scholarly journals Evolution of Thyroid Enhancement of Embryogenesis and Early Survival

2021 ◽  
Author(s):  
Arjay Pataueg ◽  
Earl T. Larson ◽  
Christopher L. Brown
Keyword(s):  
Endocrine System ◽  
Egg Yolk ◽  
Feeding Mode ◽  
Precise Control ◽  
Parental Relationship ◽  
Larval Fishes ◽  
First Feeding ◽  
Intestinal Maturation ◽  
Maternal Thyroid ◽  
Alternative Feeding

Iodine imparts protective antioxidant actions that improve the fitness of invertebrate organisms, and peptides carrying iodine initially appear to have served in a defensive capacity. Tyrosine carries multiple iodines in some echinoderms, and these peptides transferred to progeny serve both protective and signaling purposes. This parental relationship appears to be the most likely evolutionary basis for emergence of the vertebrate thyroid endocrine system, and its critically important development-promoting actions in larval and (later) fetal ontogeny. Thyroxine (T4) and Triiodothyronine (T3) induce settlement and stimulate transitions to alternative feeding modes in some echinoderms. This transgenerational relationship has been conserved and elaborated in vertebrates, including humans, which share common ancestry with echinoderms. Thyroid insufficiency is damaging or can be lethal to larval fishes; egg yolk that is insufficiently primed with maternal thyroid hormones (TH) results in compromised development and high mortality rates at the time of first-feeding. Maternally-derived TH supplied to offspring supports the onset of independent feeding in fishes (eye, mouth, lateral line, swim bladder and intestinal maturation) and survival by comparable developmental mechanisms in placental mammals. Fishes evolved precise control of TH secretion and peripheral processing; early metamorphic and feeding mode actions were joined by controlled thermogenesis in homeotherms.

75 GLUCOSE CONCENTRATION OF FREEZING EXTENDER MODULATES THE TYROSINE PHOSPHORYLATION PATTERN OF FROZEN-THAWED BOAR SPERMATOZOA

2009 ◽  
Vol 21 (1) ◽  
pp. 138
Author(s):  
J. E. Rodríguez-Gil ◽  
M. Hernández ◽  
M. M. Rivera ◽  
L. Ramió-Lluch ◽  
J. Ballester ◽  
...  
Keyword(s):  
Protein Phosphorylation ◽  
Tyrosine Phosphorylation ◽  
Glucose Concentration ◽  
Egg Yolk ◽  
Freezing And Thawing ◽  
Precise Control ◽  
Boar Sperm ◽  
Phosphorylation Pattern ◽  
Thawing Process ◽  
Boar Spermatozoa

The optimization of freezing extenders is an essential issue for enhancing boar sperm cryosurvival. The aim of the present study was to disclose the role of glucose concentration of freezing extender on the metabolic activity of frozen–thawed spermatozoa. To achieve it, pooled sperm-rich ejaculate fractions from 5 mature and fertile boars (3 ejaculates per boar) were collected using the gloved-hand method. After centrifugation (2400g for 3 min), the sperm pellet was split into 7 aliquots. The aliquots were diluted to a final concentration of 1 × 109 sperm mL–1, in a Tris-citric extender supplemented with 20% egg-yolk, 3% glycerol, and 0, 0.05, 2, 4, 10, 55, or 185 mm glucose. All the extenders were adjusted to a pH of 6.8 and 310 mOsm kg–1 to avoid osmolarity effects. Extended semen samples were dispensed into 0.5-mL straws, and frozen in a programmable cell freezer at 20°C min–1. Thawing was carried out in a water bath at 37°C for 20 s. Afterward, an analysis of protein phosphorylation in tyrosine residues was carried out through bi-dimensional electrophoresis followed by a Western blot analysis. This analysis indicated that sperm samples frozen in extenders without glucose showed specific changes in the tyrosine phosphorylation pattern compared with fresh sperm. Furthermore, the addition of glucose in increasing concentrations to the freezing extender was accompanied by a concentration-dependent decrease in the overall tyrosine phosphorylation pattern, especially in proteins with a molecular weight ranging from 150 to 200 kDa and an acidic isoelectric point (pI). The maximal decrease was observed in spermatozoa frozen in the extender containing 185 mm glucose, in which an additional decrease in the tyrosine phosphorylation of proteins ranging from 60 to 80 kDa, and a basic pI was also observed. These results suggest that glucose is a modulator in the resistance of boar sperm to support freezing and thawing process, because the precise protein phosphorylation pattern of spermatozoa is directly linked to their functional status. In this way, a precise control of the glucose concentration of the freezing extender would be required to improve boar sperm cryoresistance. Supported by CICYT (AGL2005-00760 and AGL2004-04756-C02-02/GAN), Madrid and GERM (04543/07), Murcia, Spain.

scholarly journals Effects of climate change on fish reproduction and early life history stages

2011 ◽  
Vol 62 (9) ◽  
pp. 1015 ◽  
Author(s):  
Ned W. Pankhurst ◽  
Philip L. Munday
Keyword(s):  
Climate Change ◽  
Elevated Temperatures ◽  
Endocrine System ◽  
Developmental Rate ◽  
Early Life History ◽  
Egg Survival ◽  
Life History Stages ◽  
Larval Fishes ◽  
Larval Behaviour ◽  
Temperature Ranges

Seasonal change in temperature has a profound effect on reproduction in fish. Increasing temperatures cue reproductive development in spring-spawning species, and falling temperatures stimulate reproduction in autumn-spawners. Elevated temperatures truncate spring spawning, and delay autumn spawning. Temperature increases will affect reproduction, but the nature of these effects will depend on the period and amplitude of the increase and range from phase-shifting of spawning to complete inhibition of reproduction. This latter effect will be most marked in species that are constrained in their capacity to shift geographic range. Studies from a range of taxa, habitats and temperature ranges all show inhibitory effects of elevated temperature albeit about different environmental set points. The effects are generated through the endocrine system, particularly through the inhibition of ovarian oestrogen production. Larval fishes are usually more sensitive than adults to environmental fluctuations, and might be especially vulnerable to climate change. In addition to direct effects on embryonic duration and egg survival, temperature also influences size at hatching, developmental rate, pelagic larval duration and survival. A companion effect of marine climate change is ocean acidification, which may pose a significant threat through its capacity to alter larval behaviour and impair sensory capabilities. This in turn impacts on population replenishment and connectivity patterns of marine fishes.

Ontogeny of Feeding Behavior of First-Feeding Atlantic Salmon (Salmo salar)

1991 ◽  
Vol 48 (10) ◽  
pp. 1896-1904 ◽  
Author(s):  
David J. Coughlin
Keyword(s):  
Atlantic Salmon ◽  
Feeding Behavior ◽  
Salmo Salar ◽  
Exogenous Feeding ◽  
Feeding Mode ◽  
Atlantic Salmon Salmo Salar ◽  
First Feeding ◽  
Swimming Motion ◽  
In The Wild ◽  
Time To Learn

Feeding strikes of Atlantic salmon (Salmo salar) alevins preying upon Daphnia are described using videorecording of synchronous lateral and antero-ventral views. Based on examination of characteristics such as aiming inaccuracy and capture distance, it is demonstrated that feeding behavior significantly improves during the first 2 wk after initiation of exogenous feeding. With increasing experience, young salmon tend to capture prey more quickly and with greater accuracy. First-feeding alevins use a body-ram feeding mode, relying on their swimming motion to overtake and capture prey. After 7–10 d of feeding, the fish change to a suction feeding mode that effectively uses suction generated by expansion of the orobranchial chamber to pull in prey from a distance. Also, feeding behavior of alevins raised on a commercial salmon feed lags developmentally behind the behavior offish raised on live food. This lag time is short (2–3 d), indicating that despite reports to the contrary, hatchery-raised fish do not require a Song time to learn to capture prey effectively in the wild.

scholarly journals Systematic Review of Exposure to Bisphenol A Alternatives and Its Effects on Reproduction and Thyroid Endocrine System in Zebrafish

2021 ◽  
Vol 11 (4) ◽  
pp. 1837
Author(s):  
Jiyun Lee ◽  
Kyong Whan Moon ◽  
Kyunghee Ji
Keyword(s):  
Bisphenol A ◽  
Endocrine System ◽  
Egg Yolk ◽  
Thyroid Stimulating Hormone ◽  
Limited Information ◽  
Bisphenol S ◽  
Hormone Production ◽  
Chemical Structures ◽  
Similar Chemical ◽  
Offspring Generation

Bisphenol A (BPA), which is widely used for manufacturing polycarbonate plastics and epoxy resins, has been banned from use in plastic baby bottles because of concerns regarding endocrine disruption. Substances with similar chemical structures have been used as BPA alternatives; however, limited information is available on their toxic effects. In the present study, we reviewed the endocrine disrupting potential in the gonad and thyroid endocrine system in zebrafish after exposure to BPA and its alternatives (i.e., bisphenol AF, bisphenol C, bisphenol F, bisphenol S, bisphenol SIP, and bisphenol Z). Most BPA alternatives disturbed the endocrine system by altering the levels of genes and hormones involved in reproduction, development, and growth in zebrafish. Changes in gene expression related to steroidogenesis and sex hormone production were more prevalent in males than in females. Vitellogenin, an egg yolk precursor produced in females, was also detected in males, confirming that it could induce estrogenicity. Exposure to bisphenols in the parental generation induced a decrease in the hatchability associated with offspring generation. In zebrafish exposed to bisphenols, significant decreases in thyroxine concentrations and increases in thyroid-stimulating hormone concentrations were commonly observed. Alternative compounds used to replace a chemical of concern are believed to be less toxic than the original compound; however, several BPA alternatives appear to have similar or greater effects on the endocrine system in zebrafish. Since endocrine systems interact with each other, further studies are needed to assess the primary target of BPA alternatives among the endocrine axes.

Endocrinology in pregnancy

2021 ◽  
pp. 469-498
Author(s):  
Catherine Williamson ◽  
Rebecca Scott
Keyword(s):  
Thyroid Cancer ◽  
Calcium Metabolism ◽  
Thyroid Dysfunction ◽  
Hyperemesis Gravidarum ◽  
Post Partum ◽  
Endocrine System ◽  
Thyroid Disorders ◽  
Fetal Thyroid ◽  
Maternal Thyroid ◽  
In Pregnancy

This chapter covers both the normal and abnormal changes to the endocrine system during pregnancy. It begins with the thyroid in pregnancy, covering maternal hyperthyroidism, hyperemesis gravidarum, overt and subclinical maternal hypothyroidism, post-partum thyroid dysfunction, and fetal thyroid diseases owing to maternal thyroid disorders. Calcium metabolism, thyroid cancer, hypoparathyroidism, and lactation associated osteoporosis. Secondly, the pituitary gland in pregnancy is focused on, covering prolactinoma, Cushing’s Syndrome, acromegaly, non-functioning pituitary adenoma, hypopituitarism, and Diabetes Insipidus. Pre-existing adrenal disorders during pregnancy and alterations to management are also included.

scholarly journals Hydrodynamic starvation in first-feeding larval fishes

2014 ◽  
Vol 111 (22) ◽  
pp. 8083-8088 ◽  
Author(s):  
V. China ◽  
R. Holzman
Keyword(s):  
Larval Fishes ◽  
First Feeding

scholarly journals It’s All About Timing: Early Feeding Promotes Intestinal Maturation by Shifting the Ratios of Specialized Epithelial Cells in Chicks

2020 ◽  
Vol 11 ◽  
Author(s):  
Naama Reicher ◽  
Tal Melkman-Zehavi ◽  
Jonathan Dayan ◽  
Zehava Uni
Keyword(s):  
Epithelial Cells ◽  
Goblet Cells ◽  
Histochemical Staining ◽  
Total Cell ◽  
Early Feeding ◽  
Differentiated Cells ◽  
First Feeding ◽  
Intestinal Maturation ◽  
Hatch Period

The small intestine (SI) of chicks (Gallus gallus) matures rapidly during the initial post-hatch period and acquires digestive, absorptive, and secretive capabilities. The effects of the timing of first feeding on the quantities and distribution of specialized epithelial cells, which generate and maintain SI morphology and functionality, have not yet been examined. In this study, we identified specialized SI epithelial cell sub-types, including stem, progenitor, proliferating, and differentiated cells within crypts and villi of chicks during the first 10 days post-hatch, by in situ hybridization (ISH), immunofluorescence (IF), and histochemical staining. We then examined their quantities and ratios between day of hatch and d10 in chicks that were fed upon hatch [early feeding (EF)], compared to chicks that were fed 24 h post-hatch [delayed feeding (DF)]. Results showed that EF increased total cell quantities in the crypts and villi at days 1, 3, 7, and 10, compared to DF (p < 0.0001). At d3, EF, in comparison to DF, decreased crypt stem cell proportions (p < 0.0001), increased crypt proliferating (p < 0.01) and differentiated (p < 0.05) cell proportions, and increased villus enterocyte proportions (p < 0.01). By d10, EF increased both the quantities and proportions of villus enterocytes and goblet cells, compared to DF. We conclude that feeding upon hatch, compared to 24 h-delayed feeding, enhanced SI maturation and functionality by increasing the quantities and proportions of proliferating and differentiated cells, thus expanding the digestive, absorptive, and secretive cell populations throughout the initial post-hatch period.

scholarly journals The mysterious feeding ecology of leptocephali: a unique strategy of consuming marine snow materials

2020 ◽  
Author(s):  
Katsumi Tsukamoto ◽  
Michael J. Miller
Keyword(s):  
Amorphous Materials ◽  
Trophic Position ◽  
Feeding Strategy ◽  
Egg Yolk ◽  
Gut Contents ◽  
Marine Snow ◽  
Formulated Diets ◽  
First Feeding ◽  
Behavioral Studies ◽  
Wide Range

AbstractLeptocephalus larvae have transparent bodies with tubular intestines that usually lack identifiable food items when they are collected, so mystery has surrounded efforts to determine what they feed on. Artificially spawned and reared first-feeding larvae were found to be highly selective in what they would eat, but they would consume rotifers and eventually ate specially formulated diets that contained shark egg yolk. Gut content studies on wild-caught leptocephali in the Atlantic and Pacific observed marine snow-associated materials such as discarded appendicularian houses, zooplankton fecal pellets, protists, and amorphous materials, and DNA sequencing indicated that the gut contents contain materials originating from a wide range of microorganisms and food web zooplankton species that were likely consumed in marine snow. Isotopic studies found a low trophic position of leptocephali and inter-taxa and geographic signature differences. Behavioral studies with leptocephali and the characteristics and size-scaling of the teeth are also consistent with feeding on marine snow-related particles. The feeding strategy of leptocephali appears to be based on consuming types of marine snow that contain nutritious and easily assimilated carbohydrates, fatty acids, and other materials that facilitate rapid conversion to glycosaminoglycans and tissues for energy storage and growth.

A Novel Reconstitution Method for Inducing the Formation of Regular 2-Dimensional Arrays of Membrane Proteins and Lipids

1988 ◽  
Vol 46 ◽  
pp. 152-153 ◽  
Author(s):  
A. Engel ◽  
A. Holzenburg ◽  
K. Stauffer ◽  
J. Rosenbusch ◽  
U. Aebi
Keyword(s):  
Membrane Proteins ◽  
Flow Rate ◽  
Lipid Membranes ◽  
Functional Characterization ◽  
Dimensional Structure ◽  
Electron Crystallography ◽  
Peltier Element ◽  
Protein Ratio ◽  
Precise Control ◽  
3 Dimensional

Reconstitution of solubilized and purified membrane proteins in the presence of phospholipids into vesicles allows their functions to be studied by simple bulk measurements (e.g. diffusion of differently sized solutes) or by conductance measurements after transformation into planar membranes. On the other hand, reconstitution into regular protein-lipid arrays, usually forming at a specific lipid-to-protein ratio, provides the basis for determining the 3-dimensional structure of membrane proteins employing the tools of electron crystallography.To refine reconstitution conditions for reproducibly inducing formation of large and highly ordered protein-lipid membranes that are suitable for both electron crystallography and patch clamping experiments aimed at their functional characterization, we built a flow-dialysis device that allows precise control of temperature and flow-rate (Fig. 1). The flow rate is generated by a peristaltic pump and can be adjusted from 1 to 500 ml/h. The dialysis buffer is brought to a preselected temperature during its travel through a meandering path before it enters the dialysis reservoir. A Z-80 based computer controls a Peltier element allowing the temperature profile to be programmed as function of time.

Multiple-fracturing and viewing of the same frozen sample at different depths using a low temperature FESEM

1996 ◽  
Vol 54 ◽  
pp. 820-821
Author(s):  
M.V. Parthasarathy ◽  
C. Daugherty
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Field Emission ◽  
Multiple Fracture ◽  
Precise Control ◽  
Cold Stage ◽  
Different Depths ◽  
Transfer Device

The versatility of Low Temperature Field Emission SEM (LTFESEM) for viewing frozen-hydrated biological specimens, and the high resolutions that can be obtained with such instruments have been well documented. Studies done with LTFESEM have been usually limited to the viewing of small organisms, organs, cells, and organelles, or viewing such specimens after fracturing them.We use a Hitachi 4500 FESEM equipped with a recently developed BAL-TEC SCE 020 cryopreparation/transfer device for our LTFESEM studies. The SCE 020 is similar in design to the older SCU 020 except that instead of having a dedicated stage, the SCE 020 has a detachable cold stage that mounts on to the FESEM stage when needed. Since the SCE 020 has a precisely controlled lock manipulator for transferring the specimen table from the cryopreparation chamber to the cold stage in the FESEM, and also has a motor driven microtome for precise control of specimen fracture, we have explored the feasibility of using the LTFESEM for multiple-fracture studies of the same sample.

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