Hormones and Sex-Specific Transcription Factors Jointly Control Yolk Protein Synthesis in Musca domestica

In the housefly Musca domestica, synthesis of yolk proteins (YPs) depends on the level of circulating ecdysteroid hormones. In female houseflies, the ecdysterone concentration in the hemolymph oscillates and, at high levels, is followed by expression of YP. In male houseflies, the ecdysterone titre is constantly low and no YP is produced. In some strains, which are mutant in key components of the sex-determining pathway, males express YP even though their ecdysterone titre is not significantly elevated. However, we find that these males express a substantial amount of the female variant of the Musca doublesex homologue, Md-dsx. The dsx gene is known to sex-specifically control transcription of yp genes in the fat body of Drosophila melanogaster. Our data suggest that Md-dsx also contributes to the regulation of YP expression in the housefly by modulating the responsiveness of YP-producing cells to hormonal stimuli

The transformer2 gene in Musca domestica is required for selecting and maintaining the female pathway of development

We present the isolation and functional analysis of a transformer2 homologue Mdtra2 in the housefly Musca domestica. Compromising the activity of this gene by injecting dsRNA into embryos causes complete sex reversal of genotypically female individuals into fertile males, revealing an essential function of Mdtra2 in female development of the housefly. Mdtra2 is required for female-specific splicing of Musca doublesex (Mddsx) which structurally and functionally corresponds to Drosophila dsx, the bottom-most regulator in the sex-determining pathway. Since Mdtra2 is expressed in males and females, we propose that Mdtra2 serves as an essential co-factor of F, the key sex-determining switch upstream of Mddsx. We also provide evidence that Mdtra2 acts upstream as a positive regulator of F supporting genetic data which suggest that F relies on an autocatalytic activity to select and maintain the female path of development. We further show that repression of male courtship behavior by F requires Mdtra2. This function of F and Mdtra2 appears not to be mediated by Mddsx, suggesting that bifurcation of the pathway at this level is a conserved feature in the genetic architecture of Musca and Drosophil

Sex determination in Drosophila melanogaster and Musca domestica converges at the level of the terminal regulator doublesex

Sex-determining cascades are supposed to have evolved in a retrograde manner from bottom to top. Wilkins' 1995 hypothesis finds support from our comparative studies in Drosophila melanogaster and Musca domestica, two dipteran species that separated some 120million years ago. The sex-determining cascades in these flies differ at the level of the primary sex-determining signal and their targets, Sxl in Drosophila and F in Musca. Here we present evidence that they converge at the level of the terminal regulator, doublesex (dsx), which conveys the selected sexual fate to the differentiation genes. The dsx homologue in Musca, Md-dsx, encodes male-specific (MdDSXM) and female-specific (MdDSXF) protein variants which correspond in structure to those in Drosophila. Sex-specific regulation of Md-dsx is controlled by the switch gene F via a splicing mechanism that is similar but in some relevant aspects different from that in Drosophila. MdDSXF expression can activate the vitellogenin genes in Drosophila and Musca males, and MdDSXM expression in Drosophila females can cause male-like pigmentation of posterior tergites, suggesting that these Musca dsx variants are conserved not only in structure but also in function. Furthermore, downregulation of Md-dsx activity in Musca by injecting dsRNA into embryos leads to intersexual differentiation of the gonads. These results strongly support a role of Md-dsx as the final regulatory gene in the sex-determining hierarchy of the housefl

Retrospective Analysis of Emotional Burden and the Need for Support of Patients and Their Informal Caregivers after Palliative Radiation Treatment for Brain Metastases

Cancer burdens not only the patients themselves but also their personal environment. A few studies have already focused on the mental health and personal needs of caregivers of patients. The purpose of this retrospective analysis was to further assess the emotional burden and unmet needs for support of caregivers in a population of brain metastasis patients. In the time period 2013-2020, we identified 42 informal caregivers of their respective patients after palliative radiation treatment for brain metastases. The caregivers completed two standardized questionnaires about different treatment aspects, their emotional burden, and unmet needs for support. Involvement of psycho-oncology and palliative care was examined in a chart review. The majority of the caregivers (71.4%, n = 30) suffered from high emotional burden during cancer treatment of their relatives and showed unmet needs for emotional and psychosocial support, mostly referring to information needs and the involvement in the patient's treatment decisions. Other unmet needs referred to handling personal needs and fears of dealing with the sick cancer patient in terms of practical care tasks and appropriate communication. Palliative care was involved in 30 cases and psycho-oncology in 12 cases. There is a high need for emotional and psychosocial support in informal caregivers of cancer patients. There might still be room for an improvement of psychosocial and psycho-oncological support. Care planning should cater to the emotional burden and unmet needs of informal caregivers as well. Further prospective studies in larger samples should be performed in order to confirm this analysis

Ice loss from the East Antarctic Ice Sheet during late Pleistocene interglacials

Understanding ice sheet behaviour in the geological past is essential for evaluating the role of the cryosphere in the climate system and for projecting rates and magnitudes of sea level rise in future warming scenarios1,2,3,4. Although both geological data5,6,7 and ice sheet models3,8 indicate that marine-based sectors of the East Antarctic Ice Sheet were unstable during Pliocene warm intervals, the ice sheet dynamics during late Pleistocene interglacial intervals are highly uncertain3,9,10. Here we provide evidence from marine sedimentological and geochemical records for ice margin retreat or thinning in the vicinity of the Wilkes Subglacial Basin of East Antarctica during warm late Pleistocene interglacial intervals. The most extreme changes in sediment provenance, recording changes in the locus of glacial erosion, occurred during marine isotope stages 5, 9, and 11, when Antarctic air temperatures11 were at least two degrees Celsius warmer than pre-industrial temperatures for 2,500 years or more. Hence, our study indicates a close link between extended Antarctic warmth and ice loss from the Wilkes Subglacial Basin, providing ice-proximal data to support a contribution to sea level from a reduced East Antarctic Ice Sheet during warm interglacial intervals. While the behaviour of other regions of the East Antarctic Ice Sheet remains to be assessed, it appears that modest future warming may be sufficient to cause ice loss from the Wilkes Subglacial Basin

Retinoic Acid Functions as a Key GABAergic Differentiation Signal in the Basal Ganglia

Retinoic acid (RA) is essential for the generation of GABAergic inhibitory neurons in the mouse forebrain, and RA treatment of embryonic stem cells induces the production of GABAergic neurons

Steroid hormones and transcription factors in yolk protein synthesis of Musca domestica

Die Dotterproteinsynthese im Fettkörper von Drosophila melanogaster wird durch geschlechtsspezifische Protein-Isoformen des Gens doublesex (dsx) gesteuert. In Weibchen bindet die weibliche Form des Proteins, DSXF, an den Enhancer der Dotterproteingene und verstärkt die basale Trankriptionsrate. In Männchen wird die Transkription durch DSXM vollständig unterdrückt. In der Stubenfliege Musca domestica dagegen scheinen Unterschiede in der Konzentration der Ecdysteroid- Hormone für die Regulierung der Dotterproteinsynthese verantwortlich zu sein. Es gibt allerdings Hinweise, dass weitere Faktoren zur Steuerung der Dotterproteinsynthese in Musca beitragen. In meiner Dissertation habe ich untersucht, ob Transkriptionsfaktoren - neben Hormonen - in Musca an der Steuerung der Dotterproteinsynthese beteiligt sind. Für diese Untersuchung verwendete ich zwei Musca-Stämme, in denen Männchen kleine Mengen von Dotterproteinen produzieren. Die Tatsache, dass diese Männchen keine erhöhte Edysteroidkonzentration aufweisen, unterstützt die Hypothese, dass weitere Faktoren die Synthese von Dotterproteinen in Musca beeinflussen. Tatsächlich fanden wir in Musca ein Homolog von dsx, Md-dsx. Md-dsx wird, wie dsx in Drosophila, geschlechtsspezifisch gespleisst, und es entstehen zwei verschiedene Proteine, das weiblich-spezifische Md- DSXFsowie das männlich-spezifische Md- DSXM. In Standardmännchen ist nur Md- dsxM, das männliche Transkript von Md-dsx, nachweisbar. In Männchen, die Dotterproteine produzieren, findet man dagegen auch Md- dsxF. Hinzu kommt, dass durch ektopische Expression von Md- DSXFin Standardmännchen die Synthese von Dotterproteinen induziert werden kann. Aufgrund dieser Resultate vermuteten wir, dass die Dotterproteinsynthese in Musca durch ein Zusammenspiel von Ecdysteroiden und DSX-Proteinen gesteuert wird. Wir haben folgendes Modell entwickelt: Im Fettkörper von Weibchen erhöht die Anwesenheit von Md- DSXFdie Kompetenz der Dotterproteingene, auf Ecdysteroide mit verstärkter Transkription zu reagieren. In Männchen dagegen verringert Md- DSXMdie Empfindlichkeit der Dotterproteingene und setzt die Schwelle für eine Aktivierung durch Ecdysteroide massiv hinauf. Hormone erfüllen zwei verschiedene Aufgaben in der Steuerung der Dotterproteinsynthese. Sie sind erstens verantwortlich dafür, dass die Dotterproteinsythese synchron mit der Oogenese verläuft. Zweitens ermöglichen Hormone die Anpassung der Dotterproteinproduktion an äussere Einflüsse, wie zum Beispiel an das Nahrungsangebot oder an das Vorhandensein von geeigneten Eiablageplätzen. Es ist möglich, dass dieser Mechanismus - zellautonome Faktoren für die geschlechts- und gewebespezifische Expression, Hormone für die Anpassung an Umwelteinflüsse - auch für die Steuerung der Dotterproteinsynthese in anderen Insektenarten verwendet wird. Allerdings dürfte der Beitrag dieser beiden Systeme unterschiedlich sein, und zwar abhängig davon, wie die Entwicklung der Oocyten verläuft. Ist die Oogenese zyklisch, wie etwa in Musca, spielen Hormone eine viel wichtigere Rolle als in Drosophila, wo die Ei-Entwicklung kontinuierlich erfolgt, weil in Spezies mit zyklischer Oogenese die Produktion der Dotterproteine mit der Entwicklung der Eier synchronisiert werden muss. Synthesis of yolk proteins (YP) is regulated by sex-specific proteins encoded by the gene doublesex (dsx) in the Drosophila fat body. In females, the basal transcription rate is enhanced by the binding of the female-specific protein DSXF to the enhancer of the yp genes, whereas in males, YP expression is completely repressed by the male- specific protein DSXM. Synthesis of yolk proteins in Musca domestica, on the other hand, appears to be regulated by sex-specific differences in the concentration of ecdysteroids. However, there are some indications that there must be additional factors involved in the regulation of YP expression in Musca. The objective of my thesis work was to investigate whether sex-specific transcription factors also contribute to the regulation of YP synthesis in Musca domestica. I analyzed two Musca strains in which males produce small amounts of YP, and found that these males do not have elevated ecdysteroid levels. This fact further supports the notion that additional factors take part in the regulation of YP synthesis in Musca. We were able to identify a dsx homologue, Md-dsx, which is sex-specifically spliced and gives rise to two different proteins, the female form Md- DSXF and the male form Md- DSXM. In standard males, only the male isoform of Md-dsx is expressed. However, in the YP expressing males, substantial levels of Md- dsxMtranscripts can be detected. Also, expression of Md- DSXF in standard males carrying an inducible transgene can promote the production of YP. This suggested to us that YP synthesis in Musca is controlled by a concerted action of Md-DSX proteins and ecdysteroids. We propose that presence of Md- DSXF in female fat body cells increases the competence of the YP genes to respond to activation by ecdysteroids, while in males, the threshold for activation is markedly increased by the presence of Md- DSXM. Hormones, on the other hand, serve different purposes. First, they synchronize YP synthesis with onset of vitellogenesis in oocyte development. Second, hormones adjust YP synthesis to environmental conditions such as availability of food resources and egg-laying substrate. The use of autonomous competence factors for sex- and tissue-specificity, combined with the use of non-autonomous factors that respond to extrinsic conditions, may be a common mechanism for the control of YP synthesis in insects. However, the contribution of these two systems may vary, depending on the mode of ovarian development. In Musca, hormones appear to play a more distinct role than in Drosophila, because oogenesis in Musca is not a continuous process but rather occurs in cycles, and YP synthesis thus needs to be coordinated with oocyte development

Retrospective Analysis of Emotional Burden and the Need for Support of Patients and Their Informal Caregivers after Palliative Radiation Treatment for Brain Metastases

Cancer burdens not only the patients themselves but also their personal environment. A few studies have already focused on the mental health and personal needs of caregivers of patients. The purpose of this retrospective analysis was to further assess the emotional burden and unmet needs for support of caregivers in a population of brain metastasis patients. In the time period 2013–2020, we identified 42 informal caregivers of their respective patients after palliative radiation treatment for brain metastases. The caregivers completed two standardized questionnaires about different treatment aspects, their emotional burden, and unmet needs for support. Involvement of psycho-oncology and palliative care was examined in a chart review. The majority of the caregivers (71.4%, n = 30) suffered from high emotional burden during cancer treatment of their relatives and showed unmet needs for emotional and psychosocial support, mostly referring to information needs and the involvement in the patient’s treatment decisions. Other unmet needs referred to handling personal needs and fears of dealing with the sick cancer patient in terms of practical care tasks and appropriate communication. Palliative care was involved in 30 cases and psycho-oncology in 12 cases. There is a high need for emotional and psychosocial support in informal caregivers of cancer patients. There might still be room for an improvement of psychosocial and psycho-oncological support. Care planning should cater to the emotional burden and unmet needs of informal caregivers as well. Further prospective studies in larger samples should be performed in order to confirm this analysis

LSR/angulin-1 is a tricellular tight junction protein involved in blood–brain barrier formation

The blood–brain barrier (BBB) is a term used to describe the unique properties of central nervous system (CNS) blood vessels. One important BBB property is the formation of a paracellular barrier made by tight junctions (TJs) between CNS endothelial cells (ECs). Here, we show that Lipolysis-stimulated lipoprotein receptor (LSR), a component of paracellular junctions at points in which three cell membranes meet, is greatly enriched in CNS ECs compared with ECs in other nonneural tissues. We demonstrate that LSR is specifically expressed at tricellular junctions and that its expression correlates with the onset of BBB formation during embryogenesis. We further demonstrate that the BBB does not seal during embryogenesis in Lsr knockout mice with a leakage to small molecules. Finally, in mouse models in which BBB was disrupted, including an experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis and a middle cerebral artery occlusion (MCAO) model of stroke, LSR was down-regulated, linking loss of LSR and pathological BBB leakage