RESUMEN
In vertebrates, anti-Mullerian hormone (Amh) secreted by Sertoli cells (SC) performs a pivotal function in male sex differentiation. Compared with that of higher vertebrates, the expression pattern of Amh is more diversified in fish. In this study, the full-length complementary DNA (cDNA) of Amh in Centropyge vrolikii (Cv-Amh) was cloned and analysed, which was 2,470 bp, including a 238 bp 5'UTR, a 1,602 bp ORF and a 633 bp 3'UTR; the similarity of Amh between Cv-Amh and other fish is relatively high. The quantitative real-time PCR (qRT-PCR) results of healthy tissues and gonads at sex reversal stages in C. vrolikii showed that the expression level of Amh in the testis was significantly higher than that in other tissues (P < 0.05). Amh was weakly expressed in the vitellogenic stage ovary and perinucleolus stage ovary, but its expression significantly increased in the gonads at the hermaphroditic stage, and finally reached the highest in the pure testis after sexual reversal. The results of in situ hybridization indicated that the positive signal of Amh was strongly concentrated in SCs of testis. After Amh knockdown in the gonads, the effect on sex-related genes was tested using qRT-PCR. Among these, the expression of Dmrt1, Cyp11a, Hsd11b2, Sox8 and Sox9 significantly decreased, whereas that of Cyp19a, Sox4, Foxl2 and Sox3 increased. These results suggested that Amh could be the pivotal gene in reproductive regulation in C. vrolikii, and the data will contribute to sex-related research of C. vrolikii in the future.
Asunto(s)
Hormona Antimülleriana , Testículo , Femenino , Masculino , Animales , Hormona Antimülleriana/genética , Hormona Antimülleriana/metabolismo , Testículo/metabolismo , Diferenciación Sexual/genética , Regulación del Desarrollo de la Expresión Génica , Factor de Transcripción SOX9/genética , Factor de Transcripción SOX9/metabolismoRESUMEN
As a member of the Sox gene family, Sox3 plays a vital role in gonadal development and gametogenesis. Nevertheless, the exact expression pattern of this gene in fish is still unknown. Here, we identified the Sox3 gene of Centropyge vrolikii, namely, Cv-Sox3. The Cv-Sox3 mRNA expression in the ovary and testis was detected by reverse transcription-polymerase chain reaction (RT-PCR) analysis, and the mRNA expression level of Cv-Sox3 in the ovary in the resting stage was significantly higher than that in other tissues. The phylogenetic tree and alignment of multiple sequences were constructed to analyze the evolutionary relationships of Cv-Sox3. Cv-Sox3 was relatively conserved in the evolution of teleost fish, indicating the importance and similarity of its function. The in situ hybridization results demonstrate that Cv-Sox3 was present in the follicle cells and cytoplasm of oocytes in the ovary of different stages, and the positive signals occurred in germ cells of the testis. After interfering with Cv-Sox3, the growth rate of ovarian cells in culture became slow, and the expression of ovary-bias-related genes Cyp19a and Foxl2 significantly increased. Meanwhile, the expression of testis-bias-related genes Dmrt1, Sox9, Cyp11a, Amh, and Sox8 significantly decreased. These results suggest that Cv-Sox3 gene might be expressed in the germ cells of male and female gonads during gonadal development. This study provides a precise expression pattern of Cv-Sox3 and demonstrates that Cv-Sox3 might play a significant role in the reproductive regulation of C. vrolikii. In this study, Sox3 of C. vrolikii (Cv-Sox3) was cloned to understand the expression pattern in the gonadal development, which is expressed in germ cells, involved in the process of gonadal development. The results demonstrated that Cv-Sox3 may play a significant role in the reproductive regulation of C. vrolikii.
Asunto(s)
Gónadas , Perciformes , Masculino , Femenino , Animales , Filogenia , Gónadas/metabolismo , Testículo/metabolismo , Perciformes/genética , ARN Mensajero/metabolismo , Regulación del Desarrollo de la Expresión Génica , Factor de Transcripción SOX9/genética , Factor de Transcripción SOX9/metabolismoRESUMEN
The homeodomain transcription factor Nanog plays a crucial role in the embryonic and gonadal development and the maintenance of embryonic stem cells (ESCs), interacting with transcription factors such as Oct4 and Sox2 in mammals. Nevertheless, its pathways to molecular mechanisms remain unclear as to teleosts. This study investigates the role of the Nanog gene in gonadal development and sex reversal of pearlscale angelfish (Centropyge vrolikii). To understand the expression pattern of gonadal development, we identified the Nanog gene of C. vrolikii, which we named Cv-Nanog. The full-length cDNA sequence of Cv-Nanog was 2,136 bp in length and encoded a homeodomain protein of 436 amino acid residues. The gene structure and western blot prove results that Cv-Nanog was homologous to the Nanog gene of mammalians. The protein sequence comparison demonstrates that the Cv-Nanog shared a high degree of similarity with orthologs from other vertebrates in the conserved homeodomain. The Cv-Nanog gene was substantially expressed in gonads, and the expression was significantly higher in the ovaries than in the testis, according to quantitative real-time PCR (qRT-PCR) and western blot analyses. In situ hybridization reveals that the transcripts were located in the cytoplasm and membrane of the oocytes in the ovaries and testes. The expression of Cv-Nanog mRNA was weak in Sertoli cells but strong in germ cells. After overexpression of Cv-Nanog, the expression levels of pluripotent factors Sox2 and Oct4 increased significantly with 21.5-fold and 12.2-fold, respectively. Simultaneously, the TGF-beta signaling pathway was activated, and the gonadal cell growth was promoted. The expression of ovary-bias genes Cyp19a and Foxl2 was upregulated, and the expression of testis-bias genes Sox9 and Dmrt1 was downregulated to promote ovarian development. These results imply that the Nanog gene might play a crucial role in the process of gonadal development and sexual reversion in C. vrolikii. This study provides new insight to understand the molecular regulatory mechanism of the Nanog gene further and important clues for the future studies in gonadal development.
Asunto(s)
Cíclidos , Gónadas , Animales , Femenino , Regulación del Desarrollo de la Expresión Génica , Gónadas/metabolismo , Masculino , Mamíferos , Ovario , Diferenciación Sexual , TestículoRESUMEN
Pearlscale angelfish Centropyge vrolikii is a kind of protogynous hermaphrodite fish with a natural sexual reversion. Under appropriate social conditions, a female fish can transform into a male fish spontaneously. It is an important prerequisite for artificial breeding to understand the process of its gonadal development and sexual reversion. Gonadal development is regulated by many sex-related genes. In this study, we used unreferenced RNA-Seq technology to sequence the ovary at the perinucleolus stage (OII), ovary at the yolk vesicle stage (OIV),IV and testis (T), respectively; screened the gonadal differential expression genes (DEGs); and analyzed the expression of these genes in different developmental stages of ovary and different sex gonads. The results showed that a total of 142,589 all-unigene samples were assembled, and gene annotation was performed by COG, GO, KEGG, KOG, Pfam, Swissprot, eggNOG, and NR functional database. Comparative analysis revealed that there were 1919 genes that were up-regulated and 1289 genes were down-regulated in comparison to OIV vs OII, while there were 3653 genes that were up-regulated and 2874 genes were down-regulated in comparison of OIV vs T, there were 3345 genes that were up-regulated and 2995 genes were down-regulated in comparison of the OII vs the T. At the same time, the results verified by RT-qPCR were consistent with the variation trend of transcriptome data. Among the results, amh, sox9b, dmrt1, dmrt2, cyp11a, cyp17a, and cyp19a were significantly expressed in the testes, while sox3, sox4, sox11, sox17, and hsd3b7 were significantly expressed in the ovaries. And, the expression of the amh, sox9b, dmrt2, and dmrt1 were low in the OII and OIV, while significantly increased during the ovotestis in the hermaphroditic period (OT), and finally reached the highest level in pure testis after sex reversal. The expression of sox3, sox4, hsd3b7, sox11, and sox17 was significantly reduced during the hermaphroditic period (OT). These results suggested that these genes may play an important role in the process of sex reversal. This study is helpful to further understand the molecular regulation mechanism of gonadal development and sexual reversion in Pearlscale angelfish and also provide important clues for future studies.
Asunto(s)
Ovario , Perciformes , Testículo , Animales , Femenino , Peces , Perfilación de la Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Gónadas , Masculino , Ovario/fisiología , Perciformes/genética , Perciformes/fisiología , RNA-Seq , Testículo/fisiologíaRESUMEN
Environmental temperature is an important determinant of physiological processes and life histories in ectotherms. Over latitudinal scales, variation in temperature has been linked to changes in life-history traits and demographic rates, with growth and mortality rates generally being greatest at low latitudes, and longevity and maximum length being greater at higher latitudes. Using the two-spined angelfish, Centropyge bispinosa, as our focal species, we compared growth patterns, growth rates, longevity, mortality, asymptotic length and maximum length across 22 reefs that span 13° of latitude within the Great Barrier Reef Marine Park (GBRMP) and the Coral Sea Marine Park (CSMP), Australia. We found no predictable latitudinal variation in mortality rates, growth patterns, growth rates, asymptotic or maximum length of C. bispinosa at regional to biogeographic scales. However, C. bispinosa consistently exhibited reduced longevity at lower, warmer latitudes within the CSMP. The greatest differences in mean maximum length of C. bispinosa were between continental (GBRMP) and oceanic (central CSMP) reefs of similar latitude, with individuals being larger on average on continental versus oceanic reefs. The lack of predictable life-history and demographic variation in C. bispinosa across a 13° latitudinal gradient within the CSMP, coupled with differences in mean maximum length between continental and oceanic reefs at similar latitudes, suggest that local environmental conditions have a greater influence than environmental temperature on the demographic rates and life-history traits of C. bispinosa.
Asunto(s)
Antozoos , Perciformes , Animales , Australia , Arrecifes de Coral , Demografía , PecesRESUMEN
Marine angelfish (family: Pomacanthidae) are among the most sought-after fish species in the saltwater aquarium trade. However, there is a lack of information in the literature on their early ontogeny. The objective of this study was to describe the embryonic and early larval development of two dwarf angelfish, the bicolour angelfish, Centropyge bicolor and the coral beauty angelfish, Centropyge bispinosa. The eggs of these two species were obtained from spontaneous spawning of the broodstock fish in captivity and incubated at 26.0 ± 0.2°C throughout the study. Fertilized eggs (n = 15) of both species are transparent, pelagic and spherical; the mean diameters of the eggs were measured at 703.6 ± 7.8 µm for C. bicolor and 627.6 ± 7.8 µm for C. bispinosa. The eggs of both species possessed a narrow perivitelline space, smooth and thin chorion, a homogenous and non-segmented yolk as well as a single oil globule. Overall, the observed embryonic development pattern of C. bicolor and C. bispinosa was very similar, and the main difference was the embryonic pigmentation pattern, which only became evident close to hatching. Larvae of both species started hatching at 13 h 30 min after fertilization, and the larval characteristics of both species also showed high levels of similarities. However, the mouth opening time for C. bicolor was 72 h after hatching (AH) and 96 AH for C. bispinosa. In general, the observed early ontogeny of C. bicolor and C. bispinosa also resembled that of other Centropyge species documented in the literature.
Asunto(s)
Embrión no Mamífero/embriología , Desarrollo Embrionario/fisiología , Óvulo/crecimiento & desarrollo , Perciformes/crecimiento & desarrollo , Cigoto/crecimiento & desarrollo , Animales , Blástula/citología , Blástula/embriología , Embrión no Mamífero/citología , Femenino , Gástrula/citología , Gástrula/embriología , Larva/crecimiento & desarrollo , Óvulo/citología , Perciformes/clasificación , Perciformes/embriología , Pigmentación/fisiología , Somitos/citología , Somitos/embriología , Especificidad de la Especie , Factores de Tiempo , Cigoto/citologíaRESUMEN
In this study, we used the next-generation sequencing method to deduce two complete mitogenomes of Cocos lemonpeel angelfish (Centropyge flavissima) and Eibl's angelfish (Centropyge eibli) for the first time. The assembled mitogenome, consisting of 17 010 bp and 17 101 bp, showing 98.3% identity each other. Both mitogenomes follow the typical vertebrate arrangement, including 13 protein coding genes, 22 transfer RNAs, two ribosomal RNA genes, and a non-coding control region of D-loop. D-loop contains 1302 bp in C. flavissima and 1392 bp in C. eibli and locates between tRNA-Pro and tRNA-Phe. The overall GC content is 45.2% for C. flavissima and 44.9% for C. eibli. Complete mitogenomes of C. flavissima and C. eibli provide essential and important DNA molecular data for phylogenetic and evolutionary analysis for marine angelfishes.
Asunto(s)
Genoma Mitocondrial , Perciformes/genética , Animales , Composición de Base , Proteínas de Peces/genética , Perciformes/clasificación , Filogenia , ARN Ribosómico/genética , ARN de Transferencia/genética , Homología de SecuenciaRESUMEN
The pygmy angelfishes (genus Centropyge, family Pomacanthidae) are brightly colored species that occupy reef habitats in every tropical ocean. Some species are rarely observed because they occur below conventional scuba depths. Their striking coloration can command thousands of U.S. dollars in the aquarium trade, and closely related species are often distinguished only by coloration. These factors have impeded phylogenetic resolution, and every phylogeographic survey to date has reported discordance between coloration, taxonomy, and genetic partitions. Here we report a phylogenetic survey of 29 of the 34 recognized species (N=94 plus 23 outgroups), based on two mtDNA and three nuclear loci, totaling 2272 bp. The resulting ML and Baysian trees are highly concordant and indicate that the genus Centropyge is paraphyletic, consistent with a previous analysis of the family Pomacanthidae. Two recognized genera (Apolemichthys and Genicanthus) nest within Centropyge, and two subgenera (Xiphypops and Paracentropyge) comprise monophyletic lineages that should be elevated to genus level. Based on an age estimate of 38 Ma for the family Pomacanthidae, Centropyge diverged from the closest extant genus Pygoplites about 33 Ma, three deep lineages within Centropyge diverged about 18-28 Ma, and four species complexes diverged 3-12 Ma. However, in 11 of 13 cases, putative species in these complexes are indistinguishable based on morphology and genetics, being defined solely by coloration. These cases indicate either emerging species or excessive taxonomic splitting based on brightly colored variants.