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Genome-wide identification and characteristic analysis of ETS gene family in blood clam Tegillarca granosa



ETS transcription factors, known as the E26 transformation-specific factors, assume a critical role in the regulation of various vital biological processes in animals, including cell differentiation, the cell cycle, and cell apoptosis. However, their characterization in mollusks is currently lacking.


The current study focused on a comprehensive analysis of the ETS genes in blood clam Tegillarca granosa and other mollusk genomes. Our phylogenetic analysis revealed the absence of the SPI and ETV subfamilies in mollusks compared to humans. Additionally, several ETS genes in mollusks were found to lack the PNT domain, potentially resulting in a diminished ability of ETS proteins to bind target genes. Interestingly, the bivalve ETS1 genes exhibited significantly high expression levels during the multicellular proliferation stage and in gill tissues. Furthermore, qRT-PCR results showed that Tg-ETS-14 (ETS1) is upregulated in the high total hemocyte counts (THC) population of T. granosa, suggesting it plays a significant role in stimulating hemocyte proliferation.


Our study significantly contributes to the comprehension of the evolutionary aspects concerning the ETS gene family, while also providing valuable insights into its role in fostering hemocyte proliferation across mollusks.

Peer Review reports


The ETS genes originated from the v-ets gene found in the avian retrovirus E26, which is responsible for causing leukemia. This oncogene was transferred from a homologous gene in the chicken genome and encodes a segment of a hybrid viral protein [1, 2]. Consequently, the human ETS genes (ETS-1, ETS-2, and ERG) and their corresponding proteins were discovered [3]. ETS factors have the ability to act as either positive or negative regulators in a range of biological processes, including cellular proliferation, differentiation, invasion, as well as processes such as adhesion, migration, hematopoiesis, and apoptosis [4,5,6].

The classification of human ETS factors is based on their ETS domain sequence homology, resulting in 12 subgroups: ETS, PEA3, ESE, ETV, TCF, GABP, ELF1, SPI1, TEL, ERF, SPDEF, and ERG [7]. All ETS proteins share a highly conserved ETS domain. This domain is a winged helix-turn-helix structure that interacts with the core DNA sequence 5’-GGA(A/T)-3’ [8]. The third helix primarily determines the DNA-binding specificity. Additionally, around one-third of the ETS family members encode a secondary domain known as the PNT domain, also referred to as the SAM_PNT domain [9]. Furthermore, apart from the two predominant domains mentioned above, the GABP subfamily encompasses a distinct GABPA domain that serves the purpose of enlisting cofactors [10].

The phylogenetic analysis reveals the presence of the ETS gene family across various metazoan phyla, and its expansion from invertebrates to vertebrates likely results from extensive duplications of genomic regions in vertebrates [11,12,13]. Extensive research has been conducted on the ETS genes in vertebrates, with approximately 30 different types identified in various vertebrate species, including 27 in humans and 26 in mice [2]. Dysregulation of ETS factors in humans leads to the aberrant expression of multiple target genes, which are known to play crucial roles in various processes implicated in cancer progression [14, 15]. In zebrafish, the involvement of ETS gene family members such as erg, fli1, and spi2 has been confirmed in angiogenesis and hematopoiesis [16, 17]. In invertebrates, a limited number of ETS genes have been documented. For instance, in Drosophila melanogaster, ELF1, Ets1, TEL, and GABPA have been observed to function in diverse developmental processes, including metamorphosis, oogenesis, neurogenesis, myogenesis, and eye development [18, 19]. In Caenorhabditis elegans, ETS-5 controls satiety-induced quiescence [20], while ETS-4 mutations can extend the mean lifespan of adult organisms [21]. However, no instances of ETS genes have been reported in molluscan organisms.

Tegillarca granosa, commonly known as the blood clam, is a marine bivalve species that exhibits typical filter-feeding behavior. It is widely distributed across the coastal regions of the Indo-Pacific area. T. granosa stands out among invertebrate taxa as for possessing red hemocytes within its hemolymph that are enriched with hemoglobin [22]. The blood color of T. granosa is attributed to the abundance of hemoglobin in its hemocytes, resulting in a vibrant red hue [23, 24]. Interestingly, the shade of the blood color is closely associated with the health status and nutritional value of T. granosa. A recent study indicated that the changes in blood color shade are influenced, at least in part, by the upregulation and downregulation of genes associated with cell proliferation [24]. The genome sequencing project conducted on T. granosa has recently yielded valuable genomic data, enabling systematic analyses of cell proliferation related gene families within this species [25].

Here, we systematically studied the ETS genes of eleven species from three classes of mollusks. Through comprehensive analyses of gene structure and spatiotemporal expression patterns, we gained precious understanding of the latent functions of ETS genes in T. granosa. Previous research conducted by our team has demonstrated that populations of T. granosa with high levels of total hemocyte count (THC) exhibit an increased number of proliferative cells and enhanced hematopoietic potential in comparison to populations with lower levels of THC [24]. Consequently, to expand our comprehension of the hematopoietic function of the ETS genes in T. granosa, we conducted further investigation into the transcriptional patterns of various ETS members in high and low THC populations. This is the first comprehensive study of ETS family genes in mollusks, providing useful information for their classification, evolution and function.

The findings of this study serve as a fundamental basis for future investigations into the distribution and biological functions of ETS genes in mollusks and may be beneficial for understanding the hematopoietic mechanism of T. granosa.


Genome wide identification of ETS genes in T. granosa and other mollusks

Sixteen ETS genes were identified by searching the translated CDS file of blood clam T. granosa (Table 1). The proteins encoded by ETS genes in mollusks have lengths varying from 73 to 1141 amino acids (aa) (Additional file 5). Their isoelectric points (pI) ranged from 4.45 to 10.91. Furthermore, with the exception of Sp-ETS-2 and Sp-ETS-14, the GRAVY value predictions for ETS proteins were negative, indicating that the majority of them exhibited a hydrophilic nature. Except for Bg-ETS-22, other sequences were not predicted to contain signal peptides. Subcellular localization analysis revealed that the majority of ETS proteins were predominantly localized to the nucleus, with a small fraction also distributed in the cytoplasm, mitochondria, Golgi apparatus, and extracellular space.

Table 1 Classification of ETS genes from eleven mollusks

Phylogenetic analysis

The phylogenetic analysis revealed the subdivision of all ETS proteins in mollusks into ten distinct subfamilies. Compared to humans and mice, SPI and ETV subfamily genes were absent in mollusks (Fig. 1). The ERF subfamily genes were identified in only two species of mollusks, namely O. bimaculoides and O. sinensis. In mollusks, the ERG subfamily, consisting of 42 gene sequences, is the largest subfamily, while the ERF subfamily, consisting of only 6 gene sequences, is the smallest subfamily.

Fig. 1
figure 1

Phylogenetic analysis of ETS proteins of human, mice and eleven mollusks using BI analysis. Different branch colors indicate different subfamilies, and red branches represent unclassified families due to domain missing or no matching similar reference sequences. The blue fonts represent the absence of the subfamily in mollusks

Gene structure, conserved motif and protein tertiary structure

Predictions were made for the conserved domain and motif of ETS proteins. (Fig. 2A and B). It is noteworthy that certain sequences of mollusk ETS (Ac-ETS-9, Bg-ETS-1, Cg-ETS-27/53/54, Lg-ETS-7/8/10, Mg-ETS-2/3/23/24/25/26/27/28/40/41/42/43/44, My-ETS-3/8, Ob-ETS-1/2/13, Os-ETS-10/23/24, Sc-ETS-6, Sp-ETS-2, Tg-ETS-5/7) were observed to cluster together with the ESE subfamily in constructed phylogenetic trees but lack the PNT domain (Additional file 1). Moreover, the TEL subfamily encompasses Ac-ETS-12 and Lg-ETS-4, the PDEF subfamily includes Ob-ETS-15 and Lg-ETS-3, and the ELF subfamily comprises Lg-ETS-6, all of which underwent a loss of the PNT domain (Additional file 1). In addition, the ETS protein sequences of T. granosa were selected for three-dimensional (3D) structure prediction (Fig. 2C) and annotated the structural domains. Figure 2C illustrates the structural composition of the ETS domain in blood clam T. granosa, which includes three alpha-helices and either four or three anti-parallel beta-sheets. Additionally, the PNT domain is composed of four alpha-helices and one small alpha-helix. Moreover, the GABPA domain consists of four anti-parallel beta-sheets and one small alpha-helix. Moreover, by comparing the ETS, PNT and GABPA domain of H. sapiens and M. musculus, the ETS proteins of T. granosa also share similar 3D structure, indicating a potential functional similarity between the ETS proteins of T. granosa and those of H. sapiens and M. musculus.

Fig. 2
figure 2

Domain (A) and motif (B) architecture analysis of ETS genes in T. granosa and reference genes in H. sapiens and M. musculus. The genes highlighted in red are deficient in the SAM_PNT domain. For more information on other ETS gene domains and motif, please refer to Additional file 1. C The ETS protein tertiary structure of T. granosa was predicted by AlphaFold2 and the best result was selected based on software recommendations

Chromosomal locations

The genomic locations of the 16 genes of T. granosa were determined to be on six chromosomes, while the 66 genes of C. gigas were mapped to four chromosomes and one contig. Moreover, the genomic locations of the 44 genes of M. yessoensis were found to be distributed in seven chromosomes (Fig. 3). The ERG subfamily genes tend to be distributed on two chromosomes. In T. granosa, the ERG subfamily genes were found to be situated on chromosomes 1 and 14. Likewise, in C. gigas, these genes were positioned on chromosomes NC_047565.1 and NC_047564.1, whereas in M. yessoensis, they were located on chromosomes 8 and 16. In addition, other subfamily genes tend to be distributed on the same chromosome.

Fig. 3
figure 3

Chromosome distribution of ETS genes in three bivalve T. granosa (A), C. gigas (B), and M. yessoensis (C). For the sake of conciseness, ETS proteins produced by different splicing modes of the same gene in C. gigas and M. yessoensis were hidden. The color of each gene indicated the corresponding family, and the assigned color scheme was congruent with that presented in Fig. 1. The present study highlighted the ETS genes that exhibit statistically significant differences in expression levels between the high and low THC of T. granosa, as indicated by the genes that were denoted by the red underline

The findings revealed that in T. granosa, two chromosomes contained three unevenly distributed tandem repeat gene pairs. In C. gigas, four chromosomes harbored nine tandem duplicate gene pairs that were also unevenly distributed. Furthermore, in M. yessoensis, two chromosomes contained two unevenly distributed tandem duplicate gene pairs (Additional file 6). In T. granosa, each of the ERG, ESE, and ELF subfamilies had one tandem repeat pair. In C. gigas, the ERG and ELF subfamilies had two tandem repeat pairs, while the ESE, ETS, GABPA, TEL, and TCF subfamilies each had one tandem repeat pair. In M. yessoensis, the ERG and ESE subfamily had one tandem repeat pairs.

Expression analysis

To gain a deeper understanding of the characteristics and functions of ETS genes in mollusks, comprehensive transcriptome resources were employed to analyze and assess the temporal and spatial expression patterns of ETS genes in three bivalve mollusks (Additional file 7). Our research demonstrated that approximately half of the ETS genes exhibited low or no transcriptional expression in different developmental stages and adult tissues, and these genes with low expression levels were mainly distributed in C. gigas and M. yessoensis. Furthermore, during different developmental stages, ETS1 (Tg-ETS-14, Cg-ETS-18/21, My-ETS-35) of T. granosa, C. gigas and M. yessoensis were highly expressed in the process of multicellular cleavage, and their transcription levels gradually or rapidly decreased from the trochophore (Fig. 4A). Meanwhile, in different adult tissues, ETS1 genes of M. yessoensis, C. gigas and T. granosa were highly expressed in the gill (Fig. 4B).

Fig. 4
figure 4

Heatmap of ETS1 expression profiles (TPM) in different developmental stages and different tissues in three bivalves. The heatmap utilizes a blue-to-red color scale to depict the relative expression levels, where blue indicates low expression, and red represents high expression. A Expression of ETS1 genes during embryonic development. B Expression of ETS1 genes in adult tissues. For more information on other ETS gene expression profiles, please refer to Additional file 2

qRT-PCR analysis in high and low THC populations of T. granosa

To explore the potential biological functions of the ETS gene family in T. granosa, the mRNA expression levels of ETS genes were assessed in populations with high and low THC (Fig. 5B). The findings demonstrated that, in comparison to the low THC population, the mRNA expression of the GABPA (Tg-ETS-15) gene exhibited a significant upregulation in the high THC T. granosa population. Additionally, the ELF2 (Tg-ETS-12), FEV (Tg-ETS-13), ETS1 (Tg-ETS-14), and ETV1 (Tg-ETS-16) genes also displayed significant upregulation.

Fig. 5
figure 5

A The total hemocyte count (THC) of T. granosa high and low THC populations. For more information on THC of T. granosa, please refer to Additional file 3. B Relative ETS genes expression in gill of T. granosa high and low THC populations


ETS transcription factors are known to exert a pivotal influence on diverse fundamental biological processes in animals, encompassing cell differentiation, cell cycle control, cellular apoptosis, and various other indispensable regulatory pathways. Nevertheless, the comprehensive understanding of their functional attributes within mollusks remains notably deficient. This study focused on identifying and characterizing the ETS family in eleven mollusks using genomic and transcriptomic data. Through subcellular localization prediction analysis, it was discovered that the majority of ETS sequences are localized in the nucleus. This observation suggests a potential correlation between their localization and their role in transcriptional regulation [26, 27].

According to the phylogenetic analysis, mollusks have only 17 types of ETS genes belonging to 10 subfamilies, which is fewer than the number found in vertebrates such as humans and mice, with 28 and 27 types of ETS genes respectively [8].The widespread presence of low-complexity ETS binding sites suggests the potential existence of functional redundancy among ETS factors [28]. As a result, gene loss in the mollusk ETS family may be attributed to this redundancy. Furthermore, it is noteworthy that genes from the SPI and ETV subfamilies have not been identified in mollusks. The SPI subfamily genes are known to play roles in B cell development [29, 30] and the maintenance of homeostasis in Red pulp macrophages [31]. ETV2 (The only gene in the ETV subfamily) mutant embryos had exhibited deficiencies in endocardial lineages and had demonstrated notable vessel malformations [32,33,34]. It is important to note that mollusks do not possess B cells or Red pulp macrophages, which are specific to vertebrates and absent in mollusks [35,36,37], nor do they possess a sophisticated cardiovascular system [38], which may be one contributing factor to the absence of SPI and ETS subfamily genes. Notably, the ERF and ETV3L genes of the ERF subfamily are only found in Octopus. In Xenopus laevis, loss-of-function analysis revealed that ERF and ETV3L play a crucial role in inhibiting the proliferation of neural progenitors, thereby facilitating their differentiation. Conversely, overexpression of ERF led to an increase in the number of primary neurons [39]. Meanwhile, Octopuses are one of the most intelligent invertebrates. Their sensory and motor systems are highly developed, and they possess a large, multilobed brain that facilitates complex analysis, learning, and behavioral control [40]. Therefore, we speculate that the complex nervous system in Octopuses might be the reason for the presence of the ERF subfamily genes, compared to other mollusks. It is plausible that the ERF and ETV3L genes could potentially play a significant role in the differentiation of Octopus nerve cells.

In our study, we had discovered a frequent absence of the PNT domain within ETS genes of mollusks, with the most striking occurrences observed within the ESE subfamily (including Tg-ETS-5 and Tg-ETS-7 in T. granosa) (Fig. 2). However, the absence of PNT domain was also observed in certain human ETS sequences [26]. In-depth in vitro kinetic studies have provided evidence that the PNT domain functions by facilitating signal transduction through enhanced substrate binding. This enhancement occurs in interactions such as ETS1 or ETS2 with MAP kinase ERK2 and Drosophila PNT-p2 with normal roll kinase [41,42,43]. Therefore, the PNT domains act as docking modules, engaging with corresponding docking sites found on the kinases, rather than directly altering the enzymatic kinetics [44, 45]. Presumably, this boosts the specificity and modification rate of adjacent phosphoacceptors at enzyme catalytic sites by effectively increasing their local concentration [46]. Hence, it seems reasonable that nearly half of the members in the ESE subfamily of invertebrates lack the PNT domain. These genes, which lack the PNT domain, may have weaker binding capacity compared to the normal ETS genes in mollusks.

In vertebrates, ETS1 plays a crucial role in cell proliferation, differentiation, and vascular development [47,48,49]. Our findings revealed that the expression of bivalve ETS1 genes is notably higher in gill tissues compared to other tissues. Given that the gill is considered the primary hematopoietic organ in bivalves [24, 50], this suggests that ETS1 genes in the three bivalves may be involved in regulating hemocyte proliferation and differentiation. Additionally, our observations indicate that bivalve ETS1 genes exhibit elevated mRNA expression levels during the multicellular proliferation stage, with transcription levels decreasing rapidly from the trochophore stage. This implies the involvement of ETS1 genes in the regulation of cell proliferation. Furthermore, additional experiments demonstrated a significant increase in the transcriptional expression levels of the ETS1 gene in the high THC populations of T. granosa compared to those with low THC. This suggests that the ETS1 gene plays an important role in promoting hemocyte proliferation in T. granosa.


In this study, sixteen ETS gene sequences belonging to nine subfamilies (ERG, TCF, PEA3, GABPA, ETS, ESE, TEL and ELF) were identified from T. granosa. We had observed the absence of PNT domain in the ETS gene family of mollusks, particularly evident in the ESE subfamily. The loss of the PNT domain could lead to a reduced capacity of ETS proteins to effectively bind target genes. Nonetheless, further biochemical and biological investigations are required to ascertain and validate the functional distinctions of these genes lacking PNT domain from other genes in ETS family. The examination of expression profiles during embryonic development and in adult organs provides valuable insights into the function of bivalve ETS genes. The expression patterns of ETS1 in different developmental stages and adult tissues of three bivalve species, as well as the significantly higher mRNA expression levels in high THC populations compared to low THC populations in T. granosa, suggest an important role for ETS1 in hemocyte proliferation in T. granosa. This study presents a comprehensive genome-wide characterization of the ETS gene family in T. granosa and other mollusks. The findings contribute to a deeper understanding of the function and evolution of the ETS family in mollusks.

Materials and methods

Genome-wide identification of ETS genes in T. granosa and other mollusks

The genome data of Mytilus galloprovincialis, C. gigas, M. yessoensis, Sinonovacula constricta, Octopus bimaculoides, Sepia pharaonis, Octopus sinensis, Aplysia californica, Lottia gigantea, Biomphalaria glabrata were obtained from the National Center for Biotechnology Information (NCBI) database, accessible at (last accessed on July 15, 2022). T. granosa genome sequences employed in this study were derived from data submitted by our laboratory (BioProject accession PRJNA593692).

To screen the genome data of eleven species for ETS genes, we utilized HMMsearch v3.3.2. The ETS.hmm profile was acquired from PFAM (, accession PF00178; last accessed July 15, 2022). SMART (; last accessed July 15, 2022), PFAM, and CDSearch (; last accessed July 15, 2022) were utilized to confirm the ETS domains in ETS genes.

Phylogenetic analysis

Known ETS protein sequences from Human (Homo sapiens) and Mice (Mus musculus) were downloaded from NCBI. The E-INS-I strategy was used to perform multiple sequence alignment of the amino acid sequences of ETS genes from 11 mollusks and reference ETS sequences from humans and mice, using MAFFT v7.505. The phylogenetic analysis using Bayesian inference was performed with MrBayes v3.2.8. Four Markov chains were employed for 600,000 generations, and sampling was carried out every 2,000 generations. To obtain consensus trees and posterior probability distribution, the initial 25% of trees were excluded. Subsequently, FigTree v1.4.3 was utilized to further analyze the Bayesian trees. BLAST v2.13.0 was utilized to identify the gene types to which sequences belonging to the same subfamily belong.

Gene structure, conserved motif and protein tertiary structure

MEME (; accessed on July 15, 2022) was utilized to conduct the analysis of conserved motifs, with motif number set to 15. Subsequently, all the findings from the gene structure and motif analysis were imported into TBtools [51]. AlphaFold2 was employed for predicting the tertiary structure of proteins [52], and PyMOL v2.5.3 was used for visualizing the protein tertiary structure [53].

Chromosomal locations

ETS genes were mapped to chromosomes based on the chromosomal position provided in the T. granosa, C. gigas and M. yessoensis genome database. A distribution map of ETS genes was protracted using TBtools [51]. The identification method of Gene duplication is referred to this paper [54]. Two genes located in the same chromosomal fragment of less than 100 kb and separated by five or fewer genes were identified as tandem duplicate genes [55].

Expression analysis

The TPM (transcripts per kilobase of exon model per million mapped reads) were summarized from the published RNA-seq datasets of T. granosa [25], C. gigas [56] and M. yessoensis [57]. During development, eleven embryo/larval developmental stages were chosen to perform expression analysis, including egg; multi-cells; blastula; trochophore; D-shaped larvae; early-umbo larvae and later-umbo larvae; pediveliger; and juvenile. For adults, five tissues (hemolymph, gonad, hepatopancreas, gill, and mantle) were chosen to perform expression analysis. RNASeq reads were cleaned with fastp v0.23.2 [58]. RNASeq reads were mapped to reference genome using RSEM v1.3.3 [59] and STAR v2.4.0j [60] to estimate gene expression. The expressional heatmaps were displayed by the R package Clusterprofiler [61]. Genes with an expression level less than 1 (TPM) across all tissues or developmental stages will be hidden.

qRT-PCR analysis in high and low THC populations of T. granosa

About 600 blood clams were sampled from the same pond from a blood clam farmer in Ningbo City, Zhejiang Province, China. Under controlled conditions of temperature (27.3 ± 0.48 °C) and salinity (26.18 ± 0.64‰), the blood clams were cultured in filtered seawater. They were fed with Chlorella vulgaris, with a concentration of 1 mL of concentrated algal solution (20,000 cells/mL) per liter of seawater. The feeding occurred twice daily, at 8:30 AM and 8:30 PM. After a week of continuous cultivation, healthy clams (showing normal blood color and distinct stress response) were chosen for further experiments.

Fifty blood clams from the same growth environment were selected for counting blood cells by microscope (Nikon eclipse E100) (Additional file 3). The T. granosa individuals were arranged in descending order based on THC levels, with the top 10% (THC > 7 × 107 cell/ml) considered as the high THC group, and the bottom 10% (THC < 3.4 × 107 cell/ml) regarded as the low THC group (Fig. 5A). The blood clam with the top 10 percent and the bottom 10 percent of THC were selected for RNA extraction from gill. The method of gill tissue RNA extraction and qRT-PCR is consistent with a previous article [24]. The specific primers listed in Additional file 4 were used for qRT-PCR. Data were processed with R package Stats, and significance between the groups was calculated by t-test.

Availability of data and materials

The data underlying this article are available in the article and in its online Additional files.


  1. Seth A, Watson DK. ETS transcription factors and their emerging roles in human cancer. Eur J Cancer. 2005;41(16):2462–78.

    Article  CAS  PubMed  Google Scholar 

  2. Hollenhorst PC, Shah AA, Hopkins C, Graves BJ. Genome-wide analyses reveal properties of redundant and specific promoter occupancy within the ETS gene family. Genes Dev. 2007;21(15):1882–94.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  3. Janknecht R, Nordheim A. Gene regulation by Ets proteins. Biochim Biophys Acta. 1993;1155(3):346–56.

  4. Vivekanand P. Lessons from Drosophila Pointed, an ETS family transcription factor and key nuclear effector of the RTK signaling pathway. Genesis. 2018;56(11–12):e23257.

  5. Yuan L, Le Bras A, Sacharidou A, Itagaki K, Zhan Y, Kondo M, Carman CV, Davis GE, Aird WC, Oettgen P. ETS-related gene (ERG) controls endothelial cell permeability via transcriptional regulation of the claudin 5 (CLDN5) gene. J Biol Chem. 2012;287(9):6582–91.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Oh S, Shin S, Janknecht R. ETV1, 4 and 5: an oncogenic subfamily of ETS transcription factors. Biochem Biophys Acta. 2012;1826(1):1–12.

    CAS  PubMed  Google Scholar 

  7. Hollenhorst PC, McIntosh LP, Graves BJ: Genomic and Biochemical Insights into the Specificity of ETS Transcription Factors. In: Annual Review of Biochemistry, Vol 80. Edited by Kornberg RD, Raetz CRH, Rothman JE, Thorner JW, 2011;80:437–471.

  8. Meadows SM, Myers CT, Krieg PA. Regulation of endothelial cell development by ETS transcription factors. Semin Cell Dev Biol. 2011;22(9):976–84.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  9. Hsing M, Wang YZ, Rennie PS, Cox ME, Cherkasov A. ETS transcription factors as emerging drug targets in cancer. Med Res Rev. 2020;40(1):413–30.

    Article  CAS  PubMed  Google Scholar 

  10. Kang H-S, Nelson ML, Mackereth CD, Schärpf M, Graves BJ, McIntosh LP. Identification and structural characterization of a CBP/p300-binding domain from the ETS family transcription factor GABP alpha. J Mol Biol. 2008;377(3):636–46.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Kar A, Gutierrez-Hartmann A. Molecular mechanisms of ETS transcription factor-mediated tumorigenesis. Crit Rev Biochem Mol Biol. 2013;48(6):522–43.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  12. Papas TS, Watson DK, Sacchi N, O’Brien SJ, Ascione R. Molecular evolution of ets genes from avians to mammals and their cytogenetic localization to regions involved in leukemia. Gene Amplif Anal. 1986;4:207–38.

    CAS  PubMed  Google Scholar 

  13. Wei GH, Badis G, Berger MF, Kivioja T, Palin K, Enge M, Bonke M, Jolma A, Varjosalo M, Gehrke AR, et al. Genome-wide analysis of ETS-family DNA-binding in vitro and in vivo. EMBO J. 2010;29(13):2147–60.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Watson DK, Turner DP, Scheiber MN, Findlay VJ, Watson PM. ETS Transcription Factor Expression and Conversion During Prostate and Breast Cancer Progression. TOCJ. 2010;3(1):24–39.

    Article  Google Scholar 

  15. Findlay VJ, Larue AC, Turner DP, Watson PM, Watson DK: Understanding the Role of ETS-Mediated Gene Regulation in Complex Biological Processes. In: Advances in Cancer Research, Vol 119. Edited by Tew KD, Fisher PB. 2013;119:1–61.

  16. Zhao S, Zhang A, Zhu H, Wen Z: The ETS transcription factor Spi2 regulates hematopoietic cell development in zebrafish. Development (Cambridge, England) 2022;149(19):dev200881.

  17. Liu F, Patient R. Genome-wide analysis of the zebrafish ETS family identifies three genes required for hemangioblast differentiation or angiogenesis. Circul Res. 2008;103(10):1147–54.

    Article  CAS  Google Scholar 

  18. Hsu T, Schulz RA. Sequence and functional properties of Ets genes in the model organism Drosophila. Oncogene. 2000;19(55):6409–16.

    Article  CAS  PubMed  Google Scholar 

  19. Webber JL, Zhang J, Cote L, Vivekanand P, Ni X, Zhou J, Nègre N, Carthew RW, White KP, Rebay I. The relationship between long-range chromatin occupancy and polymerization of the Drosophila ETS family transcriptional repressor Yan. Genetics. 2013;193(2):633–49.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Juozaityte V, Pladevall-Morera D, Podolska A, Nørgaard S, Neumann B, Pocock R. The ETS-5 transcription factor regulates activity states in Caenorhabditis elegans by controlling satiety. Proc Natl Acad Sci United States America. 2017;114(9):E1651–8.

    Article  CAS  Google Scholar 

  21. Thyagarajan B, Blaszczak AG, Chandler KJ, Watts JL, Johnson WE, Graves BJ. ETS-4 is a transcriptional regulator of life span in Caenorhabditis elegans. PLoS Genet. 2010;6(9): e1001125.

    Article  PubMed  PubMed Central  Google Scholar 

  22. Wang S, Yu X, Zhang S, Jin H, Chen Z, Lin Z, Bao Y. Cu2+ Inhibits the Peroxidase and Antibacterial Activity of Homodimer Hemoglobin From Blood Clam Tegillarca granosa by Destroying Its Heme Pocket Structure. Front Mar Sci. 2021;8:635210.

  23. Sauter C. Letter to the editor: Why human blood must be red. Am J Hematol. 1988;29(3):181–181.

    Article  CAS  PubMed  Google Scholar 

  24. Yang Z, He X, Jin H, Su D, Lin Z, Liu H, Bao Y. Hemocyte proliferation is associated with blood color shade variation in the blood clam, Tegillarca granosa. Aquaculture. 2023;571:739447.

  25. Bao Y, Zeng Q, Wang J, Zhang Z, Zhang Y, Wang S, Wong NK, Yuan W, Huang Y, Zhang W, et al. Genomic Insights into the Origin and Evolution of Molluscan Red-Bloodedness in the Blood Clam Tegillarca granosa. Mol Biol Evol. 2021;38(6):2351–65.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  26. Laitem C, Leprivier G, Choul-Li S, Begue A, Monte D, Larsimont D, Dumont P, Duterque-Coquillaud M, Aumercier M. Ets-1 p27: a novel Ets-1 isoform with dominant-negative effects on the transcriptional properties and the subcellular localization of Ets-1 p51. Oncogene. 2009;28(20):2087–99.

    Article  CAS  PubMed  Google Scholar 

  27. Charlot C, Dubois-Pot H, Serchov T, Tourrette Y, Wasylyk B. A review of post-translational modifications and subcellular localization of Ets transcription factors: possible connection with cancer and involvement in the hypoxic response. Methods Mol Biol. 2010;647:3–30.

    Article  CAS  PubMed  Google Scholar 

  28. Adamo P, Ladomery MR. The oncogene ERG: a key factor in prostate cancer. Oncogene. 2016;35(4):403–14.

    Article  CAS  PubMed  Google Scholar 

  29. Su GH, Chen HM, Muthusamy N, Garrett-Sinha LA, Baunoch D, Tenen DG, Simon MC. Defective B cell receptor-mediated responses in mice lacking the Ets protein. Spi-B The EMBO J. 1997;16(23):7118–29.

    Article  CAS  PubMed  Google Scholar 

  30. Rosenbauer F, Owens BM, Yu L, Tumang JR, Steidl U, Kutok JL, Clayton LK, Wagner K, Scheller M, Iwasaki H et al: Lymphoid cell growth and transformation are suppressed by a key regula tory element of the gene encoding PU.1. Nat Genet. 2006;38(1):27–37.

  31. Kohyama M, Ise W, Edelson BT, Wilker PR, Hildner K, Mejia C, Frazier WA, Murphy TL, Murphy KM. Role for Spi-C in the development of red pulp macrophages and splenic iron homeostasis. Nature. 2009;457(7227):318–21.

    Article  CAS  PubMed  Google Scholar 

  32. Lee D, Park C, Lee H, Lugus JJ, Kim SH, Arentson E, Chung YS, Gomez G, Kyba M, Lin S, et al. ER71 acts downstream of BMP, Notch, and Wnt signaling in blood and vessel progenitor specification. Cell Stem Cell. 2008;2(5):497–507.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Ferdous A, Caprioli A, Iacovino M, Martin CM, Morris J, Richardson JA, Latif S, Hammer RE, Harvey RP, Olson EN, et al. Nkx2-5 transactivates the Ets-related protein 71 gene and specifies an endothelial/endocardial fate in the developing embryo. Proc Natl Acad Sci United States America. 2009;106(3):814–9.

    Article  CAS  Google Scholar 

  34. Kim TM, Lee RH, Kim MS, Lewis CA, Park C. ETV2/ER71, the key factor leading the paths to vascular regeneration and angiogenic reprogramming. Stem Cell Res Ther. 2023;14(1):41.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  35. de la Ballina NR, Maresca F, Cao A, Villalba A. Bivalve Haemocyte Subpopulations: A Review. Front Immunol. 2022;13: 826255.

    Article  PubMed  PubMed Central  Google Scholar 

  36. Kurtz J. Memory in the innate and adaptive immune systems. Microb Infect. 2004;6(15):1410–7.

    Article  Google Scholar 

  37. Watson A, Agius J, Ackerly D, Beddoe T, Helbig K. The Role of Anti-Viral Effector Molecules in Mollusc Hemolymph. Biomolecules. 2022;12(3):345.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Kodirov SA. The neuronal control of cardiac functions in Molluscs. Comp Biochem Physiol A: Mol Integr Physiol. 2011;160(2):102–16.

    Article  CAS  PubMed  Google Scholar 

  39. Janesick A, Abbey R, Chung C, Liu S, Taketani M, Blumberg B. ERF and ETV3L are retinoic acid-inducible repressors required for primary neurogenesis. Development (Cambridge, England). 2013;140(15):3095–106.

    Article  CAS  PubMed  Google Scholar 

  40. Jung S-H, Song HY, Hyun YS, Kim Y-C, Whang I, Choi T-Y, Jo S. A Brain Atlas of the Long Arm Octopus. Octopus minor Exp Neurobiol. 2018;27(4):257–66.

    Article  PubMed  Google Scholar 

  41. Seidel JJ, Graves BJ. An ERK2 docking site in the Pointed domain distinguishes a subset of E. Genes Dev. 2002;16(1):127–37.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  42. Waas WF, Dalby KN. Transient protein-protein interactions and a random-ordered kinetic mechanism for the phosphorylation of a transcription factor by extracell ular-regulated protein kinase 2. J Biol Chem. 2002;277(15):12532–40.

    Article  CAS  PubMed  Google Scholar 

  43. Qiao F, Harada B, Song H, Whitelegge J, Courey AJ, Bowie JU. Mae inhibits Pointed-P2 transcriptional activity by blocking its MAPK docking site. EMBO J. 2006;25(1):70–9.

    Article  CAS  PubMed  Google Scholar 

  44. Biondi RM, Nebreda AR. Signalling specificity of Ser/Thr protein kinases through docking-site-mediated interactions. Biochem J. 2003;372(Pt 1):1–13.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  45. Sharrocks AD, Yang SH, Galanis A. Docking domains and substrate-specificity determination for MAP kinases. Trends Biochem Sci. 2000;25(9):448–53.

    Article  CAS  PubMed  Google Scholar 

  46. Rainey MA, Callaway K, Barnes R, Wilson B, Dalby KN. Proximity-induced catalysis by the protein kinase ERK2. J Am Chem Soc. 2005;127(30):10494–5.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  47. Taveirne S, Wahlen S, Van Loocke W, Kiekens L, Persyn E, Van Ammel E, De Mulder K, Roels J, Tilleman L, Aumercier M, et al. The transcription factor ETS1 is an important regulator of human NK cell development and terminal differentiation. Blood. 2020;136(3):288–98.

    PubMed  Google Scholar 

  48. Schmidt M, Schmidt AM, Dietl J, Kammerer U. Characterization of an intramolecular protein-protein interaction in c-Ets1 and its viral homologue v-Ets. Oncol Rep. 2007;18(2):457–63.

    CAS  PubMed  Google Scholar 

  49. Zhu H, Traver D, Davidson AJ, Dibiase A, Thisse C, Thisse B, Nimer S, Zon LI. Regulation of the lmo2 promoter during hematopoietic and vascular development in zebrafish. Dev Biol. 2005;281(2):256–69.

    Article  CAS  PubMed  Google Scholar 

  50. Li Y, Song X, Wang W, Wang L, Yi Q, Jiang S, Jia Z, Du X, Qiu L, Song L. The hematopoiesis in gill and its role in the immune response of Pacific oyster Crassostrea gigas against secondary challenge with Vibrio splendidus. Dev Comp Immunol. 2017;71:59–69.

    Article  CAS  PubMed  Google Scholar 

  51. Chen CJ, Chen H, Zhang Y, Thomas HR, Frank MH, He YH, Xia R. TBtools: An integrative toolkit developed for interactive analyses of big biological data. Mol Plant. 2020;13(8):1194–202.

    Article  CAS  PubMed  Google Scholar 

  52. Senior AW, Evans R, Jumper J, Kirkpatrick J, Sifre L, Green T, Qin CL, Zidek A, Nelson AWR, Bridgland A et al: Improved protein structure prediction using potentials from deep learning. Nature. 2020;577(7792):706-+.

  53. Seeliger D, de Groot BL. Ligand docking and binding site analysis with PyMOL and Autodock/Vina. J Comput-Aided Mol Des. 2010;24(5):417–22.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  54. Wu Z, Tang M, Zhao J, Lin Z, Wang S, Bao Y. Genome-wide identification and immune response analysis of serine protease inhibitor genes in the blood clam Tegillarca granosa. Fish Shellfish Immunol. 2022;131:1234–44.

    Article  CAS  PubMed  Google Scholar 

  55. Yang S, Zhang X, Yue J-X, Tian D, Chen J-Q. Recent duplications dominate NBS-encoding gene expansion in two woody species. Mole Genet Genom. 2008;280(3):187–98.

    Article  CAS  Google Scholar 

  56. Zhang GF, Fang XD, Guo XM, Li L, Luo RB, Xu F, Yang PC, Zhang LL, Wang XT, Qi HG, et al. The oyster genome reveals stress adaptation and complexity of shell formation. Nature. 2012;490(7418):49–54.

    Article  CAS  PubMed  Google Scholar 

  57. Wang S, Zhang JB, Jiao WQ, Li J, Xun XG, Sun Y, Guo XM, Huan P, Dong B, Zhang LL, et al. Scallop genome provides insights into evolution of bilaterian karyotype and development. Nat Ecol Evol. 2017;1(5):120.

  58. Chen SF, Zhou YQ, Chen YR, Gu J. fastp: an ultra-fast all-in-one FASTQ preprocessor. Bioinformatics. 2018;34(17):884–90.

    Article  Google Scholar 

  59. Li B, Dewey CN. RSEM: accurate transcript quantification from RNA-Seq data with or without a reference genome. BMC Bioinformatics. 2011;12(1):323.

  60. Dobin A, Davis CA, Schlesinger F, Drenkow J, Zaleski C, Jha S, Batut P, Chaisson M, Gingeras TR. STAR: ultrafast universal RNA-seq aligner. Bioinformatics. 2013;29(1):15–21.

    Article  CAS  PubMed  Google Scholar 

  61. Yu GC, Wang LG, Han YY, He QY. clusterProfiler: an R package for comparing biological themes among gene clusters. OMICS. 2012;16(5):284–7.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

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We express our gratitude to all the researchers who made contributions to this project.


This study was supported in part by grants from the Key Natural Science Foundation of Zhejiang (LZ20C190001), the National Science Foundation of China (32273123), the Zhejiang Major Program of Science and Technology (2021C02069-7), the Science Foundation of Zhejiang (LQ23C190007) and the Ningbo Public Benefit Research Key Project (2021S014).

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Authors and Affiliations



Hongyu Jin conducted the investigation and wrote the main manuscript text. Weiwei Zhang and Hongxing Liu performed the data analysis. Hongxing Liu and Yongbo Bao edited and revised the manuscript. All authors reviewed the manuscript.

Corresponding authors

Correspondence to Hongxing Liu or Yongbo Bao.

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Ethical approval for this study was obtained from the Experimental Animal Ethics Committee of Ningbo University. All the experimental procedures were approved by the Experimental Animal Ethics Committee of Ningbo University.

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The authors declare no competing interests.

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Supplementary information

Additional file 1.

 Domain and motif architecture analysis of ETS genes in mollusks.

Additional file 2.

 Heatmap of mRNA expression levels of ETS genes in different developmental stages and adult tissues.

Additional file 3.

 Total hemocyte counts (THC) of fifty blood clams from the same growth environment.

Additional file 4.

 Primers used for qRT-PCR.

Additional file 5. 

Genome wide identification of ETS genes in eleven mollusks.

Additional file 6.

 Tandem repeat gene pairs of three bivalve mollusks.

Additional file 7.

 Expressions of ETS genes in different developmental stages and adult tissues.

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Jin, H., Zhang, W., Liu, H. et al. Genome-wide identification and characteristic analysis of ETS gene family in blood clam Tegillarca granosa. BMC Genomics 24, 700 (2023).

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