Black rockfish(Sebastes schlegelii)has evolved viviparous reproduction mode.Different from the oviparous fishes,the spermatozoa of black rockfish are stored on the surface of ovarian follicle for over four months unti...Black rockfish(Sebastes schlegelii)has evolved viviparous reproduction mode.Different from the oviparous fishes,the spermatozoa of black rockfish are stored on the surface of ovarian follicle for over four months until the egg mature in ovary,while the adaptive evolution of fertilization-related genes remains to be studied.In the present study,based on the genome and transcriptome information of black rockfish,a total of 10 hyaluronidase genes were identified by phylogenetic and sequence analyses,including hyal1,hyal2,hyal3,hyal4,hyal6 and spam1a,spam1b,spam1c and spam1d.The spam1 subfamilies,including spam1a,spam1b,spam1c and spam1d,were significantly expanded compared to other species.The adaptive evolution of hyaluronidase was further investigated by selection pressure analysis of branch model and branch site model.The results showed that only spam1 subfamily was positively selected with a large number of positive selection sites,and the evolution rate was significantly higher thanthose of other teleosts.Two positively selected sites,LYS-171 and GLY-164,were located in the neutral hyaluronidase activity domain,which was pivotal for SPAM1 to participate in enzymatic hydrolysis of the extracellular hyaluronic acid matrix and mediate acrosome reaction in mammals.Furthermore,spam1 was mainly expressed in spermatocytes,secondary spermatocytes,and spermatids of testis,whereas it was not found in metamorphic sperm and mature sperm based on the spatiotemporal expression analysis.All results indicated that spam1 might originate from the testis and might be an adaptation of viviparous trait in black rockfish.展开更多
Neuronal nitric oxide synthase(nNOS)was the producer of nitric oxide(NO)which played important gas messenger molecules in biological process.It also can take effect as immune regulation molecule in organism.Black rock...Neuronal nitric oxide synthase(nNOS)was the producer of nitric oxide(NO)which played important gas messenger molecules in biological process.It also can take effect as immune regulation molecule in organism.Black rockfish(Sebastes schlegelii)is an important economic fish which were widely farmed in East Asia countries.Meanwhile,the pathogenic bacteria such as the Edwardsiella tarda and Vibrio anguillarum in seawater always brought serious obstacles to their healthy growth.In order to explore the expression pattern of n NOS gene under the pathogen stimulation and predict its immune function,the n NOS gene in black rockfish named Ssn NOS was identified.It was 3780 bp in length,located on chromosome 6,and contained 27 coding domain sequence(CDs).According to the phylogenetic analysis,the Ssn NOS showed closest relative to the counterpart gene of swamp eel(Monopterus albus).Meanwhile,analysis of Ssn NOS expression in various healthy tissues showed that Ssn NOS expression level was highest in healthy brain tissues,followed by intestinal tissues.In addition,Ssn NOS showed significant expression changes in response to stimulation by two pathogens.Particular in gill,the expression of Ssn NOS after pathogenic stimulation increased significantly.The Elisa analysis showed the Ssn NOS content in gills was much higher than that in other tissues at all time points.Moreover,the expression patterns of Ssn NOS in brain,intestine and kidney after stimulation by pathogens showed a distinct expression pattern which first down-regulated and then up-regulated.Therefore,the Ssn NOS may be an important signaling molecule for fish to respond rapidly in immune stimulation.展开更多
The quantitative real-time reverse transcription PCR(qRT-PCR)is a widely used technique to analyze gene expression levels.Selecting a suitable reference gene is a crucial step to obtain an accurate result in qRT-PCR.H...The quantitative real-time reverse transcription PCR(qRT-PCR)is a widely used technique to analyze gene expression levels.Selecting a suitable reference gene is a crucial step to obtain an accurate result in qRT-PCR.However,most previous studies on fishes adopted reference genes that were commonly used in mammals without validation.In this study,we utilized 89 transcrip-tome datasets covering early developmental stages and different adult tissues,and carried out transcriptome-wide identification and validation of reference genes in Sebastes schlegelii.Finally,121 candidate reference genes were identified based on four criteria.Eight candidates(METAP2,BTF3L4,EIF5A1,TCTP,UBC,PAIRB,RAB10,and DLD)and four commonly used reference genes in mam-mals(TUBA,ACTB,GAPDH,RPL17)were selected for validation via qRT-PCR and four statistical analysis methods(delta-Ct,Best-Keeper,geNorm,and NormFinder).The results indicated that when the black rockfish are cultured in a general condition,the eight candidate reference genes are more stable than traditional reference genes in mammals,and RAB10,EIF5A1,PAIRB and BTF3L4 are the best reference genes in rockfish.This is the first study to conduct transcriptome-wide identification and validation of reference genes for quantitative RT-PCR in the black rockfish,and lay an important foundation for gene expression analysis in teleost.展开更多
Ovoviviparous black rockfish(Sebastes schlegeli) is an important marine fish species for aquaculture and fisheries in China. Genetic information of this species is scarce because of the lack of microsatellite markers....Ovoviviparous black rockfish(Sebastes schlegeli) is an important marine fish species for aquaculture and fisheries in China. Genetic information of this species is scarce because of the lack of microsatellite markers. In this study, a large number of microsatellite markers of black rockfish were isolated by constructing microsatellite-enriched libraries. Female- and male-specific genetic linkage maps were constructed using 435 microsatellite markers genotyped in a full-sib family of the fish species. The female linkage map contained 140 microsatellite markers, in which 23 linkage groups had a total genetic length of 1334.1 c M and average inter-marker space of 13.3 c M. The male linkage map contained 156 microsatellite markers, in which 25 linkage groups had a total genetic length of 1359.6 c M and average inter-marker distance of 12.4 c M. The genome coverage of the female and male linkage maps was 68.6% and 69.3%, respectively. The female-to-male ratio of the recombination rate was approximately 1.07:1 in adjacent microsatellite markers. This paper presents the first genetic linkage map of microsatellites in black rockfish. The collection of polymorphic markers and sex-specific linkage maps of black rockfish could be useful for further investigations on parental assignment, population genetics, quantitative trait loci mapping, and marker-assisted selection in related breeding programs.展开更多
Evolutionary evidence suggests that Sox3, a member of the high-mobility-group(HMG) family of transcription factors, is an ancestral precursor of Sry and is involved in sex determination similar to Sry. However, there ...Evolutionary evidence suggests that Sox3, a member of the high-mobility-group(HMG) family of transcription factors, is an ancestral precursor of Sry and is involved in sex determination similar to Sry. However, there is limited information regarding the SOX3 gene of the black rockfish(Sebastes schlegeli). In this study, we first isolated SOX3 gene from the gonads of S. schlegeli by homology cloning. The full-length of S. schlegeli SOX3(SsSOX3) c DNA was 1386 bp, comprising a 906-bp open reading frame, which encodes a peptide showing 93.6% and 93.9% homology with the Sox3 proteins of Epinephelus coioides and Oryzias latipe, respectively. Comparison of the cDNA sequence of the Ss SOX3 gene with the corresponding genomic DNA fragment revealed that the SsSOX3 gene consists of a single exon. Phylogenetic analysis demonstrated the evolutionary relationship of Ss SOX3 with other known SOXB1 genes in fish and tetrapods. The promoter region contains binding sites of several transcriptional factors that might participate in the regulation of Ss SOX3 expression. Quantitative real-time PCR analysis indicated that SsSOX3 was expressed in all the investigated larval developmental stages from 1 to 35 days after birth and the level of expression gradually decreased as the development proceeded. SsSOX3 exhibited sexually dimorphic expression in adult gonads, with high expression in the ovary but low expression in the testis. In situ hybridization revealed that SsSOX3 was strongly expressed in oocytes and follicular cells of ovaries but slightly expressed in germ cells of testicular tissues. Therefore, this study suggests that Ss SOX3 plays an important role in oogenesis and ovary differentiation in S. schlegeli.展开更多
The assessment of population structure and abundance of fish assemblages associated with artificial reefs(ARs) is an important aspect of AR management.In the present study,we used a DiveOperated Stereo Video(stereo-DO...The assessment of population structure and abundance of fish assemblages associated with artificial reefs(ARs) is an important aspect of AR management.In the present study,we used a DiveOperated Stereo Video(stereo-DOV) technique to assess the population structure and abundance of Sebastes schlegeli associated with two metallic,and three wooden,vessel reefs in Haizhou Bay during 2012 and2013.The study used video systems to obtain length measurements and estimates of abundance.The size composition of S.schlegeli differed among reefs and individuals around vessel reefs were all adults,with total lengths(TL) of >20 cm.Juvenile fish were encountered by divers in a rocky area near the island away from the vessel reefs.The largest individual S.schlegeli(with the highest TL) among five reefs were found around a metallic vessel reef in both 2012 and 2013.TL of S.schlegeli from all reefs increased by an average of 3.2 cm(P<0.05) from 2012 to 2013,with an estimated mean weight increase of 250.4 g(P<0.05).The video survey also indicated a decrease in the biomass of schools near two metallic vessels between the years.Stereo-video technology was found to be suitable for rockfish surveys around the reefs.展开更多
Standard metabolic rates of Schlegels black rockfish with different body weights are determined in laboratory by using the flow-through respirometer at 11.2 ℃, 14.7℃ , 18.0 ℃ and 23.6 ℃ . The results indicate that...Standard metabolic rates of Schlegels black rockfish with different body weights are determined in laboratory by using the flow-through respirometer at 11.2 ℃, 14.7℃ , 18.0 ℃ and 23.6 ℃ . The results indicate that the standard metabolic rates increase with the increase of body weight at different temperatures. Relationship between them could be described as Rs = a ln W b. The mean of standard metabolic rate is significantly different among groups, but the b values are not. The standard metabolic rates of amended standard body weights decrease with the increase of temperature, and the mean of standard metabolic rate is also significantly different among groups when the standard body weights are 48.6 g, 147.9 g, and 243.1 g. Relationship between them could be described as Rsw = m e-b/T. The relations of standard metabolic rate ( Rs ) or relative metabolic rate ( Rs ) to body weight and temperature yield the following equations: Rs = 1.160 W 0.752 e -9.494/ T and Rs’= 1.160 W 0.254 e -9.494/ T.展开更多
Drag forces acting on Schlegel’s black rockfish Sebastes schlegeli were studied. A new drag force transducer was designed and used to measure the water drag on Schlegel’s black rockfish in a vertical recirculating f...Drag forces acting on Schlegel’s black rockfish Sebastes schlegeli were studied. A new drag force transducer was designed and used to measure the water drag on Schlegel’s black rockfish in a vertical recirculating flume tank. Fourteen individuals were investigated, yielding two mean drag coefficients referred to the cross sectional area and volume 2/3 respectively at water velocities ranging from 0.3 to 1.0 m s -1 . The drag coefficients can be used for estimating the drag forces acting on Sebastes schlegeli in water.展开更多
Prostaglandins(PGs)are profound hormones in teleost sexual behavior,especially in mating.PGs act as pheromones that affect the olfactory sensory neurons of males,inducing the initiation of a series of mating behaviors...Prostaglandins(PGs)are profound hormones in teleost sexual behavior,especially in mating.PGs act as pheromones that affect the olfactory sensory neurons of males,inducing the initiation of a series of mating behaviors.However,the molecular mechanism by which PGs trigger mating behavior in ovoviviparous teleosts is still unclear.In the present study,we employed the ovoviviparous black rockfish(Sebastes schlegelii),an economically important marine species whose reproductive production is limited by incomplete fertilization,as a model species.The results showed that when the dose of PGE2 was higher than 10 nmol/L,a significant(P<0.05)increase in mating behaviors was observed.Dual-fluorescence in situ hybridization indicated that PGE2 could fire specific neurons in different brain regions and receptor cells in the olfactory sac.After combining with specific neurons in the central nervous system(CNS),a series of genes related to reproduction are activated.The intracerebroventricular administration of PGE_(2) significantly increased lhb levels(P<0.05)in both sexes.Moreover,steroidogenesis in gonads was also affected,inducing an increase(P<0.05)in E_(2) levels in males and T levels in females.PGE_(2) levels were also increased significantly(P<0.05)in both sexes.The present study revealed that PGE2 can activate mating behavior in black rockfish in both hormone and pheromone pathways,leading to variations in sex steroid levels and activation of reproductive behaviors.Our results provide not only novel insight into the onset of mating behaviors in ovoviviparous teleosts but also solutions for the incomplete fertilization caused by natural mating in cage aquaculture.展开更多
高度保守的DAZ(Deleted in Azoospermia)家族成员包括Daz,Dazl(Daz-like)及Boule基因,它们是精子生成的重要调控因子并在生殖组织中特异性表达。本研究发现许氏平鲉的Daz基因家族包括Dazl及Boule基因,通过对其基因结构和氨基酸序列分析...高度保守的DAZ(Deleted in Azoospermia)家族成员包括Daz,Dazl(Daz-like)及Boule基因,它们是精子生成的重要调控因子并在生殖组织中特异性表达。本研究发现许氏平鲉的Daz基因家族包括Dazl及Boule基因,通过对其基因结构和氨基酸序列分析发现Dazl及Boule基因分别有两个剪接型,均具有一个相同的保守RNA识别域(RRM)和DAZ结构域。通过系统发育分析,发现它们分别与其它硬骨鱼类具有较高的同源性,与哺乳动物亲缘关系较远。根据转录组数据分析,Dazl和Boule在配子发生的表达模式类似,均在卵子不同发育时期高表达而胚胎各时期表达量降低甚至无表达,而在组织中仅表达于精巢和卵巢中且表现出明显的性别二态模式。本研究为探究Dazl和Boule基因在许氏平鲉中的生殖发育调控机制及在许氏平鲉两性配子发生过程中的调控作用奠定基础。展开更多
基金supported by the National Natural Science Foundation of China(Nos.32273133,31970492).
文摘Black rockfish(Sebastes schlegelii)has evolved viviparous reproduction mode.Different from the oviparous fishes,the spermatozoa of black rockfish are stored on the surface of ovarian follicle for over four months until the egg mature in ovary,while the adaptive evolution of fertilization-related genes remains to be studied.In the present study,based on the genome and transcriptome information of black rockfish,a total of 10 hyaluronidase genes were identified by phylogenetic and sequence analyses,including hyal1,hyal2,hyal3,hyal4,hyal6 and spam1a,spam1b,spam1c and spam1d.The spam1 subfamilies,including spam1a,spam1b,spam1c and spam1d,were significantly expanded compared to other species.The adaptive evolution of hyaluronidase was further investigated by selection pressure analysis of branch model and branch site model.The results showed that only spam1 subfamily was positively selected with a large number of positive selection sites,and the evolution rate was significantly higher thanthose of other teleosts.Two positively selected sites,LYS-171 and GLY-164,were located in the neutral hyaluronidase activity domain,which was pivotal for SPAM1 to participate in enzymatic hydrolysis of the extracellular hyaluronic acid matrix and mediate acrosome reaction in mammals.Furthermore,spam1 was mainly expressed in spermatocytes,secondary spermatocytes,and spermatids of testis,whereas it was not found in metamorphic sperm and mature sperm based on the spatiotemporal expression analysis.All results indicated that spam1 might originate from the testis and might be an adaptation of viviparous trait in black rockfish.
基金supported by the Natural Science Foundation of Shandong Province(No.ZR2020QC214)the Young Experts of Taishan Scholars(No.tsqn201909130)+3 种基金the Science and Technology Support Plan for Youth Innovation of Colleges and Universities in Shandong Province(No.2019KJF003)the‘First Class Fishery Discipline’Programme in Shandong Provincea special talent programme‘One Thing One Decision(YishiYiyi)’Programme in Shandong Province,Chinathe Breeding Plan of Shandong Provincial Qingchuang Research Team(2019)。
文摘Neuronal nitric oxide synthase(nNOS)was the producer of nitric oxide(NO)which played important gas messenger molecules in biological process.It also can take effect as immune regulation molecule in organism.Black rockfish(Sebastes schlegelii)is an important economic fish which were widely farmed in East Asia countries.Meanwhile,the pathogenic bacteria such as the Edwardsiella tarda and Vibrio anguillarum in seawater always brought serious obstacles to their healthy growth.In order to explore the expression pattern of n NOS gene under the pathogen stimulation and predict its immune function,the n NOS gene in black rockfish named Ssn NOS was identified.It was 3780 bp in length,located on chromosome 6,and contained 27 coding domain sequence(CDs).According to the phylogenetic analysis,the Ssn NOS showed closest relative to the counterpart gene of swamp eel(Monopterus albus).Meanwhile,analysis of Ssn NOS expression in various healthy tissues showed that Ssn NOS expression level was highest in healthy brain tissues,followed by intestinal tissues.In addition,Ssn NOS showed significant expression changes in response to stimulation by two pathogens.Particular in gill,the expression of Ssn NOS after pathogenic stimulation increased significantly.The Elisa analysis showed the Ssn NOS content in gills was much higher than that in other tissues at all time points.Moreover,the expression patterns of Ssn NOS in brain,intestine and kidney after stimulation by pathogens showed a distinct expression pattern which first down-regulated and then up-regulated.Therefore,the Ssn NOS may be an important signaling molecule for fish to respond rapidly in immune stimulation.
基金This study was supported by the National Key R&D Program of China(No.2018YFD0900101).
文摘The quantitative real-time reverse transcription PCR(qRT-PCR)is a widely used technique to analyze gene expression levels.Selecting a suitable reference gene is a crucial step to obtain an accurate result in qRT-PCR.However,most previous studies on fishes adopted reference genes that were commonly used in mammals without validation.In this study,we utilized 89 transcrip-tome datasets covering early developmental stages and different adult tissues,and carried out transcriptome-wide identification and validation of reference genes in Sebastes schlegelii.Finally,121 candidate reference genes were identified based on four criteria.Eight candidates(METAP2,BTF3L4,EIF5A1,TCTP,UBC,PAIRB,RAB10,and DLD)and four commonly used reference genes in mam-mals(TUBA,ACTB,GAPDH,RPL17)were selected for validation via qRT-PCR and four statistical analysis methods(delta-Ct,Best-Keeper,geNorm,and NormFinder).The results indicated that when the black rockfish are cultured in a general condition,the eight candidate reference genes are more stable than traditional reference genes in mammals,and RAB10,EIF5A1,PAIRB and BTF3L4 are the best reference genes in rockfish.This is the first study to conduct transcriptome-wide identification and validation of reference genes for quantitative RT-PCR in the black rockfish,and lay an important foundation for gene expression analysis in teleost.
基金supported by the National High-Tech Research and Development Program (Grant Nos.2012AA10A408 and 2012AA10A402)
文摘Ovoviviparous black rockfish(Sebastes schlegeli) is an important marine fish species for aquaculture and fisheries in China. Genetic information of this species is scarce because of the lack of microsatellite markers. In this study, a large number of microsatellite markers of black rockfish were isolated by constructing microsatellite-enriched libraries. Female- and male-specific genetic linkage maps were constructed using 435 microsatellite markers genotyped in a full-sib family of the fish species. The female linkage map contained 140 microsatellite markers, in which 23 linkage groups had a total genetic length of 1334.1 c M and average inter-marker space of 13.3 c M. The male linkage map contained 156 microsatellite markers, in which 25 linkage groups had a total genetic length of 1359.6 c M and average inter-marker distance of 12.4 c M. The genome coverage of the female and male linkage maps was 68.6% and 69.3%, respectively. The female-to-male ratio of the recombination rate was approximately 1.07:1 in adjacent microsatellite markers. This paper presents the first genetic linkage map of microsatellites in black rockfish. The collection of polymorphic markers and sex-specific linkage maps of black rockfish could be useful for further investigations on parental assignment, population genetics, quantitative trait loci mapping, and marker-assisted selection in related breeding programs.
基金supported by the National Natural Science Foundation of China (No. 31372511)
文摘Evolutionary evidence suggests that Sox3, a member of the high-mobility-group(HMG) family of transcription factors, is an ancestral precursor of Sry and is involved in sex determination similar to Sry. However, there is limited information regarding the SOX3 gene of the black rockfish(Sebastes schlegeli). In this study, we first isolated SOX3 gene from the gonads of S. schlegeli by homology cloning. The full-length of S. schlegeli SOX3(SsSOX3) c DNA was 1386 bp, comprising a 906-bp open reading frame, which encodes a peptide showing 93.6% and 93.9% homology with the Sox3 proteins of Epinephelus coioides and Oryzias latipe, respectively. Comparison of the cDNA sequence of the Ss SOX3 gene with the corresponding genomic DNA fragment revealed that the SsSOX3 gene consists of a single exon. Phylogenetic analysis demonstrated the evolutionary relationship of Ss SOX3 with other known SOXB1 genes in fish and tetrapods. The promoter region contains binding sites of several transcriptional factors that might participate in the regulation of Ss SOX3 expression. Quantitative real-time PCR analysis indicated that SsSOX3 was expressed in all the investigated larval developmental stages from 1 to 35 days after birth and the level of expression gradually decreased as the development proceeded. SsSOX3 exhibited sexually dimorphic expression in adult gonads, with high expression in the ovary but low expression in the testis. In situ hybridization revealed that SsSOX3 was strongly expressed in oocytes and follicular cells of ovaries but slightly expressed in germ cells of testicular tissues. Therefore, this study suggests that Ss SOX3 plays an important role in oogenesis and ovary differentiation in S. schlegeli.
基金Supported by the National Natural Science Foundation of China(NSFC)-Shandong Joint Fund for Marine Science Research Centers(No.U1406403)the National Key Technology Research and Development Program of China(No.2011BAD13B02)+1 种基金the National Marine Public Welfare Research Project(No.201205023)the Key Laboratory of Marine Ecology and Environmental Science and Engineering,State Oceanic Administration(No.MESE-2013-05)
文摘The assessment of population structure and abundance of fish assemblages associated with artificial reefs(ARs) is an important aspect of AR management.In the present study,we used a DiveOperated Stereo Video(stereo-DOV) technique to assess the population structure and abundance of Sebastes schlegeli associated with two metallic,and three wooden,vessel reefs in Haizhou Bay during 2012 and2013.The study used video systems to obtain length measurements and estimates of abundance.The size composition of S.schlegeli differed among reefs and individuals around vessel reefs were all adults,with total lengths(TL) of >20 cm.Juvenile fish were encountered by divers in a rocky area near the island away from the vessel reefs.The largest individual S.schlegeli(with the highest TL) among five reefs were found around a metallic vessel reef in both 2012 and 2013.TL of S.schlegeli from all reefs increased by an average of 3.2 cm(P<0.05) from 2012 to 2013,with an estimated mean weight increase of 250.4 g(P<0.05).The video survey also indicated a decrease in the biomass of schools near two metallic vessels between the years.Stereo-video technology was found to be suitable for rockfish surveys around the reefs.
基金This paper is financially supported by the Major Program of National Natural Science Foundation (No.497901001)Key Basic Research and Development Program(No.G1999043710)of China
文摘Standard metabolic rates of Schlegels black rockfish with different body weights are determined in laboratory by using the flow-through respirometer at 11.2 ℃, 14.7℃ , 18.0 ℃ and 23.6 ℃ . The results indicate that the standard metabolic rates increase with the increase of body weight at different temperatures. Relationship between them could be described as Rs = a ln W b. The mean of standard metabolic rate is significantly different among groups, but the b values are not. The standard metabolic rates of amended standard body weights decrease with the increase of temperature, and the mean of standard metabolic rate is also significantly different among groups when the standard body weights are 48.6 g, 147.9 g, and 243.1 g. Relationship between them could be described as Rsw = m e-b/T. The relations of standard metabolic rate ( Rs ) or relative metabolic rate ( Rs ) to body weight and temperature yield the following equations: Rs = 1.160 W 0.752 e -9.494/ T and Rs’= 1.160 W 0.254 e -9.494/ T.
基金supported by the National Hightech 863 Project(No.2001AA623030)the National Natural Science Foundation of China(No.30070593).
文摘Drag forces acting on Schlegel’s black rockfish Sebastes schlegeli were studied. A new drag force transducer was designed and used to measure the water drag on Schlegel’s black rockfish in a vertical recirculating flume tank. Fourteen individuals were investigated, yielding two mean drag coefficients referred to the cross sectional area and volume 2/3 respectively at water velocities ranging from 0.3 to 1.0 m s -1 . The drag coefficients can be used for estimating the drag forces acting on Sebastes schlegeli in water.
基金supported by grants from The National Natural Science Foundation of China(41976089)the National Key R&D Program of China(2018YFD0901204).
文摘Prostaglandins(PGs)are profound hormones in teleost sexual behavior,especially in mating.PGs act as pheromones that affect the olfactory sensory neurons of males,inducing the initiation of a series of mating behaviors.However,the molecular mechanism by which PGs trigger mating behavior in ovoviviparous teleosts is still unclear.In the present study,we employed the ovoviviparous black rockfish(Sebastes schlegelii),an economically important marine species whose reproductive production is limited by incomplete fertilization,as a model species.The results showed that when the dose of PGE2 was higher than 10 nmol/L,a significant(P<0.05)increase in mating behaviors was observed.Dual-fluorescence in situ hybridization indicated that PGE2 could fire specific neurons in different brain regions and receptor cells in the olfactory sac.After combining with specific neurons in the central nervous system(CNS),a series of genes related to reproduction are activated.The intracerebroventricular administration of PGE_(2) significantly increased lhb levels(P<0.05)in both sexes.Moreover,steroidogenesis in gonads was also affected,inducing an increase(P<0.05)in E_(2) levels in males and T levels in females.PGE_(2) levels were also increased significantly(P<0.05)in both sexes.The present study revealed that PGE2 can activate mating behavior in black rockfish in both hormone and pheromone pathways,leading to variations in sex steroid levels and activation of reproductive behaviors.Our results provide not only novel insight into the onset of mating behaviors in ovoviviparous teleosts but also solutions for the incomplete fertilization caused by natural mating in cage aquaculture.
文摘高度保守的DAZ(Deleted in Azoospermia)家族成员包括Daz,Dazl(Daz-like)及Boule基因,它们是精子生成的重要调控因子并在生殖组织中特异性表达。本研究发现许氏平鲉的Daz基因家族包括Dazl及Boule基因,通过对其基因结构和氨基酸序列分析发现Dazl及Boule基因分别有两个剪接型,均具有一个相同的保守RNA识别域(RRM)和DAZ结构域。通过系统发育分析,发现它们分别与其它硬骨鱼类具有较高的同源性,与哺乳动物亲缘关系较远。根据转录组数据分析,Dazl和Boule在配子发生的表达模式类似,均在卵子不同发育时期高表达而胚胎各时期表达量降低甚至无表达,而在组织中仅表达于精巢和卵巢中且表现出明显的性别二态模式。本研究为探究Dazl和Boule基因在许氏平鲉中的生殖发育调控机制及在许氏平鲉两性配子发生过程中的调控作用奠定基础。
