Regulation and Functions of the lms Homeobox Gene during Development of Embryonic Lateral Transverse Muscles and Direct Flight Muscles in Drosophila

BACKGROUND: Patterning and differentiation of developing musculatures require elaborate networks of transcriptional regulation. In Drosophila, significant progress has been made into identifying the regulators of muscle development and defining their interactive networks. One major family of transcription factors involved in these processes consists of homeodomain proteins. In flies, several members of this family serve as muscle identity genes to specify the fates of individual muscles, or groups thereof, during embryonic and/or adult muscle development. Herein, we report on the expression and function of a new Drosophila homeobox gene during both embryonic and adult muscle development. METHODOLOGY/PRINCIPAL FINDINGS: The newly described homeobox gene, termed lateral muscles scarcer (lms), which has yet uncharacterized orthologs in other invertebrates and primitive chordates but not in vertebrates, is expressed exclusively in subsets of developing muscle tissues. In embryos, lms is expressed specifically in the four lateral transverse (LT) muscles and their founder cells in each hemisegment, whereas in larval wing imaginal discs, it is expressed in myoblasts that develop into direct flight muscles (DFMs), which are important for proper wing positioning. We have analyzed the regulatory inputs of various other muscle identity genes with overlapping or complementary expression patterns towards the cell type specific regulation of lms expression. Further we demonstrate that lms null mutants exhibit reduced numbers of embryonic LT muscles, and null mutant adults feature held-out-wing phenotypes. We provide a detailed description of the pattern and morphology of the direct flight muscles in the wild type and lms mutant flies by using the recently-developed ultramicroscopy and show that, in the mutants, all DFMs are present and present normal morphologies. CONCLUSIONS/SIGNIFICANCE: We have identified the homeobox gene lms as a new muscle identity gene and show that it interacts with various previously-characterized muscle identity genes to regulate normal formation of embryonic lateral transverse muscles. In addition, the direct flight muscles in the adults require lms for reliably exerting their functions in controlling wing postures

Caracterización físico-química y nutricional de algas en polvo empleadas como ingrediente alimentario

[ES] Las algas se han consumido desde tiempos ancestrales en países asiáticos como Japón. En la actualidad su consumo está en auge en Europa, provocado por el creciente interés de los consumidores por alimentos con alto valor nutritivo, que sean saludables y sin aditivos químicos. En este sentido, el empleo de algas en el desarrollo de nuevos productos es interesante, ya que éstas pueden aportar nutrientes esenciales y además, algunas de ellas, presentan ciertas características que permitirían sustituir algunos aditivos en los productos elaborados. Dado el origen marino de las algas es muy interesante su adición a productos derivados de la pesca.   El objetivo general de este trabajo fue caracterizar las algas nori, kombu, wakame y espagueti de mar, con el fin de evaluar si su empleo como ingrediente en distintos productos alimenticios, supondría una mejora en la calidad nutricional y en las propiedades físico‐ químicas de los mismos. Se llevó a cabo un análisis de la composición nutricional de las algas deshidratadas en polvo. Así mismo, se evaluó el contenido en compuestos fenólicos totales, la capacidad antioxidante y se determinó la capacidad de retención de aceite, capacidad de retención de agua y capacidad de hinchamiento.   Las algas presentaron altos contenidos proteicos, especialmente nori y wakame, con niveles superiores al 20% en peso seco (p.s.), presentando en su composición distintos aminoácidos esenciales y otros considerados potenciadores del sabor (ácido aspártico y glutámico). Los contenidos en lípidos fueron muy bajos en todas las algas. El contenido en cenizas fue alto (variando entre un 24 y un 34 % (p.s.)), lo que indica la riqueza en minerales de las algas. En general, las 4 algas presentaron valores altos de Na, K, Ca y Mg. Dado que el K aporta sabor salado y que las algas presentan aminoácidos potenciadores del sabor, el empleo de algas podría evitar o disminuir la adición de sal a los productos de la pesca. El contenido en fibra fue muy alto en las 4 muestras, destacando kombu con un valor cercano al 45% (p.s.).   Las 4 algas presentaron contenidos altos de compuestos fenólicos totales, destacando espagueti de mar. De igual forma, la capacidad antioxidante en esta especie de alga fue significativamente mayor que en el resto. Las 4 algas presentaron propiedades importantes de retención de aceite y de agua, destacando el alga wakame, que también presentó la mayor capacidad de hinchamiento. Estos resultados demuestran que la incorporación de las algas en los productos de la pesca implicaría un valor añadido en el pescado, ya que no se vería reducido el contenido proteico, aportando minerales y fibra. Asimismo, la incorporación de estas algas permitiría evitar el uso de aditivos químicos, ya que éstas son una fuente natural de antioxidantes. Además, sus propiedades tecnológicas hacen que las algas puedan sustituir a algunos aditivos químicos empleados para mejorar la textura y jugosidad.[EN] Seaweeds had been used since ancient times in Asian countries like Japan. Nowadays, consumption is rising in Europe. The reason is due to consumers are interested in food with high nutritional value and without chemical additives. In this sense, it is interesting the use of seaweed, which provides essential nutrients, to develop new food products; moreover, some of them have certain characteristics that allow replacing some additives in the products formulated. Given the origin marine of seaweeds is very interesting to add in fishing products. The overall objective of this study was to characterize nori, kombu, wakame, and sea spaghetti, in order to assess their use as an ingredient in food products in order to increase the nutritional quality and improve physico‐chemical properties. Nutritional composition of dehydrated powder seaweed was determined. Morevoer, total phenolic compounds content and antioxidant capacity were assessed and water retention capacity, oil retention capacity and swelling capacity were determined. The seaweeds exhibited  high protein content, especially nori and wakame, with over 20% dry weight (dw) levels, containing different essential amino acids and other considered as flavor enhancers (aspartic and glutamic acid). The lipid levels were very low in all seaweeds. The ash content was high (varying between 24 and 34% (dw)), indicating the mineral wealth of seaweeds. In general, 4 seaweeds showed high Na, K, Ca and Mg levels. Due to K contributes salty taste and seaweeds amino acids act as flavor enhancers, the use of seaweeds could avoid or reduce the addition of salt to fish products. The fiber content was very high in the 4 samples, highlighting kombu with a value close to 45% (dw). The 4 seaweeds showed high levels of total phenolic compounds, mainly spaghetti sea. Similarly, the antioxidant capacity in this species of seaweed was significantly higher than the rest. The four seaweed showed significant oil and water retention properties, specially wakame seaweed, which exhibited the highest swelling capacity. These results demonstrate that the incorporation of seaweeds in fish products would imply an added value in fish since their protein content would not be reduced, providing minerals and fiber. Additionally, the incorporation of these seaweeds could avoid the use of chemical additives, as they could be a natural source of antioxidants. In addition, their technological properties would imply that seaweeds could replace some the chemical additives used to improve food texture and juiciness.Palasí Mascarós, JT. (2015). Caracterización físico-química y nutricional de algas en polvo empleadas como ingrediente alimentario. http://hdl.handle.net/10251/55641.TFG

Estudio exploratorio de la asociación de palabras evocada por la visualización de productos de Alta Pastelería en diferentes poblaciones

[ES] La repostería, y dentro de ella la "Alta Pastelería", se ha ido transformando a lo largo del último medio siglo, conforme aparecían nuevos ingredientes, técnicas, o tecnologías, siempre de la mano de los cambios en los gustos y preferencias de los consumidores. Aunque evidentemente, en la valoración sensorial de los productos el sabor y la textura juegan un papel insustituible, no podemos despreciar el efecto de la valoración visual sobretodo en la intención de compra. En la valoración visual no solo se incluyen aspectos físicos como el color, tamaño del producto, sino también aquellos valores intangibles que la visión del mismo evoca sobre el consumidor. En este trabajo se pretende registrar y analizar, mediante la metodología de asociación de palabras, las emociones sensaciones, impresiones, que evoca la visualización de cinco tipos de pasteles en personas de diferentes culturas gastronómicas.[EN] Confectionery, which encompasses "Haute Pastry", has been in constant transformation over the last half century due to the appearance of new ingredients, techniques, and technologies, taking into account changes in consumption trends according to consumer tastes and preferences. This is how food innovation emerges. "Innovation is something different that has an impact" (Anthony, 2012). To carry out this process, it is necessary to know the sensory evaluation of products, especially the visual assessment, which it is directly related to purchase intention. The visual assessment goes beyond the physical aspects, focusing on intangible values that the consumer evokes about a product through his eyes. This study aims to record and analyze, through a qualitative descriptive analysis known as Word Association, the emotions, sensations and/or impressions, which evoke the visualisation of five cakes in people from three different gastronomic cultures. With statistical tests, we seek to find out if there is a direct relationship between the socio-demographic characteristics and terms evoked, reaching a total of 12,300. The classification of these terms in categories and dimensions, previously established, will help the subsequent interpretation of the results. Aspects related to the sensory, hedonic and nutritional properties, as well as the emotions generated by the stimuli will help to know the differences and similarities between the participants.Palasí Mascarós, JT. (2021). Estudio exploratorio de la asociación de palabras evocada por la visualización de productos de Alta Pastelería en diferentes poblaciones. Universitat Politècnica de València. http://hdl.handle.net/10251/163791TFG

Shaping leg muscles in Drosophila: role of ladybird, a conserved regulator of appendicular myogenesis

Legs are locomotor appendages used by a variety of evolutionarily distant vertebrates and invertebrates. The primary biological leg function, locomotion, requires the formation of a specialised appendicular musculature. Here we report evidence that ladybird, an orthologue of the Lbx1 gene recognised as a hallmark of appendicular myogenesis in vertebrates, is expressed in leg myoblasts, and regulates the shape, ultrastructure and functional properties of leg muscles in Drosophila. ladybird expression is progressively activated in myoblasts associated with the imaginal leg disc and precedes that of the founder cell marker dumbfounded. The RNAi-mediated attenuation of ladybird expression alters properties of developing myotubes, impairing their ability to grow and interact with the internal tendons and epithelial attachment sites. It also affects sarcomeric ultrastructure, resulting in reduced leg muscle performance and impaired mobility in surviving flies. The over-expression of ladybird also results in an abnormal pattern of dorsally located leg muscles, indicating different requirements for ladybird in dorsal versus ventral muscles. This differential effect is consistent with the higher level of Ladybird in ventrally located myoblasts and with positive ladybird regulation by extrinsic Wingless signalling from the ventral epithelium. In addition, ladybird expression correlates with that of FGF receptor Heartless and the read-out of FGF signalling downstream of FGF. FGF signals regulate the number of leg disc associated myoblasts and are able to accelerate myogenic differentiation by activating ladybird, leading to ectopic muscle fibre formation. A key role for ladybird in leg myogenesis is further supported by its capacity to repress vestigial and to down-regulate the vestigial-governed flight muscle developmental programme. Thus in Drosophila like in vertebrates, appendicular muscles develop from a specialised pool of myoblasts expressing ladybird/Lbx1. The ladybird/Lbx1 gene family appears as a part of an ancient genetic circuitry determining leg-specific properties of myoblasts and making an appendage adapted for locomotion

The ladybird homeobox genes are essential for the specification of a subpopulation of neural cells

AbstractIn Drosophila, neurons and glial cells are produced by neural precursor cells called neuroblasts (NBs), which can be individually identified. Each NB generates a characteristic cell lineage specified by a precise spatiotemporal control of gene expression within the NB and its progeny. Here we show that the homeobox genes ladybird early and ladybird late are expressed in subsets of cells deriving from neuroblasts NB 5-3 and NB 5-6 and are essential for their correct development. Our analysis revealed that ladybird in Drosophila, like their vertebrate orthologous Lbx1 genes, play an important role in cell fate specification processes. Among those cells that express ladybird are NB 5-6-derived glial cells. In ladybird loss-of-function mutants, the NB 5-6-derived exit glial cells are absent while overexpression of these genes leads to supernumerary glial cells of this type. Furthermore, aberrant glial cell positioning and aberrant spacing of axonal fascicles in the nerve roots observed in embryos with altered ladybird function suggest that the ladybird genes might also control directed cell movements and cell–cell interactions within the developing Drosophila ventral nerve cord

ETUDE DE LA FONCTION DES GENES A HOMEOBOITE, LADYBIRD, DANS LA MYOGENESE CHEZ DROSOPHILA MELANOGASTER (DOCTORAT)

CLERMONT FD-BCIU-Santé (631132104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Developmental Expression and Functions of the Small Heat Shock Proteins in Drosophila

Heat shock proteins (Hsps) form a large family of evolutionarily conserved molecular chaperones that help balance protein folding and protect cells from various stress conditions. However, there is growing evidence that Hsps may also play an active role in developmental processes. Here, we take the example of developmental expression and function of one class of Hsps characterized by low molecular weight, the small Hsps (sHsps). We discuss recent reports and genome-wide datasets that support vital sHsps functions in the developing nervous system, reproductive system, and muscles. This tissue- and time-specific sHsp expression is developmentally regulated, so that the enhancer sequence of an sHsp gene expressed in developing muscle, in addition to stress-inducible elements, also carries binding sites for myogenic regulatory factors. One possible reason for sHsp genes to switch on during development and in non-stress conditions is to protect vital developing organs from environmental insults

Diversification of muscle types in Drosophila: upstream and downstream of identity genes.

International audienceUnderstanding gene regulatory pathways underlying diversification of cell types during development is one of the major challenges in developmental biology. Progressive specification of mesodermal lineages that are at the origin of body wall muscles in Drosophila embryos has been extensively studied during past years, providing an attractive framework for dissecting cell type diversification processes. In particular, it has been found that muscle founder cells that are at the origin of individual muscles display specific expression of transcription factors that control diversification of muscle types. These factors, encoded by genes collectively called muscle identity genes, are activated in discrete subsets of muscle founders. As a result, each founder cell is thought to carry a unique combinatorial code of identity gene expression. Considering this, to define temporally and spatially restricted expression of identity genes, a set of coordinated upstream regulatory inputs is required. But also, to realize the identity program and to form specific muscle types with distinct properties, an efficient battery of downstream identity gene targets needs to be activated. Here we review how the specificity of expression and action of muscle identity genes is acquired

Developmental Expression and Functions of the Small Heat Shock Proteins in <i>Drosophila</i>

Heat shock proteins (Hsps) form a large family of evolutionarily conserved molecular chaperones that help balance protein folding and protect cells from various stress conditions. However, there is growing evidence that Hsps may also play an active role in developmental processes. Here, we take the example of developmental expression and function of one class of Hsps characterized by low molecular weight, the small Hsps (sHsps). We discuss recent reports and genome-wide datasets that support vital sHsps functions in the developing nervous system, reproductive system, and muscles. This tissue- and time-specific sHsp expression is developmentally regulated, so that the enhancer sequence of an sHsp gene expressed in developing muscle, in addition to stress-inducible elements, also carries binding sites for myogenic regulatory factors. One possible reason for sHsp genes to switch on during development and in non-stress conditions is to protect vital developing organs from environmental insults