-08hb201