scholarly journals Light-Dependent Transcriptional Regulation of Genes of Biogeochemical Interest in the Diploid and Haploid Life Cycle Stages of Emiliania huxleyi

2009 ◽  
Vol 75 (10) ◽  
pp. 3366-3369 ◽  
Author(s):  
Sophie Richier ◽  
Marie-Emmanuelle Kerros ◽  
Colomban de Vargas ◽  
Liti Haramaty ◽  
Paul G. Falkowski ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Life Cycle ◽  
Emiliania Huxleyi ◽  
Life Stages ◽  
Dark Cycle ◽  
Expression Of Genes ◽  
Life Cycle Stages

ABSTRACT The expression of genes of biogeochemical interest in calcifying and noncalcifying life stages of the coccolithophore Emiliania huxleyi was investigated. Transcripts potentially involved in calcification were tested through a light-dark cycle. These transcripts were more abundant in calcifying cells and were upregulated in the light. Their application as potential candidates for in situ biogeochemical proxies is also suggested.

In situ observations of Akashiwo sanguinea (Dinophyceae) displaying life cycle stages during blooms in a subtropical estuary

2017 ◽  
Vol 60 (6) ◽  
Author(s):  
Susan Badylak ◽  
Edward J. Phlips ◽  
Ashley Loren Mathews ◽  
Karen Kelley
Keyword(s):  
Life Cycle ◽  
Algal Bloom ◽  
Harmful Algal Bloom ◽  
Life Cycle Stages ◽  
Subtropical Estuary ◽  
In Situ Observations ◽  
Akashiwo Sanguinea

AbstractThis study reports on the harmful algal bloom (HAB) dinoflagellate

Autonomy and integration in complex parasite life cycles

Parasitology ◽  
2016 ◽  
Vol 143 (14) ◽  
pp. 1824-1846 ◽  
Author(s):  
DANIEL P. BENESH
Keyword(s):  
Life Cycle ◽  
Holistic Approach ◽  
Life Cycles ◽  
Complex Life Cycle ◽  
Functional Specialization ◽  
Life Stages ◽  
Free Living ◽  
New Host ◽  
Complex Life Cycles ◽  
Life Cycle Stages

SUMMARYComplex life cycles are common in free-living and parasitic organisms alike. The adaptive decoupling hypothesis postulates that separate life cycle stages have a degree of developmental and genetic autonomy, allowing them to be independently optimized for dissimilar, competing tasks. That is, complex life cycles evolved to facilitate functional specialization. Here, I review the connections between the different stages in parasite life cycles. I first examine evolutionary connections between life stages, such as the genetic coupling of parasite performance in consecutive hosts, the interspecific correlations between traits expressed in different hosts, and the developmental and functional obstacles to stage loss. Then, I evaluate how environmental factors link life stages through carryover effects, where stressful larval conditions impact parasites even after transmission to a new host. There is evidence for both autonomy and integration across stages, so the relevant question becomes how integrated are parasite life cycles and through what mechanisms? By highlighting how genetics, development, selection and the environment can lead to interdependencies among successive life stages, I wish to promote a holistic approach to studying complex life cycle parasites and emphasize that what happens in one stage is potentially highly relevant for later stages.

scholarly journals Cnidome and Morphological Features of Pelagia noctiluca (Cnidaria: Scyphozoa) Throughout the Different Life Cycle Stages

2021 ◽  
Vol 8 ◽  
Author(s):  
Ainara Ballesteros ◽  
Carina Östman ◽  
Andreu Santín ◽  
Macarena Marambio ◽  
Mridvika Narda ◽  
...  
Keyword(s):  
Life Cycle ◽  
Developmental Stages ◽  
Later Life ◽  
Life Stages ◽  
Accurate Identification ◽  
Early Stages ◽  
Pelagia Noctiluca ◽  
Life Cycle Stages ◽  
Advanced Stages ◽  
Stage 1

Pelagia noctiluca is considered the most important jellyfish in the Mediterranean Sea, due to its abundance and the severity of its stings. Despite its importance in marine ecosystems and the health problems caused by its massive arrival in coastal areas, little is known about its early life stages and its cnidome has never been described. This study of the morphological and anatomical features throughout the life cycle identifies four early stages: two ephyra and two metaephyra stages. Ephyra stage 1, newly developed from a planula, has no velar canals, gastric filaments or nematocyst batteries. Ephyra stage 2, has velar canals, a cruciform-shaped manubrium and gastric filaments. Metaephyra stage 3 has eight tentacle buds and nematocyst clusters for the first time. Lastly, in metaephyra stage 4, the eight primary tentacles grow nearly simultaneously, with no secondary tentacles. Complete nematocyst battery patterns gradually develop throughout the later life stages. Four nematocyst types are identified: a-isorhiza, A-isorhiza, O-isorhiza and eurytele. Of these, a-isorhiza and eurytele are the most important throughout the entire life cycle, while A-isorhiza and O-isorhiza have a more important role in advanced stages. All nematocysts show a positive correlation between increasing capsule volumes and increasing body diameter of the ephyrae, metaephyrae, young medusae and adult medusae. In the early stages, the volumes of euryteles in the gastric filaments are larger than those in the exumbrella, indicating that the capsule volume is critical in the absence of marginal tentacles, specialized for feeding. This study provides updated information, the most extensive description to date, including high-resolution photographs and schematic drawings of all the developmental stages in the life cycle of P. noctiluca. Additionally, the first cnidome characterization is provided for each stage to facilitate accurate identification of this species when collected in the water column, and to raise awareness of the potential for human envenomation.

scholarly journals From Metabolite to Metabolome: Metabolomics Applications in Plasmodium Research

2021 ◽  
Vol 11 ◽  
Author(s):  
Xinyu Yu ◽  
Gaoqian Feng ◽  
Qingfeng Zhang ◽  
Jun Cao
Keyword(s):  
Life Cycle ◽  
Life Stages ◽  
Disease Etiology ◽  
Malaria Research ◽  
Metabolic Mapping ◽  
The Past ◽  
Host Parasite Interactions ◽  
Life Cycle Stages ◽  
Parasite Biology ◽  
Host Parasite

Advances in research over the past few decades have greatly improved metabolomics-based approaches in studying parasite biology and disease etiology. This improves the investigation of varied metabolic requirements during life stages or when following transmission to their hosts, and fulfills the demand for improved diagnostics and precise therapeutics. Therefore, this review highlights the progress of metabolomics in malaria research, including metabolic mapping of Plasmodium vertebrate life cycle stages to investigate antimalarials mode of actions and underlying complex host-parasite interactions. Also, we discuss current limitations as well as make several practical suggestions for methodological improvements which could drive metabolomics progress for malaria from a comprehensive perspective.

scholarly journals Rapid phenotypic evolution following shifts in life cycle complexity

2018 ◽  
Vol 285 (1871) ◽  
pp. 20172304 ◽  
Author(s):  
Ronald M. Bonett ◽  
John G. Phillips ◽  
Nicholus M. Ledbetter ◽  
Samuel D. Martin ◽  
Luke Lehman
Keyword(s):  
Life Cycle ◽  
Vertebral Column ◽  
Life Stages ◽  
Phenotypic Evolution ◽  
Trait Evolution ◽  
Life Cycle Stages ◽  
Biphasic Life Cycle ◽  
History Of ◽  
Life Cycle Evolution

Life cycle strategies have evolved extensively throughout the history of metazoans. The expression of disparate life stages within a single ontogeny can present conflicts to trait evolution, and therefore may have played a major role in shaping metazoan forms. However, few studies have examined the consequences of adding or subtracting life stages on patterns of trait evolution. By analysing trait evolution in a clade of closely related salamander lineages we show that shifts in the number of life cycle stages are associated with rapid phenotypic evolution. Specifically, salamanders with an aquatic-only (paedomorphic) life cycle have frequently added vertebrae to their trunk skeleton compared with closely related lineages with a complex aquatic-to-terrestrial (biphasic) life cycle. The rate of vertebral column evolution is also substantially lower in biphasic lineages, which may reflect the functional compromise of a complex cycle. This study demonstrates that the consequences of life cycle evolution can be detected at very fine scales of divergence. Rapid evolutionary responses can result from shifts in selective regimes following changes in life cycle complexity.

scholarly journals Microtubule polyglutamylation is important for regulating cytoskeletal architecture and motility in Trypanosoma brucei

2020 ◽  
Vol 133 (18) ◽  
pp. jcs248047 ◽  
Author(s):  
Jana Jentzsch ◽  
Adal Sabri ◽  
Konstantin Speckner ◽  
Gertrud Lallinger-Kube ◽  
Matthias Weiss ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Life Cycle ◽  
Trypanosoma Brucei ◽  
Dynamic Behaviour ◽  
Cell Movement ◽  
Post Translational Modifications ◽  
Life Cycle Stages ◽  
Associated Proteins ◽  
Flagellar Axoneme

ABSTRACTThe shape of kinetoplastids, such as Trypanosoma brucei, is precisely defined during the stages of the life cycle and governed by a stable subpellicular microtubule cytoskeleton. During the cell cycle and transitions between life cycle stages, this stability has to transiently give way to a dynamic behaviour to enable cell division and morphological rearrangements. How these opposing requirements of the cytoskeleton are regulated is poorly understood. Two possible levels of regulation are activities of cytoskeleton-associated proteins and microtubule post-translational modifications (PTMs). Here, we investigate the functions of two putative tubulin polyglutamylases in T. brucei, TTLL6A and TTLL12B. Depletion of both proteins leads to a reduction in tubulin polyglutamylation in situ and is associated with disintegration of the posterior cell pole, loss of the microtubule plus-end-binding protein EB1 and alterations of microtubule dynamics. We also observe a reduced polyglutamylation of the flagellar axoneme. Quantitative motility analysis reveals that the PTM imbalance correlates with a transition from directional to diffusive cell movement. These data show that microtubule polyglutamylation has an important role in regulating cytoskeletal architecture and motility in the parasite T. brucei.This article has an associated First Person interview with the first author of the paper.

Intron-containing β-tubulin transcripts in Cryptosporidium parvum cultured in vitro

Microbiology ◽  
2004 ◽  
Vol 150 (5) ◽  
pp. 1191-1195 ◽  
Author(s):  
Xiaomin Cai ◽  
Cheryl A. Lancto ◽  
Mitchell S. Abrahamsen ◽  
Guan Zhu
Keyword(s):  
Life Cycle ◽  
Cryptosporidium Parvum ◽  
Late Life ◽  
Host Cells ◽  
Intron Splicing ◽  
Transcript Processing ◽  
Life Cycle Stages ◽  
Tubulin Mrna

The genome of Cryptosporidium parvum contains a relatively small number of introns, which includes the β-tubulin gene with only a single intron. Recently, it was observed that the intron was not removed from some of the β-tubulin transcripts in the late life cycle stages cultured in vitro. Although normally spliced β-tubulin mRNA was detected in all parasite intracellular stages by RT-PCR (e.g. HCT-8 or Caco-2 cells infected with C. parvum for 12–72 h), at 48–72 h post-infection unprocessed β-tubulin transcripts containing intact introns started to appear in parasite mRNA within infected host cells. The intron-containing transcripts could be detected by fluorescence in situ hybridization (FISH) using an intron-specific probe. The intron-containing β-tubulin transcripts appeared unique to the in vitro-cultured C. parvum, since they were not detected in parasite-infected calves at 72 h. As yet, it is unclear whether the late life cycle stages of C. parvum are partially deficient in intron-splicing or the intron-splicing processes have merely slowed, both of which would allow the detection of intron-containing transcripts. Another possible explanation is that the decay in transcript processing might simply be due to the onset of parasite death. Nonetheless, the appearance of intron-containing transcripts coincides with the arrest of C. parvum development in vitro. This unusual observation prompts speculation that the abnormal intron-splicing of β-tubulin transcripts may be one of the factors preventing complete development of this parasite in vitro. Furthermore, the presence of both processed and unprocessed introns in β-tubulin transcripts in vitro may provide a venue for studying overall mechanisms for intron-splicing in this parasite.

Aspects of the morphology of the juvenile life stages of Paradiplozoon ichthyoxanthon Avenant-Oldewage, 2013 (Monogenea: Diplozoidae)

2014 ◽  
Vol 59 (2) ◽  
Author(s):  
Annemariè Avenant-Oldewage ◽  
Simon Milne
Keyword(s):  
Life Cycle ◽  
Ventral Sucker ◽  
Adult Stage ◽  
Life Stages ◽  
Reproductive Tissue ◽  
Larval Life ◽  
Vaal Dam ◽  
First Time

AbstractThere are eight life stages in the life-cycle of Diplozoon paradoxum and limited knowledge of the life-cycle for other diplozoid genera exists. The aim of this study was to record the number of life-stages of Paradiplozoon ichthyoxanthon obtained from, Labeobarbus aeneus and Labeobarbus kimberlyensis, in the Vaal Dam from 2005 to 2007. Six larval life stages and one adult stage of P. ichtyoxanthon were identified from specimens collected in vitro and in situ. In vitro, eggs hatched after 21 days at 18°C. Eggs collected during winter were significantly larger than those laid during spring or summer. Paradiplozoon ichthyoxanthon oncomiracidia have peripheral eyes with pink pigmentation, a tubular anterior bladder-like structure, bicuspid basal pharynx valve and a branched digestive caecum and residual shell material or vitellaria in the caecum. Immature reproductive tissue connected to the ventral sucker and dorsal papillae were noted for the first time in diporpa. Large nervous ganglia and innervation of muscle were observed around the ventral sucker.

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