RESUMEN

Groupers (Epinephelidae and Serranidae) have attracted special attention to fish farming, and their species offer good opportunities for successful hybridizations. Cytogenetic data allow a better understanding of the role of karyotypic diversification in the acquisition of post-zygotic reproductive isolation (RI). Thus, chromosomal analyses were performed on E. striatus (Caribbean Sea), E. coioides and E. tauvina (Indo-Pacific Region), using standard procedures and mapping of six repetitive DNA classes by the in situ hybridization. The three species have 2n=48 chromosomes. The karyotypes of E. coioides and E. striatus are composed only of acrocentric chromosomes (FN=48), while E. tauvina has 8 submetacentric chromosomes (FN=56). Heterochromatin has a preferential centromeric distribution, and the microsatellite repeats are dispersed throughout the chromosomes of all species. The 18S and 5S rDNA sites are unique but show a colocalization arrangement in E. tauvina and E. striatus. The chromosomal organization suggests that the three species still maintain a significant amount of syntenic regions. The range of the karyotype divergence and the RI levels showed low, but goes turn proportionally greater in relation to the divergence time between the parental species. The slow acquisition of postzygotic RI is consistent with the high karyotype homogeneity presented by Epinephelidae family.

Asunto(s)

Lubina , Perciformes , Animales , Lubina/genética , Aislamiento Reproductivo , Cariotipo , Cariotipificación

RESUMEN

Wastes from iron ore mining activities are potentially damaging to adjacent aquatic ecosystems. We aimed to determine biomarkers of environmental exposure to this xenobiotic in the dusky grouper Epinephelus marginatus by differential gene expression analysis. For this, fish were exposed to iron ore (15.2 mg/L) and gene expression in liver was assessed by RNA-Seq and compared to the control group. A total of 124 differentially expressed genes were identified, from which 52 were upregulated and 72 were downregulated in response to iron ore. From these, ferritin (medium subunit), cytochrome b reductase and epoxide hydrolase genes were selected for validation by RT-qPCR that confirmed the upregulation of epoxide hydrolase in fish exposed to iron ore.

Asunto(s)

Lubina , Animales , Lubina/genética , Biomarcadores , Ecosistema , Epóxido Hidrolasas , Expresión Génica , Hierro , Hígado

RESUMEN

Exocyst complex component 3 Sec6 of mammals, one of the components of the exocyst complex, participates in numerous cellular functions, such as promoting cell migration and inhibiting apoptosis. In this study, the Sec6 was obtained from Epinephelus coioides, an economically important cultured fish. The full length of E. coioides Sec6 was 2655 bp including a 245 bp 5' UTR, a 154 bp 3' UTR, and a 2256 bp open reading frame (ORF) encoding 751 amino acids, with a molecular mass of 86.76 kDa and a theoretical pI of 5.57. Sec6 mRNA was detected in all the tissues examined, but the expression level is different in these tissues. Using fluorescence microscopy, Sec6 were distributed in both the nucleus and the cytoplasm. After SGIV infection, the expression of E. coioides Sec6 was significantly up-regulated in both trunk kidney and spleen response to Singapore grouper iridovirus (SGIV), an important pathogens of E. coioides. Sec6 could increase the SGIV-induced cytopathic effects (CPE), the expression of the SGIV genes VP19, LITAF, MCP, ICP18 and MCP, and the viral titers. Besides, E. coioides Sec6 significantly downregulated the promoter of NF-κB and AP-1, and inhibited the SGIV-induced apoptosis. The results demonstrated that E. coioides Sec6 might play important roles in SGIV infection.

Asunto(s)

Lubina , Infecciones por Virus ADN , Enfermedades de los Peces , Iridovirus , Ranavirus , Animales , Lubina/genética , Lubina/metabolismo , Clonación Molecular , Infecciones por Virus ADN/veterinaria , Proteínas de Peces/genética , Proteínas de Peces/metabolismo , Mamíferos/genética , Mamíferos/metabolismo , Filogenia

RESUMEN

Social factors and aromatase gene expression in the leopard grouper Mycteroperca rosacea was studied when captive fish were separated by sex during the reproductive (April-June) and post-reproductive (July-September) seasons. Monosex females, monosex males, and mixed-sex, held in social sextet units were analyzed for sex steroids throughout confinement. At the end of the experiment, the gonad-sex was defined by histology, and gonad and brain aromatase gene expressions were quantified. Only males held in the monosex social units changed sex. Histology showed one male remained unchanged, six were found in a transitional sexual stage, in which two had intersex-predominantly-testes, and four had a more defined intersex ovo-testes pattern, and 11 were immature de novo females (neofemales). Neofemales and most intersex fish did not survive. In spring, 11-ketosterone showed a specific male profile, which suggests that male-to-female sex change was not triggered during the reproductive season. The low steroid levels in summer made it impossible to associate the sex change to a gonad hormonal shift; in September, gonad aromatase gene expression was not significantly different among groups. However, brain aromatase expression in intersex fish was significantly higher than monosex females, mixed-sex females, and neofemale groups. These results suggest that in the absence of female hormonal compounds, and at a time when male gonad steroidogenesis was diminished, the brain mediated male-to-male social-behavioral interactions, including stress, by increasing aromatization, resulting in derived intersex-male, which triggered more aromatization, followed by a sex change.

Asunto(s)

Aromatasa/genética , Lubina/genética , Lubina/fisiología , Regulación Enzimológica de la Expresión Génica , Procesos de Determinación del Sexo/genética , Conducta Social , Animales , Aromatasa/metabolismo , Lubina/anatomía & histología , Lubina/sangre , Encéfalo/enzimología , Encéfalo/metabolismo , Femenino , Hormonas Esteroides Gonadales/sangre , Gónadas/metabolismo , Masculino , Reproducción , Estaciones del Año , Análisis de Supervivencia

RESUMEN

For thousands of years, leaves from the Ginkgo biloba tree have been a common treatment in Chinese medicine. The present study was conducted to investigate the effects of dietary ginkgo biloba leaf extract (GBE) supplementation on growth performance, plasma biochemical parameters, fish composition, immune responses, liver histology, and immune and apoptosis-related genes expression of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀) fed high lipid diets. A basal diet supplemented with GBE at 0, 0.50, 1.00, 2.00, 4.00 and 10.00 g kg-1 was fed to hybrid grouper for 8 weeks. The study indicated that dietary GBE did not improve growth performance and feed utilization but it reduced intraperitoneal fat rate. There were no significant differences in condition factor, viscerosomatic index, hepatosomatic index, spleen index, relative gut length, food intake, protein deposit rate and survival among all groups (P > 0.05). Dietary supplementation with 0.50-4.00 g GBE kg-1 diets effectively increased plasma HDL content and decreased plasma GLU, LDL and TG content in fish. Furthermore, dietary GBE had a significant effect on moisture, crude protein and lipid in the liver, and protein in the whole body of fish (P < 0.05). Dietary supplementation with 0.50-1.00 g GBE kg-1 diets effectively decreased occurrence rates of the hepatocyte swelling, hepatocyte vacuolization, and nuclei shifting to the cellular periphery cytoplasmic vacuolization, meanwhile hepatic antioxidant enzymes (SOD, CAT and T-AOC) activities significantly increased whereas MDA content significantly decreased in fish fed diets supplemented with GBE (P < 0.05). Moreover, dietary GBE up-regulated the expression of antioxidant genes (CAT, GPx and GR), immune-related genes (MHC2 and TLR3) and anti-inflammatory cytokines (IL-10 and TGF-ß1), while dietary supplementation with 0.50-4.00 g GBE kg-1 diets down-regulated apoptosis-related genes (p53, caspase-9, caspase-8 and caspase-3) expression in the head kidney of hybrid grouper. These results indicated that hybrid grouper fed diets supplemented with GBE did not improve growth performance and feed utilization but it had hypolipidemic effects, improved hepatic antioxidant status, maintained normal liver histology and preserved liver function, increased immune-related genes expression and decreased apoptosis-related genes expression in the head kidney of hybrid grouper.

Asunto(s)

Apoptosis/efectos de los fármacos , Lubina/fisiología , Expresión Génica/efectos de los fármacos , Inmunidad Innata/efectos de los fármacos , Extractos Vegetales/metabolismo , Alimentación Animal/análisis , Animales , Lubina/genética , Lubina/crecimiento & desarrollo , Lubina/inmunología , Dieta/veterinaria , Suplementos Dietéticos/análisis , Proteínas de Peces/genética , Ginkgo biloba , Extractos Vegetales/administración & dosificación , Distribución Aleatoria

RESUMEN

Growth, plasma biochemical parameters, fish composition, immune parameters, intestinal histology, and expressions of immune-related genes were examined in hybrid grouper (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀) that fed respectively six diets containing Panax notoginseng extract (PNE) at 0, 0.5, 1, 2, 4, and 10 g kg-1 after 8 weeks. Results indicated that dietary PNE significantly improved growth, feed efficiency ratio, protein efficiency ratio, and protein deposit rate, and significantly increased crude protein and crude lipid levels of whole body and crude protein level of muscle. Dietary PNE significantly increased plasma total protein, alkaline phosphatase, immunoglobulin, complement 3 and complement 4 contents, but significantly decreased cholesterol, triglyceride, glucose, and low density lipoprotein cholesterol contents. Furthermore, dietary PNE increased villus length and muscle thickness in foregut, midgut, and hindgut, activities of hepatic superoxide dismutase and total antioxidant capacity, and increased the expression levels of immune related genes (IL-10, TGF-ß1, TOR, MHC2 and TLR3) in the head kidney and the expression levels of antioxidant genes (CAT and GR) in fish that fed PNE at 0.5-4 g kg-1. In conclusion, grouper fed high lipid diets supplemented with PNE at 0.5-10 g kg-1 improved growth, feed utilization, blood immune parameters, hepatic antioxidant status, intestine morphology and expression levels of immune related genes in the head kidney.

Asunto(s)

Lubina/fisiología , Medicamentos Herbarios Chinos/metabolismo , Expresión Génica/inmunología , Inmunidad Innata/genética , Intestinos/efectos de los fármacos , Metabolismo de los Lípidos , Alimentación Animal/análisis , Animales , Lubina/anatomía & histología , Lubina/genética , Lubina/inmunología , Dieta/veterinaria , Suplementos Dietéticos/análisis , Medicamentos Herbarios Chinos/administración & dosificación , Hibridación Genética , Intestinos/anatomía & histología , Distribución Aleatoria

RESUMEN

Orange-spotted grouper (Epinephelus coioides) is one of the most important marine fish and has a high market value. The insulin-like growth factor type 1 receptor (IGF1R) is a component of the insulin-like growth factor signaling system, and demonstrates important roles during growth. Based on information from livestock, we used IGF1R as a candidate gene to survey single nucleotide polymorphisms. In the present study, the sequences of IGF1Ra and IGF1Rb from orange-spotted grouper were obtained from the genome sequences and their clustering in clades a and b, respectively, was confirmed by phylogenetic analysis. Fourteen critical amino acids underlying functional divergence were detected between the two clades, revealing the molecular basis of their functional differences. Nearly one-fourth (22 kbp) of the genomic sequence of IGF1Ra was sequenced in a mass cross population, and nucleotide diversity and linkage disequilibrium levels were investigated. Nucleotide diversity was 0.00328 for π and 0.00344 for θw. The half decay of the squared allele-frequency correlation was 10,835 base pairs. Comparatively, the relatively high level of linkage and the significant deviation from neutrality-based codons in IGR1R showed that this gene was under selection. A site (KR269824.1:g. 63762C>T), located in the sixth intron, was significantly associated with eyeball diameter (P = 1.39 x 10-4, Q-value: 2.33 x 10-2), which accounted for 11.1% of phenotypic variance. These results highlight the important function of IGF1R in orange-spotted grouper and may be beneficial in the breeding of this species.

Asunto(s)

Lubina/genética , Polimorfismo Genético , Receptores de Somatomedina/genética , Animales , Estudios de Asociación Genética , Genotipo , Funciones de Verosimilitud , Fenotipo , Filogenia

RESUMEN

Determining correlations between certain traits of economic importance constitutes an essential component of selective activities. In this study, our aim was to provide effective indicators for breeding programs of Lateolabrax maculatus, an important aquaculture species in China. We analyzed correlations between 20 morphometric traits and body weight, using correlation and path analyses. The results indicated that the correlations among all 21 traits were highly significant, with the highest correlation coefficient identified between total length and body weight. The path analysis indicated that total length (X1), body width (X5), distance from first dorsal fin origin to anal fin origin (X10), snout length (X16), eye diameter (X17), eye cross (X18), and slanting distance from snout tip to first dorsal fin origin (X19) significantly affected body weight (Y) directly. The following multiple-regression equation was obtained using stepwise multiple-regression analysis: Y = -472.108 + 1.065X1 + 7.728X5 + 1.973X10 - 7.024X16 - 4.400X17 - 3.338X18 + 2.138X19, with an adjusted multiple-correlation coefficient of 0.947. Body width had the largest determinant coefficient, as well as the highest positive direct correlation with body weight. At the same time, high indirect effects with six other morphometric traits on L. maculatus body weight, through body width, were identified. Hence, body width could be a key factor that efficiently indicates significant effects on body weight in L. maculatus.

Asunto(s)

Lubina/anatomía & histología , Lubina/genética , Animales , Acuicultura/métodos , Peso Corporal , China , Fenotipo , Alimentos Marinos , Selección Artificial

RESUMEN

Thyrotropin receptor (TSHR) is a G-protein-coupled receptor that regulates the synthesis, storage, and secretion of thyroid hormones in the thyroid tissue. The aims of the present study were to characterize the full-length TSHR cDNA in largemouth bass (Micropterus salmoides), and to determine the TSHR gene transcription levels in different tissues. In addition, the response of TSHR transcription levels to daily feeding in thyroid tissue was investigated. The results showed that the full-length cDNA sequence was 2743 bp with an open reading frame of 2340 bp encoding a 779-amino acid peptide. BLAST analysis indicated that the amino acid sequence displayed 58.4-90.2% identity and 5.6-125.8 divergence, compared with other known fish species. The most abundant TSHR transcription levels were found in the spleen, head kidney, and kidney. Feeding did not affect the transcription level of TSHR in thyroid tissue over the course of the day. Thus, the current study suggests that there was no relationship between daily nutritional status and TSHR transcription level in the thyroid tissue of largemouth bass. The spleen, head kidney, and kidney exhibited the most abundant TSHR transcription levels.

Asunto(s)

Lubina/genética , Proteínas de Peces/genética , Receptores de Tirotropina/genética , Secuencia de Aminoácidos , Animales , Lubina/fisiología , Clonación Molecular , Conducta Alimentaria , Proteínas de Peces/biosíntesis , Especificidad de Órganos , Filogenia , Receptores de Tirotropina/biosíntesis , Homología de Secuencia de Aminoácido , Glándula Tiroides/metabolismo , Transcripción Genética

RESUMEN

In the present study, ten novel microsatellite markers were developed from an enriched-(CA)13 genomic library of Epinephelus akaara. The mean number of alleles per locus was 21.6, with a range of 12 to 33. Observed heterozygosity ranged from 0.767 to 0.967, and expected heterozygosity ranged from 0.831 to 0.975, with mean values of 0.877 and 0.923, respectively. Among the ten loci, three loci deviated from Hardy-Weinberg equilibrium after sequential Bonferroni's correction. These polymorphic microsatellite markers may be useful for studies on the population genetics of E. akaara.

Asunto(s)

Lubina/genética , Repeticiones de Microsatélite , Polimorfismo Genético , Animales , Sitios de Carácter Cuantitativo

RESUMEN

The spotted sea bass, Lateolabrax maculatus, is an important commercial and recreational fishery resource in Korea. Aquacultural production of this species has increased because of recent resource declines, growing consumption, and ongoing government-operated stock release programs. Therefore, the genetic characterization of hatchery populations is necessary to maintain the genetic diversity of this species and to develop more effective aquaculture practices. In this study, the genetic diversity and structure of three cultured populations in Korea were assessed using multiplex assays with 12 highly polymorphic microsatellite loci; 144 alleles were identified. The number of alleles per locus ranged from 6 to 28, with an average of 13.1. The mean observed and expected heterozygosities were 0.724 and 0.753, respectively. Low levels of inbreeding were detected according to the inbreeding coefficient (mean FIS = 0.003-0.073). All hatchery populations were significantly differentiated from each other (overall fixation index (FST) = 0.027, P < 0.01), and no population formed a separate cluster. Pairwise multilocus FST tests, estimates of genetic distance, mantel test, and principal component analyses did not show a consistent relationship between geographic and genetic distances. These results could reflect the exchange of breeds and eggs between hatcheries and/or genetic drift due to intensive breeding practices. For optimal resource management, the genetic variation of hatchery stocks should be monitored and inbreeding controlled within the spotted sea bass stocks that are being released every year. This genetic information will be useful for the management of both L. maculatus fisheries and the aquaculture industry.

Asunto(s)

Lubina/genética , Variación Genética , Repeticiones de Microsatélite/genética , Reacción en Cadena de la Polimerasa Multiplex/métodos , Alelos , Animales , Acuicultura , Lubina/crecimiento & desarrollo , Femenino , Explotaciones Pesqueras/métodos , Frecuencia de los Genes , Genética de Población , Genotipo , Geografía , Endogamia , Masculino , Polimorfismo Genético , República de Corea , Análisis de Secuencia de ADN

RESUMEN

Seafood mislabeling distorts the true abundance of fish in the sea, defrauds consumers, and can also cause unwanted exposure to harmful pollutants. By combining genetic data with analyses of total mercury content, we have investigated how species substitutions and fishery-stock substitutions obscure mercury contamination in Patagonian toothfish (Dissostichus eleginoides), also known as "Chilean sea bass". Patagonian toothfish show wide variation in mercury concentrations such that consumers may be exposed to either acceptable or unacceptable levels of mercury depending on the geographic origins of the fish and the allowable limits of different countries. Most notably, stocks of Patagonian toothfish in Chile accumulate significantly more mercury than stocks closer to the South Pole, including the South Georgia/Shag Rocks stock, a fishery certified by the Marine Stewardship Council (MSC) as sustainably fished. Consistent with the documented geography of mercury contamination, our analysis showed that, on average, retail fish labeled as MSC-certified Patagonian toothfish had only half the mercury of uncertified fish. However, consideration of genetic data that were informative about seafood substitutions revealed a complex pattern of contamination hidden from consumers: species substitutions artificially inflated the expected difference in mercury levels between MSC-certified and uncertified fish whereas fishery stock substitutions artificially reduced the expected difference in mercury content between MSC-certified and uncertified fish that were actually D. eleginoides. Among MSC-certified fish that were actually D. eleginoides, several with exogenous mtDNA haplotypes (i.e., not known from the certified fishery) had mercury concentrations on par with uncertified fish from Chile. Overall, our analysis of mercury was consistent with inferences from the genetic data about the geographic origins of the fish, demonstrated the potential negative impact of seafood mislabeling on unwanted mercury exposure for consumers, and showed that fishery-stock substitutions may expose consumers to significantly greater mercury concentrations in retail-acquired fish than species substitutions.

Asunto(s)

Lubina/metabolismo , Contaminación de Alimentos/análisis , Mercurio/análisis , Alimentos Marinos/análisis , Animales , Lubina/genética , ADN Mitocondrial/genética , Monitoreo del Ambiente , Explotaciones Pesqueras , Georgia , Haplotipos/genética

RESUMEN

Integrative taxonomy, in which multiple disciplines are combined to address questions related to biological species diversity, is a valuable tool for identifying pelagic marine fish larvae and recognizing the existence of new fish species. Here we combine data from DNA barcoding, comparative morphology, and analysis of color patterns to identify an unusual fish larva from the Florida Straits and demonstrate that it is the pelagic larval phase of a previously undescribed species of Liopropoma sea bass from deep reefs off Curaçao, southern Caribbean. The larva is unique among larvae of the teleost family Serranidae, Tribe Liopropomini, in having seven elongate dorsal-fin spines. Adults of the new species are similar to the golden bass, Liopropoma aberrans, with which they have been confused, but they are distinct genetically and morphologically. The new species differs from all other western Atlantic liopropomins in having IX, 11 dorsal-fin rays and in having a unique color pattern-most notably the predominance of yellow pigment on the dorsal portion of the trunk, a pale to white body ventrally, and yellow spots scattered across both the dorsal and ventral portions of the trunk. Exploration of deep reefs to 300 m using a manned submersible off Curaçao is resulting in the discovery of numerous new fish species, improving our genetic databases, and greatly enhancing our understanding of deep-reef fish diversity in the southern Caribbean. Oh the mother and child reunion is only a moment away. Paul Simon.

Asunto(s)

Distribución Animal , Lubina/anatomía & histología , Lubina/genética , Arrecifes de Coral , Filogenia , Azul Alcián , Aletas de Animales/anatomía & histología , Animales , Antraquinonas , Clasificación/métodos , Análisis por Conglomerados , Código de Barras del ADN Taxonómico , Florida , Técnicas Histológicas , Larva/anatomía & histología , Antillas Holandesas , Fotomicrografía , Pigmentación de la Piel/fisiología , Especificidad de la Especie

RESUMEN

Major histocompatibility complex (MHC) molecules play vital roles in triggering adaptive immune responses and are considered the most variable molecules in vertebrates. Recently, many studies have focused on the polymorphism and evolution mode of MHC in both model and non-model organisms. Here, we analyzed the MHC class II exon 2-encoding ß chain in comparison with the mitochondrial Cytb gene and our previously published microsatellite data set in three cultured stocks and four wild populations of the orange-spotted grouper (Epinephelus coioides) in order to investigate its genetic variation and mechanism of evolution. We detected one to four alleles in one individual, suggesting that at least two loci exist in the orange-spotted grouper, as well as a particularly high level of allelic diversity at the MHC loci. Furthermore, the cultured stocks exhibited reduced allelic diversity compared to the wild counterparts. We found evidence of balancing selection at MHC class II exon 2, and codon sites under positive selection were largely correspondent to the protein-binding region. In addition, MHC class II exon 2 revealed significant differences between population differentiation patterns from the neutral mitochondrial Cytb and microsatellites, which may indicate local adaptation at MHC loci in orange-spotted grouper originating from the South China Sea and Southeast Asia.

Asunto(s)

Animales Salvajes/genética , Lubina/crecimiento & desarrollo , Lubina/genética , Exones/genética , Genes MHC Clase II/genética , Variación Genética , Selección Genética , Animales , Animales Salvajes/crecimiento & desarrollo , Asia Sudoriental , China , Citocromos b/genética , Genética de Población , Geografía , Antígenos de Histocompatibilidad Clase II/genética , Funciones de Verosimilitud , Mitocondrias/genética , Datos de Secuencia Molecular , Filogenia , Pigmentación/genética

RESUMEN

An economically important marine fish species, the giant grouper Epinephelus lanceolatus (Serranidae) is widely cultured in Taiwan and costal areas of China. We isolated and characterized 32 polymorphic microsatellite loci from a CA-enriched genomic library of giant grouper. The number of alleles per locus ranged from 3 to 7, with a mean of 4.69. Observed and expected heterozygosities per locus varied from 0.387 to 1.000 and from 0.377 to 0.843, respectively. Six loci significantly deviated from Hardy-Weinberg equilibrium. After sequential Bonferroni's correction, only two loci showed deviation from Hardy-Weinberg equilibrium, and no linkage disequilibrium was found between any pair of loci. These microsatellites can be useful tools for the study of population genetics in the giant grouper.

Asunto(s)

Lubina/genética , Sitios Genéticos , Repeticiones de Microsatélite , Alelos , Animales , Genética de Población , Heterocigoto , Desequilibrio de Ligamiento

RESUMEN

Hepcidin is a cysteine-rich peptide involved in iron metabolism, inflammatory response and as antimicrobial peptide. Despite the fact that hepcidins have been identified in several fish species, only few have been completely characterized. This study, described the identification and complete molecular characterization of the hepcidin antimicrobial peptide 1 (HAMP1) gene of Alphestes immaculatus. Moreover, its specific expression level at both basal and lipopolysaccharide (LPS)-induced conditions in different tissues was also determined by real-time PCR. Results showed that the HAMP1gene consists of three exons and two introns encoding a preprohepcidin composed of 90 aa (24 aa for signal peptide, 40 aa for prodomain and 26 aa for mature peptide). The promoter region analysis revealed a TATA box sequence and several putative transcription factor binding sites. A comparative analysis showed CEBPα, CEBPß, NF-kB, HNF3, GATA-1 and c-Rel as the most common found in fishes. The mature peptide possesses a pI of 8.34, which is the average among fish hepcidin. In addition, the structural modeling showed a hairpin structure with four putative disulfide bonds. A phylogenetic analysis revealed that this hepcidin gene is a HAMP1 class, and is clustered into the same group with the Serranid fish Epinephelus moara and the Antarctic fish Lycodichthys dearborni. Finally, the relative expression levels showed high basal values in liver and muscle, whereas in LPS-induced fish the relative expression tendency changed, with the highest values in spleen and head kidney tissues. This study describes the completely characterized HAMP1 gene of A. immaculatus and their patterns of expression level at different conditions and in different tissues, showing by first time muscle hepcidin expression could be relevant in the immune response in fish.

Asunto(s)

Péptidos Catiónicos Antimicrobianos/genética , Péptidos Catiónicos Antimicrobianos/metabolismo , Lubina/genética , Regulación de la Expresión Génica/fisiología , Modelos Moleculares , Filogenia , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Análisis por Conglomerados , Cartilla de ADN/genética , Componentes del Gen , Regulación de la Expresión Génica/efectos de los fármacos , Riñón Cefálico/metabolismo , Hepcidinas , Lipopolisacáridos , Hígado/metabolismo , México , Datos de Secuencia Molecular , Músculo Esquelético/metabolismo , Regiones Promotoras Genéticas/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Análisis de Secuencia de ADN , Bazo/metabolismo

RESUMEN

The spatial scale of dispersal in coral reef fishes eludes ecologists despite the importance of this parameter for understanding the dynamics of ecological and evolutionary processes. Genetic isolation by distance (IBD) has been used to estimate dispersal in coral reef fishes, but its application in marine systems has been limited by insufficient sampling at different spatial scales and a lack of information regarding population density. Here, we present an analysis of IBD in the barred hamlet (Hypoplectrus puella, Serranidae) at spatial scales ranging from 10 to 3200 km complemented with SCUBA surveys of population densities covering 94000 m2 of reef. We used 10 hypervariable DNA markers to genotype 854 fish from 15 locations, and our results establish that IBD in H. puella emerges at a spatial scale of 175 km and is preserved up to the regional scale (3200 km). Assuming a normal or a Laplace dispersal function, our data are consistent with mean dispersal distances in H. puella that range between 2 and 14 km. Such small mean dispersal distances is a surprising result given the three-week pelagic larval duration of H. puella and the low level of genetic structure at the Caribbean scale (Wright's fixation index, F(ST), estimate = 0.005). Our data reinforce the importance of considering population density when estimating dispersal from IBD and underscore the relevance of sampling at local scales, even when genetic structure is weak at the regional scale.

Asunto(s)

Lubina/genética , Variación Genética , Animales , Lubina/fisiología , Región del Caribe , Demografía

RESUMEN

Striped bass Morone saxatilis populations in drainages along the Gulf of Mexico coast (Gulf) were depleted in the 1950s and 1960s, probably because of anthropogenic influences. It is believed that only the Apalachicola-Chattahoochee-Flint (A-C-F) river system continually supported a naturally reproducing population of Gulf lineage. Striped bass juveniles of Atlantic coast (Atlantic) ancestry were introduced to restore population abundances in the A-C-F from the late 1960s to the mid 1970s and in many other Gulf rivers from the 1960s to the present. We previously identified mtDNA polymorphisms that were unique to approximately 60% of striped bass from the A-C-F and which confirmed the continued successful natural reproduction of striped bass of Gulf maternal ancestry within the system. However, the genetic relatedness of the extant A-C-F population to 'pure' Gulf striped bass was not addressed. In this study, we determined the frequency of a diagnostic mtDNA XbaI polymorphism in samples of 'pure' Gulf striped bass that were collected from the A-C-F prior to the introduction of Atlantic fish, that were obtained from museum collections, and that were originally preserved in formalin. PCR primers were developed that allowed for amplification of a 191-bp mtDNA fragment that contained the diagnostic XbaI restriction site. Using RFLP and direct sequence analyses of the PCR amplicons, we found no significant differences in mtDNA XbaI genotype frequencies between the archived samples and extant A-C-F samples collected over a 15-year period. This indicates that significant maternally mediated introgression of Atlantic mtDNA genomes into the A-C-F gene pool has not occurred. Additionally, we found no evidence of the unique Gulf mtDNA genotype in striped bass from extant populations in Texas, Louisiana and the Mississippi River. These results highlight the importance of the A-C-F as a repository of striped bass to restore extirpated Gulf populations and the potential use of museum collections in retrospective population studies.

Asunto(s)

Lubina/genética , ADN Mitocondrial/genética , Animales , Océano Atlántico , Secuencia de Bases , Cartilla de ADN/genética , Ecosistema , Evolución Molecular , Formaldehído , Genética de Población , Genotipo , México , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción