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Pigment evolution

Zachary B Rodriguez, Susan L Perkins, Christopher C Austin
Several species of lizards from the megadiverse island of New Guinea have evolved green blood. An unusually high concentration of the green bile pigment biliverdin in the circulatory system of these lizards makes the blood, muscles, bones, tongue, and mucosal tissues bright green in color, eclipsing the crimson color from their red blood cells. This is a remarkable physiological feature because bile pigments are toxic physiological waste products of red blood cell catabolism and, when chronically elevated, cause jaundice in humans and all other vertebrates...
May 2018: Science Advances
Maurizio Petrozziello, Fabrizio Torchio, Federico Piano, Simone Giacosa, Maurizio Ugliano, Antonella Bosso, Luca Rolle
Since the end of the last century, many works have been carried out to verify the effect of controlled oxygen intake on the chemical and organoleptic characteristics of red wines. In spite of the large number of studies on this subject, oxygen remains a cutting-edge research topic in oenology. Oxygen consumption leads to complex and not univocal changes in wine composition, sometimes positive such as color stabilization, softening of mouthfeel, increase of aroma complexity. However, the variability of these effects, which depend both on the oxygenation conditions and the composition of the wine, require more efforts in this research field to effectively manage wine oxygen exposure...
2018: Frontiers in Chemistry
Alexander Bean, Rasika Sunnadeniya, Neda Akhavan, Annabelle Campbell, Matthew Brown, Alan Lloyd
The key enzymatic step in betalain biosynthesis involves conversion of l-3,4-dihydroxyphenylalanine (l-DOPA) to betalamic acid. One class of enzymes capable of this is 3,4-dihydroxyphenylalanine 4,5-dioxygenase (DODA). In betalain-producing species, multiple paralogs of this gene are maintained. This study demonstrates which paralogs function in the betalain pathway and determines the residue changes required to evolve a betalain-nonfunctional DODA into a betalain-functional DODA. Functionalities of two pairs of DODAs were tested by expression in beets, Arabidopsis and yeast, and gene silencing was performed by virus-induced gene silencing...
May 13, 2018: New Phytologist
Jake Morris, Iulia Darolti, Natasha I Bloch, Alison E Wright, Judith E Mank
Sex chromosomes form once recombination is halted around the sex-determining locus between a homologous pair of chromosomes, resulting in a male-limited Y chromosome. We recently characterized the nascent sex chromosome system in the Trinidadian guppy ( Poecilia reticulata ). The guppy Y is one of the youngest animal sex chromosomes yet identified, and therefore offers a unique window into the early evolutionary forces shaping sex chromosome formation, particularly the rate of accumulation of repetitive elements and Y-specific sequence...
May 3, 2018: Genes
Verena A Kottler, Manfred Schartl
Teleost fish provide some of the most intriguing examples of sexually dimorphic coloration, which is often advantageous for only one of the sexes. Mapping studies demonstrated that the genetic loci underlying such color patterns are frequently in tight linkage to the sex-determining locus of a species, ensuring sex-specific expression of the corresponding trait. Several genes affecting color synthesis and pigment cell development have been previously described, but the color loci on the sex chromosomes have mostly remained elusive as yet...
May 3, 2018: Genes
Yazhi Gao, Wei Liu, Xiaoxiong Wang, Lihua Yang, Su Han, Shiguo Chen, Reto Jörg Strasser, Bernal E Valverde, Sheng Qiang
The effects of four phytotoxins usnic acid (UA), salicylic acid (SA), cinnamic acid (CA) and benzoic acid (BA) on photosynthesis of Chlamydomonas reinhardtii were studied in vivo to identify and localise their initial action sites on two photosystems. Our experimental evidence shows that the four phytotoxins have multiple targets in chloroplasts, which mainly lie in photosystem II (PSII), not photosystem I (PSI). They share an original action site by blocking electron transport beyond QA (primary plastoquinone acceptor) at PSII acceptor side since a fast increase of the J-step level is the greatest change in chlorophyll a fluorescence induction kinetics OJIP in C...
May 4, 2018: Plant Physiology and Biochemistry: PPB
Antoaneta V Popova, Konstantin Dobrev, Maya Velitchkova, Alexander G Ivanov
The high-light-induced alterations in photosynthetic performance of photosystem II (PSII) and photosystem I (PSI) as well as effectiveness of dissipation of excessive absorbed light during illumination for different periods of time at room (22 °C) and low (8-10 °C) temperature of leaves of Arabidopsis thaliana, wt and lut2, were followed with the aim of unraveling the role of lutein in the process of photoinhibition. Photosynthetic parameters of PSII and PSI were determined on whole leaves by PAM fluorometer and oxygen evolving activity-by a Clark-type electrode...
May 3, 2018: Photosynthesis Research
Helena Bilandžija, Lindsey Abraham, Li Ma, Kenneth J Renner, William R Jeffery
Multiple cave populations of the teleost Astyanax mexicanus have repeatedly reduced or lost eye and body pigmentation during adaptation to dark caves. Albinism, the complete absence of melanin pigmentation, is controlled by loss-of-function mutations in the oca2 gene. The mutation is accompanied by an increase in the melanin synthesis precursor l-tyrosine, which is also a precursor for catecholamine synthesis. In this study, we show a relationship between pigmentation loss, enhanced catecholamine synthesis and responsiveness to anaesthesia, determined as a proxy for catecholamine-related behaviours...
May 16, 2018: Proceedings. Biological Sciences
Masato Yoshizawa, Ernest Hixon, William R Jeffery
Evolutionary changes in Astyanax mexicanus cavefish with respect to conspecific surface fish, including the regression of eyes, loss of pigmentation, and modification of the cranial skeleton, involve derivatives of the neural crest. However, the role of neural crest cells in cavefish evolution and development is poorly understood. One of the reasons is that experimental methods for neural crest analysis are not well developed in the Astyanax system. Here we describe neural crest transplantation between Astyanax surface fish and cavefish embryos...
April 27, 2018: Integrative and Comparative Biology
Hailin Chen, Meijie Li, Changqing Liu, Haibo Zhang, Mo Xian, Huizhou Liu
BACKGROUND: Lycopene is a terpenoid pigment that has diverse applications in the food and medicine industries. A prospective approach for lycopene production is by metabolic engineering in microbial hosts, such as Escherichia coli. Isopentenyl diphosphate isomerase (IDI, E.C. is one of the rate-limiting enzymes in the lycopene biosynthetic pathway and one major target during metabolic engineering. The properties of IDIs differ depending on the sources, but under physiological conditions, IDIs are limited by low enzyme activity, short half-life and weak substrate affinity...
April 30, 2018: Microbial Cell Factories
Louis Dumas, Francesca Zito, Pascaline Auroy, Xenie Johnson, Gilles Peltier, Jean Alric
Site-directed mutagenesis of chloroplast genes was developed three decades ago and has greatly advanced the field of photosynthesis research. Here, we describe a new approach for generating random chloroplast gene mutants that combines error-prone PCR of a gene of interest with chloroplast complementation of the knock-out Chlamydomonas reinhardtii mutant. As a proof-of-concept, we targeted a 300-bp sequence of the petD gene, which encodes subunit IV of the thylakoid membrane-bound cytochrome b6f complex. By sequencing chloroplast transformants, we revealed 149 mutations in the 300-bp target petD sequence that resulted in 92 amino acid substitutions in the 100-residue target subunit IV sequence...
April 27, 2018: Plant Physiology
Jaime Martinez-Harms, Anne-Christin Warskulat, Bettina Dudek, Grit Kunert, Sybille Lorenz, Bill S Hansson, Bernd Schneider
Despite the increasing evidence for biosynthetic connections between flower pigments and volatiles, examples of such relationships in polymorphic plant species remains limited. Here, we investigated color-scent associations in flowers from Papaver nudicaule (Papaveraceae). We determined the spectral reflectance and the scent composition of flowers of four color cultivars. We found that pigments and volatiles occur in specific combinations in flowers of P. nudicaule. The presence of indole in the bouquets is strongly associated with the occurrence of yellow pigments called nudicaulins, for which indole is one of the final biosynthetic precursors...
April 26, 2018: Chembiochem: a European Journal of Chemical Biology
Andrea Di Cesare, Pedro J Cabello-Yeves, Nathan A M Chrismas, Patricia Sánchez-Baracaldo, Michaela M Salcher, Cristiana Callieri
BACKGROUND: Many cyanobacteria are capable of fixing atmospheric nitrogen, playing a crucial role in biogeochemical cycling. Little is known about freshwater unicellular cyanobacteria Synechococcus spp. at the genomic level, despite being recognised of considerable ecological importance in aquatic ecosystems. So far, it has not been shown whether these unicellular picocyanobacteria have the potential for nitrogen fixation. Here, we present the draft-genome of the new pink-pigmented Synechococcus-like strain Vulcanococcus limneticus...
April 16, 2018: BMC Genomics
José Luis Ferran, Luis Puelles
Amphioxus is the living chordate closest to the ancestral form of vertebrates, and in a key position to reveal essential aspects of the evolution of the brain Bauplan of vertebrates. The dorsal neural cord of this species at the larval stage is characterized by a small cerebral vesicle at its anterior end and a large posterior region. The latter is comparable in some aspects to the hindbrain and spinal cord regions of vertebrates. The rostral end of the cerebral vesicle contains a median pigment spot and associated rows of photoreceptor and other nerve cells; this complex is known as "the frontal eye...
April 16, 2018: Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology
Carlos A Moreira-Neto, Eric M Moult, James G Fujimoto, Nadia K Waheed, Daniela Ferrara
The purpose of this review is to summarize the current knowledge on choriocapillaris loss in advanced age macular degeneration (AMD). Several histopathological studies in animal models and human eyes had showed that the choriocapillaris density decreases with age. However, the role of choriocapillaris loss is still unclear in AMD and its advanced forms, either choroidal neovascularization (CNV) or geographic atrophy (GA). Some authors have hypothesized that choriocapillaris loss might precede overt retinal pigment epithelium atrophy...
2018: Journal of Ophthalmology
Sidharth Sonthalia, Sangeeta Varma, Abhijeet Kumar Jha, Deepak Jakhar, Feroze Kaliyadan
Dermoscopy, a non-invasive technique for cutaneous diagnosis is being increasingly studied in various disorders of the skin, nails and scalp. However, it has been under-utilized for the diagnosis and characterization of mucosal disorders. The dermoscopic characterization of cutaneous lichen planus and its variants has been well documented with Wickham's striae constituting the hallmark of the condition. However, the dermoscopic features of oral lichen planus with hand-held or videodermoscopy remain to be elucidated...
2018: F1000Research
Yusuke Nagao, Hiroyuki Takada, Motohiro Miyadai, Tomoko Adachi, Ryoko Seki, Yasuhiro Kamei, Ikuyo Hara, Yoshihito Taniguchi, Kiyoshi Naruse, Masahiko Hibi, Robert N Kelsh, Hisashi Hashimoto
Mechanisms generating diverse cell types from multipotent progenitors are fundamental for normal development. Pigment cells are derived from multipotent neural crest cells and their diversity in teleosts provides an excellent model for studying mechanisms controlling fate specification of distinct cell types. Zebrafish have three types of pigment cells (melanocytes, iridophores and xanthophores) while medaka have four (three shared with zebrafish, plus leucophores), raising questions about how conserved mechanisms of fate specification of each pigment cell type are in these fish...
April 2018: PLoS Genetics
Eduardo de A Gutierrez, Ryan K Schott, Matthew W Preston, Lívia O Loureiro, Burton K Lim, Belinda S W Chang
Bats represent one of the largest and most striking nocturnal mammalian radiations, exhibiting many visual system specializations for performance in light-limited environments. Despite representing the greatest ecological diversity and species richness in Chiroptera, Neotropical lineages have been undersampled in molecular studies, limiting the potential for identifying signatures of selection on visual genes associated with differences in bat ecology. Here, we investigated how diverse ecological pressures mediate long-term shifts in selection upon long-wavelength ( Lws ) and short-wavelength ( Sws1 ) opsins, photosensitive cone pigments that form the basis of colour vision in most mammals, including bats...
April 11, 2018: Proceedings. Biological Sciences
Christen M Klinger, Lucas Paoli, Robert J Newby, Matthew Yu-Wei Wang, Hyrum D Carroll, Jeffrey D Leblond, Christopher J Howe, Joel B Dacks, Chris Bowler, Aubery Bruce Cahoon, Richard G Dorrell, Elisabeth Richardson
Dinoflagellates are a group of unicellular protists with immense ecological and evolutionary significance and cell biological diversity. Of the photosynthetic dinoflagellates, the majority possess a plastid containing the pigment peridinin, whereas some lineages have replaced this plastid by serial endosymbiosis with plastids of distinct evolutionary affiliations, including a fucoxanthin pigment-containing plastid of haptophyte origin. Previous studies have described the presence of widespread substitutional RNA editing in peridinin and fucoxanthin plastid genes...
April 1, 2018: Genome Biology and Evolution
Sergio F Nigenda-Morales, Ryan J Harrigan, Robert K Wayne
Phenotypic variation along environmental gradients can provide evidence suggesting local adaptation has shaped observed morphological disparities. These differences, in traits such as body and extremity size, as well as skin and coat pigmentation, may affect the overall fitness of individuals in their environments. The Virginia opossum ( Didelphis virginiana ) is a marsupial that shows phenotypic variation across its range, one that has recently expanded into temperate environments. It is unknown, however, whether the variation observed in the species fits adaptive ecogeographic patterns, or if phenotypic change is associated with any environmental factors...
2018: PeerJ
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