Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “exon 2”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources

Protein kinase A enhances, whereas glycogen synthase kinase-3 beta inhibits, the activity of the exon 2-encoded transactivator domain of heterogeneous nuclear ribonucleoprotein D in a hierarchical fashion.

Heterogeneous nuclear ribonucleoprotein D (hnRNP D) is implicated in transcriptional regulation. Alternative splicing of exons 2 and 7 generates four isoforms of the protein. We report here that only isoforms that contain the product of exon 2 (amino acids 79-97) were able to transactivate. Moreover, the exon 2-encoded protein domain alone was sufficient to drive transcription. TATA-binding protein and p300 interacted with a synthetic peptide corresponding to exon 2, and both proteins co-precipitated with hnRNP D. Stimulation of protein kinase A (PKA) and protein kinase C (PKC) synergistically induced the transactivating ability of hnRNP D, and the exon 2-encoded domain was sufficient for this inducibility. In kinase assays PKA phosphorylated Ser-87 of hnRNP D, whereas glycogen synthase kinase-3 beta (GSK-3 beta) phosphorylated Ser-83, but only if Ser-87 had been pre-phosphorylated by PKA. Phosphorylation of Ser-87 enhanced, whereas phosphorylation of Ser-83 repressed, transactivation. Overexpression of GSK-3 beta inhibited transactivation by hnRNP D, but stimulation of PKC negated the inhibitory effect of GSK-3 beta. We suggest that a hierarchical phosphorylation pathway regulates the transactivating ability of hnRNP D: PKA activates hnRNP D, but at the same time renders it sensitive to inhibition by GSK-3 beta; the latter inhibition can be suspended by inactivating GSK-3 beta with PKC.

Alternative Splicing↗

Exon 2 containing myelin basic protein (MBP) transcripts are expressed in lesions of experimental allergic encephalomyelitis (EAE).

Exon 2 containing myelin basic protein (MBP) transcripts are expressed during developmental myelination in mice and humans, and during remyelination subsequent to virally induced demyelination in adult mice. Since remyelination characterizes CNS lesions during experimental allergic encephalomyelitis (EAE) and multiple sclerosis (MS), we investigated whether exon 2 containing isoforms of MBP are expressed in EAE lesions during relapsing disease. Exon 2 containing MBP transcripts were detected by in situ hybridization in 17 of 52 EAE mice and in 16 of 30 mice at the peak of the first or second episode of paralysis. Thus exon 2 containing MBP transcripts are expressed in lesions of the CNS during active phases of chronic relapsing autoimmune disease. Implications of these findings with respect to future therapies aimed toward enhancing remyelination in EAE and, possibly MS, are discussed.

Animals↗

[A new point mutation on exon 2 of parkin gene in Parkinson's disease].

OBJECTIVE: To detect the relationship between point mutations on exon 2 of parkin gene and sporadic early-onset Parkinson's disease. METHODS: The point mutations on exon 2 of parkin gene were detected using polymerase chain reaction(PCR), agarose electrophoresis, single strand conformation polymorphism(SSCP), DNA sequencing and analysis of restrict enzyme in DNA of 60 Parkinson's disease patients with an onset age under 50 and 120 normal controls. RESULTS: One homozygous mutation (G(237)-->C) on exon 2 was found by sequencing and verified by analysis of restrict enzyme, whereas no mutation was found in normal controls. CONCLUSION: Point mutations on exon 2 of parkin gene are likely to be related to sporadic early-onset Parkinson's disease.

Adult↗

Monoclonal antibody E-13 (M-810) to human cytomegalovirus recognizes an epitope encoded by exon 2 of the major immediate early gene.

Monoclonal antibody (MAb) E-13 to human cytomegalovirus is used widely for diagnostic and fundamental studies, and has been shown to be directed against an immediate early (IE) protein(s). To determine which viral antigen is detected by MAb E-13, four subfragments from the open reading frame encoded by exons 2, 3 or 4 of IE-1 were cloned in the bacterial expression vector pROS. The resulting fusion proteins contained amino acids 77 to 491 encoded by mainly exon 4, amino acids 25 to 78 encoded by exon 3, amino acids 1 to 85 encoded by exons 2 and 3, and amino acids 1 to 24 encoded by exon 2. The reactivity of MAb E-13 with the fusion proteins was assayed by Western blotting. MAb E-13 was shown to react exclusively with proteins encoded by exon 2 and therefore recognizes IE proteins which contain the N-terminal amino acid sequence encoded by exon 2, namely the major 72K IE protein, the 82K to 86K IE-2 protein and the 52K to 55K IE-2 protein. MAb E-13 can be used to detect both IE-1- and IE-2-encoded proteins, which share the polypeptide encoded by exon 2.

Antibodies, Monoclonal↗

Functional analysis of splicing mutations and of an exon 2 polymorphic variant of SERPING1/C1NH.

Several sequence changes have been reported in hereditary angioedema patients in intron 2 of the SERPING1/C1NH gene, but their consequences on splicing have not been determined. We examined in cell transfection assays the consequences at the mRNA level of splicing mutations affecting either the +3 or the +5 donor site positions, or the conserved canonical splicing signals of exon 2, using mutant C1 inhibitor minigene constructs. Both intron 2 mutations, c.51+3A>G and c.51+5G>A, resulted in marked exon 2 skipping in these assays, but also yielded a large fraction of normal transcripts. We show that the c.51+3A>G mutation cosegregates with low C1 inhibitor protein levels in one family. Moreover, the second base of exon 2 of the SERPING1/C1NH gene is the site of a polymorphic variant, which has been proposed as a modifier of disease severity. We found that the c.-21C allele at this position yields low but significant levels of exon 2 skipping in transfected Hep G2 or Hep 3B cells, suggesting that this allele may contribute, at the RNA level, to more severe forms of angioedema. Furthermore, we describe a previously not detected alternative splicing of exon 3, found in peripheral blood cell mRNA but not in the liver or in hepatoma cell lines and we show that, in cultured monocytes of a patient carrying the c.51+3A>G mutation, this alternative splicing is shifted from exon 3 exclusion to skipping of both exons 2 and 3. The latter finding suggests that mutations affecting splicing of exon 2 of the SERPING1/C1NH gene may have different consequences in monocytes versus other cell types.

Adolescent↗

Rescue of common and rare exon 2 skipping variants of the GAA gene using modified U1 snRNA.

BACKGROUND: Pompe disease (PD) is an autosomal recessive lysosomal storage disorder caused by the deficient activity of acid alpha glucosidase (GAA) enzyme due to mutations in the GAA gene. As a result, undigested glycogen accumulates within lysosomes causing their dysfunction. From a clinical point of view, the disease can be classified in infantile-onset (IO) and late-onset (LO) forms. The common GAA c.-32-13T>G variant, found in 40-70% of LO-PD alleles, is a leaky splicing mutation interfering with the correct GAA exon 2 recognition by the spliceosome leading to the production of non-functional GAA transcripts. In this study, we used modified, GAA-tailored U1 snRNAs to correct the aberrant splicing determined by the c.-32-13T>G and other GAA exon 2-skipping mutations. METHODS: A set of constructs expressing 5 different engineered U1 snRNAs was generated. A functional splicing assay using a GAA hybrid minigene carrying different variants known to affect GAA exon 2 splicing was used to test the effect of engineered U1 snRNAs on exon 2 inclusion. The effect on endogenously expressed GAA transcript and GAA enzymatic activity was assessed by transfecting patient-derived fibroblasts bearing the common c.-32-13T>G with the best performing modified U1 snRNA. RESULTS: Modified U1-3, U1+1 and U1+6 snRNAs were all able to increase, in a dose-dependent manner, the inclusion of exon 2 within the transcript derived from the GAA minigene harbouring the c.-32-13T>G variant. The U1+1 was the most effective one (2,5 fold increase). Moreover, U1+1 snRNA partially rescued the correct splicing of GAA minigenes harbouring mutations that affect the 3'ss (c.-32-3C>G, c.-32-2A>G) and the 5'ss (c.546G>A, c.546G>C, c.546G>T). Notably, the treatment of patient-derived fibroblasts carrying the c.-32-13T>G mutation with the U1+1 snRNA increased the amount of normal GAA mRNA by 1,8 fold and the GAA enzymatic activity by 70%. CONCLUSIONS: we provide the proof-of-concept for the use of modified GAA-tailored U1 snRNAs, designed to potentiate the recognition of the GAA exon 2 5'ss, as therapeutic tools to correct the aberrant transcripts carrying variants that affect exon 2 splicing, including the common c.-32-13T>G variant.

Humans↗

Sequence analysis of deletion mutations at the HPRT locus of human T-lymphocytes: association of a palindromic structure with a breakpoint cluster in exon 2.

To study the structure and mechanism of deletion mutation in human somatic cells in vivo, we have identified and sequenced the breakpoints of 16 independent deletions at the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus in human T-lymphocytes. Seven deletions were found in exon 2, three in each of exon 3 and 6, and one in each of intron 3, exon 8 and exon 9. Most of the deletions seemed to result from non-homologous recombination, possibly by a slippage-misalignment mechanism between short repeat sequences. Putative secondary DNA structures, possibly acting as intermediates in the deletion formation, were identified in several mutants. Six of the seven exon 2 deletions had a breakpoint within a 12 bp region (in the 5' end of exon 2) which contains a 9 nucleotide palindrome (AACCAGGTT) and is preceded by a TGA direct repeat tract. One of the mutants had two deletions in tandem, separated by the palindrome. Another mutant, in which 23 bp containing the palindromic sequence was deleted, had an additional base (C) inserted between the breakpoints forming a direct repeat (gACGAC) in the deletion junction. Taken together with previously reported deletion mutations at the HPRT locus, these results suggest that the deletion cluster in the 5' part of HPRT exon 2 in T-cells in vivo is promoted by the 9 nucleotide palindrome sequence and the TGA repeat tract. The former may act as a stabilizer in a putative intermediate structure, and the latter may induce slippage and misalignment during replication.

Base Sequence↗

Alternative splicing of type II procollagen exon 2 is regulated by the combination of a weak 5' splice site and an adjacent intronic stem-loop cis element.

Alternative splicing of the type II procollagen gene (COL2A1) is developmentally regulated during chondrogenesis. Chondroprogenitor cells produce the type IIA procollagen isoform by splicing (including) exon 2 during pre-mRNA processing, whereas differentiated chondrocytes synthesize the type IIB procollagen isoform by exon 2 skipping (exclusion). Using a COL2A1 mini-gene and chondrocytes at various stages of differentiation, we identified a non-classical consensus splicing sequence in intron 2 adjacent to the 5' splice site, which is essential in regulating exon 2 splicing. RNA mapping confirmed this region contains secondary structure in the form of a stem-loop. Mutational analysis identified three cis elements within the conserved double-stranded stem region that are functional only in the context of the natural weak 5' splice site of exon 2; they are 1) a uridine-rich enhancer element in all cell types tested except differentiated chondrocytes; 2) an adenine-rich silencer element, and 3) an enhancer cis element functional in the context of secondary structure. This is the first report identifying key cis elements in the COL2A1 gene that modulate the cell type-specific alternative splicing switch of exon 2 during cartilage development.

Alternative Splicing↗

The expression of myelin basic protein exon 1 and exon 2 containing transcripts during myelination of the neonatal rat spinal cord--an in situ hybridization study.

During myelination, myelin proteins are expressed in a highly coordinated sequence. Of the four major isoforms of myelin basic protein, the proportion of the 21.5kDa and 17 kDa isoforms (which contain sequences encoded by myelin basic protein [MBP] exon 2) is enriched during active myelination in the mouse, suggesting that the alternative splicing of MBP transcripts containing exon 2 information is developmentally regulated. In this study, we compare the expression of MBP exon 1 and MBP exon 2 mRNAs in the neonatal rat spinal cord to establish whether developmental regulation of exon 2 mRNAs occurs in the rat in a manner similar to that previously described in the mouse. The expression of MBP mRNAs, together with that of proteolipid protein (PLP/DM-20) mRNA, in the developing white matter tracts increased dramatically between P7 and P10, corresponding to an increase in the extent of myelination. High levels of expression of each mRNA species examined were maintained between P10 and P14 as myelination proceeded. At P21, the expression of MBP exons 1 and 2 was reduced in the ventrolateral funiculi but was maintained at high levels in the dorsal funiculus. At P45, a further downregulation of both MBP mRNAs was apparent. By contrast, high levels of PLP/DM-20 expression were maintained from P10 onwards. In the grey matter, expression of MBP and PLP/DM-20 mRNAs increased more gradually and peak expression occurred later than in the white matter tracts. In this study, we therefore provide a description of myelin protein gene expression during post-natal development of the rat spinal cord. We have also shown that in the rat spinal cord, changes in the levels of MBP exon 2 expression associated with myelination reflect the changes of all MBP transcripts.

Alternative Splicing↗

Influence of the small leader exons 2 and 3 on human immunodeficiency virus type 1 gene expression.

The human immunodeficiency virus type 1 (HIV-1) uses an elaborate alternative splicing pattern for the generation of both the 1.8-kb as well as the 4-kb classes of mRNA. An additional diversity of transcripts in both classes is created by the optional inclusion of the small exons 2 and 3 in the leader sequence. To analyze a possible influence of these leader exons on HIV-1 gene expression, several series of expression vectors with different leaders were constructed, expressing either Rev and Env or a heterologous coding sequence, i.e., the chloramphenicol acetyl transferase (CAT) ORF. Transfection experiments of HeLa-T4(+) cells revealed for all series of constructs that mRNA as well as protein expression was stimulated by the presence of exon 2 and reduced by exon 3. The function of the leader exons 2 and 3 is neither dependent on the regulatory proteins Tat or Rev nor on viral coding sequences. Neither transcription rates nor stability of polyadenylated RNAs were found to be responsible for the different levels of steady-state mRNA. When either exon 2 or 3 was inserted into a heterologous intron, processing of the primary transcripts generated identical mRNA species while maintaining the differences in exon 2/3-dependent mRNA steady-state levels. These results may be explained by exon-specific nuclear RNA degradation rates, as also indicated by results from an in vitro degradation assay using a HeLa nuclear extract.

Alternative Splicing↗

Methylation of exon 2 of p16 is associated with late stage oesophageal cancer.

Methylation of the p16 gene was studied in 16 oesophageal tumours. Five (31%) of the tumours were found to be methylated in exon 1 and eight (50%) were methylated in exon 2. The loss of p16 protein correlated with methylation of exon 1 (P = 0.005). However, methylation of exon 2, but not exon 1, was found to be associated with late stage tumours (P = 0.01). We conclude that the methylation of exon 2 of p16 may have effects on the progression of oesophageal tumours that are independent of the expression of the p16 protein.

Adenocarcinoma↗

L1 mediated homophilic binding and neurite outgrowth are modulated by alternative splicing of exon 2.

The neural cell adhesion molecule (CAM) L1 is a member of the immunoglobulin superfamily that has been implicated in neuronal adhesion, neurite outgrowth, and axon guidance. The clinical importance of L1 is illustrated by pathological mutations that lead to hydrocephalus, mental retardation, motor defects, and early mortality. The L1 gene is composed of 28 exons, including exons 2 and 27 that are spliced alternatively, and mutations in exon 2 are associated with severe neurological abnormalities in humans. To elucidate the role of L1 exon 2, a recombinant Fc fusion protein called Delta2L1 was constructed lacking the second exon in the extracellular domain of L1. When bound to fluorescent beads, L1 exhibited homophilic binding while Delta2L1 did not. However, L1 beads coaggregated with the Delta2L1 beads. Similarly, in cell binding studies, L1 bound to L1 and Delta2L1 did not bind to Delta2L1 but it bound moderately to L1. Given the reduced binding of Delta2L1, we tested its effect on neurons. By comparison to L1, a lower percentage of dissociated neurons extended neurites on Delta2L1, and there was a modest decrease in the length of the neurites that grew. Neurite outgrowth from reaggregated neurons was much less robust on Delta2L1 than on L1. The combined results indicate that Delta2L1 does not bind homophilically but it can interact with L1 containing exon 2. The reduced binding and neurite promoting activity of Delta2L1 provides an explanation for certain pathological mutations in L1 that lead to clinically apparent disease in the absence of the normal form of L1 in the nervous system.

Alternative Splicing↗

Cis-acting intronic elements that regulate cartilage-specific alternative splicing of the type II collagen (Col2) pre-mRNA lie at or near splice site junction sequences flanking exon 2 of the gene.

UNLABELLED: Knowledge of the cis-acting elements is required for identifying trans-acting splicing factors underlying cartilage-specific alternative splicing of Col2 pre-mRNA. By performing desired deletions in the mouse Col2 pre-mRNA, location of the intronic cis-acting elements was narrowed down to be at or near splice-junction sequences flanking exon 2 of the gene. INTRODUCTION: Type II collagen (Col2) pre-mRNA undergoes cartilage-specific alternative splicing involving exon 2 during chondrocyte differentiation. Thus, the trans-acting protein factors that regulate the splicing are associated with the differentiation of chondrocytes. Knowledge of the cognate cis-acting elements is necessary to eventually identify the trans-acting factors. MATERIALS AND METHODS: To localize the cis-acting sequences, we created several deletions within a minigene containing exon 1 to exon 4 of mouse Col 2 gene and evaluated alternative splicing of the resulting pre-mRNAs in ATDC5 cells, a model of insulin-stimulated chondrocyte differentiation. The first deletion reduced intron 1 from 3799 to 259 bp, the second reduced intron 2 from 1108 to 94 bp, the third combined the above two deletions, and the fourth was derived from the third by removing intron 3 and exon 4. ATDC5 cells harboring these constructs were cultured for up to 21 days with or without insulin. Alternative splicing was evaluated by determining the ratio of Col2B (lacks exon 2) to Col2A (has exon 2) RNAs by reverse transcription-polymerase chain reaction. RESULTS: The deletion in intron 1 had no effect on the alternative splicing while other deletions affected splicing (demonstrated by the presence of splicing intermediates) in cells cultured without insulin or with insulin for 1 week. The splicing intermediates were not seen from any construct when cells were cultured longer (14-21 days) with insulin. CONCLUSION: These results show that the 259-bp intron 1, the 94-bp intron 2, and exon 2 sequences retained in the fourth construct provide cis-acting signal sufficient for insulin-induced cartilage-specific alternative splicing of Col2 pre-mRNA.

Alternative Splicing↗

Analysis of point mutation in exon 2 of CYP2E1 gene in renal cell/urothelial cancer patients in comparison with control population.

OBJECTIVE: Genetic polymorphisms of human cytochrome P450s have been implicated to be of importance for susceptibility to different cancers. Recently, a point mutation was found in the exon 2 of the CYP2E1 gene (CYP2E1*2) [Hu et al. 1997]. In order to evaluate a possible link between the point mutation in exon 2 of the CYP2E1 gene and the susceptibility to renal cell/urothelial cancer, we developed a screening method based on the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). MATERIAL: DNA of peripheral white blood cells was isolated from 158 renal cell/urothelial cancer patients as well as from 150 controls. METHOD: Primers for PCR were designed by the Primer 3 release 0.1 program. The PCR yield a product of 215 base pairs (bp), which was digested with the restriction enzyme Hha I. The DNA fragments were separated on a 3% agarose gel stained with ethidium bromide. Restriction enzyme digestion of the PCR product obtained from the wild-type DNA resulted in the appearance of a 66 bp, a 43 bp, a 40 bp, a 39 bp and a 28 bp DNA fragment. In contrast to the wild-type, the digestion of the PCR product from DNA carrying the point mutation resulted in the loss of the 39 bp and 40 bp fragments and the appearance of an additional 79 bp fragment. Therefore, the loss of one Hha I restriction site caused by a single nucleotide exchange is suitable for the identification of the point mutation in exon 2 of CYP2E1 gene. RESULTS: However, we could not detect any point mutation in any of the 158 renal cell/urothelial cancer patients or the 150 controls. The distribution of the point mutation in exon 2 of CYP2E1 gene did not show any difference in renal cell/urothelial cancer patients and controls. CONCLUSION: This might indicate a lack of association between this CYP2E polymorphism (CYP2E1*2) and renal cell/urothelial cancer.

Base Sequence↗

Gaucher disease: A G+1----A+1 IVS2 splice donor site mutation causing exon 2 skipping in the acid beta-glucosidase mRNA.

Gaucher disease is the most frequent lysosomal storage disease and the most prevalent Jewish genetic disease. About 30 identified missense mutations are causal to the defective activity of acid beta-glucosidase in this disease. cDNAs were characterized from a moderately affected 9-year-old Ashkenazi Jewish Gaucher disease type 1 patient whose 80-year-old, enzyme-deficient, 1226G (Asn370----Ser [N370S]) homozygous grandfather was nearly asymptomatic. Sequence analyses revealed four populations of cDNAs with either the 1226G mutation, an exact exon 2 (delta EX2) deletion, a deletion of exon 2 and the first 115 bp of exon 3 (delta EX2-3), or a completely normal sequence. About 50% of the cDNAs were the delta EX2, the delta EX2-3, and the normal cDNAs, in a ratio of 6:3:1. Specific amplification and characterization of exon 2 and 5' and 3' intronic flanking sequences from the structural gene demonstrated clones with either the normal sequence or with a G+1----A+1 transition at the exon 2/intron 2 boundary. This mutation destroyed the splice donor consensus site (U1 binding site) for mRNA processing. This transition also was present at the corresponding exon/intron boundary of the highly homologous pseudogene. This new mutation, termed "IVS2 G+1----A+1," is the first splicing mutation described in Gaucher disease and accounted for about 3.4% of the Gaucher disease alleles in the Ashkenazi Jewish population. The occurrence of this "pseudogene"-type mutation in the structural gene indicates the role of acid beta-glucosidase pseudogene and structural gene rearrangements in the pathogenesis of this disease.

Aged↗

K-ras exon 2 point mutations in human endometrial cancer.

In the present study, we screened for the K-ras exon 2 point mutations in a group of 87 gynecological neoplasms (82 endometrial carcinomas, four carcinomas of the uterine cervix and one uterine carcinosarcoma) using the non-isotopic PCR-SSCP-direct sequencing techniques. Direct sequencing analysis revealed CAA-->CAC (Gln-->His) K-ras codon 61 point mutations in two (2.4%) of the 82 endometrial carcinomas mentioned above. These two cases were endometrial endometrioid carcinomas at an early clinical stage of disease (stage IB and IC due to FIGO). Those endometrial carcinomas that showed K-ras exon 2 point mutations revealed a strong positivity for heterogeneous nuclear retinoblastoma protein staining; none of these, however, have had the K-ras codon 12 point mutation. In addition, there were no K-ras gene point mutations in three endometrial carcinomas lacking the Rb protein immunohistochemically. None of the cervical carcinomas tested had K-ras gene point mutations, whereas one carcinosarcoma harbored K-ras codon 61 point mutation (CAA-->CAC). In conclusion, our data support the view that K-ras exon 2 point mutations are rare events in human endometrial cancer. Rb and K-ras gene abnormalities may occur independently of each other during endometrial carcinogenesis in humans.

Aged↗

Natural splicing of exon 2 of human interleukin-15 receptor alpha-chain mRNA results in a shortened form with a distinct pattern of expression.

We report the existence of eight different interleukin-15 receptor alpha-chain (IL-15Ralpha) transcripts resulting from exon-splicing mechanisms within the IL-15Ralpha gene. Two main classes of transcripts can be distinguished that do or do not (Delta2 isoforms) contain the exon 2-coding sequence. Both classes were expressed in numerous cell lines and tissues (including peripheral blood lymphocytes) at comparable levels and could be transcribed in COS-7 cells, and the proteins were expressed at the cell surface. Both receptor forms displayed numerous glycosylation states, reflecting differential usage of a single N-glycosylation site as well as extensive O-glycosylations. Whereas IL-15Ralpha bound IL-15 with high affinity, Delta2IL-15Ralpha was unable to bind IL-15, thus revealing the indispensable role of the exon 2-encoded domain in cytokine binding. A large proportion of IL-15Ralpha was expressed at the nuclear membrane with some intranuclear localization, supporting a potential direct action of the IL-15.IL-15Ralpha complex at the nuclear level. In sharp contrast, Delta2IL-15Ralpha was found only in the non-nuclear membrane compartments, indicating that the exon 2-encoded domain (which is shown to contain a potential nuclear localization signal) plays an important role in receptor post-translational routing. Together, our data indicate that exon 2 splicing of human IL-15Ralpha is a natural process that might play regulatory roles at different levels.

Animals↗