The Drosophila foraging gene mediates adult plasticity and gene-environment interactions in behaviour, metabolites, and gene expression in response to food deprivation.

Nutrition is known to interact with genotype in human metabolic syndromes, obesity, and diabetes, and also in Drosophila metabolism. Plasticity in metabolic responses, such as changes in body fat or blood sugar in response to changes in dietary alterations, may also be affected by genotype. Here we show that variants of the foraging (for) gene in Drosophila melanogaster affect the response to food deprivation in a large suite of adult phenotypes by measuring gene by environment interactions (GEI) in a suite of food-related traits. for affects body fat, carbohydrates, food-leaving behavior, metabolite, and gene expression levels in response to food deprivation. This results in broad patterns of metabolic, genomic, and behavioral gene by environment interactions (GEI), in part by interaction with the insulin signaling pathway. Our results show that a single gene that varies in nature can have far reaching effects on behavior and metabolism by acting through multiple other genes and pathways

An activated form of UFO alters leaf development and produces ectopic floral and inflorescence meristems

Plants are unique in their ability to continuously produce new meristems and organ primordia. In Arabidopsis, the transcription factor LEAFY (LFY) functions as a master regulator of a gene network that is important for floral meristem and organ specification. UNUSUAL FLORAL ORGANS (UFO) is a co-activator of LEAFY and is required for proper activation of APETALA3 in the floral meristem during the specification of stamens and petals. The ufo mutants display defects in other parts of the flower and the inflorescence, suggestive of additional roles. Here we show that the normal determinacy of the developing Arabidopsis leaves is affected by the expression of a gain-of-function UFO fusion protein with the VP16 transcriptional activator domain. In these lines, the rosette and cauline leaf primordia exhibit reiterated serration, and upon flowering produce ectopic meristems that develop into flowers, bract leaves and inflorescences. These striking phenotypes reveal that developing leaves maintain the competency to initiate flower and inflorescence programs. Furthermore, the gain-of-function phenotypes are dependent on LFY and the SEPALLATA (SEP) MADS-box transcription factors, indicative of their functional interactions with UFO. The findings of this study also suggest that UFO promotes the establishment of the lateral meristems and primordia in the peripheral zone of the apical and floral meristems by enhancing the activity of LFY. These novel phenotypes along with the mutant phenotypes of UFO orthologs in other plant species suggest a broader function for UFO in plants.Peer reviewed: YesNRC publication: Ye

Phenotypes of tobacco plants expressing <i>p35S:UFO</i> and <i>p35S:UFO-VP16</i>.

<p>(A–C) 6 week-old tobacco plants of WT (A), <i>p35S:UFO</i> (B) and <i>p35S:UFO-VP16</i> at vegetative, bolting and flowering stages respectively. (D–H) <i>p35S:UFO</i> plant showing light green sepal-like (D) and pink petal-like (E) sectors in the vegetative leaves; flowers with spiral phyllotaxy of the sepal, petal and stamen whorls showing stamen [s], petal-stamen [pst], petal [p], petal-sepal [ps], sepal [s] and sepal-cauline leaf [sc] subtending a co-florescence [cf] (F–H); the flower in (F) shows a split corolla; the mature flower in (H) has shed its petals and stamens and shows a developing pod. (I) Wild type flower. (J) 8 week-old <i>p35S:UFO-VP16</i> showing abnormal leaves and early flowering. (K–M) Cross sections of a wild type leaf (K), a sepal (L), and a light green sector of a <i>p35S:UFO</i> vegetative leaf (M). The palisade (pm) and spongy (sm) mesophyll layers seen in the leaf are not present in the sepals and in the modified <i>p35S:UFO</i> leaf sectors. Bar = 0.1 mm.</p

Genetic interactions between UFO and LFY, SEP.

<p>Inflorescence of <i>lfy-1</i> (A) compared to that of <i>lfy-1 p35S:UFO-VP16</i> (B). Normal rosette of <i>lfy-1 p35S:UFO-VP16</i> (C). (D, E) GUS expression of a <i>pLFY:GUS</i> in wild type (D) and <i>p35S:UFO-VP16</i> (E) seedling. (F) <i>pAP1:GUS p35S:UFO-VP16</i> seedling with GUS expression in the primary leaves. (G) <i>AP3:GUS p35S:UFO-VP16</i> shoot apex after evocation with GUS expression appearing in the leaves. (H) <i>ap1-10 p35S:UFO-VP16</i> cauline leaf with ectopic <i>ap1</i> like flowers. (I-Q) sep mutants compared with their corresponding sep UFO-VP16 transgenic lines: (I-K) <i>sep1 sep2-1 sep3-2 sep4-1/+</i>; (L–M) <i>sep1 SEP2-1rev/rev sep3-2/+ sep4-1</i>; and (O-Q) <i>sep1 sep2-1 sep3-2/+ SEP4</i>. Control flowers (I, L, O); flowers (J, M, P) and rosettes (K, N, Q) of mutants transformed with <i>UFO-VP16</i> transgene. <i>sep2-1</i> carries an En-1 insertion in the seventh intron, which has excised in the <i>SEP2-1rev</i> revertant allele. Flowers with bract-like organs (I,J) and a normal rosette (K); normal flowers (L,M) and rosette (N): normal flower (O) and <i>UFO-VP16</i> like flowers that have short pedicels with a flowering cauline leaf (arrow, P); <i>UFO-VP16</i> like rosette (Q). (R) <i>p35S:SEP1</i> inflorescence terminating in a flower. (S, T) <i>p35S:SEP4-VP16</i> rosette with leaves showing serration (S) and inflorescence producing flowers with short pedicels (T).</p

Characterization of ectopic flowers produced on the rosette leaves of <i>p35S:UFO-VP16</i> Arabidopsis plants with a medium phenotype.

<p>(A–D) Upper rosette leaves of <i>p35S:UFO-VP16</i> plant (A) with ectopic flowers (B; C-close-up), occasionally subtended by an ectopic bract (D). (E–F) Ectopic inflorescences on the rosette leaves of <i>p35S:UFO-VP16</i> plants (E) that produce siliques (F) and fertile seeds upon pollination (inset in F). (G–N) Ontogeny of the ectopic flower/inflorescence formation on the leaves of <i>p35S:UFO-VP16</i> plants. Developing lower rosette leaf primordia showing serrations along the margins (G) that produce secondary serrations (arrows) at a later stage (H). Developing upper rosette leaves of WT (I) and <i>p35S:UFO-VP16</i> (J–Q); rosette leaf prior to flowering showing deep serrations and an excess of enlarged trichomes (J); serrated rosette leaves formed at flowering with ectopic floral/inflorescence meristems (K–Q) that show progressive floral developmental stages (insets in K, O–Q). Grey boxed regions in K and L are magnified in M and N; red arrows indicate the emerging floral primordia that are positioned at distal ends of the serrations (yellow stars). Green stars in J–L, O–Q indicate axillary meristems. Bar = 1 mm (I, J); 0.1 mm (G, H, K–Q).</p

Phenotypes of <i>Brassica napus</i> plants expressing <i>p35S:UFO-VP16</i>.

<p>Wild type plant (A) showing normal lobed leaves (B). (C–F) <i>p35S:UFO-VP16</i> plant (C) showing severe lobing of the leaf (D); expanding young leaf (E) showing meristematic activity along the leaf margin (F) that leads to the enhanced lobing. Inset in (C) shows prolonged meristematic activity of the leaf margin. (G–J) Inflorescences of <i>p35S:UFO-VP16</i> plants showing severe proliferation of floral organs produced by the inflorescence meristem (G) and by the cauline leaves (G, I; white arrows); weaker phenotype showing the development of modified flowers with short pedicels (H) and prolonged meristematic activity of the cauline leaf margins (H, J).</p