Stilbenes are a small family of phenylpropanoids produced in a number of unrelated plant species, including grapevine (Vitis vinifera). In addition to their participation in defense mechanisms in ...plants, stilbenes, such as resveratrol, display important pharmacological properties and are postulated to be involved in the health benefits associated with a moderate consumption of red wine. Stilbene synthases (STSs), which catalyze the biosynthesis of the stilbene backbone, seem to have evolved from chalcone synthases (CHSs) several times independently in stilbene-producing plants. STS genes usually form small families of two to five closely related paralogs. By contrast, the sequence of grapevine reference genome (cv PN40024) has revealed an unusually large STS gene family. Here, we combine molecular evolution and structural and functional analyses to investigate further the high number of STS genes in grapevine. Our reannotation of the STS and CHS gene families yielded 48 STS genes, including at least 32 potentially functional ones. Functional characterization of nine genes representing most of the STS gene family diversity clearly indicated that these genes do encode for proteins with STS activity. Evolutionary analysis of the STS gene family revealed that both STS and CHS evolution are dominated by purifying selection, with no evidence for strong selection for new functions among STS genes. However, we found a few sites under different selection pressures in CHS and STS sequences, whose potential functional consequences are discussed using a structural model of a typical STS from grapevine that we developed.
Since its identification in 2003, grapevine Pinot gris virus (GPGV,
Trichovirus
) has now been detected in most grape-growing countries. So far, little is known about the epidemiology of this newly ...emerging virus. In this work, we used datamining as a tool to monitor
in-silico
the sanitary status of three vineyards in Italy. All data used in the study were recovered from a work that was already published and for which data were publicly available as SRA (Sequence Read Archive, NCBI) files. While incomplete, knowledge gathered from this work was still important, with evidence of differential accumulation of the virus in grapevine according to year, location, and variety-rootstock association. Additional data regarding GPGV genetic diversity were collected. Some advantages and pitfalls of datamining are discussed.
Previous studies have equated FOXL2 as a crucial actor in the ovarian differentiation process in different vertebrate species. Its transcriptional extinction in the polled intersex syndrome (PIS) ...leads primarily to a drastic decrease of aromatase (CYP19) expression in the first steps of goat ovarian development. In this study, we provide a better characterization of early ovarian development in goat, and we provide experimental evidence demonstrating that FOXL2 represents a direct transcriptional activator of the CYP19 gene through its ovarian-specific promoter 2. Moreover, the ovarian location of FOXL2 and CYP19 proteins, together with their expression profiles in the female gonads, stress the involvement of FOXL2 co-factor(s) for regulating CYP19 transcription. Expressional analyses show that activin-betaA can be considered as a strong candidate for being one of these FOXL2 co-factors. Finally, we discuss evidence for a role of activin and estrogens in somatic and germinal cell proliferation occurring before germ cell meiosis. This period, of 20 days in goat, seems to have no equivalent in mouse. This species-specific difference could explain the phenotype discrepancy observed between XX goat PIS(-/-) and XX mouse Foxl2(-/-).
Studies on XX sex reversal in polled goats (PIS mutation: polled intersex syndrome) have led to the discovery of a female-specific locus crucial for ovarian differentiation. This genomic region is ...composed of at least two genes,
FOXL2 and
PISRT1, sharing a common transcriptional regulatory region, PIS. In this paper, we describe a third gene,
PFOXic (promoter
FOXL2 inverse complementary), located near
FOXL2 in the opposite orientation. This gene composed of five exons encodes a 1723-bp cDNA, enclosing two repetitive elements in its 3′ end.
PFOXic mRNA encodes a putative protein of 163 amino acids with no homologies in any of the databases tested. The transcriptional expression of
PFOXic is driven by a bidirectional promoter also enhancing
FOXL2 transcription. In goats,
PFOXic is expressed in developing ovaries, from 36 days postcoïtum until adulthood. Ovarian-specific expression of
PFOXic is regulated by the PIS region.
PFOXic is found conserved only in Bovidae. But, a human gene located in the opposite orientation relative to
FOXL2 can be considered a human
PFOXic. Finally, we discuss evidence arguing for regulation of the level of
FOXL2 transcription via the bidirectional promoter and the level of transcription of
PFOXic.
The testis-determining gene
SRY is not well-conserved among mammals, particularly between mouse and other mammals, both in terms of protein structure and of expression regulation. To evaluate
SRY ...phylogenic conservation in regards to its function, we expressed the goat gene (
gSRY) in XX transgenic mouse gonads. Here, we show that
gSRY induces testis formation, despite a goat expression profile. Our results demonstrate that sex-reversal can be induced in XX-mice by a non-mouse
SRY thus suggesting a conserved molecular mechanism of action of this testis-determining gene across mammalian species.
Up to now, two loci have been involved in XX sex-reversal in mammals following loss-of-function mutations, PIS (Polled Intersex Syndrome) in goats and R-spondin1 (RSPO1) in humans. Here, we analyze ...the possible interaction between these two factors during goat gonad development. Furthermore, since functional redundancy between different R-spondins may influence gonad development, we also studied the expression patterns of RSPO2, 3 and 4.
Similarly to the mouse, RSPO1 shows a sex-dimorphic expression pattern during goat gonad development with higher levels in the ovaries. Interestingly, the PIS mutation does not seem to influence its level of expression. Moreover, using an RSPO1 specific antibody, the RSPO1 protein was localized in the cortical area of early differentiating ovaries (36 and 40 dpc). This cortical area contains the majority of germ cell that are surrounded by FOXL2 negative somatic cells. At latter stages (50 and 60 dpc) RSPO1 protein remains specifically localized on the germ cell membranes. Interestingly, a time-specific relocation of RSPO1 on the germ cell membrane was noticed, moving from a uniform distribution at 40 dpc to a punctuated staining before and during meiosis (50 and 60 dpc respectively). Interestingly, also RSPO2 and RSPO4 show a sex-dimorphic expression pattern with higher levels in the ovaries. Although RSPO4 was found to be faintly and belatedly expressed, the expression of RSPO2 increases at the crucial 36 dpc stage, as does that of FOXL2. Importantly, RSPO2 expression appears dramatically decreased in XX PIS-/- gonads at all three tested stages (36, 40 and 50 dpc).
During goat ovarian development, the pattern of expression of RSPO1 is in agreement with its possible anti-testis function but is not influenced by the PIS mutation. Moreover, our data suggest that RSPO1 may be associated with germ cell development and meiosis. Interestingly, another RSPO gene, RSPO2 shows a sex-dimorphic pattern of expression that is dramatically influenced by the PIS mutation.
In vertebrates, 2 main genetic pathways have been shown to regulate ovarian development. Indeed, a loss of function mutations in Rspo1 and Foxl2 promote partial female-to-male sex reversal. In mice, ...it has been shown that the secreted protein RSPO1 is involved in ovarian differentiation and the transcription factor FOXL2 is required for follicular formation. Here, we analysed the potential interactions between these 2 genetic pathways and have shown that while Rspo1 expression seems to be independent of Foxl2 up-regulation, Foxl2 expression partly depends of Rspo1 signalisation. This suggests that different Foxl2-positive somatic cell lineages exist within the ovaries. In addition, a combination of both mutated genes in XX Foxl2(-/-)/Rspo1(-/-) gonads promotes sex reversal, detectable at earlier stages than in XX Rspo1(-/-) mutants. Ectopic development of the steroidogenic lineage is more pronounced in XX Foxl2(-/-)/Rspo1(-/-) gonads than in XX Rspo1(-/-) embryos, suggesting that Foxl2 is involved in preventing ectopic steroidogenesis in foetal ovaries.
Stilbenes are a small family of phenylpropanoids produced in a number of unrelated plant species, including grapevine (
Vitis vinifera
). In addition to their participation in defense mechanisms in ...plants, stilbenes, such as resveratrol, display important pharmacological properties and are postulated to be involved in the health benefits associated with a moderate consumption of red wine. Stilbene synthases (
STSs
), which catalyze the biosynthesis of the stilbene backbone, seem to have evolved from chalcone synthases (
CHSs
) several times independently in stilbene-producing plants.
STS
genes usually form small families of two to five closely related paralogs. By contrast, the sequence of grapevine reference genome (cv PN40024) has revealed an unusually large
STS
gene family. Here, we combine molecular evolution and structural and functional analyses to investigate further the high number of
STS
genes in grapevine. Our reannotation of the
STS
and
CHS
gene families yielded 48
STS
genes, including at least 32 potentially functional ones. Functional characterization of nine genes representing most of the
STS
gene family diversity clearly indicated that these genes do encode for proteins with STS activity. Evolutionary analysis of the
STS
gene family revealed that both
STS
and
CHS
evolution are dominated by purifying selection, with no evidence for strong selection for new functions among
STS
genes. However, we found a few sites under different selection pressures in
CHS
and
STS
sequences, whose potential functional consequences are discussed using a structural model of a typical STS from grapevine that we developed.
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