Foxl2基因在虾夷扇贝发育过程中的表达模式分析

Expression Pattern of the Foxl2 Gene in the Scallop Patinopecten yessoensis during Development

Foxl2是叉头状转录因子(forkhead transcription factor,Fox)基因家族的重要成员之一,在卵巢发育和性别调控中发挥着重要作用。为探究Foxl2在虾夷扇贝(Patinopecten yessoensis)性腺发育中的表达调控模式,利用生物信息学方法分析了虾夷扇贝Foxl2的序列特征;采用半定量PCR(RT-PCR)检测了Foxl2在不同组织中的表达差异。实时荧光定量PCR(q RT-PCR)和原位杂交技术(ISH)揭示了Foxl2在性腺发育4个时期(增殖期、生长期、成熟期和排放期)的时空表达变化。结果显示,虾夷扇贝Foxl2序列包含Fox基因家族共有的FH结构域;多重序列比较分析显示,虾夷扇贝与栉孔扇贝(Chlamys farreri)、欧洲大扇贝(Pecten maximus)的相似性最高,分别为98%、96%。系统进化树分析显示,在不同物种以及进化的过程中,Foxl2基因具有较高的保守性。定量分析和原位杂交结果显示,原位杂交阳性信号主要定位在生殖细胞的细胞质中。在虾夷扇贝的鳃、肾、肝胰腺、精巢中,都可检测到少量Foxl2转录本的存在,在卵巢中表达量最高,且在卵巢成熟期达到最高值。随着性腺发育和精细胞的逐级分化,Foxl2的表达量呈下降趋势,这与原位杂交的结果一致。研究表明,Foxl2在虾夷扇贝卵巢发育中可能发挥重要作用,推测其是雌性虾夷扇贝性腺发育调控中的关键基因,可为今后阐明其在虾夷扇贝性别分化进程中的功能提供理论依据。

Foxl2,an important member of the Fox(forkhead transcription factor)gene family,plays an important role in ovarian development and sex regulation.To explore the mode of expression regulation in the sex differentiation of the scallop Patinopecten yessoensis,we analyzed the Foxl2 gene sequence characteristics of P.yessoensis using bioinformatics methods,and the expression of Foxl2 in different tissues was detected via semi-quantitative real-time polymerase chain reaction(RT-PCR).Quantitative RT-PCR and in situ hybridization revealed the temporal and spatial expression changes of Foxl2 in the four stages of gonadal development(proliferation,growth,maturation,and emission stage).The results showed that the Foxl2 sequence of P.yessoensis contains the FH domain shared by the Fox gene family,and the multiple sequence comparison analysis showed that P.yessoensis has the highest similarity with Chlamys farreri and Pecten maximus(98%and 96%,respectively).The phylogenetic tree analysis showed that the Foxl2 gene is highly conserved in different species and in the process of evolution.The results of the quantitative analysis and in situ hybridization showed that the positive signal of the in situ hybridization was mainly located in the cytoplasm of the germ cells.A small amount of PyFoxl2transcripts were detected in the gills,kidneys,hepatopancreas,and testes.The expression level of Foxl2was the highest in the ovary and peaked in the mature stage of the ovary.In contrast,with the development of the testis and the gradual differentiation of the male gametes,the expression of Foxl2showed a declining trend,which is consistent with the results of the in situ hybridization.In conclusion,Foxl2 may play a key role in the ovarian development of P.yessoensis.It is a key gene in the regulation of sex differentiation in female P.yessoensis.This study provides a theoretical basis for advancing our understanding of the sex differentiation and gonadal development of P.yessoensis.