A pheromone-induced developmental switch in Moina macrocopa (Cladocera, Moinidae): The “Hunger!” signal forms the dauer stage

Salinity is a known factor in shaping population dynamics and community structure through direct and indirect effects on aquatic ecosystems. Salinity changes further influence food webs through competition and predation. The responses of Moina macrocopa (Cladocera) collected from Setiu Wetland lagoon (Terengganu) was evaluated through manipulative laboratory experiments to understand the ability of M. macrocopa to tolerate high salinity stress. Specifically, the fatty acid composition, growth, survival, and reproduction of this cladocerans species was examined. Sodium chloride (NaCl) as used in the treatments water with the concentration 0, 4, 6, 8, 12, and 15 salinity. Fatty acid levels were determined using Gas Chromatography and Mass Spectrophotometry (GC-MS). The results indicated that optimal conditions produced the highest fatty acid content, especially the polyunsaturated fatty acid content, such as EPA (eicosapentaenoic acid), ALA (alpha-linoleic acid), ARA (arachidonic acid), and DHA (docosahexaenoic acid). Furthermore, M. macrocopa survival was best at salinity 0, with a percentage of 98%, whereas the opposite occurred at salinity 15, with approximately 20% of viable animals surviving. Besides, M. macrocopa also showed the highest reproduction rate at salinity 0 (e.g., average initial age of reproduction, 4.33 ± 0.58 days) compared with other salinities level. Interestingly, the difference in growth at different salinities was not evident, an unusual finding when considering adverse effects such as osmoregulation pressure on the organism. Based on the results, we conclude that M. macrocopa can only tolerate salinity below salinity 8 and cannot withstand stressful environmental conditions associated with salinities above 8.

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Available Food and Crowding as Factors Influencing the Sex of Moina macrocopa. I

Physiological Zoology ◽

10.1086/physzool.4.4.30151162 ◽

1931 ◽

Vol 4 (4) ◽

pp. 581-593 ◽

Cited By ~ 7

Author(s):

C. A. Stuart ◽

Juanita Tallman ◽

H. J. Cooper

Keyword(s):

Moina Macrocopa ◽

Factors Influencing

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Understanding heterogeneity of fetal hemoglobin induction through comparative analysis of F and A erythroblasts

Blood ◽

10.1182/blood.2020005058 ◽

2020 ◽

Vol 135 (22) ◽

pp. 1957-1968 ◽

Cited By ~ 5

Author(s):

Eugene Khandros ◽

Peng Huang ◽

Scott A. Peslak ◽

Malini Sharma ◽

Osheiza Abdulmalik ◽

...

Keyword(s):

Fetal Hemoglobin ◽

Erythroid Cell ◽

Transcriptional Level ◽

Globin Genes ◽

Proteomic Profiling ◽

A Cells ◽

F Cells ◽

Adult Hemoglobin ◽

Differentiation Stage ◽

Developmental Switch

Abstract Reversing the developmental switch from fetal hemoglobin (HbF, α2γ2) to adult hemoglobin (HbA, α2β2) is an important therapeutic approach in sickle cell disease (SCD) and β-thalassemia. In healthy individuals, SCD patients, and patients treated with pharmacologic HbF inducers, HbF is present only in a subset of red blood cells known as F cells. Despite more than 50 years of observations, the cause for this heterocellular HbF expression pattern, even among genetically identical cells, remains unknown. Adult F cells might represent a reversion of a given cell to a fetal-like epigenetic and transcriptional state. Alternatively, isolated transcriptional or posttranscriptional events at the γ-globin genes might underlie heterocellularity. Here, we set out to understand the heterogeneity of HbF activation by developing techniques to purify and profile differentiation stage-matched late erythroblast F cells and non–F cells (A cells) from the human HUDEP2 erythroid cell line and primary human erythroid cultures. Transcriptional and proteomic profiling of these cells demonstrated very few differences between F and A cells at the RNA level either under baseline conditions or after treatment with HbF inducers hydroxyurea or pomalidomide. Surprisingly, we did not find differences in expression of any known HbF regulators, including BCL11A or LRF, that would account for HbF activation. Our analysis shows that F erythroblasts are not significantly different from non-HbF–expressing cells and that the primary differences likely occur at the transcriptional level at the β-globin locus.

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Developmental switch of intestinal antimicrobial peptide expression

Journal of Experimental Medicine ◽

10.1084/jem.20071022 ◽

2008 ◽

Vol 205 (1) ◽

pp. 183-193 ◽

Cited By ~ 88

Author(s):

Sandrine Ménard ◽

Valentina Förster ◽

Michael Lotz ◽

Dominique Gütle ◽

Claudia U. Duerr ◽

...

Keyword(s):

Antimicrobial Peptide ◽

High Performance ◽

Bacterial Colonization ◽

Paneth Cell ◽

Active Form ◽

Constitutive Expression ◽

Postnatal Period ◽

Enteric Infection ◽

Immune Effector ◽

Developmental Switch

Paneth cell–derived enteric antimicrobial peptides provide protection from intestinal infection and maintenance of enteric homeostasis. Paneth cells, however, evolve only after the neonatal period, and the antimicrobial mechanisms that protect the newborn intestine are ill defined. Using quantitative reverse transcription–polymerase chain reaction, immunohistology, reverse-phase high-performance liquid chromatography, and mass spectrometry, we analyzed the antimicrobial repertoire in intestinal epithelial cells during postnatal development. Surprisingly, constitutive expression of the cathelin-related antimicrobial peptide (CRAMP) was observed, and the processed, antimicrobially active form was identified in neonatal epithelium. Peptide synthesis was limited to the first two weeks after birth and gradually disappeared with the onset of increased stem cell proliferation and epithelial cell migration along the crypt–villus axis. CRAMP conferred significant protection from intestinal bacterial growth of the newborn enteric pathogen Listeria monocytogenes. Thus, we describe the first example of a complete developmental switch in innate immune effector expression and anatomical distribution. Epithelial CRAMP expression might contribute to bacterial colonization and the establishment of gut homeostasis, and provide protection from enteric infection during the postnatal period.

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