Nutritional programming by maternal diet alters offspring lipid metabolism in a marine teleost.

Nutritional programming - the association between the early nutritional environment and long-term consequences for an animal - is an emerging area of research in fish biology. Previous studies reported correlations between maternal provisioning of essential fatty acids to eggs and the whole-body fatty acid composition of larvae reared under uniform conditions for red drum, Sciaenops ocellatus. This study aimed to further investigate the nutritional stimulus and the consequences of nutritional programming by feeding adult red drum several distinct diets and rearing larvae under uniform conditions until 21 days post-hatching when larval lipid and fatty acid compositions were assessed.

Involvement of epidermal growth factor receptors and mitogen-activated protein kinase in progestin-induction of sperm hypermotility in Atlantic croaker through membrane progestin receptor-alpha.

The intracellular pathways mediating rapid, nongenomic progestin stimulation of sperm motility remain unclear. The role of epidermal growth factor receptors (Egfr and ErbB2) and mitogen-activated protein kinase (Mapk) in membrane progestin receptor-alpha (mPRα)-mediated progestin stimulation of sperm hypermotility was examined in a teleost, Atlantic croaker. Inhibition of upstream regulators of Egfr, intracellular tyrosine kinase (Src) with PP2, and matrix metalloproteinase (MMP) with Ilomastat, abolished progestin-initiated sperm hypermotility by 17,20β,21-trihydroxy-4-pregnen-3-one (20β-S; 20 nM) and a specific mPRα agonist, Org OD 02-0 (20 nM).

Population Structure and Seasonal Migration of the Spotted Eagle Ray, Aetobatus narinari.

Few studies have reported on the fine-scale population genetics of batoid species in the Atlantic basin. Here, we investigate the genetic diversity and population structure of the spotted eagle ray, Aetobatus narinari, sampled in the northeastern and southwestern parts of the Gulf of Mexico and in the northwestern Caribbean Sea. Samples were collected from 286 individuals sampled across 3 geographic localities.

Molecular classification of an elasmobranch angiotensin receptor: quantification of angiotensin receptor and natriuretic peptide receptor mRNAs in saltwater and freshwater populations of the Atlantic stingray.

Among the most conserved osmoregulatory hormone systems in vertebrates are the renin-angiotensin system (RAS) and the natriuretic peptides (NPs). We examined the RAS and NP system in the euryhaline Atlantic stingray, Dasyatis sabina (Lesueur). To determine the relative sensitivity of target organs to these hormonal systems, we isolated cDNA sequences encoding the D.

Regulation of mRNAs encoding the steroidogenic acute regulatory protein and cholesterol side-chain cleavage enzyme in the elasmobranch interrenal gland.

The rate-limiting and regulated step in steroidogenesis, the conversion of cholesterol to pregnenolone, is facilitated by the steroidogenic acute regulatory protein (StAR) and cytochrome P450 cholesterol side-chain cleavage (P450scc). We have isolated cDNAs encoding StAR and P450scc from the Atlantic stingray, Dasyatis sabina, and characterized the steroidogenic activity of the encoded proteins using a heterologous expression system. Green monkey kidney (COS-1) cells cotransfected with D.

Adaptation of a corticosterone ELISA to demonstrate sequence-specific effects of angiotensin II peptides and C-type natriuretic peptide on 1alpha-hydroxycorticosterone synthesis and steroidogenic mRNAs in the elasmobranch interrenal gland.

It is thought that a single corticosteroid, 1alpha-hydroxycorticosterone (1alpha-B), is both a glucocorticoid and mineralocorticoid in the elasmobranch fishes. We investigated the putative mineralocorticoid role of 1alpha-B by examining regulation of interrenal 1alpha-B synthesis by osmoregulatory hormones in the euryhaline stingray Dasyatis sabina. Using synthesized steroid, a commercial enzyme-linked immunoassay was validated for the quantification of 1alpha-B.

Hormonal regulation of the steroidogenic acute regulatory protein (StAR) in gonadal tissues of the Atlantic croaker (Micropogonias undulatus).

The steroidogenic acute regulatory protein (StAR), a member of the StAR-related lipid transfer domain (START) family, is critical to regulated steroidogenesis in vertebrates. We have isolated a cDNA encoding StAR from a well-studied model of teleost physiology, the Atlantic croaker Micropogonias undulatus. This cDNA (1204 nucleotides total length) contains an open reading frame of 858 nucleotides encoding a protein of 286 amino acids.

Maternal body burdens of methylmercury impair survival skills of offspring in Atlantic croaker (Micropogonias undulatus).

Methylmercury (MeHg), the organic form of mercury, bioaccumulates easily through the food chain. Fish in high trophic levels can accumulate substantial levels of MeHg and transfer it to their developing eggs. Here, the effects of maternally derived MeHg on the planktonic larval stage of Atlantic croaker were investigated.

Characterization of cDNAs encoding cholesterol side chain cleavage and 3beta-hydroxysteroid dehydrogenase in the freshwater stingray Potamotrygon motoro.

The interrenal gland (adrenocortical homolog) of elasmobranchs produces a unique steroid, 1alpha-hydroxycorticosterone (1alpha-B). The synthesis of this and most other steroids requires both cholesterol side chain cleavage (CYP11A) and 3beta-hydroxysteroid dehydrogenase (HSD3). To facilitate the study of elasmobranch steroidogenesis, we isolated complementary DNAs encoding CYP11A and HSD3 from the freshwater stingray Potamotrygon motoro.

Tissue- and sex-specific regulation of CYP19A1 expression in the Atlantic croaker (Micropogonias undulatus).

To better define the tissue- and sex-specific roles of aromatase in fishes, we have isolated a CYP19A1 cDNA sequence from a well-developed model of teleost reproduction, the Atlantic croaker (Micropogonias undulatus). This cDNA encodes a protein which has high identity (57-90%) to known CYP19A1 proteins and segregates with teleost CYP19A1 proteins in molecular phylogenetic analysis. In both sexes, the gene encoding Atlantic croaker CYP19A1 is expressed primarily in gonadal tissue, but also in the brain and other tissues at much lower levels, as determined relative to ribosomal 18S RNA expression by real-time quantitative RT-PCR.

Cloning and characterization of cDNAs encoding steroidogenic acute regulatory protein from freshwater stingrays (Potamotrygon spp.).

The steroidogenic acute regulatory protein (StAR) is critical to the regulated synthesis of steroids in vertebrates. We have isolated cDNA sequences encoding StAR in the freshwater stingrays Potamotrygon hystrix and P. motoro.

Androgen binding profiles of two distinct nuclear androgen receptors in Atlantic croaker (Micropogonias undulatus).

In the present study, the binding affinities of 28 androgens for two nuclear androgen receptors (AR), termed AR1 and AR2, in Atlantic croaker (Micropogonias undulatus) brain and ovarian tissues, respectively, were determined using competitive binding assays. The 5alpha-reduction of steroids, in general, increased the metabolite's binding affinity for AR2 while decreasing it for AR1. In addition, few androgens bound to AR1 with high affinity and modifications to the basic 3-ketone,4-ene,17beta-hydroxy structure of testosterone usually reduced its binding affinity for AR1.

Identification of two nuclear androgen receptors in kelp bass (Paralabrax clathratus) and their binding affinities for xenobiotics: comparison with Atlantic croaker (Micropogonias undulatus) androgen receptors.

Two distinct nuclear androgen receptors (ARs) were identified in brain and ovarian tissues of kelp bass, Paralabrax clathratus, termed kbAR1 and kbAR2, which correspond to the two nuclear ARs we have previously characterized in Atlantic croaker, Micropogonias undulatus, termed acAR1 and acAR2. Scatchard analysis of nuclear fractions of whole brain tissue demonstrated that kbAR1 had a single class of high-affinity binding sites for testosterone (T; K(d) of 1. 8 nM and B(max) of 1.

Photosynthetic and respiratory rates of two psychrophilic diatoms.

The photosynthetic rates in two psychrophilic diatoms, Chaetoceros sp. strain K3-10 and Nitzschia sp. K3-3 for cells grown at 0 degrees C were 8 to 10 microliters O(2) evolved per milligram dry weight per hour, and 10-fold higher, about 80 for cells grown at 10 degrees C.

Biochemical effects of technetium-99-pertechnetate on microorganisms.

The biochemical effects of technetium-99 as pertechnetate (TcO(4) (-)) were investigated in a variety of microorganisms (a nonsulfur purple bacterium, five blue-green algae, a protozoan, a diatom, two heterotrophic bacteria, a red alga and two green algae). Sensitivity to pertechnetate as measured by growth ranged from marked inhibition at 1 mug Tc/ml (nonsulfur purple bacterium) to no effect at 600 mug Tc ml (both green algae). No correlation between organism type and growth susceptibility to pertechnetate was apparent.