大黄鱼sox9a/b基因的克隆与表达分析

为探究sox9基因在大黄鱼性别决定与分化过程中的作用,利用RACE方法克隆得到大黄鱼sox9a和sox9b 2个基因,采用实时荧光定量PCR (qRT-PCR)分析其在雌雄个体不同组织和不同发育阶段的表达规律,并检测了其在17β-雌二醇处理后的遗传雄性和17α-甲基睾酮诱导处理后遗传雌性幼鱼中的表达变化。结果显示,大黄鱼sox9a c DNA全长2 442 bp(NCBI登录号:MH996431),包含476 bp 5′UTR、466 bp 3′UTR、1 500 bp ORF,编码499个氨基酸。大黄鱼sox9b cDNA全长为2 199 bp (NCBI登录号:MH996432),包含335 bp5′UTR、415 bp 3′UTR、1 449 bp ORF,编码482个氨基酸。qRT-PCR分析显示,sox9a基因主要在性腺、眼、脑、肝脏中表达,精巢中的表达量显著高于卵巢;sox9b在大黄鱼各组织中广泛表达,但以精巢中表达量最高,而卵巢中只有痕量表达。在鱼苗性腺发育初期,sox9a/b的表达量都维持在较低水平;随着鱼苗长大,sox9a/b的表达量在84 dph、123 dph 2次达到高峰,随后开始下降,10 mph后又逐渐上升。17β-雌二醇处理能够显著下调遗传雄性大黄鱼sox9a和sox9b基因在性腺中的表达,17α-甲基睾酮处理则显著上调遗传雌性大黄鱼sox9a和sox9b基因在性腺中的表达。研究表明,sox9a/b基因与大黄鱼性别发育和分化过程密切相关,对大黄鱼精巢的发育与维持起重要的调控作用,而且两个基因的功能可能具有一定程度的分化。     

圆斑星鲽促性腺激素释放激素基因克隆及表达特性

采用RACE技术,在圆斑星鲽(Verasper variegatus)脑中克隆到3种GnRH基因的cDNA序列: cGnRH-Ⅱ、sGnRH和sbGnRH.每种GnRH都包括1个信号肽、1个Gly-Lys-Arg连接序列和1个GnRH相关肽.其中, cGnRH-Ⅱ的cDNA全长为568 bp,编码85个氨基酸, ORF为255 bp,5′UTR为141 bp,3′UTR为169 bp.sGnRH的cDNA全长为457 bp,编码90个氨基酸, ORF为270 bp,5′UTR为41 bp,3′UTR为143 bp.sbGnRH的cDNA全长为381 bp,编码98个氨基酸, ORF为294 bp,5′UTR为48 bp,3′UTR为36 bp.分析了3种GnRH基因的编码氨基酸序列与其他脊椎动物的同源性,圆斑星鲽 GnRH 与鲽形目鱼类氨基酸同源性最高,其次为鲈形目鱼类.对3种 GnRH 基因的系统进化分析表明,圆斑星鲽 GnRH 基因与其他鲽形目鱼类亲缘关系最近,其次为鲈形目、鲑形目和鳗鲡目鱼类.荧光定量PCR分析表明,3种GnRH基因都在脑中表现出最高表达水平且具有性别特异性表达模式:雌性中不同组织的 GnRH mRNA 表达水平都相应高于雄性.组织表达分析表明, cGnRH-Ⅱ的 mRNA 仅在脑中表达,而sbGnRH在各个组织都有表达, sGnRH仅在脑、垂体和性腺中表达.脑中sbGnRH mRNA的表达水平在卵巢成熟过程中变化显著(P<0.05),而其他两种GnRH的mRNA表达水平变化不显著(P>0.05).本研究首次在圆斑星鲽脑中克隆到3种GnRH基因,其组织和季节表达水平变化表明sbGnRH可能是圆斑星鲽生殖调控的关键GnRH类型,本结果可为圆斑星鲽生殖调控机制和人工繁育技术研究提供理论支撑.     

圆斑星鲽piwil2基因的克隆与表达分析

本研究采用RACE末端扩增方法，得到全长为3872 bp的圆斑星鲽(Verasper variegatus) piwil2基因序列，命名为Vvpiwil2，开放阅读框(ORF)长为3192 bp，编码1063个氨基酸，5?-UTR和3?-UTR的长度分别140 bp和540 bp。基于ExPASy、SMART、Signal4.1和NCBI的保守结构域(CDD)数据库在线分析对蛋白序列结构进行预测，推断Vvpiwil2编码的氨基酸分子量为118.6 kDa，理论等电点为9.02，无跨膜结构及信号肽，有3个结构域：ArgoL1结构域、PAZ结构域及PIWI结构域。利用实时荧光定量PCR技术对圆斑星鲽不同发育时期的胚胎、仔稚鱼以及雌雄成鱼的不同组织表达模式进行分析。结果显示，Vvpiwil2基因从胚胎发育早期至高囊胚期均大量表达，之后呈下降趋势，直至孵化阶段。由于胚胎从卵裂至囊胚时期的发育过程主要受细胞质成分引导，直至原肠早期，mRNA开始大量转录合成，实现由母源型向合子型的过渡，推断Vvpiwil2是母源性基因。孵化后仔稚鱼68 d时，Vvpiwil2基因表达量显著高于其他时期，表明Vvpiwil2的功能可能与圆斑星鲽性腺分化过程相关；Vvpiwil2基因在雌雄成鱼性腺中的表达量显著高于其他组织，且卵巢中的表达量显著高于精巢，推测Vvpiwil2基因在卵巢功能的维持中发挥重要作用。本研究结果为解析圆斑星鲽性别决定机制提供了新的靶标基因，为建立全雌化苗种繁育技术打下坚实的理论基础。     

拟赤梢鱼卵巢早期发育与sox3基因cDNA克隆及表达分析

为初步阐明拟赤梢鱼(Pseudaspius leptocephalus)卵巢发育特征及sox3 (sry related high mobility group box 3)基因在其卵巢发育过程中的作用,本研究通过组织切片观察了拟赤梢鱼卵巢早期发育过程,利用RACE技术克隆了该鱼sox3基因cDNA全长序列,并进行生物信息学分析;利用实时荧光定量PCR技术分析了sox3基因在拟赤梢鱼不同组织及性腺不同发育时期的表达模式。结果显示,拟赤梢鱼卵巢在孵化后45 d分化形成,160 d时由Ⅰ期进入Ⅱ期,孵化后360 d,卵巢仍处于Ⅱ期。拟赤梢鱼sox3基因cDNA全长为1 800 bp (GenBank登录号：MT952206),编码299 个氨基酸,存在保守的HMG (histidine, methionine, glycine-rich)结构域。氨基酸序列比对和系统进化树分析结果显示,拟赤梢鱼SOX3蛋白与斑马鱼(Danio rerio)和翘嘴鲌(Culter alburnus)亲缘关系最近。此外,sox3基因在拟赤梢鱼卵巢中表达量最高,其次是脑和眼睛,在精巢和其他组织中微量表达;在性腺分化过程中,sox3基因在卵巢中表达量显著高于未分化性腺和精巢,在卵巢发育阶段表达量不断升高,而在精巢中持续低水平表达。综上,本研究推测sox3基因主要参与拟赤梢鱼卵巢的分化和发育。     

圆斑星蝶MHC ⅡB基因结构、多态性及组织表达分析

通过表达序列标签法和cDNA末端快速扩增(RACE)技术,分离和克隆了圆斑星鲽(Verasper variegatus)主要组织相容性复合体(MHC)IIB的全长cDNA序列,该cDNA全长为1 144 bp,5'UTR(untranslated region)为7 bp,3'UTR为450 bp,开放阅读框(ORF)长度为687 bp,可编码228个氨基酸,包含信号肽、抗原结合域(β1),IGC区(β2),跨膜区和胞质区5个结构域.同源分析表明,圆斑星鲽MHC IIB氨基酸序列与其他硬骨鱼具有49%-79%的同源性,与鼠、人、红原鸡和护士鳖的相似性较低,分别为34%,33%,31%和30%.圆斑星鲽MHC IIB基因含有5个内含子,与其他硬骨鱼不同,其β2结构域编码区内存在I个109 bp的内含子.根据获得的MHC IIB基因组序列设计特异性引物,在10尾野生圆斑星鲽中扩增了包括完整内含子1和外显子2的长度约388 bp的DNA片段,PCR产物直接测序后发现在270 bp的抗原结合域中共有23个位点发生变异,密码子第1位和第2位的变异明显高于第3位.利用荧光定量PCR分析组织表达发现,MHC IIB基因在健康圆斑星鲽9种组织中均有表达,但表达量存在差异,肾的表达量最高,肌肉的表达量最低,肾、心、脾脏和鳃的表达量显著高于肝、皮肤、脑、血和肌肉.本研究旨在为MHC基因家族的遗传进化分析、结构与功能的解析提供基础,同时为圆斑星鲽的分子免疫学和标记辅助育种研究提供参考依据.     

半滑舌鳎StAR基因克隆及其在不同组织的时空表达分析

利用半滑舌鳎性腺转录组测序获得的StAR基因部分序列,设计RACE引物,克隆了半滑舌鳎StAR基因的cDNA序列,全长为1 294 bp,5'端UTR为132 bp,3'端UTR为310 bp,开放阅读框(ORF)为852 bp,共编码283个氨基酸。将半滑舌鳎StAR基因与其他物种StAR基因进行氨基酸同源性分析,结果显示,半滑舌鳎StAR与塞内加尔鳎、大口黑鲈、花鲈、金头鲷的同源性都达到了85%,与虹鳟、斜带石斑鱼及日本鳗鲡的同源性分别为81%、83%和76%。雌、雄鱼不同组织StAR基因的表达分析表明,StAR基因在雄鱼性腺中高表达,在雄鱼的肝脏、脑及心脏中表达量较低,而在雄鱼的其他组织中不表达;在雌鱼肠中不表达,在其他组织(卵巢、肝脏、脾脏、脑、垂体、肌肉、心脏、肾脏)中微量表达。荧光定量PCR分析不同组织与不同时期性腺表达谱表明,雄鱼性腺中StAR基因的表达量显著高于雌、雄鱼其他各组织(P0.05),提示StAR基因对雄鱼精巢发育起重要作用。雄鱼不同时期表达谱分析结果显示,StAR基因在66天前的精巢中不表达,在150天时表达量急剧增加,至2龄时表达量最高,3龄时表达量下降,说明该基因在精巢发育成熟过程中起重要作用。原位杂交结果显示,StAR基因主要在雄鱼精巢的精子细胞中表达,而在雌鱼的卵巢中不表达。研究表明,StAR基因在半滑舌鳎精巢发育中发挥作用,且可能在精子形成中发挥重要作用。     

圆斑星鲽MHC IIB基因结构、多态性及组织表达分析

通过表达序列标签法和cDNA末端快速扩增(RACE)技术,分离和克隆了圆斑星鲽(Verasper variegatus)主要组织相容性复合体(MHC)IIB的全长cDNA序列,该cDNA全长为1144bp,5'UTR(untranslated region)为7bp,3'UTR为450bp,开放阅读框(ORF)长度为687bp,可编码228个氨基酸,包含信号肽、抗原结合域(β1)、IGC区(β2)、跨膜区和胞质区5个结构域。同源分析表明,圆斑星鲽MHCIIB氨基酸序列与其他硬骨鱼具有49%～79%的同源性,与鼠、人、红原鸡和护士鲨的相似性较低,分别为34%、33%、31%和30%。圆斑星鲽MHC ⅡB基因含有5个内含子,与其他硬骨鱼不同,其β2结构域编码区内存在1个109bp的内含子。根据获得的MHC ⅡB基因组序列设计特异性引物,在10尾野生圆斑星鲽中扩增了包括完整内含子1和外显子2的长度约388bp的DNA片段,PCR产物直接测序后发现在270bp的抗原结合域中共有23个位点发生变异,密码子第1位和第2位的变异明显高于第3位。利用荧光定量PCR分析组织表达发现,MHCIIB基因在健康圆斑星鲽9种组织中均有...     

半滑舌鳎Shh基因的克隆与表达及甲基化分析

通过RACE方法获得半滑舌鳎(Cynoglossus semilaevis)Hh基因家族的Shh基因,该基因全长1 922 bp,其中5′UTR 266 bp,3′UTR 360 bp,ORF1 296 bp,编码431个氨基酸,经预测该多肽的相对分子质量为47.28 k D,理论等电点6.95,具有Hh基因家族特有的保守结构域。氨基酸序列分析表明,半滑舌鳎Shh与牙鲆的同源性最高,为82%,与其他鱼类同源性为74%~81%,与非洲爪蟾的同源性为61%,与人和鼠的同源性为63%~64%。甲基化结果显示,Shh基因在1龄卵巢中的甲基化程度普遍低于雄鱼与伪雄鱼精巢。基因表达分析显示,Shh基因在胚胎期的囊胚期表达显著高于其它时期(P0.05),在雌雄成鱼8个组织器官均表达,在雌性性腺分化的关键期孵化后50 d,雌性性腺中表达量较前期升高,且显著高于同时期雄性性腺中的表达(P0.05),在雄性性腺分化的关键期80~95 d,Shh基因在雄性中的表达水平显著升高(P0.05),在8月龄、1龄及2龄雌鱼性腺中表达显著高于雄鱼与伪雄鱼。本研究表明,半滑舌鳎Shh基因在进化中高度保守,与胚胎分化、组织器官形成、雌雄性腺分化及性腺发育密切相关。     

花鲈性腺分化组织学及性别相关基因cyp11b和cyp19a1a的表达分析

以花鲈(Lateolabrax maculatus) 1~214 dph (day post hatching)的仔稚鱼、幼鱼以及18月龄的雌鱼和雄鱼为研究对象,研究了花鲈早期性腺发生、发育和分化情况;分析了性腺分化过程中性别相关基因(cyp11b和cyp19a1a)的表达及与性别之间的关系。结果显示,在30 dph [全长为(1.28± 0.10) cm],首次在中肾管前端的腹腔膜周围观察到原始生殖细胞(primordial germ cells, PGCs),说明30 dph前是花鲈胚后PGCs迁移至生殖嵴的关键时期;在55 dph [全长为(2.45±0.19) cm],观察到一对呈对称分布的原始性腺已经形成,说明花鲈幼鱼的原始性腺在30~55 dph (全长为1.28~2.45 cm)之间发生;55~180 dph时(全长为2.45~12.28 cm),原始性腺不断发育变大,并且一直处于未分化状态;180 dph后性腺开始分化;在195 dph [全长(14.54±1.54) cm]观察到精巢开始分化,卵巢于205 dph [全长为(15.86±0.94) cm]开始分化,且性腺的解剖学分化要早于细胞学分化;18月龄的花鲈幼鱼性腺发育到Ⅱ期。性别分化相关基因cyp19a1a在花鲈卵巢中的表达量高于同期精巢,说明其在卵巢的分化及维持中发挥更关键的作用,而cyp11b在18月龄幼鱼Ⅱ期精巢中的表达量显著高于同时期的卵巢及Ⅰ期精巢,说明其主要在精巢的分化及维持中扮演重要角色。本研究结果不仅可以丰富花鲈的繁殖生理学资料,也为其性别调控技术的研究提供了科学依据。     

栉孔扇贝sox9基因的cDNA克隆及其在不同发育时期性腺中的表达特征

SOX9是SOX家族的SOXE亚族成员,在脊椎动物骨骼发育、胰腺发育、性别决定与分化以及肿瘤形成中发挥重要的作用。sox9在不同种类脊椎动物性腺中的表达存在差异,在无脊椎动物性腺中的表达特征尚不清楚。本研究利用RACE技术克隆了栉孔扇贝(Chlamys farreri)sox9(Cf-sox9)全长的c DNA序列,其长度为2835 bp,开放阅读框为1413 bp,编码470个氨基酸。预测的氨基酸序列具有SOX家族的HMG-box和SOXE亚族的高保守区域,但没有脊椎动物羧基端的Pro-Gln-Ser rich区域。原位杂交和免疫组织化学技术确定Cf-sox9 m RNA和Cf-SOX9蛋白均定位在栉孔扇贝精巢和卵巢的所有生殖细胞中,并且在不同发育时期性腺中呈现了类似的表达规律,即在精巢中,阳性信号在精母细胞中最强,在精子中最弱;在卵巢中,阳性信号在卵原细胞、卵母细胞以及成熟卵中呈现逐渐减弱的趋势。这一表达特征与脊椎动物性腺中多样的性别差异表达特征不同,提示sox9在贝类性腺发育和配子发生中的作用可能与大多数脊椎动物不同。     

多鳞铲颌鱼RPL34基因3’端序列的克隆与表达

采用同源克隆和cDNA末端快速扩增技术,从多鳞铲颌鱼雄生殖腺中首次克隆得到核糖体蛋白L34 3’末端cDNA序列。该3’末端cDNA序列长297bp,预测开放阅读框为162bp,编码53个氨基酸的蛋白质,经BLAST比对,该cDNA序列与斑马鱼、斑点叉尾鱼回、非洲爪蟾、大西洋鲑同源率达到82%～85%。利用实时定量RT-PCR检测核糖体蛋白L34mRNA在多鳞铲颌鱼组织中的表达,以及注射激素后在生殖腺中的表达。研究结果表明,核糖体蛋白L34基因在多鳞铲颌鱼雄生殖腺中特异性表达;核糖体蛋白L34在雌性生殖腺、心、脑、鳃、肠和肌肉中表达量较少,其中在雌性生殖腺表达量最低,雄性生殖腺表达量高于雌性生殖腺、肝、心、脑、鳃、肠、肌肉、脾,差异极显著(P0.01)。在雄性生殖腺注射甲基睾丸酮后,核糖体蛋白L34基因的表达量对照组高于注射组,差异显著(P0.05),在雌性生殖腺注射雌二醇后,核糖体蛋白L34基因表达量对照组高于注射组,差异极显著(P0.01)。     

Expression of dmrt1 and sox9 during gonadal development in the Siberian sturgeon (Acipenser baerii)

The sex differentiation period of the Siberian sturgeon was investigated through expression profiling of two testicular markers (dmrt1 and sox9). At the molecular level, a clear sexual dimorphism of dmrt1 and sox9 was observed in 3-year-old fish with immature gonads, in which males showed higher expression of these genes. Among 16-month-old sturgeons cultured in Uruguay, gonad morphology analyses showed one group of fish with undifferentiated gonads and a second group which had started their histological differentiation into ovaries or testes. dmrt1 showed a significantly higher expression in testes of recently differentiated fish, but this was not the case for sox9. In undifferentiated fish, we observed two clearly different groups in terms of expression: one group of fish over-expressing male markers (dmrt1, sox9) and another group of fish showing very low expression of these genes. This suggests that fish undergoing male differentiation can be identified by their profiles of gene expression before they undergo morphological differentiation.     

WD Repeat‐containing Protein 73, A Novel Gene Correlated with Gonad Development in Large Yellow Croaker,Larimichthys crocea

The genome of Larimichthys crocea harbors more than 200 putative WD40 proteins. Yet, the function of these WD40 proteins remains unknown. Here a WD40 gene, wd73, was cloned and characterized in L. crocea (named as Lcwdr73). The cDNA is 1706 bp, including a 5′ untranslated region (UTR) of 51 bp, a 3′ UTR of 509 bp, and an open reading frame of 1146 bp encoding 381 amino acid residues. The putative LcWDR73 protein contains three WD40 domain motifs. The tissue expression profiles of both sexes revealed that Lcwdr73 was extremely highly expressed in testis and ovary, moderate in kidney and brain, and low in the other tissues by quantitative polymerase chain reaction analysis. Based on histology, the gonad development of L. crocea was divided into four phases: proliferative stage (Phase I), small developmental stage (Phase II), grand developmental stage (Phase III), and mature stage (Phase IV). With the gonad development, Lcwdr73 mRNA increased and reached a peak in Phase IV, and the expression in testes is significantly higher than that in ovaries, especially from Phase II to Phase IV, indicating that Lcwdr73 may play an important role during gonad development in L. crocea. The resutlts lay a foundation to control precocious puberty of L. crocea.     

Involvement of FGF9/16/20 subfamily in female germ cell development of the Nile tilapia, Oreochromis niloticus

Fibroblast growth factors (FGFs) have been proved to participate in a wide variety of processes, including growth, differentiation, cell proliferation, migration, sex determination and sex differentiation. The roles of FGF9/16/20 subfamily members in the gonadal development of teleost fish have not yet been reported. Three FGFs (16, 20a and 20b) of the FGF9/16/20 subfamily were cloned from the Nile tilapia by RT-PCR and RACE. Phylogenetic, bioinformatic and syntenic analyses demonstrated that these cloned FGFs are genuine FGF16, 20a and 20b. Our analyses further supported the non-existence of FGF9 ortholog and the existence of two FGF20 paralogs in teleost genomes. Tissue distribution analysis by RT-PCR demonstrated that FGF16 was expressed in a wide range of tissues including the testis and ovary, FGF20b in the brain, pituitary, intestine and ovary, but not in the testis, while FGF20a in the brain, pituitary and spleen, but not in the gonad. These results were consistent with the Northern blot analysis. The expression profiles of FGF16 and FGF20b during normal and sex reversed gonadal development were investigated by real-time PCR. Both showed much higher expression in the XX ovary and 17 beta-estradiol induced XY ovary compared with the XY testis and fadrozole and tamoxifen induced XX testis, with the highest in both sexes at 120?dah. Strong signals of FGF16 and FGF20b were detected in phase II oocytes by in situ hybridization. These data suggest that FGF9/16/20 subfamily is involved in the early oocyte development of the female.     

胡子鲇脑型芳香化酶基因全长cDNA克隆及表达

采用RT-PCR和RACE法,克隆了胡子鲇(Clarias fuscus)脑型芳香化酶基因Cyp19a1b,应用荧光实时定量PCR检测其在前脑、下丘脑、脑垂体、肝、精巢和卵巢6种组织,以及性腺分化前后(出膜后12～30 d)全鱼中的mRNA表达。结果表明,Cyp19a1b cDNA全长2 347 bp,5′端非编码区219 bp,3′端[不包括poly(A)]596 bp,开放阅读框(ORF)1 503 bp,编码500个氨基酸,推测其编码蛋白质分子量为56.388 kD。序列分析及分子系统进化树结果表明,胡子鲇Cyp19a1b氨基酸序列与非洲鲇(Clarias gariepinus)Cyp19a1b同源性最高,达95.6%;与南方大口鲇(Silurusmeridionalis)、黄颡鱼(Pelteobagrus fulvidraco)、斑马鱼(Danio rerio)、斑点叉尾(Ictalurus punctatus)、赤点石斑鱼(Epinephelus akaara)、鲤(Cyprinus carpio)、鲫(Carassius auratus)及稀有鲫(Gobiocypris rarus)Cyp19a1b同源性达75%以上,但与上述鱼类的性腺型芳香化酶基因(Cyp19a1a)同源性低于62%,表明其为脑型芳香化酶,同源性分析结果与根据传统形态学和生化特征分类的结果相一致。荧光实时定量PCR结果显示,Cyp19a1b在胡子鲇上述组织中均有表达,其中下丘脑中表达量最高,肝和精巢最低,在脑部的表达存在明显的性别差异(P<0.05)。此外,在胡子鲇性腺分化前(出膜后12 d)Cyp19a1b即开始表达,但分化前后表达量无显著性差异(P>0.05)。结果暗示Cyp19a1b可能不是引起胡子鲇性腺分化的直接因素,但其可能通过"下丘脑垂体性腺轴"对性腺分化过程产生间接影响。     

Sex steroid level and sexual dimorphism expression of genes in gonads of the great sturgeon Huso huso Linneaus, 1758 during maturity developmental stages

Little is known about molecular mechanisms involved in gonad differentiation in sturgeon species. In non‐mammalian vertebrates, sox9, dmrt1, cyp17a1 and ar are male specific genes in testicular differentiation and are highly conserved. In order to understand the mechanism underlying testicular development in sturgeon, we investigated sex steroids level of 11‐ketotestosterone (KT) and testosterone (T) and relative expression of sox9, dmrt1, cyp17a1 and ar in great sturgeon gonads during different stages of sexual maturity. The results showed all studied genes had dimorphic patterns in males. In immature gonads (stage I), only cyp17a1 expressed in male gonads, while other genes did not express, and KT and T levels were low. Dmrt1 showed dimorphic expression pattern in male gonads at maturity stage II, III and IV. Furthermore, sox9 and ar mRNA presented significant dimorphic expression pattern in male gonads only at maturity stage 4. Plasma androgens levels were significantly higher in males compared to females during maturity stages II, III and IV. The results showed that among these four genes, only cyp17a1 expressed in male gonads at maturity stage I (immature), suggesting that this gene may be applicable as a sex marker in recently differentiated male great sturgeon. Sexually dimorphic patterns in other studied genes (sox9, dmrt1 and ar) suggesting that these genes may be important for testicular development and differentiation in premature great sturgeon. The obtained results provide a foundation for further research on sex differentiation and developing strategies for the sexing of sturgeon for aquaculture.