scholarly journals Convergent evolution of sex-specific leg ornaments in Drosophilidae – from cells to structures

2019 ◽  
Author(s):  
K. Tanaka ◽  
O. Barmina ◽  
J. H. Massey ◽  
A. Kopp
Keyword(s):  
Convergent Evolution ◽  
Phylogenetic Reconstruction ◽  
Sexually Dimorphic ◽  
Developmental Constraint ◽  
Cellular Mechanisms ◽  
Cellular Processes ◽  
The Face ◽  
Male Specific ◽  
Novel Structures ◽  
Female Abdomen

AbstractSexually dimorphic morphological traits are among the fastest evolving animal features. Similar sex-specific structures have sometimes evolved independently in multiple lineages, presumably as targets of parallel sexual selection. In such cases, comparing the cellular mechanisms that generate these structures in different species can elucidate the interplay between selection and developmental constraint in evolution. In Drosophilidae, male-specific tarsal brushes on the front legs are found in at least four separate lineages. In this study, we combine phylogenetic reconstruction with developmental analyses and behavioral observations to investigate the evolutionary origin of these structures. We show that the sex brush has evolved independently at least three times from sexually monomorphic ancestral morphology. However, all sex brushes have very similar fine structure and develop through indistinguishable cellular processes, providing a striking example of developmental convergence. In all examined species, males use their sex brushes to grasp the female abdomen prior to copulation. We discuss potential reasons why convergent evolution of novel structures is rare even in the face of similar functional demands.

scholarly journals Maternal Uterine Vascular Remodeling During Pregnancy

Physiology ◽  
2009 ◽  
Vol 24 (1) ◽  
pp. 58-71 ◽  
Author(s):  
George Osol ◽  
Maurizio Mandala
Keyword(s):  
Extracellular Matrix ◽  
Blood Flow ◽  
Vascular Remodeling ◽  
Normal Pregnancy ◽  
Uterine Blood Flow ◽  
Growth And Remodeling ◽  
Cellular Mechanisms ◽  
Cellular Processes ◽  
Uteroplacental Blood Flow ◽  
Uterine Circulation

Sufficient uteroplacental blood flow is essential for normal pregnancy outcome and is accomplished by the coordinated growth and remodeling of the entire uterine circulation, as well as the creation of a new fetal vascular organ: the placenta. The process of remodeling involves a number of cellular processes, including hyperplasia and hypertrophy, rearrangement of existing elements, and changes in extracellular matrix. In this review, we provide information on uterine blood flow increases during pregnancy, the influence of placentation type on the distribution of uterine vascular resistance, consideration of the patterns, nature, and extent of maternal uterine vascular remodeling during pregnancy, and what is known about the underlying cellular mechanisms.

scholarly journals Proteotoxicity from aberrant ribosome biogenesis compromises cell fitness

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Blake W Tye ◽  
Nicoletta Commins ◽  
Lillia V Ryazanova ◽  
Martin Wühr ◽  
Michael Springer ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Ribosome Assembly ◽  
Maximal Growth ◽  
Proliferating Cells ◽  
Cellular Processes ◽  
Direct Contribution ◽  
The Face ◽  
Cellular Phenotypes

To achieve maximal growth, cells must manage a massive economy of ribosomal proteins (r-proteins) and RNAs (rRNAs) to produce thousands of ribosomes every minute. Although ribosomes are essential in all cells, natural disruptions to ribosome biogenesis lead to heterogeneous phenotypes. Here, we model these perturbations in Saccharomyces cerevisiae and show that challenges to ribosome biogenesis result in acute loss of proteostasis. Imbalances in the synthesis of r-proteins and rRNAs lead to the rapid aggregation of newly synthesized orphan r-proteins and compromise essential cellular processes, which cells alleviate by activating proteostasis genes. Exogenously bolstering the proteostasis network increases cellular fitness in the face of challenges to ribosome assembly, demonstrating the direct contribution of orphan r-proteins to cellular phenotypes. We propose that ribosome assembly is a key vulnerability of proteostasis maintenance in proliferating cells that may be compromised by diverse genetic, environmental, and xenobiotic perturbations that generate orphan r-proteins.

Abstract 497: Cholesterol and Toll-like Receptor Signaling Are Important Regulators of Macrophage Interactions with Atherosclerotic Lipoprotein Aggregates

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Harvey F Chin ◽  
Abigail Haka ◽  
Frederick R Maxfield
Keyword(s):  
Molecular Mechanisms ◽  
Atherosclerotic Plaques ◽  
Cholesteryl Esters ◽  
Cellular Mechanisms ◽  
Downstream Signaling ◽  
Cellular Processes ◽  
Atherosclerotic Plaque Formation ◽  
Subendothelial Space ◽  
Morphological Responses ◽  
Cytoskeletal Rearrangements

Macrophages encounter deposits of aggregated low-density lipoproteins (agLDL) in the subendothelial space of blood vessels during the first stages of atherosclerotic plaque formation. Notably, current models for the mechanism of macrophage internalization of cholesterol in early atherosclerotic plaques are incomplete due to the lack of attention paid to the unique cellular mechanisms that are required for macrophages to degrade aggregates of LDL in particular, which can comprise >90% of the LDL in atherosclerotic plaques. In fact, internalization of cholesterol from cholesteryl esters in agLDL involves the development of intriguing cellular processes in which extracellular acidic compartments, lysosomal synapses (LSs), are formed whereby agLDL is partially degraded prior to internalization. This process requires extensive cytoskeletal rearrangements and secretion of lysosomal enzymes responsible for hydrolysis of cholesteryl esters from the agLDL. Subsequent delivery of free cholesterol from agLDL to the macrophage plasma membrane is central for development of the LS. Nonetheless, the molecular mechanism underlying initiation and propagation of the LS are currently largely unknown. This research proposal aims to elucidate the molecular mechanisms of LS formation and the role that cholesterol plays in eliciting these morphological responses to agLDL. Fluorescence microscopy assays were used to identify activation of TLR4 and downstream signaling involving PI3K and Akt as important events leading to LS formation. Furthermore, morphological responses of macrophages to cholesterol overloading require overlapping signaling pathways, indicating the role of interplay of cholesterol and TLR4 signaling in development of this novel macrophage interaction with aggregated LDL found in plaques. Identification of specific molecular pathways involved in this process will not only contribute to the basic understanding of one of the primary cellular processes contributing to atherosclerosis, one of the primary causes of heart disease, but also provide tangible molecular targets for the ultimate development of therapies.

Corrigendum to: Convergent evolution of sexually dimorphic glands in an amphi-Pacific harvestman family

2020 ◽  
Vol 34 (8) ◽  
pp. 906
Author(s):  
Guilherme Gainett ◽  
Rodrigo H. Willemart ◽  
Gonzalo Giribet ◽  
Prashant P. Sharma
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
New Species ◽  
Convergent Evolution ◽  
Evolutionary Dynamics ◽  
Sexually Dimorphic ◽  
Ecological Significance ◽  
Character Mapping ◽  
Recent Attention ◽  
Scanning Electron

Sexually dimorphic traits are widespread in animals, and include sex-specific weapons, ornamentation and, although less noticed, glands and associated structures. In arachnids, certain lineages of the order Opiliones exhibit diverse forms of dimorphism in the armature and length of appendages (common in Laniatores), as well as in the presence of sexually dimorphic glands (mostly investigated in Cyphophthalmi), positing harvestmen as promising models to study sexual dimorphism. Whereas the evolution and ecological significance of armature have been the focus of recent attention, sexually dimorphic glands remain understudied in groups other than Cyphophthalmi, despite being widespread in Opiliones. We therefore selected the amphi-Pacific family Zalmoxidae as an ideal taxon to investigate the evolutionary dynamics of this trait. We first describe four new species of Palaeotropical Zalmoxis, including a species with sexually dimorphic glands, and describe the morphology of zalmoxid species with sexually dimorphic glands using scanning electron microscopy. Using a previously assembled six-locus dataset supplemented with new terminals, and applying stochastic character mapping, we infer that sexually dimorphic glands evolved once in the Neotropics and at least four times in the Palaeotropic zalmoxids, revealing the evolutionary lability of this trait.

scholarly journals Molecular and Clinical Insights into the Invasive Capacity of Glioblastoma Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Carlos Velásquez ◽  
Sheila Mansouri ◽  
Carla Mora ◽  
Farshad Nassiri ◽  
Suganth Suppiah ◽  
...  
Keyword(s):  
Treatment Resistance ◽  
Host Cells ◽  
Cellular Mechanisms ◽  
Poor Overall Survival ◽  
Cellular Processes ◽  
New Therapeutic Approaches ◽  
Invasive Capacity ◽  
Molecular Machinery ◽  
The Impact ◽  
Infiltrative Tumor

The invasive capacity of GBM is one of the key tumoral features associated with treatment resistance, recurrence, and poor overall survival. The molecular machinery underlying GBM invasiveness comprises an intricate network of signaling pathways and interactions with the extracellular matrix and host cells. Among them, PI3k/Akt, Wnt, Hedgehog, and NFkB play a crucial role in the cellular processes related to invasion. A better understanding of these pathways could potentially help in developing new therapeutic approaches with better outcomes. Nevertheless, despite significant advances made over the last decade on these molecular and cellular mechanisms, they have not been translated into the clinical practice. Moreover, targeting the infiltrative tumor and its significance regarding outcome is still a major clinical challenge. For instance, the pre- and intraoperative methods used to identify the infiltrative tumor are limited when trying to accurately define the tumor boundaries and the burden of tumor cells in the infiltrated parenchyma. Besides, the impact of treating the infiltrative tumor remains unclear. Here we aim to highlight the molecular and clinical hallmarks of invasion in GBM.

New Oriental Trogini (Hymenoptera: Ichneumonidae)

1960 ◽  
Vol 92 (2) ◽  
pp. 107-109 ◽  
Author(s):  
Gerd H. Heinrich
Keyword(s):  
The Face ◽  
Female Abdomen

Type.-Neofacydes sinensis n.sp.Flagellum.—Female flagellum moderately long, lanceolate, widened beyond the middle and strongly attenuated at the apex; basal segments of the male flagellum cylindric, at the apes however obliquely cut and overlapping, becoming gradually more distinct nodose bevond the seventh segment.Head.—Occiput hardly emarginate, sloping down steeply behind the ocelli and eyes; cheek profile strongly narrowed with straight outline; median field of the face well defined; clypeus normal with straight apical border; frons concave; mandibles normal with small teeth.Thorax.—Mesoscutum moderately convex, a little longer than wide; scutellum pyramidal; propodeum as in Trogus Panzer, the area posteromedia wide, parallel-sided, the upper border arched; areae posteroexternae with strong lateral carinae.Legs.—Relatively long and slender.Abdomen.—Female abdomen oxypygous, similar in appearance to a Coelichneumon abdomen; surface of tergites 1-5 strongly aciculated, tergites 1-5 strongly separated, sometimes with sharp lateral edges, but not bulging laterally; postpetiolus with aciculate median field; gastrocoeli deep, transverse.

scholarly journals Nixalone is sufficient to convert femaleAedes aegyptiinto fertile males andmyo-sexis needed for male flight

2020 ◽  
Vol 117 (30) ◽  
pp. 17702-17709 ◽  
Author(s):  
Azadeh Aryan ◽  
Michelle A. E. Anderson ◽  
James K. Biedler ◽  
Yumin Qi ◽  
Justin M. Overcash ◽  
...  
Keyword(s):  
Mosquito Control ◽  
Control Strategies ◽  
Reproductive Organs ◽  
Dominant Male ◽  
Chain Gene ◽  
Sexually Dimorphic ◽  
Wild Type ◽  
Transgenic Lines ◽  
Male Sex ◽  
Male Specific

A dominant male-determining locus (M-locus) establishes the male sex (M/m) in the yellow fever mosquito,Aedes aegypti.Nix, a gene in the M-locus, was shown to be a male-determining factor (M factor) as somatic knockout ofNixled to feminized males (M/m) while transient expression ofNixresulted in partially masculinized females (m/m), with male reproductive organs but retained female antennae. It was not clear whether any of the other 29 genes in the 1.3-Mb M-locus are also needed for complete sex-conversion. Here, we report the generation of multiple transgenic lines that expressNixunder the control of its own promoter. Genetic and molecular analyses of these lines provided insights unattainable from previous transient experiments. We show that theNixtransgene alone, in the absence of the M-locus, was sufficient to convert females into males with all male-specific sexually dimorphic features and male-like gene expression. The converted m/m males are flightless, unable to perform the nuptial flight required for mating. However, they were able to father sex-converted progeny when presented with cold-anesthetized wild-type females. We show thatmyo-sex, a myosin heavy-chain gene also in the M-locus, was required for male flight as knockout ofmyo-sexrendered wild-type males flightless. We also show thatNix-mediated female-to-male conversion was 100% penetrant and stable over many generations. Therefore,Nixhas great potential for developing mosquito control strategies to reduce vector populations by female-to-male sex conversion, or to aid in a sterile insect technique that requires releasing only non-biting males.

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